176 results on '"Lawrie GM"'
Search Results
2. Mitral valve repair in patients with low left ventricular ejection fractions: early and late results.
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Talwalkar NG, Earle NR, Earle EA, and Lawrie GM
- Abstract
STUDY OBJECTIVES: This retrospective study was performed to examine the outcome of mitral valve repair (ie, mitral valvuloplasty [MVP]) in relation to preoperative low left ventricular ejection fraction (LVEF). DESIGN AND SETTINGS: From our series of 338 consecutive patients who underwent MVP between 1983 and 2001, we compared the course of 302 patients with preoperative LVEF of > 35% (group I) to that of 36 patients with LVEF of = 35% (group II). RESULTS: Preoperatively, group II patients were more likely to be associated with ischemic heart disease (IHD) [p < 0.0002], and to have undergone emergency surgery (p < 0.02) and concomitant coronary artery bypass graft surgery (CABG) [p < 0.02]. The perioperative mortality rate was 8% for group II and 2% for group I (p < 0.03). On multivariate analysis, predictors of increased operative mortality were emergent operation (p < 0.001) and preoperative New York Heart Association (NYHA) class IV (p < 0.02). Predictors of overall mortality (early and late) included emergency operation (p < 0.02), preoperative NYHA class IV (p < 0.002), and IHD (p < 0.0001). Postoperatively, 78% of patients from both groups were in NYHA class I/II. The 5-year rate of freedom from reoperation was 89%. The estimated overall 5-year survival rate (early and late) was 82% for group I and 54% for group II (p < 0.02), and when associated with prior CABG, prior myocardial infarction, or concomitant CABG, it was 0%, 37%, and 63%, respectively, in group II. CONCLUSIONS: Good symptomatic relief and acceptable overall survival can be obtained in patients in both groups after they have undergone MVP, in the absence of serious comorbidities. Preoperative NYHA class IV and end-stage IHD increase early and late mortality, particularly in group II patients, in whom surgery may be a salvage effort only. Prognosis is dismal in group II patients who have previously undergone CABG. In chronic cases, an early referral for MVP electively before deterioration to end-stage heart disease would improve survival even in patients with low LVEF. [ABSTRACT FROM AUTHOR]
- Published
- 2004
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3. Reply: Progress versus immortal truth: Motion versus paralysis.
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Lawrie GM
- Published
- 2023
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4. Mitral measurement: All or nothing?
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Lawrie GM
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- Humans, Mitral Valve diagnostic imaging, Mitral Valve surgery, Mitral Valve Insufficiency diagnostic imaging, Mitral Valve Insufficiency surgery, Mitral Valve Stenosis
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- 2023
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5. "A New Frontier" or "More of the Same"?
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Lawrie GM
- Subjects
- Humans, Mitral Valve
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- 2022
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6. Differential proteome profile, biological pathways, and network relationships of osteogenic proteins in calcified human aortic valves.
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Han RI, Hu CW, Loose DS, Yang L, Li L, Connell JP, Reardon MJ, Lawrie GM, Qutub AA, Morrisett JD, and Grande-Allen KJ
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- Aortic Valve metabolism, Aortic Valve surgery, Humans, Osteogenesis physiology, Proteome metabolism, Proteomics, Aortic Valve Stenosis metabolism, Aortic Valve Stenosis surgery, Calcinosis metabolism
- Abstract
Calcific aortic valve disease (CAVD) is the most common heart valve disease requiring intervention. Most research on CAVD has focused on inflammation, ossification, and cellular phenotype transformation. To gain a broader picture into the wide range of cellular and molecular mechanisms involved in this disease, we compared the total protein profiles between calcified and non-calcified areas from 5 human valves resected during surgery. The 1413 positively identified proteins were filtered down to 248 proteins present in both calcified and non-calcified segments of at least 3 of the 5 valves, which were then analyzed using Ingenuity Pathway Analysis. Concurrently, the top 40 differentially abundant proteins were grouped according to their biological functions and shown in interactive networks. Finally, the abundance of selected osteogenic proteins (osteopontin, osteonectin, osteocalcin, osteoprotegerin, and RANK) was quantified using ELISA and/or immunohistochemistry. The top pathways identified were complement system, acute phase response signaling, metabolism, LXR/RXR and FXR/RXR activation, actin cytoskeleton, mineral binding, nucleic acid interaction, structural extracellular matrix (ECM), and angiogenesis. There was a greater abundance of osteopontin, osteonectin, osteocalcin, osteoprotegerin, and RANK in the calcified regions than the non-calcified ones. The osteogenic proteins also formed key connections between the biological signaling pathways in the network model. In conclusion, this proteomic analysis demonstrated the involvement of multiple signaling pathways in CAVD. The interconnectedness of these pathways provides new insights for the treatment of this disease., (© 2021. Springer Japan KK, part of Springer Nature.)
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- 2022
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7. Time to rest on our laurels or escape our bed of thorns?
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Lawrie GM
- Published
- 2021
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8. Extracellular Volume in Primary Mitral Regurgitation.
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Kitkungvan D, Yang EY, El Tallawi KC, Nagueh SF, Nabi F, Khan MA, Nguyen DT, Graviss EA, Lawrie GM, Zoghbi WA, Bonow RO, Quinones MA, and Shah DJ
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- Humans, Predictive Value of Tests, Mitral Valve Insufficiency diagnostic imaging, Mitral Valve Insufficiency surgery
- Abstract
Objectives: This study used cardiovascular magnetic resonance (CMR) to evaluate whether elevated extracellular volume (ECV) was associated with mitral valve prolapse (MVP) or if elevated ECV was a consequence of remodeling independent of primary mitral regurgitation (MR) etiology., Background: Replacement fibrosis in primary MR is more prevalent in MVP; however, data on ECV as a surrogate for diffuse interstitial fibrosis in primary MR are limited., Methods: Patients with chronic primary MR underwent comprehensive CMR phenotyping and were stratified into an MVP cohort (>2 mm leaflet displacement on a 3-chamber cine CMR) and a non-MVP cohort. Factors associated with ECV and replacement fibrosis were assessed. The association of ECV and symptoms related to MR and clinical events (mitral surgery and cardiovascular death) was ascertained., Results: A total of 424 patients with primary MR (229 with MVP and 195 non-MVP) were enrolled. Replacement fibrosis was more prevalent in the MVP cohort (34.1% vs. 6.7%; p < 0.001), with bi-leaflet MVP having the strongest association with replacement fibrosis (odds ratio: 10.5; p < 0.001). ECV increased with MR severity in a similar fashion for both MVP and non-MVP cohorts and was associated with MR severity but not MVP on multivariable analysis. Elevated ECV was independently associated with symptoms related to MR and clinical events., Conclusions: Although replacement fibrosis was more prevalent in MVP, diffuse interstitial fibrosis as inferred by ECV was associated with MR severity, regardless of primary MR etiology. ECV was independently associated with symptoms related to MR and clinical events. (DeBakey Cardiovascular Magnetic Resonance Study [DEBAKEY-CMR]; NCT04281823)., Competing Interests: Funding Support And Author Disclosures Dr. Shah has received support from the National Science Foundation (CNS-1931884) and the Beverly B. and Daniel C. Arnold Distinguished Centennial Chair Endowment. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2021 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)
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- 2021
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9. Valve Strain Quantitation in Normal Mitral Valves and Mitral Prolapse With Variable Degrees of Regurgitation.
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El-Tallawi KC, Zhang P, Azencott R, He J, Herrera EL, Xu J, Chamsi-Pasha M, Jacob J, Lawrie GM, and Zoghbi WA
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- Humans, Mitral Valve diagnostic imaging, Predictive Value of Tests, Prolapse, Stroke Volume, Ventricular Function, Left, Mitral Valve Prolapse diagnostic imaging
- Abstract
Objectives: The aim of this study was to quantitate patient-specific mitral valve (MV) strain in normal valves and in patients with mitral valve prolapse with and without significant mitral regurgitation (MR) and assess the determinants of MV strain., Background: Few data exist on MV deformation during systole in humans. Three-dimensional echocardiography allows for dynamic MV imaging, enabling digital modeling of MV function in health and disease., Methods: Three-dimensional transesophageal echocardiography was performed in 82 patients, 32 with normal MV and 50 with mitral valve prolapse (MVP): 12 with mild mitral regurgitation or less (MVP - MR) and 38 with moderate MR or greater (MVP + MR). Three-dimensional MV models were generated, and the peak systolic strain of MV leaflets was computed on proprietary software., Results: Left ventricular ejection fraction was normal in all groups. MV annular dimensions were largest in MVP + MR (annular area: 13.8 ± 0.7 cm
2 ) and comparable in MVP - MR (10.6 ± 1 cm2 ) and normal valves (10.5 ± 0.3 cm2 ; analysis of variance: p < 0.001). Similarly, MV leaflet areas were largest in MVP + MR, particularly the posterior leaflet (8.7 ± 0.5 cm2 ); intermediate in MVP - MR (6.5 ± 0.7 cm2 ); and smallest in normal valves (5.5 ± 0.2 cm2 ; p < 0.0001). Strain was overall highest in MVP + MR and lowest in normal valves. Patients with MVP - MR had intermediate strain values that were higher than normal valves in the posterior leaflet (p = 0.001). On multivariable analysis, after adjustment for clinical and MV geometric parameters, leaflet thickness was the only parameter that was retained as being significantly correlated with mean MV strain (r = 0.34; p = 0.008)., Conclusions: MVs that exhibit prolapse have higher strain compared to normal valves, particularly in the posterior leaflet. Although higher strain is observed with worsening MR and larger valves and annuli, mitral valve leaflet thickness-and, thus, underlying MV pathology-is the most significant independent determinant of valve deformation. Future studies are needed to assess the impact of MV strain determination on clinical outcome., Competing Interests: Funding Support and Author Disclosures Supported by the Elkins Family Distinguished Chair in cardiac health and the John and Maryanne McCormack Cardiology Fund. The authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2021 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)- Published
- 2021
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10. Surgery for Ventricular Tachycardia.
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Lawrie GM
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- Action Potentials, Diffusion of Innovation, Electrophysiologic Techniques, Cardiac, History, 20th Century, History, 21st Century, Humans, Postoperative Complications etiology, Recurrence, Tachycardia, Ventricular diagnosis, Tachycardia, Ventricular history, Tachycardia, Ventricular physiopathology, Time Factors, Treatment Outcome, Cardiac Surgical Procedures adverse effects, Cardiac Surgical Procedures history, Heart Rate, Tachycardia, Ventricular surgery
- Abstract
The treatment of drug-refractory chronic ventricular tachycardia (VT) has undergone a revolution over the last 50 years. We now have automatic implantable cardioverter defibrillator therapy with pace-terminating capabilities, and catheter ablation of VT has refined mapping and improved methods of lesion generation. Between 1980 and 1993, Houston Methodist Hospital became a leader in the diagnosis and surgical ablation of VT and other arrhythmias. This is a brief account of that period and some of the experiences and lessons that have led to significant advances used today.
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- 2021
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11. Mitral Valve Remodeling and Strain in Secondary Mitral Regurgitation: Comparison With Primary Regurgitation and Normal Valves.
- Author
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El-Tallawi KC, Zhang P, Azencott R, He J, Xu J, Herrera EL, Jacob J, Chamsi-Pasha M, Lawrie GM, and Zoghbi WA
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- Echocardiography, Transesophageal, Humans, Mitral Valve diagnostic imaging, Predictive Value of Tests, Echocardiography, Three-Dimensional, Mitral Valve Insufficiency diagnostic imaging, Mitral Valve Insufficiency etiology
- Abstract
Objectives: The aim of this study was to assess mitral valve (MV) remodeling and strain in patients with secondary mitral regurgitation (SMR) compared with primary MR (PMR) and normal valves., Background: A paucity of data exists on MV strain during the cardiac cycle in humans. Real-time 3-dimensional (3D) echocardiography allows for dynamic MV imaging, enabling computerized modeling of MV function in normal and disease states., Methods: Three-dimensional transesophageal echocardiography (TEE) was performed in a total of 106 subjects: 36 with SMR, 38 with PMR, and 32 with normal valves; MR severity was at least moderate in both MR groups. Valve geometric parameters were quantitated and patient-specific 3D MV models generated in systole using a dedicated software. Global and regional peak systolic MV strain was computed using a proprietary software., Results: MV annular area was larger in both the SMR and PMR groups (12.7 ± 0.7 and 13.3 ± 0.7 cm
2 , respectively) compared with normal subjects (9.9 ± 0.3 cm2 ; p < 0.05). The leaflets also had significant remodeling, with total MV leaflet area larger in both SMR (16.2 ± 0.9 cm2 ) and PMR (15.6 ± 0.8 cm2 ) versus normal subjects (11.6 ± 0.4 cm2 ). Leaflets in SMR were thicker than those in normal subjects but slightly less than those with PMR posteriorly. Posterior leaflet strain was significantly higher than anterior leaflet strain in all 3 groups. Despite MV remodeling, strain in SMR (8.8 ± 0.3%) was overall similar to normal subjects (8.5 ± 0.2%), and both were lower than in PMR (12 ± 0.4%; p < 0.0001). Valve thickness, severity of MR, and primary etiology of MR were correlates of strain, with leaflet thickness being the multivariable parameter significantly associated with MV strain. In patients with less severe MR, anterior leaflet strain in SMR was lower than normal, whereas strain in PMR remained higher than normal., Conclusions: The MV in secondary MR remodels significantly and similarly to PMR with a resultant larger annular area, leaflet surface area, and leaflet thickness compared with that of normal subjects. Despite these changes, MV strain remains close to or in some instances lower than normal and is significantly lower than that of PMR. Strain determination has the potential to improve characterization of MV mechano-biologic properties in humans and to evaluate its prognostic impact in patients with MR, with or without valve interventions., Competing Interests: Funding Support and Author Disclosures This study was supported by the Elkins Family distinguished Chair in cardiac health, and the John and Maryanne McCormack Cardiology Fund. The authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2021 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)- Published
- 2021
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12. Resolving the Disproportionate Left Ventricular Enlargement in Mitral Valve Prolapse Due to Barlow Disease: Insights From Cardiovascular Magnetic Resonance.
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El-Tallawi KC, Kitkungvan D, Xu J, Cristini V, Yang EY, Quinones MA, Lawrie GM, Zoghbi WA, and Shah DJ
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- Heart Ventricles, Humans, Magnetic Resonance Spectroscopy, Predictive Value of Tests, Mitral Valve Insufficiency diagnostic imaging, Mitral Valve Insufficiency etiology, Mitral Valve Prolapse diagnostic imaging
- Abstract
Objectives: This study hypothesized that left ventricular (LV) enlargement in Barlow disease can be explained by accounting for the total volume load that consists of transvalvular mitral regurgitation (MR) and the prolapse volume., Background: Barlow disease is characterized by long prolapsing mitral leaflets that can harbor a significant amount of blood-the prolapse volume-at end-systole. The LV in Barlow disease can be disproportionately enlarged relative to MR severity, leading to speculation of Barlow cardiomyopathy., Methods: Cardiac magnetic resonance (CMR) was used to compare MR, prolapse volume, and heart chambers remodeling in patients with Barlow disease (bileaflet prolapse [BLP]) and in single leaflet prolapse (SLP)., Results: A total of 157 patients (81 with BLP, 76 with SLP) were included. Patients with SLP were older and more had hypertension. Patients with BLP had more heart failure. Indexed LV end-diastolic volume was larger in BLP despite similar transvalvular MR. However, the prolapse volume was larger in BLP, which led to larger total volume load compared with SLP. Increasing tertiles of prolapse volume and MR both led to an incremental increase in LV end-diastolic volume in BLP. Using the total volume load improved the correlation with indexed LV end-diastolic volume in the BLP group, which closely matched that of SLP. A multivariable model that incorporated the prolapse volume explained left heart chamber enlargement better than a MR-based model, independent of prolapse category., Conclusions: The prolapse volume is part of the total volume load exerted on the LV during the cardiac cycle and could help explain the disproportionate LV enlargement relative to MR severity noted in Barlow disease., Competing Interests: Funding Support and Author Disclosures Dr. Shah is supported by the National Science Foundation (grant CNS-1646566 and CNS-1931884) and the National Institutes of Health (1R01HL137763-01). All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2021 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)
- Published
- 2021
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13. Surgical treatment of mitral regurgitation.
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Lawrie GM
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- Humans, Mitral Valve diagnostic imaging, Mitral Valve surgery, Polytetrafluoroethylene, Suture Techniques, Treatment Outcome, Mitral Valve Annuloplasty, Mitral Valve Insufficiency surgery
- Abstract
Purpose of Review: Mitral repair is the best treatment for degenerative mitral regurgitation. Many patients are referred too late for optimal outcomes. The US repair vs. replacement rate is only 60-80%, at a time when the inferiority of replacement has been established. Therefore, widely used traditional techniques of repair are being reappraised., Recent Findings: Identification of risk factors predictive of poor early and late outcome have improved timing for surgical referral. Composite risk scores have been developed. Novel echocardiographic, cardiac MRI, and molecular level risk factors could improve timing. Analysis of factors contributing to low repair rates is also of critical importance. The role of institutional and surgeon volumes have been identified. More detailed data on the importance of dynamic function of the mitral valve have led to improved repair techniques such as intraoperative simulation of end diastole and early systole, use of expanded polytetrafluoroethylene neochords instead of leaflet resection, and dynamic instead of rigid annuloplasty., Summary: Our perception of mitral regurgitation has changed from a seemingly simple condition to one of considerable complexity at multiple levels. National guidelines should be studied and followed.
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- 2020
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14. Is the fate of the anterior leaflet determined by original sin or by the weakness of man?
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Lawrie GM
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- 2020
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15. Prognostic Implications of Diffuse Interstitial Fibrosis in Asymptomatic Primary Mitral Regurgitation.
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Kitkungvan D, Yang EY, El Tallawi KC, Nagueh SF, Nabi F, Khan MA, Nguyen DT, Graviss EA, Lawrie GM, Zoghbi WA, Bonow RO, Quinones MA, and Shah DJ
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- Extracellular Fluid physiology, Female, Fibrosis diagnostic imaging, Fibrosis physiopathology, Humans, Magnetic Resonance Imaging, Cine methods, Male, Middle Aged, Mitral Valve Insufficiency physiopathology, Prognosis, Prospective Studies, Extracellular Fluid diagnostic imaging, Mitral Valve Insufficiency diagnostic imaging
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- 2019
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16. Surgical Approaches to Hypertrophic Cardiomyopathy and Implications for Perioperative Management.
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Herrera EL and Lawrie GM
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- Cardiomyopathy, Hypertrophic diagnosis, Cardiomyopathy, Hypertrophic pathology, Echocardiography, Humans, Cardiomyopathy, Hypertrophic surgery, Perioperative Care methods
- Published
- 2018
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17. Myocardial Fibrosis in Patients With Primary Mitral Regurgitation With and Without Prolapse.
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Kitkungvan D, Nabi F, Kim RJ, Bonow RO, Khan MA, Xu J, Little SH, Quinones MA, Lawrie GM, Zoghbi WA, and Shah DJ
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- Aged, Aged, 80 and over, Cohort Studies, Female, Fibrosis diagnostic imaging, Fibrosis epidemiology, Follow-Up Studies, Humans, Male, Middle Aged, Prospective Studies, Mitral Valve Insufficiency diagnostic imaging, Mitral Valve Insufficiency epidemiology, Mitral Valve Prolapse diagnostic imaging, Mitral Valve Prolapse epidemiology, Ventricular Dysfunction, Left diagnostic imaging, Ventricular Dysfunction, Left epidemiology
- Abstract
Background: Recent studies reported left ventricular (LV) fibrosis in patients with primary mitral regurgitation (MR) thought to be principally due to mitral valve prolapse (MVP)., Objectives: This study sought to evaluate the prevalence, characteristics, and prognostic implications of LV fibrosis in a large cohort of primary MR patients with and without MVP using cardiovascular magnetic resonance (CMR)., Methods: Patients referred for contrast CMR assessment of chronic primary MR were enrolled and underwent comprehensive assessment of cardiac remodeling, severity of MR, and LV replacement fibrosis. Primary MR patients were stratified into: an MVP group if there was >2 mm mitral leaflet displacement on cine-CMR, or a non-MVP group. Patients were followed for arrhythmic events (sudden cardiac death, aborted sudden cardiac arrest, and sustained or inducible ventricular arrhythmia)., Results: A total of 356 primary MR patients (177 MVP and 179 non-MVP) were enrolled. LV fibrosis was more prevalent in the MVP group than the non-MVP group (36.7% vs. 6.7%; p < 0.001). The presence of MVP had the strongest association (odds ratio: 6.82; p < 0.001) with LV fibrosis even after adjustment for clinical variables, measures of cardiac remodeling, and MR severity. During follow-up (median 1,354 days), MVP patients with LV fibrosis had the highest event rate for arrhythmic events., Conclusions: In primary MR patients, LV fibrosis is more prevalent in MVP than non-MVP, suggesting a unique pathophysiology beyond volume overload in MVP. LV fibrosis in primary MR may represent a risk marker of arrhythmic events., (Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.)
- Published
- 2018
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18. Effect of Mitral Valve Repair on Mitral Valve Leaflets Strain: A Pilot Study.
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Ben Zekry S, Freeman J, Jajoo A, He J, Little SH, Lawrie GM, Azencott R, and Zoghbi WA
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- Aged, Echocardiography, Three-Dimensional, Echocardiography, Transesophageal, Female, Heart Valve Prosthesis, Humans, Male, Middle Aged, Mitral Valve diagnostic imaging, Mitral Valve physiopathology, Mitral Valve Insufficiency diagnostic imaging, Mitral Valve Insufficiency physiopathology, Mitral Valve Prolapse diagnostic imaging, Mitral Valve Prolapse physiopathology, Patient-Specific Modeling, Pilot Projects, Predictive Value of Tests, Prosthesis Design, Stress, Mechanical, Treatment Outcome, Heart Valve Prosthesis Implantation instrumentation, Hemodynamics, Mitral Valve surgery, Mitral Valve Annuloplasty instrumentation, Mitral Valve Insufficiency surgery, Mitral Valve Prolapse surgery
- Published
- 2018
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19. Aneurysmal left sinus of Valsalva in Marfan's syndrome.
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Chamsi-Pasha MA and Lawrie GM
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- Adult, Female, Humans, Tomography, X-Ray Computed, Aortic Aneurysm diagnostic imaging, Aortic Aneurysm pathology, Marfan Syndrome diagnostic imaging, Marfan Syndrome pathology, Sinus of Valsalva diagnostic imaging, Sinus of Valsalva pathology
- Published
- 2018
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20. Early Trifecta valve failure: Report of a cluster of cases from a tertiary care referral center.
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Kalra A, Rehman H, Ramchandani M, Barker CM, Lawrie GM, Reul RM, Reardon MJ, and Kleiman NS
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- Aged, Equipment Failure Analysis, Female, Hemodynamics, Humans, Male, Middle Aged, Mortality, Postoperative Complications diagnosis, Postoperative Complications epidemiology, Postoperative Complications etiology, Prosthesis Design, United States, Aortic Valve surgery, Bioprosthesis adverse effects, Heart Valve Diseases surgery, Heart Valve Prosthesis adverse effects, Heart Valve Prosthesis Implantation adverse effects, Heart Valve Prosthesis Implantation instrumentation, Heart Valve Prosthesis Implantation methods, Prosthesis Failure
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Background: The Trifecta valve (St Jude Medical, Inc, St Paul, Minn) was approved for commercial use by the US Food and Drug Administration in 2011. Several isolated cases have been reported since then, describing early structural valve deterioration. We report a case series of 8 Trifecta valve failures, describing patients' clinical substrate and management, and the pathologic characteristics of the explanted valves., Methods: Trifecta valve failure occurred in 7 patients (8 valves) receiving 19-mm (n = 2), 21-mm (n = 3), 23-mm (n = 1), and 25-mm (n = 2) valves. The mean duration of valve durability was 32 ± 21 months, and the most common lesion was prosthetic regurgitation. The mean Society of Thoracic Surgeons risk score for perioperative mortality at the time of reintervention was 9.75% ± 8.1%. Heart failure exacerbation was the most common presenting symptom., Results: Five patients underwent surgical aortic valve replacement, 2 patients received valve-in-valve transcatheter aortic valve replacement, and 1 patient died of cardiogenic shock before reintervention. The most common pathologic finding in the explanted valves was a tan-yellow fibrofatty circumferential pannus adherent to the inflow portion of the Trifecta valve., Conclusions: Our findings provide further insights into the pathologic mechanisms leading to early Trifecta valve failure. In addition to tear of the noncoronary cusp of the Trifecta prosthesis described as the most common mechanism in the literature for its failure, circumferential pannus formation composed of fibrofatty tissue in the inflow portion and leaflet calcification concentrated around the posts in the outflow portion are important mechanisms contributing toward early Trifecta valve failure., (Copyright © 2017 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.)
- Published
- 2017
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21. Mitral annuloplasty ring dehiscence: Optimal force distribution with flexible rings.
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Spratt JR, Spratt JA, and Lawrie GM
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- Mitral Valve, Heart Valve Prosthesis, Mitral Valve Annuloplasty
- Published
- 2016
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22. Left Atrial Myxoma Embolism Presenting with Acute Vascular Occlusion: A Rare Presentation with a Potentially Debilitating Outcome.
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Saththasivam P, Herrera E, and Lawrie GM
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- Embolism, Female, Heart Atria, Humans, Middle Aged, Atrial Fibrillation diagnosis, Heart Neoplasms diagnosis, Myxoma diagnosis
- Published
- 2016
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23. Novel parameters of global and regional mitral annulus geometry in man: comparison between normals and organic mitral regurgitation, before and after mitral valve repair.
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Ben Zekry S, Jain S, Alexander SK, Li Y, Aggarwal A, Jajoo A, Little SH, Lawrie GM, Azencott R, and Zoghbi WA
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- Aged, Female, Humans, Male, Middle Aged, Mitral Valve surgery, Mitral Valve Insufficiency surgery, Prospective Studies, Echocardiography, Three-Dimensional, Mitral Valve diagnostic imaging, Mitral Valve physiopathology, Mitral Valve Insufficiency diagnostic imaging, Mitral Valve Insufficiency physiopathology
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Aims: The mitral annulus (MA) saddle shape is complex but vital for a normal functioning mitral apparatus. Although conventional parameters of MA geometry such as area and height are helpful, they fall short of describing its complex regional geometry., Methods and Results: In this prospective study, novel parameters of MA curvature and torsion were derived from three-dimensional (3D) transoesophageal echocardiography. These quantitative indices were computed in 15 patients with normal valves (age 53 ± 8 years) and in 15 patients with organic significant mitral regurgitation (MR, age 66 ± 11 years), before and after mitral valve repair (MVR). The MA was traced and modelled in mid- and end-systole. Curvature and torsion were computed at 500 points across the MA to derive regional and global indices. Overall, patients with organic MR presented the smallest global curvature and torsion; this decrease in curvature and torsion reflects a loss of tonicity of the MA tissue. These changes were largely corrected with MVR surgery, to higher values, compared with normals. The regional analysis revealed similar trends. The maximal MA curvature was found to be at the MA 'anterior horn', whereas the MA 'posterior horn' had the lowest curvature values., Conclusion: Novel MA parameters of curvature and torsion can be computed from 3D echocardiography and provide quantitative characteristics of dynamic regional MA geometry. In patients with organic MR, the reduced regional and global curvatures improve following surgical MVR. These quantitative parameters may help further refine the quantitative description of MA geometry in various mitral valve pathologies and after MVR., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.)
- Published
- 2016
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24. Morphometric analysis of calcification and fibrous layer thickness in carotid endarterectomy tissues.
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Han RI, Wheeler TM, Lumsden AB, Reardon MJ, Lawrie GM, Grande-Allen KJ, Morrisett JD, and Brunner G
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- Female, Humans, Male, Carotid Artery Diseases metabolism, Carotid Artery Diseases pathology, Carotid Artery Diseases surgery, Endarterectomy, Carotid, Plaque, Atherosclerotic metabolism, Plaque, Atherosclerotic pathology, Plaque, Atherosclerotic surgery, Vascular Calcification metabolism, Vascular Calcification pathology, Vascular Calcification surgery
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Background: Advanced atherosclerotic lesions are commonly characterized by the presence of calcification. Several studies indicate that extensive calcification is associated with plaque stability, yet recent studies suggest that calcification morphology and location may adversely affect the mechanical stability of atherosclerotic plaques. The underlying cause of atherosclerotic calcification and the importance of intra-plaque calcium distribution remains poorly understood., Method: The goal of this study was the characterization of calcification morphology based on histological features in 20 human carotid endarterectomy (CEA) specimens. Representative frozen sections (10μm thick) were cut from the common, bulb, internal and external segments of CEA tissues and stained with von Kossa׳s reagent for calcium phosphate. The morphology of calcification (calcified patches) and fibrous layer thickness were quantified in 135 histological sections., Results: Intra-plaque calcification was distributed heterogeneously (calcification %-area: bulb segment: 14.2±2.1%; internal segment: 12.9±2.8%; common segment: 4.6±1.1%; p=0.001). Calcified patches were found in 20 CEAs (patch size: <0.1mm(2) to >1.0mm(2)). Calcified patches were most abundant in the bulb and least in the common segment (bulb n=7.30±1.08; internal n=4.81±1.17; common n=2.56±0.56; p=0.0007). Calcified patch circularity decreased with increasing size (<0.1mm(2): 0.77±0.01, 0.1-1mm(2): 0.62±0.01, >1.0mm(2): 0.51±0.02; p=0.0001). A reduced fibrous layer thickness was associated with increased calcium patch size (p<0.0001)., Conclusions: In advanced carotid atherosclerosis, calcification appears to be a heterogeneous and dynamic atherosclerotic plaque component, as indicated by the simultaneous presence of few large stabilizing calcified patches and numerous small calcific patches. Future studies are needed to elucidate the associations of intra-plaque calcification size and distribution with atherothrombotic events., (Copyright © 2016 Elsevier Ltd. All rights reserved.)
- Published
- 2016
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25. One Hundred Percent Reparability of Degenerative Mitral Regurgitation: Intermediate-Term Results of a Dynamic Engineered Approach.
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Lawrie GM, Zoghbi W, Little S, Shah D, Ben-Zekry Z, Earle N, and Earle E
- Subjects
- Echocardiography, Female, Follow-Up Studies, Humans, Male, Middle Aged, Mitral Valve Insufficiency diagnostic imaging, Prosthesis Design, Reoperation, Retrospective Studies, Time Factors, Treatment Outcome, Heart Valve Prosthesis, Mitral Valve surgery, Mitral Valve Insufficiency surgery
- Abstract
Background: Advances in understanding dynamic mitral valve function have led to a repair technique with no leaflet resection, accurate dynamic annular and chordal sizing, and preservation of left ventricular outflow tract dynamics., Methods: This approach uses inflation of the left ventricle and ascending aorta with pressurized saline to achieve diastolic mitral valve locking and early isovolumic systole. The left ventricle is maximally dilated, the aorta and root are distended, and the mitral leaflets are opposed. This is used to adjust the length of the artificial chordae and size the fully flexible annuloplasty ring in three dimensions for accurate apposition of the zones of leaflet coaptation. We monitored 752 consecutive patients after repairs performed between 2001 and 2013., Results: There were 510 men (68.8%). Mean age was 61.3 ± 13.54 years. The leaflet repaired was anterior in 127 patients (17%), posterior in 451 (60%), both 55 (7.3%), and Barlow's in 119 (16%). Repair was isolated in 76% (573 of 752). Reparability was 100%. No prosthetic valve was implanted in patients with myxomatous or degenerative disease. Perioperative mortality was 2.3% (17 of 752) overall and was 1.6% (9 of 573) for isolated repair and 0.2% (1 of 451) for isolated posterior leaflet. Nonsignificant leaflet systolic anterior leaflet motion was observed in 0.2% (14 of 739) of patients. At 10 years, survival by Kaplan-Meier analysis was 66.4%, and freedom from reoperation was 91.8%. Freedom from significant mitral regurgitation at 5 years was 90.3%. Cox analysis showed male gender was a predictor of reoperation (p = 0.63)., Conclusions: This dynamic approach enabled 100% reparability of myxomatous and degenerative valves with no occurrence of significant systolic anterior leaflet motion. Despite 100% of patients having been repaired, intermediate-term durability measured by reoperation rates, freedom from prosthetic valve, and intermediate echocardiographic follow-up have been good., (Copyright © 2016 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)
- Published
- 2016
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26. Patient-Specific Quantitation of Mitral Valve Strain by Computer Analysis of Three-Dimensional Echocardiography: A Pilot Study.
- Author
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Ben Zekry S, Freeman J, Jajoo A, He J, Little SH, Lawrie GM, Azencott R, and Zoghbi WA
- Subjects
- Aged, Case-Control Studies, Female, Humans, Male, Middle Aged, Pilot Projects, Prospective Studies, Reproducibility of Results, Software, Echocardiography, Three-Dimensional methods, Echocardiography, Transesophageal methods, Image Interpretation, Computer-Assisted methods, Mitral Valve Insufficiency diagnostic imaging
- Abstract
Background: A paucity of data exists on mitral valve (MV) deformation during the cardiac cycle in man. Real-time 3-dimensional (3D) echocardiography now allows dynamic volumetric imaging of the MV, thus enabling computerized modeling of MV function directly in health and disease., Methods and Results: MV imaging using 3D transesophageal echocardiography was performed in 10 normal subjects and 10 patients with moderate-to-severe or severe organic mitral regurgitation. Using proprietary 3D software, patient-specific models of the mitral annulus and leaflets were computed at mid- and end-systole. Strain analysis of leaflet deformation was derived from these models. In normals, mean strain intensity averaged 0.11±0.02 and was higher in the posterior leaflet than in the anterior leaflet (0.13±0.03 versus 0.10±0.02; P<0.05). Mean strain intensity was higher in patients with mitral regurgitation (0.15±0.03) than in normals (0.11±0.02; P=0.05). Higher mean strain intensity was noted for the posterior leaflet in both normal and organic valves. Regional valve analysis revealed that both anterior and posterior leaflets have the highest strain concentration in the commissural zone, and the boundary zone near the annulus and at the coaptation line, with reduced strain concentration in the central leaflet zone., Conclusions: In normals, MV strain is higher in the posterior leaflet, with the highest strain at the commissures, annulus, and coaptation zones. Patients with organic mitral regurgitation have higher strain than normals. Three-dimensional echocardiography allows noninvasive and patient-specific quantitation of strain intensities because of MV deformations and has the potential to improve noninvasive characterization and follow-up of MV disease., (© 2015 American Heart Association, Inc.)
- Published
- 2016
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27. Barlow disease: Simple and complex.
- Author
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Lawrie GM
- Subjects
- Female, Humans, Male, Genetic Diseases, X-Linked surgery, Heart Valve Prosthesis Implantation, Mitral Valve surgery, Mitral Valve Annuloplasty, Mitral Valve Insufficiency surgery, Mitral Valve Prolapse surgery
- Published
- 2015
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28. Invited commentary.
- Author
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Lawrie GM
- Subjects
- Female, Humans, Male, Aspirin administration & dosage, Coronary Artery Bypass, Off-Pump, Graft Occlusion, Vascular prevention & control, Platelet Aggregation Inhibitors administration & dosage, Postoperative Complications prevention & control, Preoperative Care, Saphenous Vein transplantation
- Published
- 2015
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29. 'American correction' resembles the 'respect or resect' approach.
- Author
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Lawrie GM
- Subjects
- Humans, Cardiac Valve Annuloplasty methods, Genetic Diseases, X-Linked surgery, Mitral Valve surgery, Mitral Valve Prolapse surgery
- Published
- 2012
30. Use of "maximal regurgitant area" as the sole parameter for evaluation of severity of recurrent mitral regurgitation after mitral valve repair: importance of the American Society of Echocardiography Guidelines.
- Author
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Lawrie GM
- Subjects
- Female, Humans, Male, Cardiac Surgical Procedures adverse effects, Mitral Valve Insufficiency epidemiology, Mitral Valve Insufficiency etiology, Mitral Valve Prolapse surgery
- Published
- 2012
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31. Role of transcatheter aortic valve implantation (TAVI) versus conventional aortic valve replacement in the treatment of aortic valve disease.
- Author
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Lawrie GM
- Subjects
- Aortic Valve pathology, Aortic Valve Stenosis surgery, Aortic Valve Stenosis therapy, Bicuspid Aortic Valve Disease, Heart Defects, Congenital pathology, Heart Defects, Congenital therapy, Heart Valve Diseases pathology, Heart Valve Diseases therapy, Humans, Risk, Aortic Valve surgery, Cardiac Catheterization methods, Heart Defects, Congenital surgery, Heart Valve Diseases surgery, Heart Valve Prosthesis Implantation methods
- Abstract
Conventional aortic valve replacement (AVR) surgery has been in clinical use since 1960. Results, particularly in high-risk populations such as the very elderly and frail, continue to improve in response to the challenges posed by this growing segment of the patient population. Transcatheter aortic valve implantation (TAVI) is a fairly recent development, performed for the first time in 2002. The last decade has seen an exponential growth in the application of this technology in higher-risk populations. Results of recent randomized prospective trials demonstrate both the future promise and current problems of the TAVI approach. Many patients deemed inoperable for AVR have been treated successfully by TAVI. However, elevated procedural and late mortality rates, excessive early and late stroke, and a significant incidence of periprosthetic aortic valve insufficiency and patient-prosthesis mismatch all suggest caution in extending this technology to patients able to undergo conventional AVR with a low risk of early or late complications.
- Published
- 2012
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32. Mitral annulus dynamics early after valve repair: preliminary observations of the effect of resectional versus non-resectional approaches.
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Ben Zekry S, Lang RM, Sugeng L, McCulloch ML, Weinert L, Raman J, Little SH, Xu J, Lawrie GM, and Zoghbi WA
- Subjects
- Female, Hemodynamics, Humans, Male, Middle Aged, Mitral Valve diagnostic imaging, Mitral Valve physiopathology, Cardiac Surgical Procedures methods, Echocardiography, Transesophageal, Mitral Valve surgery, Mitral Valve Insufficiency diagnostic imaging, Mitral Valve Insufficiency surgery
- Abstract
Background: Mitral repair is recommended for patients with significant organic mitral regurgitation (MR). The nonresectional dynamic mitral valve repair (NVR) method involves a complete flexible ring and artificial chordal insertion but without leaflet resection or annular plication. The aim of this study was to compare changes in mitral annular structure and function after the NVR technique with those after a resectional mitral valve repair (RVR) method, which involves leaflet resection and annuloplasty with a partial flexible ring., Methods: Patients with organic severe MR undergoing mitral valve repair with either technique underwent three-dimensional transesophageal echocardiography before and after surgery. The mitral annulus was tracked offline and measured throughout the cardiac cycle. Mitral leaflet mobility was also measured., Results: Fifteen patients underwent repair with NVR, and 13 underwent repair with RVR (age, 56 vs 61 years, respectively). Both operations reduced mitral annular area significantly (maximum area reduction, from 18.5 ± 4.6 to 6.6 ± 1.7 cm(2) and from 20.1 ± 4.8 to 6 ± 1.5 cm(2) with the NVR and RVR techniques, respectively; P < .001). In contrast to RVR, patients who underwent NVR maintained dynamic changes in mitral annular area, circumference, and anterior-posterior diameter during the cardiac cycle. Mitral leaflet mobility was reduced with both techniques, but posterior leaflet mobility was restricted with RVR., Conclusions: The size of the mitral annulus is reduced after repair with either surgical approach. Compared with resectional valve repair, more dynamic changes in the structure of the mitral annulus are maintained during the cardiac cycle with the NVR technique early postoperatively, along with more preserved motion of the posterior leaflet., (Copyright © 2011 American Society of Echocardiography. Published by Mosby, Inc. All rights reserved.)
- Published
- 2011
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33. Comparative accuracy of two- and three-dimensional transthoracic and transesophageal echocardiography in identifying mitral valve pathology in patients undergoing mitral valve repair: initial observations.
- Author
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Ben Zekry S, Nagueh SF, Little SH, Quinones MA, McCulloch ML, Karanbir S, Herrera EL, Lawrie GM, and Zoghbi WA
- Subjects
- Female, Follow-Up Studies, Humans, Male, Middle Aged, Mitral Valve physiopathology, Mitral Valve surgery, Mitral Valve Insufficiency physiopathology, Mitral Valve Insufficiency surgery, Mitral Valve Prolapse physiopathology, Mitral Valve Prolapse surgery, Prognosis, Prospective Studies, Reproducibility of Results, Echocardiography, Three-Dimensional methods, Echocardiography, Transesophageal methods, Heart Valve Prosthesis, Mitral Valve diagnostic imaging, Mitral Valve Insufficiency diagnostic imaging, Mitral Valve Prolapse diagnostic imaging
- Abstract
Background: Identification of mitral regurgitation (MR) mechanism and pathology are crucial for surgical repair. The aim of the present investigation was to evaluate the comparative accuracy of real-time three-dimensional (3D) transesophageal echocardiography (TEE) and transthoracic echocardiography (TTE) with two-dimensional (2D) TEE and TTE in diagnosing the mechanism of MR compared with the surgical standard., Methods: Forty patients referred for surgical mitral valve repair were studied; 2D and 3D echocardiography with both TTE and TEE were performed preoperatively. Two independent observers reviewed the studies for MR pathology, functional or organic. In organic disease, the presence and localization of leaflet prolapse and/or flail were noted. Surgical findings served as the gold standard., Results: There was 100% agreement in identifying functional versus organic MR among all four modalities. Overall, 2D TTE, 2D TEE, and 3D TEE performed similarly in identifying a prolapse or a flail leaflet; 3D TEE had the best agreement in identifying anterior leaflet prolapse, and it also showed an advantage for segmental analysis. Three-dimensional TTE was less sensitive and less accurate in identifying flail segments., Conclusion: All modalities were equally reliable in identifying functional MR. Both 2D TEE and 3D TEE were comparable in diagnosing MR mechanism, while 3D TEE had the advantage of better localizing the disease. With current technology, 3D TTE was the least reliable in identifying valve pathology.
- Published
- 2011
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34. Real-time co-registration using novel ultrasound technology: ex vivo validation and in vivo applications.
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Yang EY, Polsani VR, Washburn MJ, Zang W, Hall AL, Virani SS, Hodge MD, Parker D, Kerwin WS, Lawrie GM, Garami Z, Ballantyne CM, Morrisett JD, and Nambi V
- Subjects
- Carotid Artery Diseases pathology, Humans, Magnetic Resonance Imaging methods, Plaque, Atherosclerotic pathology, Reproducibility of Results, Carotid Artery Diseases diagnostic imaging, Carotid Intima-Media Thickness, Phantoms, Imaging, Plaque, Atherosclerotic diagnostic imaging, Ultrasonography, Doppler methods
- Abstract
Objective: The study objective was to evaluate whether a novel global position system (GPS)-like position-sensing technology will enable accurate co-registration of images between imaging modalities. Co-registration of images obtained by different imaging modalities will allow for comparison and fusion between imaging modalities, and therefore has significant clinical and research implications. We compared ultrasound (US) and magnetic resonance imaging (MRI) scans of carotid endarterectomy (CEA) specimens using a novel position-sensing technology that uses an electromagnetic (EM) transmitter and sensors mounted on a US transducer. We then evaluated in vivo US-US and US-MRI co-registration., Methods: Thirteen CEA specimens underwent 3.0 Tesla MRI, after which images were uploaded to a LOGIQ E9 3D (GE Healthcare, Wauwatosa, WI) US system and registered by identifying two to three common points. A similar method was used to evaluate US-MRI co-registration in patients with carotid atherosclerosis. For carotid intima-media thickness (C-IMT) measurements, 10 volunteers underwent bilateral carotid US scans co-registered to three-dimensional US maps created on the initial visit, with a repeat scan 2 days later., Results: For the CEA specimens, there was a mean of 20 (standard error [SE] 2.0) frames per MRI slice. The mean frame difference, over 33 registration markers, between MRI and US scans for readers 1 and 2 was -2.82 ± 19.32 and 2.09 ± 14.68 (mean ± 95% CI) frames, respectively. The US-MRI intraclass correlation coefficients (ICCs) for the first and second readers were 0.995 and 0.997, respectively. For patients with carotid atherosclerosis, the mean US frames per MRI slice (9 [SE 2.3]) was within range of that observed with CEA specimens. Inter-visit, intra-reader, and inter-reader reproducibility of C-IMT measurements were consistently high (side-averaged ICC >0.9)., Conclusion: Accurate co-registration between US and other modalities is feasible with a GPS-like technology, which has significant clinical and research applicability., (Copyright © 2011 Elsevier Ltd. All rights reserved.)
- Published
- 2011
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35. Intermediate-term results of a nonresectional dynamic repair technique in 662 patients with mitral valve prolapse and mitral regurgitation.
- Author
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Lawrie GM, Earle EA, and Earle N
- Subjects
- Aged, Chi-Square Distribution, Chordae Tendineae diagnostic imaging, Echocardiography, Transesophageal, Female, Heart Valve Prosthesis, Heart Valve Prosthesis Implantation adverse effects, Heart Valve Prosthesis Implantation instrumentation, Heart Valve Prosthesis Implantation mortality, Humans, Kaplan-Meier Estimate, Male, Middle Aged, Mitral Valve Insufficiency diagnostic imaging, Mitral Valve Insufficiency etiology, Mitral Valve Insufficiency mortality, Mitral Valve Prolapse complications, Mitral Valve Prolapse diagnostic imaging, Mitral Valve Prolapse mortality, Polytetrafluoroethylene, Proportional Hazards Models, Prospective Studies, Prosthesis Design, Recurrence, Reoperation, Risk Assessment, Risk Factors, Severity of Illness Index, Texas, Time Factors, Treatment Outcome, Chordae Tendineae surgery, Mitral Valve Annuloplasty adverse effects, Mitral Valve Annuloplasty instrumentation, Mitral Valve Annuloplasty mortality, Mitral Valve Insufficiency surgery, Mitral Valve Prolapse surgery
- Abstract
Objective: A nonresectional technique has been developed for repair of mitral leaflet prolapse causing mitral regurgitation. Polytetrafluoroethylene chordae are used for correction of edge misalignment of the prolapsed mitral leaflet. New chordal length is adjusted during progressive left ventricular inflation to systolic pressure. Annular sizing is determined dynamically after leaflet edge alignment is accomplished to produce an optimal zone of predefined leaflet apposition. The aim of this study was to document the 8- to 10-year durability of this nonresectional approach., Methods: From 1983 through 2008, 1121 consecutive patients had mitral valve repair on one service. Of these, 662 had repair of mitral leaflet prolapse. From 1983 until 1998, standard quadratic leaflet resection/plication was used in 72 (11.1%) patients, similar but smaller resection in 93 (14.1%) patients, and then smaller resection and polytetrafluoroethylene chordae in 24 (3.7%) patients. All received Puig-Massana fully flexible rings (Shiley, Inc, Irvine, Calif). After 1998, no leaflet resections or valve replacements have been performed regardless of leaflet size in 566 consecutive patients. Of the 662 patients, the mean age was 62.6±14.1 years, and 424 (64.1%) patients were male. Coronary artery disease was present in 147 (22.2%) patients and 33 (5.0%) had prior coronary artery bypass. Leaflets corrected were as follows: anterior, 152 (23.0%) patients; posterior, 427 (64.5%); and both, 83 (12.5%) Common pathologic characteristics of prolapsing valves were as follows: myxomatous, 332 (50.2%) patients, degenerative, 83 (12.5%), ischemic, 31 (4.7%), and rheumatic, 29 (4.4%)., Results: Perioperative mortality was 2.9% (19/662) overall and 0.49% (2/414) for isolated repair. Freedom from reoperation at 10 years (Kaplan-Meier) was 90.1% and freedom from significant mitral regurgitation (echocardiography) was 93.9%., Conclusions: This study confirms that mitral regurgitation from mitral leaflet prolapse can be repaired in all cases by a nonresectional technique provided that accurate dynamic evaluation of chordal length and annular sizing is achieved. The intermediate-term results are durable., (Copyright © 2011 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.)
- Published
- 2011
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36. Dynamic annular geometry and function in patients with mitral regurgitation: insight from three-dimensional annular tracking.
- Author
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Little SH, Ben Zekry S, Lawrie GM, and Zoghbi WA
- Subjects
- Adult, Aged, Aged, 80 and over, Female, Humans, Image Enhancement methods, Male, Middle Aged, Reproducibility of Results, Sensitivity and Specificity, Echocardiography, Three-Dimensional methods, Image Interpretation, Computer-Assisted methods, Imaging, Three-Dimensional methods, Mitral Valve diagnostic imaging, Mitral Valve Insufficiency diagnostic imaging, Mitral Valve Insufficiency etiology, Mitral Valve Prolapse complications, Mitral Valve Prolapse diagnostic imaging
- Abstract
Background: Real-time three-dimensional (3D) echocardiography and unique software permit mitral annular (MA) tracking throughout systole to assess MA remodeling and function. Whether MA structure and function are altered differently depending on the etiology of mitral regurgitation (MR) is currently not known., Methods: We evaluated dynamic MA characteristics in patients with significant MR secondary to mitral valve prolapse and functional MR and compared them with normal controls. Novel 3D tracking software (based on 3D optical flow combined with block matching) was used to identify 16 circumferential equidistant MA points and to track changes in MA area and apical descent from end-diastole to end-systole. Twenty-eight patients with at least moderate MR and 15 normal controls underwent complete transthoracic two-dimensional and quantitative Doppler studies with 3D full-volume MA imaging from the apical 4-chamber view., Results: For each group studied, left ventricular size, systolic function, and dynamic MA characteristics were characterized. Patients with functional MR demonstrated end-diastolic MA area enlargement with reduced systolic area change and reduced apical descent (11.1 + or - 2.7 cm(2), 13 + or - 5%, and 6 + or - 2 mm, respectively) compared with normal controls (9 + or - 2 cm(2), 26 + or - 8%, 11 + or - 2 mm, respectively) (P < .05). In comparison, patients with prolapse MR demonstrated the largest end-diastolic MA areas with preserved annular area change and only mild reduction of apical descent (16.1 + or - 3.5 cm(2), 21 + or - 6%, and 9 + or - 3 mm; P < .05 for area change and apical descent compared with normal). This finding suggests that the pathophysiology of mitral leaflet prolapse may involve significant MA remodeling without deterioration of dynamic MA function., Conclusion: Patients with MR have significant MA enlargement, irrespective of MR etiology. In contrast to functional MR, patients with MR secondary to leaflet prolapse have the largest annular remodeling-almost 80% increase in area-and yet have preserved annular function and dynamicity. These findings may influence surgical repair technique., (Copyright 2010 American Society of Echocardiography. Published by Mosby, Inc. All rights reserved.)
- Published
- 2010
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37. Structure, function, and dynamics of the mitral annulus: importance in mitral valve repair for myxamatous mitral valve disease.
- Author
-
Lawrie GM
- Subjects
- Chordae Tendineae surgery, Heart Valve Prosthesis, Humans, Mitral Valve pathology, Mitral Valve physiopathology, Mitral Valve Insufficiency pathology, Mitral Valve Insufficiency physiopathology, Prosthesis Design, Recurrence, Treatment Outcome, Heart Valve Prosthesis Implantation adverse effects, Heart Valve Prosthesis Implantation instrumentation, Heart Valve Prosthesis Implantation methods, Mitral Valve surgery, Mitral Valve Insufficiency surgery
- Abstract
The first successful open repair of a mitral valve for mitral insufficiency was performed by Dr. Dwight McGoon in 1958. He employed a triangular plication of the prolapsing portion of the posterior leaflet and no annuloplasty. Other surgeons subsequently introduced a variety of techniques. Of these, the repair techniques developed by Dr. Alain Carpentier, which incorporated both leaflet repair by a quadrangular resection and annuloplasty, soon proved to be the most effective and reproducible method at that time. Because of the limited knowledge of normal and pathological mitral valve function available in the late 1960s, this repair was based on anatomical and pathological studies obtained through autopsies as well as intraoperatively. While the Carpentier technique continues to be used widely, most centers have found it difficult to repair more than 50-60% of insufficient valves. Only a few centers have achieved higher early success rates. Most have done this by modifications of the classical techniques. Recent reports have documented high rates of recurrence of significant mitral regurgitation in the 5- to 10-year follow-up interval. Our own experience with the Carpentier technique began in 1983. By this time, a growing body of knowledge was accumulating that demonstrated the highly dynamic behavior and important interactions of the six elements of the mitral complex: the left atrium, leaflets, mitral annulus, chordae, papillary muscles, and left ventricle. Because the Carpentier technique uses leaflet resection and rigid or semi-rigid annuloplasty rings, it produces a substantial disruption of these important functions. The mitral annulus is flattened and fully immobilized, and the leaflets also are flattened at their annular attachment. The loss of surface area amd distortion of the subvalvular chordae and papillary muscles from the leaflet resection produces diminished or absent leaflet movement. The entire mitral valve is left in a highly stressed state. In order to overcome these problems, we developed a new technique called the American Correction (Figure 1). The mitral leaflets are never resected, regardless of size. Artificial polytetrafluoroethylene (PTFE) chordae are used to correct localized leaflets prolapse. A full, totally flexible annuloplasty ring is utilized. Most importantly, all adjustments of leaflet position and annular sizing are done during inflation of the heart, with pressurized normal saline delivered at 4 liters a minute into the cavity of the left ventricle. In a controllable fashion, the left ventricular intracavitary and aortic root pressure can be elevated to systolic levels. This produces a series of reproducible changes in the leaflets and annulus that can be correlated with the normally functioning mitral valve in the beating heart (Figures 2-5).
- Published
- 2010
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38. Nonresectional repair of the barlow mitral valve: importance of dynamic annular evaluation.
- Author
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Lawrie GM, Earle EA, and Earle NR
- Subjects
- Angiography, Echocardiography, Transesophageal, Female, Follow-Up Studies, Humans, Male, Middle Aged, Mitral Valve Insufficiency diagnostic imaging, Mitral Valve Insufficiency physiopathology, Prospective Studies, Severity of Illness Index, Stroke Volume physiology, Treatment Outcome, Ventricular Function, Left physiology, Cardiac Surgical Procedures methods, Mitral Valve Insufficiency surgery, Suture Techniques instrumentation, Sutures
- Abstract
Background: The most extensive form of myxomatous degeneration of the mitral valve causing severe mitral regurgitation is "Barlow disease." Surgical repair of this condition has been considered difficult because of the extent and magnitude of annular, leaflet, and chordal abnormalities and has usually involved partial resection of one or both mitral leaflets., Methods: A surgical approach has been developed which does not involve leaflet resection. Instead, by means of precise dynamic annular sizing, a predetermined zone of leaflet apposition is achieved. The leaflets are positioned so that their large area is contained within the left ventricle. Normal annular, leaflet, and papillary muscle dynamic function is restored., Results: This procedure was performed in 61 patients. The repair rate was 100%. The mean age was 57.6 +/- 12.7 years. They were 67.2% male. The preoperative anteroposterior annular dimension was 52.1 +/- 4.3 mm. The full, flexible complete ring size was 33.4 +/- 1.9 mm. There was no perioperative mortality. There was no systolic anterior leaflet motion. All patients were discharged with no or mild mitral regurgitation. At a follow-up interval of 1.2 +/- 2.1 years one patient had developed recurrent mitral regurgitation, secondary to marked remodeling to normal left ventricular function., Conclusions: Initial experience with a nonresectional approach for Barlow disease has produced good early results.
- Published
- 2009
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39. Quantitative segmentation of principal carotid atherosclerotic lesion components by feature space analysis based on multicontrast MRI at 1.5 T.
- Author
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Karmonik C, Basto P, Vickers K, Martin K, Reardon MJ, Lawrie GM, and Morrisett JD
- Subjects
- Algorithms, Cluster Analysis, Coloring Agents, Histological Techniques, Humans, Models, Cardiovascular, Atherosclerosis pathology, Carotid Stenosis pathology, Magnetic Resonance Imaging methods, Signal Processing, Computer-Assisted
- Abstract
The purpose of this paper is to evaluate the capability of feature space analysis (FSA) for quantifying the relative volumes of principal components (thrombus, calcification, fibrous, normal intima, and lipid) of atherosclerotic plaque tissue in multicontrast magnetic resonance images (mc-MRI) acquired in a setup resembling clinical conditions ex vivo. Utilizing endogenous contrast, proton density, T1-weighted, and T2-weighted images were acquired for 13 carotid endarterectomy (CEA) tissues under near-clinical conditions (human 1.5 T GE Excite scanner with sequence parameters comparable to an in vivo acquisition). An FSA algorithm was utilized to segment and quantify the principal components of atherosclerotic plaques. Pilot in vivo mc-MRI images were analyzed in the same way as the ex vivo images for exploring the possible adaptation of this technique to in vivo imaging. Relative abundance of principal plaque components in CEA tissues as determined by mc-MRI/FSA were compared to those measured by histology. Mean differences +/- standard deviations were 5.8 +/- 4.1% for thrombus, 1.5 +/-1.4 % for calcification, 4.0 +/-2.8% for fibrous, 8.2 +/- 10% for normal intima, and 2.4 +/- 2.2% for lipid. Reasonable quantitative agreement between the classification results obtained with FSA and histological data was obtained for near-clinical imaging conditions. Combination of mc-MRI and FSA may have an application for determining atherosclerotic lesion composition and monitoring treatment in vivo.
- Published
- 2009
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40. Ensuring proper leaflet apposition during mitral valve repair.
- Author
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Lawrie GM
- Subjects
- Heart Valve Prosthesis Implantation, Humans, Cardiac Surgical Procedures methods, Mitral Valve surgery
- Published
- 2008
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41. Outcome of surgical myectomy after unsuccessful alcohol septal ablation for the treatment of patients with hypertrophic obstructive cardiomyopathy.
- Author
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Nagueh SF, Buergler JM, Quinones MA, Spencer WH 3rd, and Lawrie GM
- Subjects
- Aged, Female, Humans, Male, Middle Aged, Pacemaker, Artificial, Retrospective Studies, Salvage Therapy, Treatment Failure, Cardiac Catheterization, Cardiac Surgical Procedures, Cardiomyopathy, Hypertrophic surgery, Ethanol therapeutic use
- Abstract
Objectives: We sought to determine the outcome of myectomy after unsuccessful alcohol ablation., Background: Alcohol septal ablation results in symptomatic improvement and a reduction in dynamic obstruction in most hypertrophic obstructive cardiomyopathy patients. However, a few patients remain with severe symptoms and obstruction and need surgery. The outcome of these cases is not well known., Methods: The medical records of 375 patients who underwent alcohol ablation at our institution were reviewed. Twenty patients (5.3%, mean age 53 +/- 18 years, 17 women) subsequently needed surgical myectomy. The New York Heart Association (NYHA) functional class, angina class, exercise duration, left ventricular outflow tract (LVOT) gradient, ejection fraction, and septal thickness were tabulated. The anatomy and distribution of the septal perforator arteries were examined., Results: After ablation, NYHA functional class (3 to 2.5; p < 0.05) and LVOT gradient (93 +/- 23 mm Hg to 71 +/- 26 mm Hg; p < 0.05) were slightly improved, without a change in exercise duration (171 +/- 124 s to 168 +/- 148 s; p > 0.5). Myectomy was performed at 19 +/- 15 months after ablation. There was no operative mortality, but permanent pacing was needed in 2 patients after surgery, and 3 other cases needed pacing before, or as a complication of, alcohol ablation. A significant improvement was noted, with the NYHA functional class decreasing to 1, exercise duration increasing to 423 +/- 171 s, and LVOT gradient decreasing to 6 +/- 11 mm Hg (all p < 0.05 versus post-alcohol ablation)., Conclusions: Myectomy can be successfully performed after failed alcohol ablation, but with a higher incidence of heart block than in cases where only surgery is performed. Otherwise, alcohol ablation does not appear to adversely affect surgical outcome.
- Published
- 2007
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42. Feasibility and intermediate term outcome of repair of prolapsing anterior mitral leaflets with artificial chordal replacement in 152 patients.
- Author
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Lawrie GM, Earle EA, and Earle NR
- Subjects
- Aged, Coronary Artery Bypass, Feasibility Studies, Female, Follow-Up Studies, Humans, Male, Middle Aged, Mitral Valve pathology, Multivariate Analysis, Myocardial Infarction epidemiology, Time Factors, Treatment Outcome, Heart Valve Prosthesis Implantation, Mitral Valve Prolapse surgery
- Abstract
Background: Mitral valve repair of the anterior leaflet has been more difficult than at other sites., Methods: Between February 1983 and June 2004, 607 mitral valve repairs were performed on one service. Of these, 410 patients had leaflet repair procedures: 152 were anterior leaflet repairs; isolated in 94, and combined with posterior repair in 58 patients. The results in these patients were compared with the results of posterior leaflet repair in 258 patients. All patients received flexible ring annuloplasty., Results: Age and sex of the anterior leaflet and posterior leaflet patients were similar: mean age 62.5 +/- 14.3, 62.9 +/- 14.9 years; males, 50.6%, p = not significant (NS). Preoperative ejection fraction was for anterior repairs 52.6 +/- 12.8%; posterior repair, 58.2 +/- 11.8%, p = NS. Coronary artery bypass was more frequently performed with anterior leaflet repair in 18 patients (19.1%) versus 45 (6.6%) for posterior leaflet repair (p = NS). The median number of chordae was similar in the anterior leaflet and posterior leaflet patients 4 (2-8), 4 (2-6), p = NS. Perioperative mortality was similar: anterior leaflet patients, 3.3% (2/94); posterior leaflet patients, 1.1% (2/258), p = NS. Hospital stay was for anterior leaflet patients and posterior leaflet patients: 12.86 +/- 13.3 vs 11.0 +/- 12.3, p = NS. Kaplan-Meier estimates of freedom from reoperation at 3 years were: for anterior leaflet patients, 91.9%: for posterior leaflet patients, 90.7%, p = 0.77. No structural polytetrafluoroethylene (PTFE) chordal failures were observed. Late echocardiographic data were obtained in 136 patients on 222 occasions at a mean of 3.2 +/- 3.34 years. Severe mitral regurgitation was present in 10 patients (7.3%)., Conclusions: Repair of the anterior leaflet is facilitated by the use of PTFE replacement. Anterior leaflet repair can be performed reproducibly with the same results as posterior leaflet repair.
- Published
- 2006
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43. Mitral valve: toward complete repairability.
- Author
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Lawrie GM
- Subjects
- Clinical Trials as Topic trends, Heart Valve Prosthesis Implantation instrumentation, Humans, Prosthesis Design, Plastic Surgery Procedures methods, Treatment Outcome, Heart Valve Prosthesis trends, Heart Valve Prosthesis Implantation methods, Heart Valve Prosthesis Implantation trends, Mitral Valve Insufficiency surgery, Practice Patterns, Physicians' trends, Plastic Surgery Procedures instrumentation, Plastic Surgery Procedures trends
- Abstract
During the last 50 years, there has been an exponential increase in our understanding of the structure and function of the mitral valve in health and disease. Large numbers of patients have undergone mitral-valve reparative procedures worldwide with variable results. In our initial 10-year experience in which traditional techniques were used for repair of mitral regurgitation, a 70% success rate was achieved. In 1995, a critical reappraisal of the common causes of failure to repair, or failure of repair and developed improved surgical approaches for these patients began. The conditions addressed were massive bileaflet prolapse ("Barlow's valves"); anterior leaflet prolapse; multisegment chordal failure; commissural accessory leaflet tissue prolapse; and leaflet destruction by endocarditis. A widely applicable standard technique was developed that the author and colleagues called the "American Correction." It emphasizes chordal replacement with polytetrafluoroethylene (PTFE) artificial chordae, importance of the line of apposition of the leaflets, and importance of simultaneous dynamic adjustment of the chordal length and anteroposterior dimension of the mitral annulus. In addition, use of multiple techniques in 30% of patients to complete the repair has been emphasized. These techniques resulted in a 90% repairability rate for all pathologies and 100% for myxomatous-mitral insufficiency. These techniques also have led to a decline in reoperation rates, and improved long-term durability. Continued evaluation with intraoperative and postoperative three-dimensional (3-D) echo provides further insights and refinement of mitral-repair techniques.
- Published
- 2006
44. Surgical outcome in 85 patients with primary cardiac tumors.
- Author
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Bakaeen FG, Reardon MJ, Coselli JS, Miller CC, Howell JF, Lawrie GM, Espada R, Ramchandani MK, Noon GP, Weilbaecher DG, and DeBakey ME
- Subjects
- Adolescent, Adult, Aged, Aged, 80 and over, Female, Heart Neoplasms diagnosis, Heart Neoplasms mortality, Humans, Male, Middle Aged, Neoplasm Recurrence, Local, Postoperative Complications, Retrospective Studies, Survival Rate, Heart Neoplasms surgery
- Abstract
Background: We present a large, single institution experience with adult cardiac tumors and address factors affecting outcome., Methods: A retrospective review was made of all patients who underwent surgery for primary cardiac tumors from April 1975 through August 2002., Results: Eighty-five patients (33 male and 52 female) with a mean age of 54 years were identified with follow-up available for 80 (94%) patients. There were 68 (80%) benign tumors and 17 (20%) malignant tumors. Three tumors recurred and were resected giving a total of 88 surgeries. All benign tumors were grossly resected and the extent of resection for malignant disease ranged from 14 (78%) gross resections and 3 (17%) debulkings to 1 (5%) biopsy. There were 4 (5%) early hospital deaths. Median survival was 9.6 months and 322 months for patients with malignant and benign diseases, respectively. Significant predictors of long-term mortality were malignant disease (P <0.0001) and New York Heart Association class (P <0.03)., Conclusions: Surgical resection provides excellent outcome in patients with benign cardiac tumors. Malignant tumors continue to pose a challenge with good local tumor control but limited survival owing to metastatic disease.
- Published
- 2003
- Full Text
- View/download PDF
45. Identification of hibernating myocardium with quantitative intravenous myocardial contrast echocardiography: comparison with dobutamine echocardiography and thallium-201 scintigraphy.
- Author
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Shimoni S, Frangogiannis NG, Aggeli CJ, Shan K, Verani MS, Quinones MA, Espada R, Letsou GV, Lawrie GM, Winters WL, Reardon MJ, and Zoghbi WA
- Subjects
- Aged, Blood Flow Velocity, Coronary Artery Disease complications, Coronary Artery Disease diagnosis, Coronary Artery Disease surgery, Coronary Circulation, Female, Humans, Injections, Intravenous, Male, Middle Aged, Myocardial Contraction, Myocardial Stunning diagnostic imaging, Observer Variation, Predictive Value of Tests, ROC Curve, Radionuclide Imaging, Recovery of Function, Sensitivity and Specificity, Ventricular Dysfunction diagnosis, Ventricular Dysfunction etiology, Contrast Media administration & dosage, Dobutamine, Echocardiography, Myocardial Stunning diagnosis, Thallium Radioisotopes
- Abstract
Background: There are currently no data on the accuracy of intravenous myocardial contrast echocardiography (MCE) in detecting myocardial hibernation in man and its comparative accuracy to dobutamine echocardiography (DE) or thallium 201 (Tl(201)) scintigraphy., Methods and Results: Twenty patients with coronary artery disease and ventricular dysfunction underwent MCE 1 to 5 days before bypass surgery and repeat echocardiography at 3 to 4 months. Patients also underwent DE (n=18) and rest-redistribution Tl(201) tomography (n=16) before revascularization. MCE was performed using continuous Optison infusion (12 to 16 cc/h) with intermittent pulse inversion harmonics and incremental triggering (1:1 to 1:8). Myocardial contrast intensity (MCI) replenishment curves were constructed to derive quantitative MCE indices of blood velocity and flow. Recovery of function occurred in 38% of dysfunctional segments. MCE parameters of perfusion in hibernating myocardium were similar to segments with normal function and higher than dysfunctional myocardium without recovery of function (P<0.001). The best MCE parameter for predicting functional recovery was Peak MCIxbeta, an index of myocardial blood flow (area under the curve, 0.83). MCE parameters were higher in segments with contractile reserve and Tl(201) uptake > or =60% (P<0.05) and identified viable segments without contractile reserve by DE. The sensitivity of Peak MCIxbeta >1.5 dB/s for recovery of function was 90% and was similar to Tl(201) scintigraphy (92%) and any contractile reserve (80%); specificity was higher than for Tl(201) and DE (63%, 45%, and 54%, respectively; P<0.05)., Conclusions: MCE with intravenous contrast identifies myocardial hibernation in humans. Prediction of viable myocardium with MCE is best using quantification of myocardial blood flow and provides improved accuracy compared with DE and Tl(201) scintigraphy.
- Published
- 2003
- Full Text
- View/download PDF
46. Microvascular structural correlates of myocardial contrast echocardiography in patients with coronary artery disease and left ventricular dysfunction: implications for the assessment of myocardial hibernation.
- Author
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Shimoni S, Frangogiannis NG, Aggeli CJ, Shan K, Quinones MA, Espada R, Letsou GV, Lawrie GM, Winters WL, Reardon MJ, and Zoghbi WA
- Subjects
- Aged, Biopsy, Capillaries pathology, Coronary Angiography, Coronary Artery Disease diagnostic imaging, Coronary Artery Disease pathology, Coronary Artery Disease surgery, Coronary Circulation, Coronary Vessels pathology, Female, Fibrosis, Heart physiopathology, Humans, Male, Microcirculation pathology, Middle Aged, Myocardial Stunning diagnostic imaging, Myocardial Stunning pathology, Myocardial Stunning surgery, Myocardium pathology, Observer Variation, Ventricular Dysfunction, Left diagnostic imaging, Ventricular Dysfunction, Left pathology, Ventricular Dysfunction, Left surgery, Coronary Artery Disease diagnosis, Echocardiography, Transesophageal methods, Myocardial Stunning diagnosis, Ventricular Dysfunction, Left diagnosis
- Abstract
Background: Myocardial contrast echocardiography (MCE) has been used to evaluate myocardial viability. There are no data, however, on the pathological determinants of myocardial perfusion by MCE in humans and the implications of such determinants., Methods and Results: MCE was performed in 20 patients with coronary artery disease and ventricular dysfunction within 24 hours before myocardial biopsy at surgery using a continuous Optison infusion (12 to 16 cc/h), with intermittent pulse inversion harmonics and incremental triggering. Peak myocardial contrast intensity (MCI) and the rate of increase in MCI (beta) were quantitated. Thirty-six transmural myocardial biopsies (2 per patient) were obtained by transesophageal echocardiography. Total microvascular (<100 microm) density, capillary density and area, arteriolar and venular density, and percent collagen content were quantitated with immunohistochemistry. Peak MCI correlated with microvascular density (r=0.59, P<0.001) and capillary area (r=0.64, P<0.001) and inversely correlated with percent collagen content (r=-0.45, P=<0.01). The best relation was observed when the ratio of peak MCI in the 2 biopsied segments in each patient was compared with the ratio of microvascular density and capillary area (r=0.84 and 0.87, respectively; P<0.001). A significant overlap in microvascular density was seen between segments with and without recovery of function. The new MCE indices of blood velocity (beta) and flow (peak MCIxbeta) better identified recovery of function compared with microvascular density and the sole use of peak MCI., Conclusions: Microvascular integrity is a significant determinant of maximal MCI in humans. MCE indices of blood velocity and flow are important parameters that predict recovery of function after revascularization.
- Published
- 2002
- Full Text
- View/download PDF
47. Mitral Valve Repair: the Multimodal Approach and the Role of Minimally Invasive Procedures.
- Author
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Lawrie GM
- Abstract
In recent years mitral valve repair has gained increasing acceptance as the preferred treatment for mitral insufficiency. Mitral valve repair has many advantages. The surgical risk is lower than prosthetic valve replacement. Improved preservation of left ventricular function due to maintenance of the papillary muscle - mitral annular continuity - has been demonstrated. Thromboembolism is rare after mitral repair in patients in sinus rhythm. These patients receive no coumadin and thus are free from bleeding complications. The repaired valves have been shown to have durability comparable to or better than prosthetic valves.
- Published
- 2000
48. Quantification in situ of crystalline cholesterol and calcium phosphate hydroxyapatite in human atherosclerotic plaques by solid-state magic angle spinning NMR.
- Author
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Guo W, Morrisett JD, DeBakey ME, Lawrie GM, and Hamilton JA
- Subjects
- Animals, Carotid Artery Diseases pathology, Carotid Artery, Common chemistry, Carotid Artery, Common pathology, Chickens, Crystallization, Humans, Phosphorus analysis, Calcium Phosphates analysis, Carotid Artery Diseases metabolism, Cholesterol analysis, Durapatite analysis, Magnetic Resonance Spectroscopy methods
- Abstract
Because of renewed interest in the progression, stabilization, and regression of atherosclerotic plaques, it has become important to develop methods for characterizing structural features of plaques in situ and noninvasively. We present a nondestructive method for ex vivo quantification of 2 solid-phase components of plaques: crystalline cholesterol and calcium phosphate salts. Magic angle spinning (MAS) nuclear magnetic resonance (NMR) spectra of human carotid endarterectomy plaques revealed (13)C resonances of crystalline cholesterol monohydrate and a (31)P resonance of calcium phosphate hydroxyapatite (CPH). The spectra were obtained under conditions in which there was little or no interference from other chemical components and were suitable for quantification in situ of the crystalline cholesterol and CPH. Carotid atherosclerotic plaques showed a wide variation in their crystalline cholesterol content. The calculated molar ratio of liquid-crystalline cholesterol to phospholipid ranged from 1.1 to 1.7, demonstrating different capabilities of the phospholipids to reduce crystallization of cholesterol. The spectral properties of the phosphate groups in CPH in carotid plaques were identical to those of CPH in bone. (31)P MAS NMR is a simple, rapid method for quantification of calcium phosphate salts in tissue without extraction and time-consuming chemical analysis. Crystalline phases in intact atherosclerotic plaques (ex vivo) can be quantified accurately by solid-state (13)C and (31)P MAS NMR spectroscopy.
- Published
- 2000
- Full Text
- View/download PDF
49. Commentary
- Author
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Lawrie GM
- Published
- 1999
- Full Text
- View/download PDF
50. Can retrograde cardioplegia alone provide adequate protection for cardiac valve surgery?
- Author
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Talwalkar NG, Lawrie GM, Earle N, and DeBakey ME
- Subjects
- Adult, Aged, Aged, 80 and over, Aortic Aneurysm, Thoracic surgery, Cardioplegic Solutions administration & dosage, Combined Modality Therapy, Coronary Artery Bypass, Coronary Disease surgery, Female, Humans, Male, Middle Aged, Myocardial Reperfusion Injury etiology, Postoperative Complications etiology, Postoperative Complications prevention & control, Risk Factors, Heart Valve Diseases surgery, Heart Valve Prosthesis Implantation, Hypothermia, Induced, Myocardial Reperfusion Injury prevention & control
- Abstract
Background: When aortic insufficiency is present, antegrade delivery of cardioplegia requires coronary cannulation. Use of retrograde cardioplegia simplifies administration. The efficacy of the retrograde route alone in ensuring adequate myocardial protection may be assessed by the clinical outcome., Methods and Results: We used closed transatrial coronary sinus perfusion as the sole method of cardioplegia delivery in 100 patients who underwent valve operations, either isolated or combined with coronary (n=24), ascending aortic aneurysm (n=8), or other procedures. Eighty-one patients were in New York Heart Association (NYHA) Class III or IV; 23 had undergone previous heart operations; 23 were admitted from the coronary care unit (CCU); and 20 had left ventricular ejection fraction (LVEF) of < or = 40%. Operative mortality was 2%. An intra-aortic balloon pump was required in eight patients. On univariate analysis, perioperative use of inotropes (n=26) was related to age > or = 70 years (p=0.02), COPD (p=0.05), pulmonary hypertension (p=0.005), higher NYHA Class (p=0.0006), preoperative heart failure (p=0.006), lower LVEF (p=0.0003), urgency (p=0.00001), admission from the CCU (p=0.006), repeat operation (p=0.03), coronary artery disease (p=0.02), and longer ischemic (p=0.02) and bypass times (p=0.0003). On multivariate stepwise logistic regression analysis, use of inotropes was related to preoperative lower LVEF (p=0.02) and urgency of operation (p=0.0002). Perioperative complications included ventricular arrhythmia in six, heart block in one, renal dysfunction in nine, and stroke in two patients; no patient had myocardial infarction., Conclusion: Good clinical results can be obtained by using retrograde cardioplegia alone without prior doses of antegrade cardioplegia in all valve operations.
- Published
- 1999
- Full Text
- View/download PDF
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