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Purpose There is controversy over the use of durable left ventricular assist devices (LVADs) in supporting patients with hypertrophic cardiomyopathy (HCM) and advanced heart failure. HCM patients have smaller left ventricular (LV) dimensions and are at higher risk of LVAD inflow cannula occlusion from ventricular decompression. Right ventricular (RV) failure is also a concern in these patients. This study describes a single-centre experience of LVAD implantation in patients with heart failure due to HCM. Methods Cases were reviewed from a prospective registry of all LVAD implants at the University Health Network (Toronto, Canada) between 2006 and 2020 to identify patients with HCM. We determined baseline characteristics, peri-operative course and outcomes, including requirement for RV support, ICU and hospital length of stay and eventual outcome from LVAD support. Results We identified 15 patients with LVAD implantation for HCM with a history of heart failure of 6 (interquartile range: 4-12) years and peak VO2 of 9.6 (9.2-10.4) ml/kg/min. Median age was 57 (46-60) years, 1 (7%) patient was female (Table). During the index admission for LVAD implant, 5 (33%) patients required renal replacement therapy and 3 (20%) died due to ischemic bowel, tracheobronchitis and liver failure/sepsis, respectively. No patients required RV support. ICU stay was 8 (6-11) days and hospital stay 33 (16-65) days in those discharged from hospital. Overall, patients were supported for 5153 patient-days; 9 (60%) patients underwent heart transplant after LVAD support of 206 (110-458) days, 2 (13%) are currently supported and 1 died after 1671 days from presumed pump thrombosis. One patient required LVAD exchange for late pump thrombosis. Conclusion This single-centre experience demonstrated that LVAD support in patients with HCM is safe and effective as a bridge to transplant or destination therapy. Further work should explore patient characteristics favourable to LVAD therapy in HCM patients.

Hypertrophic cardiomyopathy (HCM) is characterized by unexplained usually asymmetrical cardiac hypertrophy with variable degrees of myocardial fiber disarray and fibrosis. Although there was initial controversy about whether true obstruction to the left ventricular outflow tract (LVOT) existed, it

Background Nonsustained ventricular tachycardia (NSVT) detected by ambulatory Holter (Holter NSVT) is a major risk factor for sudden cardiac death in hypertrophic cardiomyopathy (HCM). We hypothesized that the prognostic utility of Holter NSVT in HCM would improve with prolonged monitoring and a higher heart rate cut-off for detection. Methods We enrolled 60 patients (44 ± 14 years) with HCM, who had a prophylactic implantable cardioverter defibrillator (ICD). Positive Holter NSVT (prior to implant) was defined as ≥3 beats at ≥120 beats per minute (bpm). We assessed the prevalence of rapid NSVT (RNSVT) detected by their ICD within 12 months of its implant, defined as 4-16 beats at ≥150-200 bpm. The primary outcome was appropriate ICD therapy (antitachycardia pacing and shocks) for sustained ventricular arrhythmia (VA). Results Holter NSVT was detected in 34 patients. RNSVT occurred in 21 (35%) patients of whom five did not have Holter NSVT. Over a median follow-up of 61 (interquartile range 29, 129) months after ICD implant, nine patients had VA. RNSVT, but not Holter NSVT, was significantly associated with VA (hazard ratio 6.2, 95% confidence interval [1.3-30], P = 0.01) by multivariable Cox regression analysis that included conventional risk factors. Receiver operating characteristic analysis for RNSVT (area under curve 0.80, P = 0.005) showed that the occurrence of ≥2 episodes of RNSVT discriminated patients for VA optimally (sensitivity 78%, specificity 84%, positive predictive value 47%, negative predictive value 96%). Conclusions In this pilot study, RNSVT detected by continuous monitoring independently predicted VA in HCM and offered superior discrimination of VA risk compared to conventional risk factors, including Holter NSVT. Future studies are needed to validate these findings in a larger, unselected HCM cohort.

Sudden cardiac death (SCD) is usually defined as an unexpected death either within 1 h of symptom onset or within 24 h of having been observed alive and symptom free. Its annual incidence is estimated at 42–95/100,000 and is higher in men. With the exception of infants in their first 2 years of life, SCD in children is exceedingly rare (

Hypertrophic cardiomyopathy (HC) is a heterogenous disease with a variable clinical course. Predictors of long-term adverse cardiovascular events are needed. Our objectives were to determine the long-term prognostic value of a single and serial point of care (POC) B-type natriuretic-peptide (BNP) measurements in HC. One hundred and eleven ambulatory patients with HC (mean age 53 ± 16 years) were prospectively recruited over a 2-year period (2004 to 2006). A clinical assessment, comprehensive echocardiogram, and a POC BNP level was obtained at baseline and at a 1- to 2-year follow-up. They were subsequently followed for the occurrence of major adverse cardiac events (MACE). The median baseline BNP concentration was 114 pg/ml (range 5.3 to 1550 pg/ml). During a mean follow-up of 6.2 ± 3.4 years, 42 patients (38%) had a MACE. In a multivariable Cox model including clinical and echocardiographic predictors, logBNP (HR 4.30; 95% confidence interval 1.97 to 9.37, p0.001) and left ventricualr ejection fraction (LVEF) (HR 0.96; 95% confidence interval 0.94 to 0.99, p = 0.011) remained significant predictors of MACE. Nested models demonstrated incremental prognostic value of logBNP for MACE (chi-square increased from 4.3 to 22.8, p0.01) over clinical and echocardiographic factors. Patients with persistently elevated BNP (100 pg/ml) at baseline and at the second visit were at a higher risk of developing MACE during follow-up (5-year MACE-free survival of 0.91 (SE 0.06) vs 0.45 (SE 0.09), p0.001). In conclusion, POC BNP levels in patients with HC were predictive of long-term MACE and had independent and incremental value. Patients with persistently elevated BNP levels were at a higher risk of MACE.

Background Mitral valve (MV) repair is the procedure of choice for patients with degenerative MV disease (DMVD) with severe mitral regurgitation. The aim of this study was to identify specific quantitative MV parameters from preoperative three-dimensional (3D) transesophageal echocardiography that are associated with the length of the mitral annuloplasty band implanted and the performance of leaflet resection in patients with DMVD undergoing MV repair. Methods Ninety-four patients (mean age, 60 ± 11 years; 68% men) referred for MV surgery with adequate-quality preoperative 3D transesophageal echocardiographic studies were retrospectively identified. Parametric maps of the MV were generated using semiautomated MV modeling software. Annular and valvular parameters were measured and indexed to body surface area. The implanted annuloplasty band size and leaflet resection were determined on the basis of surgical reports. Results Three-dimensional annular circumference correlated best ( r = 0.74) with the implanted annuloplasty band length and remained an independent predictor on multivariate linear regression analysis. A third of our cohort ( n = 33) had posterior leaflet resection. On receiver operating characteristic curve analysis, P2 segment length ≥ 20 mm (area under the curve, 0.86; sensitivity, 88%; specificity, 74%) and P2 leaflet area ≥ 3.4 cm 2 (area under the curve, 0.84; sensitivity, 85%; specificity, 74%) best discriminated the need for leaflet resection. Conclusions In DMVD, quantitative 3D annular circumference obtained from semiautomatically generated parametric maps of the MV from 3D transesophageal echocardiographic data was associated with the surgically implanted annuloplasty band length, while P2 leaflet length ≥ 20 mm and area ≥ 3.4 cm 2 were associated with the performance of leaflet resection. These parameters should be further investigated for preoperative planning in patients with DMVD undergoing MV repair.

Background Appropriate use criteria (AUC) for transthoracic echocardiography (TTE) were developed to address concerns regarding inappropriate use of TTE. A previous pilot study suggests that an educational and feedback intervention can reduce inappropriate TTEs ordered by physicians in training. It is unknown if this type of intervention will be effective when targeted at attending level physicians in a variety of clinical settings. Aims The aim of this international, multicenter study is to evaluate the hypothesis that an AUC-based educational and feedback intervention will reduce the proportion of inappropriate echocardiograms ordered by attending physicians in the ambulatory environment. Methods In an ongoing multicentered, investigator-blinded, randomized controlled trial across Canada and the United States, cardiologists and primary care physicians practicing in the ambulatory setting will be enrolled. The intervention arm will receive (1) a lecture outlining the AUC and most recent available evidence highlighting appropriate use of TTE, (2) access to the American Society of Echocardiography mobile phone app, and (3) individualized feedback reports e-mailed monthly summarizing TTE ordering behavior including information on inappropriate TTEs and brief explanations of the inappropriate designation. The control group will receive no education on TTE appropriate use and order TTEs as usual practice. Conclusions The Echo WISELY (Will Inappropriate Scenarios for Echocardiography Lessen Significantly in an education RCT) study is the first multicenter randomized trial of an AUC-based educational intervention. The study will examine whether an education and feedback intervention will reduce the rate of outpatient inappropriate TTEs ordered by attending level cardiologists and primary care physicians (www.clinicaltrials.gov identifier NCT02038101).

We report one surgeon's experience of corrective surgery for hypertrophic obstructive cardiomyopathy (HOCM) over a 10-year span and comment on factors that influence longer term outcomes. Septal myectomy (SM) and adjunctive procedures, including shortening of the aorta, a novel technique in HOCM patients, are described.Perioperative data were obtained by retrospective review of institutional surgical databases between 2001 and 2011. Review of most recent echocardiogram and clinical status by telephone interview was performed.A total of 211 patients underwent SM for HOCM. There was a bimodal age distribution related to sex; mean age for males and females was 46 ± 13 and 54 ± 14 years, respectively (p0.001). Functional New York Heart Association (NYHA) class improved significantly after surgery; 79% were in class III-IV preoperatively and 84% were in class I-II at follow-up (p0.001). Sixty percent had angina of Canadian Cardiovascular Society (CCS) grade III-IV preoperatively and 89% were in CCS I-II at follow-up (p0.001). There were significant improvements in resting left ventricular outflow tract gradient (64 ± 36 to 5 ± 5 mm Hg, p0.001), right ventricular systolic pressure (36 ± 7.3 to 32 ± 8 mm Hg, p0.001), left atrial size (4.6 ± 0.7 to 4.3 ± 0.6 cm, p0.001), and grade of mitral regurgitation (moderate to severe mitral regurgitation 28% to 3.5%, p0.001). In-hospital mortality was 0.5%, 1 year survival 98.6%, and 5-year survival 98.1%. Predictors of worse clinical outcomes were preoperative NYHA and CCS class III-IV (p0.001, p = 0.05), new onset atrial fibrillation (p0.001), and female sex (p = 0.03).Septal myectomy in patients with obstructive HOCM offers excellent symptom relief and minimal operative risk.

Symptomatic patients with severe aortic stenosis (AS) demonstrate abnormal left ventricular (LV) mechanics. The aim of this study was to compare mechanics in asymptomatic and symptomatic patients with severe AS using two-dimensional myocardial strain imaging.One hundred fifty-four patients with severe AS (aortic valve area ≤ 1.0 cm(2)) referred to a heart valve clinic from 2004 to 2011 were studied. Thirty patients were asymptomatic, with normal LV ejection fractions (≥ 55%), without other significant valvular disease or wall motion abnormalities. Thirty-two symptomatic patients who underwent early aortic valve replacement, with similar age, gender, LV ejection fraction, and aortic valve area, were selected for comparison. Both groups were also compared with 32 healthy subjects with similar age and gender distributions and normal echocardiographic results who served as controls. LV longitudinal and circumferential strain and rotation were measured using speckle-tracking software applied to archived echocardiographic studies. Conventional echocardiographic and myocardial mechanical parameters were compared among the study subgroups.Patients with asymptomatic severe AS demonstrated smaller reductions in longitudinal strain, higher (supernormal) apical circumferential strain (-38 ± 6% vs -35 ± 4%, P.05), and extreme (supernormal) apical rotation (12.2 ± 4.9° vs 2.9 ± 1.7°, P.0005) compared with symptomatic patients. Apical rotation6° was the single significant predictor of symptoms in logistic regression analysis of clinical, echocardiographic, and mechanical parameters. Twelve asymptomatic patients underwent eventual aortic valve replacement and showed decreases in strain and apical rotation compared with baseline values.Longitudinal strain was uniformly low in patients with severe AS and lower in those with symptoms. Compensatory circumferential myocardial mechanics (increased apical circumferential strain and rotation) were absent in symptomatic patients. Thus, myocardial mechanics may help in the follow-up of patients with severe AS and timing of valve surgery.

PURPOSE: The purpose of this study was to determine the prognostic significance of cardiac magnetic resonance imaging (MRI) findings in patients with apical hypertrophic cardiomyopathy (HCM). MATERIALS AND METHODS: Cardiac MRI studies of 93 consecutive patients with apical HCM were retrospectively evaluated. Quantification of late gadolinium enhancement (LGE) was determined and expressed as a percentage of total left ventricular (LV) myocardial mass (%LGE). Morphologic features including presence of apical aneurysm, right ventricular hypertrophy, and LV thrombus were also assessed. Clinical data were collected during follow-up to assess for occurrence of major adverse events, defined as: heart failure, stroke, appropriate automatic implantable cardioverter defibrillator discharge, sustained ventricular tachycardia, aborted sudden cardiac death, and/or all-cause death. RESULTS: The mean age of the patients was 54.9±13.8 years, and 72.0% (n=67) were male. LGE, right ventricular hypertrophy, apical aneurysm, and LV thrombus were identified in 69.4%, 25.8%, 18.3%, and 4.3%, respectively. Mean %LGE was 10.8%±11.1%. Over 2.4±1.7 years of follow-up, 14 subjects (15.1%) experienced a major adverse event (event rate, 6.3%/y): heart failure (6.5%), stroke (6.5%), appropriate automatic implantable cardioverter defibrillator discharge (2.2%), sustained ventricular tachycardia (2.2%), aborted sudden cardiac death (1.1%), and all-cause death (0.0%). Presence of apical aneurysm and extent of LGE were significant predictors of major adverse events [odds ratio (OR) 4.6, P=0.015; and OR 1.4/5% LGE, P=0.030, respectively]. Patients with both apical aneurysm and >5% LGE were at highest risk for major adverse events (OR 6.7, P=0.004) and had shortest event-free survival (P=0.001). CONCLUSIONS: Within our population of apical HCM patients, the extent of LGE and the presence of an apical aneurysm identified by cardiac MRI were both significant predictors of major adverse clinical events.

Background— We sought to compare maximal left ventricular (LV) wall thickness (WT) measurements as obtained by routine clinical practice between echocardiography and cardiac magnetic resonance (CMR) and document causes of discrepancy. Methods and Results— One-hundred and ninety-five patients with hypertrophic cardiomyopathy (median age, 52.8±15.1 years) who underwent echocardiography and CMR imaging within 6 months (median, 41 days; interquartile range, 16–97 days) were included. LVWT was assessed in parasternal long and short axis by 2-dimensional echocardiography and in short axis by CMR. By Bland–Altman plot, mean maximal LVWT difference between echocardiography and CMR was 0.5 mm (95% confidence interval, −6.9, 7.8) with equal distribution of discrepancy along the full range of LVWT. Ninety-seven patients (49.7%) were identified to have intermodal measurement discrepancies ≥10%. In 7 patients (7.2%), reported measurement by CMR was inaccurate because of interpretation error. In 90 patients (92.8%), echocardiography underestimated (n=32; 33.0%) or overestimated (n=58; 59.8%) maximal LVWT. Underestimation was because of focal LV hypertrophy (n=10; 10.3%) or poor acoustic windows (n=22; 22.7%) while overestimation resulted from inclusion of right ventricular myocardium (n=37; 38.1%), LV trabeculations (n=5; 5.2%), papillary muscle (n=3; 3.1%), and apical-septal bundle (n=1; 1.0%), as well as imaging plane obliquity (n=7; 12.5%). In 31 (15.9%) patients, measurement discrepancy occurred at diagnostic or prognostic cut-offs. Conclusions— Although maximal LVWT by echocardiography in general measured similar to CMR, discordance because of limitations in echocardiography technique was present in a significant subset of patients. As measurement of LVWT impacts diagnosis and sudden death management, CMR should be considered as part of routine evaluation of all patients with hypertrophic cardiomyopathy.

This review discusses the complementary roles of echocardiography and cardiac magnetic resonance in the diagnosis and management of patients with hypertrophic cardiomyopathy (HCM). Imaging using novel echocardiographic techniques and cardiac magnetic resonance (CMR) imaging in HCM has demonstrated incremental utility in diagnosis and management guidance. Application of 3-D imaging has improved assessment of left ventricular (LV) mass and volume by echocardiography. Quantification of myocardial mechanics has shown promise for clarification of diagnosis, prognosis, and assessment of LV dysfunction. CMR permits 3-D tomographic characterization of cardiac structure and tissue characterization which has shown utility for assessing the diverse phenotypes in HCM and quantification of left ventricular fibrosis, an increasingly recognized poor prognostic marker. Non-invasive cardiac imaging remains central for the evaluation of HCM patients. An approach integrating echocardiography and CMR as complementary modalities allows for improved diagnostic and prognostic assessment.

Appropriate use criteria (AUC) have defined transthoracic echocardiogram (TTE) indications for which there is a clear lack of benefit as rarely appropriate (rA).This study sought to investigate the impact of an AUC-based educational intervention on outpatient TTE ordering by cardiologists and primary care providers.The authors conducted a prospective, investigator-blinded, multicenter, randomized controlled trial of an AUC-based educational intervention aimed at reducing rA outpatient TTEs. The study was conducted at 8 hospitals across 2 countries. The authors randomized cardiologists and primary care providers to receive either intervention or control (no intervention). The primary outcome measure was the proportion of rA TTEs.One hundred and ninety-six physicians were randomized, and 179 were included in the analysis. From December 2014 to April 2016, the authors assessed 14,697 TTEs for appropriateness, of which 99% were classifiable using the 2011 AUC. The mean proportion of rA TTEs was significantly lower in the intervention versus the control group (8.8% vs. 10.1%; odds ratio [OR]: 0.75; 95% confidence interval [CI]: 0.57 to 0.99; p = 0.039). In physicians who ordered, on average, at least 1 TTE per month, there was a significantly lower proportion of rA TTEs in the intervention versus the control group (8.6% vs. 11.1%; OR: 0.76; 95% CI: 0.57 to 0.99; p = 0.047). There was no difference in the TTE ordering volume between the intervention and control groups (mean 77.7 ± 89.3 vs. 85.4 ± 111.4; p = 0.83).An educational intervention reduced the number of rA TTEs ordered by attending physicians in a variety of ambulatory care environments. This may prove to be an effective strategy to improve the use of imaging. (A Multi-Centered Feedback and Education Intervention Designed to Reduce Inappropriate Transthoracic Echocardiograms [Echo WISELY]; NCT02038101).

Background Myocardial contrast echocardiography during angiography is critical in identifying appropriate septal perforator(s) for alcohol septal ablation (ASA) in patients with hypertrophic obstructive cardiomyopathy. We evaluated whether there were other angiographic and/or echocardiographic markers that might identify patients who are anatomically suitable for ASA. Methods We performed quantitative coronary angiographic analysis and echocardiographic assessment on 74 patients referred for ASA from January 2004 to July 2012 at the Peter Munk Cardiac Centre, University Health Network, Toronto, Ontario, Canada. Patients who proceeded to ASA were compared with those in whom ASA was aborted. Results Of the 74 patients referred for ASA, 63 proceeded to ASA and in 11 patients ASA was aborted because of various anatomic and technical reasons. There were no clinically significant differences observed in quantitative angiographic and echocardiographic measurements between the 2 groups. The ratio of ostial left main (LM) to ablated septal distance on angiography vs the basal septum to the septum area where the mitral valve contacted the septum because of systolic anterior motion (SAM) was 1.53. In the whole cohort, a significant correlation was observed between the ostial LM to the target septal distance and the distance from basal septum to SAM-septal contact point on echocardiography ( r = 0.39; P = 0.008). A stronger correlation was evident when analysis was restricted to patients undergoing ASA only ( r = 0.44; P = 0.006). Conclusions Echocardiographic and angiographic assessments of the distance between the basal septum to SAM-septal contact point and ostial LM to the target septal distance might be useful in preprocedural selection of the appropriate septal perforator for ASA.

Pathologic left ventricular hypertrophy due to hypertrophic cardiomyopathy is typically diagnosed based on compatible clinical and imaging findings. In a subset of patients however, the diagnosis is unclear, either due to the finding of concentric hypertrophy raising the possibility of physiologic hypertrophy due to athlete's heart or due to the potential of so-called hypertrophic cardiomyopathy 'phenocopies', which include Anderson-Fabry disease and cardiac amyloidosis. We review each of these diseases, highlighting important distinguishing features, the knowledge of which should permit the resolution of such diagnostic dilemmas.

The association between appropriate use criteria and echocardiographic findings in patients with chronic cardiovascular diseases is unknown.As a substudy of the Echo WISELY (Will Inappropriate Scenarios for Echocardiography Lessen Significantly) trial, 9,230 transthoracic echocardiographic (TTE) examinations from six Ontario academic hospitals were linked to a registry of echocardiographic findings. The TTE studies were rated appropriate), rarely appropriate, or may be appropriate according to the 2011 appropriate use criteria. TTE findings of appropriately ordered examinations were compared with those of rarely appropriate examinations for specific disease subsets, including heart failure and valvular heart disease.There were 7,574, 1,087, and 569 TTE examinations ordered for appropriate, rarely appropriate, and may be appropriate indications, and of the 7,574 appropriate studies, 6,399 were ordered for specific indications and 1,175 for general indications. TTE examinations ordered for general indications had lower rates of left ventricular dysfunction (19.6% vs 9.1%, P .001) and moderate to severe aortic stenosis (15.5% vs 2.6%, P .001). Of the 2,395 TTE examinations ordered for patients with heart failure, appropriately ordered studies were more likely to result in left ventricular segmental abnormality (37.0% vs 24.9%, P = .012) but similar rates of right ventricular dilatation (15.4% vs 14.7%, P = .79), right ventricular dysfunction (14.8% vs 11.3%, P = .22), and moderate to severe mitral regurgitation (12.1% vs 9.2%, P = .35). Of the 2,859 studies ordered to assess valvular heart disease, appropriately ordered studies were significantly more likely to find moderate to severe valvular pathology, including aortic stenosis (30.4% vs 24.6%, P = .008), aortic regurgitation (8.9% vs 1.6%, P .001), mitral stenosis (6.7% vs 3.1%, P = .002), and mitral regurgitation (16.1% vs 6.1%, P .001), but similar rates of tricuspid regurgitation (11.2% vs 13.0%, P = .60).Overall, appropriately ordered TTE examinations for heart failure and valvular heart disease were significantly more likely to have abnormal findings than rarely appropriate examinations. TTE studies ordered for general indications had fewer, although still a significant proportion, of abnormalities compared with studies ordered for specific indications.

Significant left ventricular outflow tract obstruction (LVOTO) in hypertrophic cardiomyopathy (HCM) may result in symptoms and is associated with adverse outcomes. Although disopyramide can reduce resting gradients through its negative inotropic properties, nearly one third of HCM patients with

Hypertrophic cardiomyopathy (HCM) has been one of the most interesting and controversial disorders in cardiovascular medicine. Although initial descriptions of the pathology of HCM were published over a century ago, it was not until the surgical and pathological observations of Brock and Teare, respectively, that this cardiac entity came to attention in the modern era. HCM is a primary disorder of the myocardium characterized by myocyte hypertrophy and fiber disarray, myocardial fibrosis, and abnormal coronary intramural microvasculature. Although HCM is characterized by tremendous diversity in terms of phenotypic expression, genetic substrate, and clinical presentation, left ventricular outflow tract (LVOT) obstruction is an integral component of the disease, occurring in up to 70% of patients either at rest or with provocation.1 Article see p 209 Dynamic LVOT obstruction has long been recognized as a clinical feature of HCM, but the pathophysiology and clinical significance of intraventricular pressure gradients sparked much controversy and debate. While initially thought to result from early excessive and rapid ejection from a hypercontractile left ventricle (LV) as opposed to true mechanical impedance to blood flow, this hypothesis was later refuted by Wigle and colleagues,2 who demonstrated a prolonged LV ejection time in the presence of such intraventricular pressure gradients. The pathophysiology of LVOT obstruction is now widely accepted to be attributable to an eject-obstruct-leak concept, driven by Venturi and drag forces of the anterior mitral valve leaflet. Echocardiographic and cardiac magnetic resonance studies have documented that reduction in the LVOT cross-sectional area is attributable to morphological features such as narrowing of the LVOT by septal hypertrophy, intrinsic abnormalities of the mitral valve leaflets, anterior displacement of the mitral apparatus, and anterior malposition of the papillary muscles, either alone or in combination. Rapid LV ejection through a narrowed outflow tract results in the anterior mitral leaflet …

Objectives In this study we sought to explore the relationship between cardiac magnetic resonance (CMR) with late gadolinium enhancement (LGE) and histopathological parameters including interstitial fibrosis and replacement fibrosis (scar) in patients with hypertrophic cardiomyopathy (HCM). Background CMR-LGE is a well-established tool for the assessment of scar in ischemic heart disease. Its role in HCM has evolved in recent years, and an association with nonsustained ventricular tachycardia has been demonstrated. Methods HCM patients who underwent septal myectomy during the period 2004 through 2010 and had undergone CMR-LGE no more than 6 months before surgery were selected. Histopathological assessment of the myectomy specimens included quantitative digital analysis (interstitial and replacement fibrosis) and semiquantitative assessment (small intramural coronary arteriole dysplasia and disarray). Correlations between CMR-LGE measured with various techniques, SD above the signal intensity for the normal remote myocardium (2, 4, 5, 6, and 10 SD) and the full width at half maximum (FWHM) technique, at the myectomy site, and interstitial fibrosis, replacement fibrosis (scar), and their sum (fibrosis + scar) were evaluated. Results Twenty-nine patients were included. Statistically significant correlations between CMR-LGE (at 2, 4, 5, 6, 10 SD and by the FWHM technique), and both interstitial fibrosis and the combined interstitial and replacement fibrosis were found. The strongest correlation was between combined interstitial and replacement fibrosis and CMR-LGE measured at 5 SD (r = 0.78, p Conclusions CMR-LGE measured at 4 SD and 5 SD yields the closest approximation to the extent of total fibrosis measured by the histopathological standard of reference. These findings have implications for future investigations of CMR-LGE and its association with important clinical endpoints in HCM, including sudden cardiac death.

We synthesized a cationic microbubble (CMB) with the aim of enhancing its DNA-carrying capacity to improve targeted gene transfection of the ischemic heart for cardiac regeneration. We previously reported that ultrasound-targeted microbubble destruction (UTMD) employing the commercial Definity microbubble (MB) successfully transfected genes into rodent hearts, but the transfection efficiency was modest. We synthesized a CMB and compared its DNA-carrying capacity and reporter gene transfection efficiency with the Definity MB. The CMB bound 70% more plasmid DNA than the Definity MB. UTMD-mediated gene delivery with the CMB enhanced both transfection efficiency and gene expression. In vivo studies assessed the ability of the CMB to deliver the therapeutic AKT gene to the ischemic rat myocardium and evaluated the effects on apoptosis, angiogenesis, and cardiac function. AKT transfection with the CMB reduced infarct size (p < 0.05), increased infarct thickness (p < 0.05), reduced apoptosis (p < 0.05), increased vascular density (p < 0.05), and improved cardiac perfusion and function (p < 0.05) compared to the Definity MB. Delivery of AKT with the CMB resulted in greater cardiac functional improvements compared to the Definity MB. UTMD therapy with this CMB provides an efficient platform for the targeted delivery of factors required to regenerate the ischemic heart and preserve cardiac function.

Background— Genotyping in hypertrophic cardiomyopathy has gained increasing attention in the past decade. Its major role is for family screening and rarely influences decision-making processes in any individual patient. It is associated with substantial costs, and cost-effectiveness can only be achieved in the presence of high-detection rates for disease-causing sarcomere protein gene mutations. Therefore, our aim was to develop a score based on clinical and echocardiographic variables that allows prediction of the probability of a positive genotype. Methods and Results— Clinical and echocardiographic variables were collected in 471 consecutive patients undergoing genetic testing at a tertiary referral center between July 2005 and November 2010. Logistic regression for a positive genotype was used to construct integer risk weights for each independent predictor variable. These were summed for each patient to create the Toronto hypertrophic cardiomyopathy genotype score. A positive genotype was found in 163 of 471 patients (35%). Independent predictors with associated-risk weights in parentheses were as follows: age at diagnosis 20 to 29 (−1), 30 to 39 (−2), 40 to 49 (−3), 50 to 59 (−4), 60 to 69 (−5), 70 to 79 (−6), ≥80 (−7); female sex (4); arterial hypertension (−4); positive family history for hypertrophic cardiomyopathy (6); morphology category (5); ratio of maximal wall thickness:posterior wall thickness P =0.22. Conclusions— The Toronto genotype score is an accurate tool to predict a positive genotype in a hypertrophic cardiomyopathy cohort at a tertiary referral center.

BACKGROUND Diastolic cardiac dysfunction is an important complication of end-stage renal disease (ESRD), but quantification remains a challenge. Given that diastolic dysfunction is reflected in both left atrial (LA) and ventricular (LV) function, we aimed to identify abnormalities in LV and LA volume and function using measures of myocardial mechanics. METHODS We retrospectively studied 53 incident ESRD patients (46±16 y/o 44% male) and compared them to 85 normal controls. LA phasic volumes and functional parameters were obtained from the apical 4CH view. Global ventricular peak longitudinal and circumferential strain, strain rate (GLS, GL-SR, CS), and rotation were obtained from apical and short-axis views. LA and LV measurements were taken off line using dedicated software (eSie VVI). RESULTS ESRD patients had abnormal systolic function with lower LV ejection fraction and peak endocardial strain parameters (mean: GLS -16.6% vs -19.9%, GL-SR -0.91 vs -1.04, and CS -25.6% vs 27.9%, P≤.01 for all). Traditional Doppler parameters remained similar between groups, while diastolic mechanics were abnormal in ESRD. Reduced LV-derived diastolic parameters, fractional early reverse rotation, a marker of ventricular relaxation (P

Background— The 2 most commonly affected genes in hypertrophic cardiomyopathy (HCM) are MYH7 (β-myosin heavy chain) and MYBPC3 (β-myosin-binding protein C). Phenotypic differences between patients with mutations in these 2 genes have been inconsistent. Scarce data exist on the genotype–phenotype association as assessed by tomographic imaging using cardiac magnetic resonance imaging. Methods and Results— Cardiac magnetic resonance imaging was performed on 358 consecutive genotyped hypertrophic cardiomyopathy probands at 5 tertiary hypertrophic cardiomyopathy centers. Genetic testing revealed a pathogenic mutation in 159 patients (44.4%). The most common genes identified were MYH7 (n=53) and MYBPC3 (n=75); 33.1% and 47% of genopositive patients, respectively. Phenotypic characteristics by cardiac magnetic resonance imaging of these 2 groups were similar, including left ventricular volumes, mass, maximal wall thickness, morphology, left atrial volume, and mitral valve leaflet lengths (all P =non-significant). The presence of late gadolinium enhancement (65% versus 64%; P =0.99) and the proportion of total left ventricular mass (%late gadolinium enhancement; 10.4±13.2% versus 8.5±8.5%; P =0.44) were also similar. Conclusions— This multicenter multinational study shows lack of phenotypic differences between MYH7- and MYBPC3-associated hypertrophic cardiomyopathy when assessed by cardiac magnetic resonance imaging. Postmutational mechanisms appear more relevant to thick-filament disease expression and outcome than the disease-causing variant per se.

Nonsustained ventricular tachycardia (NSVT), defined as ≥3 consecutive ventricular beats at ≥120 beats/min lasting30 seconds, is an independent predictor of sudden cardiac death (SCD) in hypertrophic cardiomyopathy (HC). Current guidelines recommend 24- to 48-hour Holter monitoring as part of SCD risk stratification. We sought to assess the difference in diagnostic yield of 14-day Holter monitoring compared to 24-48 hours for the detection of NSVT and to assess the prevalence and characteristics of NSVT in patients with HC with prolonged monitoring. We retrospectively analyzed the 14-day Holter monitors of 77 patients with HC from May 2014 to March 2016. Number of episodes and maximal length and rate on each day were recorded. NSVT was detected in 75.3% of patients during 14-day Holter monitoring. The median number of runs was 2 (range 0 to 26 runs). The median number of beats of the longest run was 10.5 (range 3 to 68 beats) with a mean maximum rate of 159.5 ± 20.8.4 beats/min (range 102 to 203 beats/min). First episodes of NSVT were detected throughout the 14 days, with only 22.5% and 44.8% of the episodes captured within the first 24 and 48 hours of monitoring, respectively. In conclusion, prolonged Holter monitoring revealed ≥1 episode of NSVT in 75% of patients with HC of which50% were detected within the first 48 hours. Hence, prolonged Holter monitoring may be superior for SCD risk stratification in HC. However, the high prevalence of NSVT in this population may limit its utility in evaluating the risk for SCD of the individual patient.

Background— Available data suggests that double mutations in patients with hypertrophic cardiomyopathy are not rare and are associated with a more severe phenotype. Most of this data, however, is based on noncontemporary variant classification. Methods and Results— Clinical data of all hypertrophic cardiomyopathy patients with 2 rare genetic variants were retrospectively reviewed and compared with a group of patients with a single disease-causing variant. Furthermore, a literature search was performed for all studies with information on prevalence and outcome of patients with double mutations. Classification of genetic variants was reanalyzed according to current guidelines. In our cohort (n=1411), 9% of gene-positive patients had 2 rare variants in sarcomeric genes but only in 1 case (0.4%) were both variants classified as pathogenic. Patients with 2 rare variants had a trend toward younger age at presentation when compared with patients with a single mutation. All other clinical variables were similar. In data pooled from cohort studies in the literature, 8% of gene-positive patients were published to have double mutations. However, after reanalysis of reported variants, this prevalence diminished to 0.4%. All patients with 2 radical mutations in MYBPC3 in the literature had severe disease with death or heart transplant during the first year of life. Data on other specific genotype–phenotype correlations were scarce. Conclusions— Double mutations in patients with hypertrophic cardiomyopathy are much less common than previously estimated. With the exception of double radical MYBPC3 mutations, there is little data to guide clinical decision making in cases with double mutations.

Sudden cardiac death (SCD) is the most devastating complication of hypertrophic cardiomyopathy (HCM). Although the annual rate of SCD in the general HCM population is

Background: Hypertrophic cardiomyopathy (HCM) is usually associated with marked diastolic dysfunction, characterized by impaired myocardial relaxation and increased myocardial stiffness. The noninvasive evaluation of diastolic function in these patients remains a challenge since usual methods have shown a modest correlation with invasive measurements of left ventricular (LV) relaxation and filling pressures. Methods and Results: We retrospectively analyzed 44 patients with obstructive HCM who underwent cardiac catheterization and echocardiography performed within 48 hours. Standard echocardiographic diastolic parameters and systolic and diastolic myocardial mechanics (including longitudinal and circumferential strain [S] and strain rate [Sr]), LV rotation, and early reverse rotation rate (fraction of early apical reverse rotation [FEARR]) were correlated with diastolic hemodynamic indices. Estimated LA pressure by echo and the LV end-diastolic pressure (LVEDP) or the LV pre-A pressure did not correlate. Longitudinal strain was low and circumferential strain was abnormally higher than normal. FEARR and negative dp/dt inversely correlated (R =−0.57, P = 0.0001), and early diastolic Sr to systolic Sr ratio (SrE/SrS) correlated with the LVEDP (r = 0.61, P < 0.0001). Furthermore, a SrE to SrS ratio ≥0.79 had a sensitivity of 87% and a specificity of 75% for predicting elevated LVEDP (≥15 mmHg). Average circumferential strain rate during atrial contraction and LV pre-A pressure (r =−0.62, P < 0.001) inversely correlated. Conclusions: FEARR is decreased in HCM and appears to be a good measure of diastolic dysfunction. Myocardial mechanics can be used to assess LV relaxation and filling pressures in patients with obstructive HCM.

Objectives: Anderson–Fabry disease (AFD) is a lysosomal storage disease, which can involve the heart, mimicking hypertrophic cardiomyopathy (HCM). The underlying mechanism of disease in AFD is an infiltrative, diffuse process, whereas HCM is a primary heart muscle condition with patchy distribution, which may prompt differences in myocardial mechanics. The aim of this study was to assess myocardial mechanics in AFD according to the presence of left ventricular hypertrophy (LVH) compared to nonobstructive HCM (NHCM) and healthy controls. Methods and Results: We carried out a single-center, retrospective study in a small, genetically confirmed AFD cohort, which was divided into a subgroup with LVH (LVH+, n = 19), and without LVH (LVH–, n = 21). Comparison groups were healthy controls (n = 40) and NHCM patients (n = 19). Vector Velocity Imaging was applied to two-dimensional echocardiography studies for assessment of longitudinal strain (LS), circumferential strain (CS), and base-to-apex CS gradients. AFD LVH+ patients had lower global LS than AFD LVH– patients (–14 ± 4% vs –17 ± 3%, P < 0.05), but similarly lowered global CS (–24 ± 5% vs –22 ± 5%, P = ns). AFD LVH+ and NHCM had similarly lowered global LS compared to normals, but significantly lower global CS was observed in AFD LVH+ (–24 ± 5% vs –28 ± 4%, P < 0.05), whereas it was significantly increased in NHCM (–31 ± 2% vs –28 ± 4%, P < 0.05). Unlike NHCM, in both AFD subgroups, patients lost their normal base-to-apex CS gradient. Conclusions: AFD patients without LVH already show abnormal systolic myocardial mechanics. Relevant differences in myocardial mechanics between AFD patients with LVH compared to NHCM reflect the different underlying mechanisms of disease.

Left atrial (LA) volumes are known to be increased in hypertrophic cardiomyopathy (HCM) and are a predictor of adverse outcome. In addition, LA function is impaired and is presumed to be due to left ventricular (LV) diastolic dysfunction as a result of hypertrophy and myocardial fibrosis. In the current study, we assess the incremental effect of outflow tract obstruction (and concomitant mitral regurgitation) on LA function as assessed by LA strain. Patients with HCM (50 obstructive, 50 nonobstructive) were compared to 50 normal controls. A subset of obstructive patients who had undergone septal myectomy was also studied. Utilising feature-tracking software applied to cardiovascular magnetic resonance images, LA volumes and functional parameters were calculated. LA volumes were significantly elevated and LA ejection fraction and strain were significantly reduced in patients with HCM compared with controls and were significantly more affected in patients with obstruction. LA volumes and function were significantly improved after septal myectomy. LVOT obstruction and mitral regurgitation appear to further impair LA mechanics. Septal myectomy results in a significant reduction in LA volumes, paralleled by an improvement in function.

Hypertrophic cardiomyopathy (HCM) is the most common genetic cardiomyopathy, affecting approximately 1:500 people. As the yield of genetic testing is only about 35-60%, the diagnosis of HCM is still clinical and based on the demonstration of unexplained and usually asymmetric left ventricular (LV) hypertrophy by imaging modalities. In the past, echocardiography was the sole imaging modality used for the diagnosis and management of HCM. However, in recent years other imaging modalities such as cardiac magnetic resonance have played a major role in the diagnosis, management and risk stratification of HCM, particularly when the location of left ventricular hypertrophy is atypical (apex, lateral wall) and when the echocardiographic imaging is sub-optimal. However, the most unique contribution of cardiac magnetic resonance is the quantification of myocardial fibrosis. Exercise stress echocardiography is the preferred provocative test for the assessment of LV outflow tract obstruction, which is detected only on provocation in one-third of the patients.

Introduction: Regional variations in longitudinal strain (LS) have been demonstrated on echocardiography in patients with cardiac amyloidosis (CA). Hypothesis: We aimed to describe regional patterns in LS using feature-tracking software applied to cardiac MRI images (CMR) in CA, hypertrophic cardiomyopathy (HCM), and Anderson-Fabry’s disease (AFD) and to relate these patterns to late gadolinium enhancement (LGE). Methods: Patients with CA (n=51) were compared to left ventricular mass index balanced patients with HCM (n=20) and AFD (n=20). LS analysis was performed using Velocity Vector Imaging (VVI) on steady state free precession cine images (4, 3, and 2-chamber views). Values were recorded for each of 18 myocardial segments. A regional LS ratio representing “apical sparing” was calculated as the ratio of the sum of the apical segmental LS values divided by the sum of the basal and mid-segmental LS values. LGE was quantified for the basal, mid, and apical myocardial segments using a threshold of 5SD above remote myocardium. A regional LGE ratio was calculated similar to the “apical sparing” ratio. Results: The regional LS ratio was significantly higher in patients with CA (1.05±0.49) than in patients with AFD (0.79±0.24; p=0.025) and HCM (0.84±0.32; p=0.025). In patients with CA there was a regional difference in LGE burden, with lower LGE in the apex (31.9±20%) compared to the basal (52.7±22%) and mid-segments (37.9±19%). The regional LGE ratio was significantly lower in patients with CA (0.34±0.14) than in patients with AFD (0.54±0.64; p Conclusions: Cardiac amyloidosis is characterized by regional variations in LS from base to apex. “Apical sparing” in LS is seen with CMR images and can be an additional tool to differentiate CA from other causes of LVH. The concomitant presence of a base to apex gradient in LGE burden by CMR suggests that the regional strain gradient may be associated with burden of amyloid deposition.

Background: The presence of two or more pathogenic sarcomere mutations in patients with hypertrophic cardiomyopathy (HCM) has been reported to be associated with early disease onset, particularly marked left ventricular (LV) hypertrophy, and advanced heart failure. Objective: The aim of the study was to clarify the relationship between multiple disease-causing sarcomere mutations and major cardiovascular outcomes in a large HCM cohort. Methods and Results: Between June 1, 1995, and January 2015, 1104 probands with a diagnosis of HCM were routinely referred for systematic sarcomeric mutational screening at a single HCM center. Pathogenic mutations were identified in 273 (25%). Of these patients, 10 (3.6%) were identified with double/compound sarcomere mutations. They were mostly male (70%), presented at an average age of 33±13 years (range, 21-58), with an average maximal wall thickness of 17 mm (range, 13-26). Of the 9 patients who had a cardiac MRI, 8 (88%) had late gadolinium enhancement (LGE), none of which were considered to be extensive (>20% of LV myocardium). Over a mean follow up of 17.4 ±14 years (range, 3-48 years) there were no sudden cardiac death events. Adverse cardiovascular events or severe disease progression occurred in 4 (40%) patients, with an event rate of 3.4 per 100 patient-years follow up including: 2 (20%) with stroke, 3 (30%) with progression to end-stage HCM (EF Conclusion: These observations do not support the hypothesis that double (or compound) mutations confer a gene dosage effect in HCM, nor is it associated with an adverse prognosis. Mutation analysis has proven imprecise in predicting the phenotype or prognosis for patients with HCM, suggesting that genome-wide association studies and gene expression profiling may be needed for better understanding of its utility in the management of HCM patients.

Alice K. Jacobs, MD, FACC, FAHA, Chair, 2009–2011; Sidney C. Smith, Jr, MD, FACC, FAHA, Immediate Past Chair, 2006–2008[¶¶][1]; Jeffrey L. Anderson, MD, FACC, FAHA, Chair-Elect; Nancy M. Albert, PhD, CCNS, CCRN, FAHA; Christopher E. Buller, MD, FACC[¶¶][1]; Mark A. Creager, MD, FACC, FAHA

Objectives The aim of this study was to compare the survival of patients with hypertrophic cardiomyopathy (HCM) and resting left ventricular outflow tract (LVOT) obstruction managed with an invasive versus a conservative strategy. Background In patients with resting obstructive HCM, clinical benefit can be achieved after invasive septal reduction therapy. However, it remains controversial whether invasive treatment improves long-term survival. Methods We studied a consecutive cohort of 649 patients with resting obstructive HCM. Total and HCM-related mortality were compared in 246 patients who were conservatively managed with 403 patients who were invasively managed by surgical myectomy, septal ethanol ablation, or dual-chamber pacing. Results Multivariable analyses (with invasive therapy treated as a time-dependent covariate) showed that an invasive intervention was a significant determinant of overall mortality (hazard ratio: 0.6, 95% confidence interval: 0.4 to 0.97, p = 0.04). Overall survival rates were greater in the invasive (99.2% 1-year, 95.7% 5-year, and 87.8% 10-year survival) than in the conservative (97.3% 1-year, 91.1% 5-year, and 75.8% 10-year survival, p = 0.008) cohort. However, invasive therapy was not found to be a significant independent predictor of HCM-related mortality (hazard ratio: 0.7, 95% confidence interval: 0.4 to 1.3, p = 0.3). The HCM-related survival was 99.5% (1 year), 96.3% (5 years), and 90.2% (10 years) in the invasive cohort, and 97.8% (1 year), 94.6% (5 years), and 86.9% (10 years) in the conservative cohort (p = 0.3). Conclusions Patients treated invasively have an overall survival advantage compared with conservatively treated patients, with the latter group more likely to die from noncardiac causes. The HCM-related mortality is similar, regardless of a conservative versus invasive strategy.

Objectives The purpose of this study was to investigate whether a relationship exists between an acute reduction in resting left ventricular outflow tract (LVOT) gradient with balloon occlusion and the final invasive gradient response following alcohol septal ablation (ASA). Background ASA is an alternative therapy to myectomy surgery to reduce the basal septal thickness and decrease the resting and/or provocable LVOT gradient in patients with hypertrophic cardiomyopathy. Patients have a variable gradient response to occlusion of the septal perforator artery before ethanol infusion for ASA. Methods From November 1998 to November 2008, 120 patients (mean age 60 years [range 16 to 87 years], 50% women) with hypertrophic cardiomyopathy underwent ASA at our institution. The resting LVOT gradient (peak systolic left ventricle [LV] pressure – peak systolic aortic pressure) was measured continuously during the ASA procedure. The time to significant LVOT gradient decrease (defined as >50% decrease from baseline) was recorded following balloon occlusion of the dominant septal perforator coronary artery, which was found to perfuse the basal septum based on contrast echocardiographic studies. Results The mean baseline resting LVOT gradient was 86 ± 43 mm Hg, and it decreased to 17 ± 11 mm Hg following ASA (−80.2%). The mean time to significant gradient reduction was 3.6 ± 2 min (range 25 s to 11 min). The time to significant LVOT gradient reduction strongly correlated with the final magnitude of gradient reduction following ASA (r = –0.81, p Conclusions This study demonstrates a correlation between the time to significant LVOT gradient reduction following septal perforator balloon occlusion and the magnitude of final gradient response after ASA.

Background— Apical hypertrophic cardiomyopathy (HCM) is a unique form of HCM with left ventricular hypertrophy confined to the cardiac apex. The purpose of our study was to report genetic findings in a large series of unrelated patients with apical HCM and compare them with a nonapical HCM cohort. Methods and Results— Overall, 429 patients with HCM underwent genetic testing. The panel included 8 sarcomere protein genes and 3 other genes (GLA, PRKAG2, and LAMP2). Sixty-one patients were diagnosed with apical HCM. A positive genotype was found in 8 patients with apical HCM. The genotype-positive and genotype-negative patients had similar maximal wall thicknesses (17.5±3.5 mm versus 17.6±3.3 mm, P =0.71) and similar frequency of HCM-related events (2/8; 25% versus 13/53; 25%; P =0.98). Thirteen percent with apical HCM and 40% with nonapical HCM had a positive genotype ( P MYBPC3 and MYH7 genes. Conclusions— In apical HCM, a positive genotype was found less frequently than in nonapical HCM, and it was most often involving MYBPC3 and MYH7 genes. Only 13% of patients with apical HCM were found to be genotype positive, indicating that genome-wide association studies and gene expression profiling are needed for better understanding of the genetic background of the disease. There was no significant genotype-phenotype correlation in our cohort with apical HCM.

Background: Echocardiographic speckle tracking strain has gained clinical importance. However, the comparability of measurements between different software systems is not well defined. Methods: In 47 healthy subjects left ventricular (LV) two-dimensional (2D) peak strain and time to peak strain (TTP) generated by EchoPAC (2DS) and velocity vector imaging (VVI) were compared. For each type of strain (longitudinal [LS], circumferential [CS], and radial strain [RS]) we compared global, anatomical level and segmental values. Results: When comparing 2DS to VVI, Pearson correlation coefficients (r) of global LS, CS, and RS were 0.68, 0.44, and 0.59, respectively (all P < 0.05). Correlation of global TTP was higher: 0.81(LS), 0.80 (CS), and 0.68 (RS), all P < 0.01. Segmental peak strain differed significantly between 2DS and VVI in 8/18 (LS), 17/18 (CS), and 15/18 (RS) LV segments (P < 0.05). However, segmental TTP significantly differed only in 5/18 (LS), 7/18 (CS), and 4/18 (RS) of LV segments. Similar strain gradients were found for both systems: apical strain was higher than basal and midventricular strain in LS and CS, with a reversed pattern for RS (P < 0.05). Conclusion: TTP strain as well as strain gradients were comparable between VVI and 2DS, but most peak strain values were not. The software-dependency of peak strain values must be considered in clinical application. Further studies comparing the diagnostic and prognostic accuracy of strain values generated by different software systems are mandatory. (Echocardiography 2011;28:539-547)

ASSESSMENT OF MITRAL VALVE ANATOMY by real-time 3-dimensional (3D) transesophageal echocardiography (TEE) has proven to be superior compared to 2-dimensional TEE ([1,2][1]). The standard modalities of real-time 3D TEE have recently been described ([3][2]). Demonstration of the mitral valve as seen

Hypertrophic cardiomyopathy (HCM) is a heterogeneous inherited cardiac condition that affects 0.2% of the general population [(1)][1]. It is typified by a hypertrophied nondilated left ventricle (LV) with resting or provocable LV outflow tract (OT) obstruction, observed in up to two-thirds of

Hypertrophic cardiomyopathy (HCM) is associated with considerable phenotypic heterogeneity. Previous studies have shown a relationship between the degree and location of hypertrophy and the prognosis of patients. The aim of this study was to compare left ventricular (LV) circumferential and longitudinal regional mechanics in patients with septal HCM and apical HCM to study the relationship between hypertrophy and function as assessed by myocardial mechanics.Seventy-two patients with HCM (27 with apical HCM, 45 with septal HCM) were compared with 25 clinically normal and age-matched subjects. Myocardial mechanics were assessed using Velocity Vector Imaging, which extracts myocardial motion estimates from B-mode clips by tracking user-defined points and feature tracking. The Velocity Vector Imaging software generated data on global and regional systolic and diastolic longitudinal and circumferential strain, strain rate, and rotational angle velocities. One-way analysis of variance with post hoc multiple comparisons was used among the three groups.Normal subjects had relatively uniform strain and strain rates for all LV segments. Compared with the normal group, patients with septal HCM had decreased LV regional longitudinal strain rates and strain at both the basal and mid septal and lateral segments (all P.01). Compared with patients with apical HCM, those with septal HCM had higher LV circumferential strain rates and strain at the basal and mid segments (P.05 to P.01). There were significant differences in rotational velocities at the mid segments among the three groups (P.05 to P.001).Patients with HCM have abnormalities in myocardial mechanics that are related to the site of abnormal myocardial hypertrophy.

Hypertrophic cardiomyopathy (HCM) is characterized by myocardial hypertrophy, fiber disarray, and fibrosis interfering with myocardial force generation and relaxation. Because conventional Doppler echocardiographic methods inadequately assess diastolic function in HCM, the aim of this study was to determine local and global left ventricular (LV) relaxation mechanics in patients with HCM.Seventy-two patients with HCM and 32 normal controls were studied. Using Velocity Vector Imaging, longitudinal and circumferential strain, strain rate, and rotation at the base, middle, and apex of the septal and lateral LV walls were measured. Differences between patients' functional class subgroups were assessed using analysis of variance, and Tukey's post hoc analysis was used to compare patients in HCM clinical subgroups with normal controls.Longitudinal strain and systolic and early diastolic strain rates were lower than normal in patients with HCM, whereas their circumferential values were higher. This suggests that shortening and relaxation orientation in HCM was more circumferential. The ratio of peak early diastolic to peak systolic strain rate decreased longitudinally and circumferentially in moderately to severely symptomatic (New York Heart Association class III or IV) patients (0.95 +/- 0.35 vs 0.89 +/- 0.35, P.001). LV untwist was similarly prolonged in all HCM subgroups. LV relaxation assessed using the early apical reverse rotation fraction was significantly lower in patients with worse functional status (34 +/- 14% vs 18 +/- 4% in class I or II vs class III or IV). Left atrial volume increased, paralleling the severity of symptoms and the degree of diastolic dysfunction.The evaluation of biplane myocardial mechanics offers new insights into the evaluation of diastolic function and its relationship to clinical status.