68 results on '"Thomas N. Skelton"'
Search Results
52. Inhibition of restenosis lesion formation in the swine coronary artery by dietary potassium
- Author
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Thomas N. Skelton, Andrew W. Grady, David B. Young, Peter G. Anderson, N.T. Srivastava, and Ge Ma
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medicine.medical_specialty ,biology ,business.industry ,Family suidae ,Lesion formation ,medicine.disease ,biology.organism_classification ,Dietary Potassium ,medicine.anatomical_structure ,Restenosis ,Suidae ,Internal medicine ,Internal Medicine ,medicine ,Cardiology ,business ,Artery - Published
- 1998
53. Analysis of the early rise in aortic transvalvular gradient after aortic valvuloplasty
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Katherine B. Kisslo, Thomas M. Bashore, Joseph Kisslo, Robert H. Jones, Charles J. Davidson, Thomas N. Skelton, and David A. Harpole
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Male ,Aortic valve ,medicine.medical_specialty ,Percutaneous ,Heart Ventricles ,medicine.medical_treatment ,Hemodynamics ,Doppler echocardiography ,Catheterization ,Radionuclide angiography ,Internal medicine ,Humans ,Medicine ,Radionuclide Imaging ,Aged ,Aged, 80 and over ,medicine.diagnostic_test ,business.industry ,Calcinosis ,Heart ,Aortic Valve Stenosis ,Middle Aged ,medicine.disease ,Echocardiography, Doppler ,Aortic valvuloplasty ,Stenosis ,medicine.anatomical_structure ,Aortic Valve ,Angiography ,cardiovascular system ,Cardiology ,Female ,Cardiology and Cardiovascular Medicine ,business - Abstract
The relationship between dynamic changes in aortic valve gradient and left ventricular ejection performance in the early period after successful percutaneous aortic valvuloplasty has not been described in detail. Accordingly 20 adult patients with severe symptomatic calcific aortic stenosis underwent first-pass radionuclide angiography and Doppler echocardiography before, immediately after, and 2 to 4 days after the valvuloplasty procedure. A significant (p less than 0.001) reduction in peak-to-peak (72 +/- 24 mm Hg to 36 +/- 11 mmHg) and mean (60 +/- 20 mm Hg to 34 +/- 9 mm Hg) transaortic gradient and an increase in aortic valve area (0.5 +/- 0.2 cm2 to 0.8 +/- 0.2 cm2) were measured by high-fidelity micromanometer catheters immediately after aortic valvuloplasty. Results of Doppler echocardiography showed a significant (p less than 0.001) immediate decrease in peak instantaneous (81 +/- 22 mm Hg to 53 +/- 15 mm Hg) and mean (48 +/- 14 mm Hg to 31 +/- 9 mm Hg) aortic gradients. However, 2 to 4 days later a significant (p less than 0.001) return of peak (56 +/- 15 mm Hg to 65 +/- 20 mm Hg) and mean (31 +/- 9 mm Hg to 39 +/- 12 mm Hg) transvalvular gradient occurred. Aortic valve area as determined by the continuity equation also increased from 0.4 +/- 0.2 cm2 to 0.6 +/- 0.2 cm2 immediately after the procedure (p less than 0.001), then partially returned to baseline (0.5 +/- 0.2 cm2; p less than 0.005) at 2 to 4 days.(ABSTRACT TRUNCATED AT 250 WORDS)
- Published
- 1989
54. Doppler left ventricular diastolic filling abnormalities in aortic stenosis and their relation to hemodynamic parameters
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Charles J. Davidson, Thomas N. Skelton, Dalane W. Kitzman, Thomas M. Bashore, Michael B. Honan, Khalid H. Sheikh, Joseph Kisslo, Michael B. Higginbotham, and Katherine B. Kisslo
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Male ,medicine.medical_specialty ,Diastole ,Hemodynamics ,Doppler echocardiography ,Internal medicine ,Mitral valve ,medicine ,Humans ,Heart Atria ,Aged ,Aged, 80 and over ,Ejection fraction ,medicine.diagnostic_test ,business.industry ,Aortic Valve Stenosis ,Blood flow ,Middle Aged ,medicine.disease ,Myocardial Contraction ,Echocardiography, Doppler ,medicine.anatomical_structure ,Aortic valve stenosis ,cardiovascular system ,Cardiology ,Mitral Valve ,End-diastolic volume ,Female ,Cardiology and Cardiovascular Medicine ,business - Abstract
Doppler mitral flow indexes and their relation to invasively measured hemodynamic diastolic indexes were assessed in 13 patients with isolated aortic stenosis (AS), and compared to Doppler indexes in 10 normal subjects matched for age, heart rate, left ventricular (LV) ejection fraction and LV load. Patients with AS showed no difference in Doppler early filling (E) indexes, but demonstrated greater Doppler atrial filling (A) indexes in comparison to normal subjects: atrial velocity (89 +/- 31 vs 56 +/- 7 cm/s), atrial integral (11.4 +/- 4.8 vs 5.7 +/- 1.6 cm), A/E velocity (1.69 +/- 0.89 vs 1.06 +/- 0.26) and A/E integral (3.53 +/- 6.64 vs 0.81 +/- 0.27) (all p less than 0.05). Doppler indexes in patients with AS did not correlate with hemodynamic indexes of LV relaxation or chamber stiffness. Significant correlations were observed between Doppler and angiographic peak filling rates (r = 0.70) and between Doppler atrial filling velocity and LV end-diastolic volume (r = -0.66), LV end-diastolic pressure (r = -0.48) and LV ejection fraction (r = 0.53) (all p less than 0.05). These data indicate that, compared to matched normal subjects, most patients with AS have an increased atrial contribution to LV filling. However, in patients with decreased LV function, atrial function may also be depressed, as indicated by a decreased atrial contribution to LV filling, resulting in "normalization" of the Doppler mitral flow pattern.
- Published
- 1989
55. Validation of pressure-volume data obtained in patients by initial transit radionuclide angiocardiography
- Author
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Thomas N. Skelton, David H. Harpole, Charles J. Davidson, Robert H. Jones, and Thomas M. Bashore
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Male ,Aortic valve ,medicine.medical_specialty ,Correlation coefficient ,Hemodynamics ,Blood Pressure ,Internal medicine ,Linear regression ,medicine ,Humans ,Radionuclide Angiography ,End-systolic volume ,Aged ,Aged, 80 and over ,Blood Volume ,Ejection fraction ,business.industry ,Angiography, Digital Subtraction ,Heart ,Stroke Volume ,Aortic Valve Stenosis ,medicine.disease ,body regions ,Stenosis ,medicine.anatomical_structure ,Cardiology ,Ventricular pressure ,Female ,Cardiology and Cardiovascular Medicine ,business ,Nuclear medicine - Abstract
In order to validate the measurement of pressure-volume loops and stroke work in humans, simultaneous digital subtraction ventriculography (DSA) and first-pass radionuclide angiocardiography (RNA) coupled with high-fidelity micromanometer left ventricular pressure measurements were undertaken in 34 patients, mean age 75 +/- 9 years, with aortic stenosis. Twenty-nine patients had a repeat study after balloon valvuloplasty, for a total of 63 DSA and RNA pressure-volume loops. All data were analyzed in a systemic fashion in order to minimize intra- and interobserver error. Linear regression analysis was used to calculate the degree of agreement between the two technologies. Left ventricular ejection fraction (RNA: 0.47 +/- 0.17, DSA: 0.49 +/- 0.18) had a correlation coefficient of 0.96; left ventricular end-diastolic volume (RNA: 171 +/- 42 ml, DAS: 168 +/- 52 ml) and end-systolic volume (RNA: 95 +/- 50 ml, DSA: 89 +/- 50 ml) had correlation coefficients of 0.89 and 0.95, respectively. Left ventricular stroke volume (RNA: 75 +/- 26 ml, DSA: 75 +/- 27 ml) had a correlation coefficient of 0.92, while integrated pressure-volume loop or stroke work (RNA: 15.6 +/- 6.6 ergs 10(6), DSA: 15.9 +/- 6.3 ergs 10(6] had a correlation coefficient of 0.89. These data demonstrate that RNA measurements of left ventricular chamber dynamics concur with that obtained with DSA. With semiautomated data analysis, the portable first-pass RNA pressure-volume data are also less labor-intensive. Moreover, multiple measurements of ventricular performance during hemodynamic manipulations in the catheterization laboratory or operating room would allow for a more precise estimation of left ventricular performance.
- Published
- 1989
56. Interatrial septal thickening preventing percutaneous mitral valve balloon valvuloplasty
- Author
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James W. Nesmith, Khalid H. Sheikh, Thomas N. Skelton, Thomas M. Bashore, Katherine B. Kisslo, and Charles J. Davidson
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medicine.medical_specialty ,Percutaneous ,business.industry ,Balloon valvuloplasty ,Atrial septum ,Catheterization ,Surgery ,medicine.anatomical_structure ,Echocardiography ,Mitral valve ,Internal medicine ,Heart Septum ,cardiovascular system ,medicine ,Cardiology ,Humans ,Mitral Valve Stenosis ,Heart Atria ,cardiovascular diseases ,Thickening ,Cardiology and Cardiovascular Medicine ,business ,Retrospective Studies - Abstract
Avant de faire une dilatation mitrale par voie percutanee, il faut verifier l'epaisseur de la cloison interauriculaire par echocardiographie car, trop epaisse, elle est infranchissable
- Published
- 1989
57. A clinical comparison of mitral valve repair versus valve replacement in ischemic mitral regurgitation
- Author
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Andrew S. Wechsler, J. Scott Rankin, Richard D. Floyd, David C. Sabiston, Hickey Ms, Thomas N. Skelton, Joseph G. Reves, Michael P. Feneley, Lawrence H. Muhlbaier, James E. Lowe, and Robert M. Califf
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Pulmonary and Respiratory Medicine ,medicine.medical_specialty ,Mitral valve repair ,Mitral regurgitation ,business.industry ,medicine.medical_treatment ,Mitral valve replacement ,Ischemia ,medicine.disease ,Surgery ,medicine.anatomical_structure ,Valve replacement ,Mitral valve ,Internal medicine ,cardiovascular system ,medicine ,Cardiology ,cardiovascular diseases ,Myocardial infarction ,Cardiology and Cardiovascular Medicine ,business ,Papillary muscle - Abstract
Severe mitral regurgitation caused by acute myocardial infarction has been a particularly difficult management problem with disappointing clinical results. Over a 75-month period, ending March 31, 1987, 611 patients underwent mitral valve operations at Duke University Medical Center. Within this group, 55 patients had clearly defined ischemic mitral regurgitation, and 37 of these required emergency operations. Thirty-one of the 55 patients had isolated posterior papillary muscle dysfunction, nine had papillary muscle rupture, and 15 had severe ventricular dysfunction and generalized annular dilatation. Thirty-two patients were treated with primary mitral valve replacement, and 23 had mitral valve repair. In 18, repair was accomplished by a transventricular approach, combining the techniques of commissural annuloplasty, papillary muscle shortening or reimplantation, and infarct exclusion. Transventricular mitral valve repair proved to be safe, expeditious, and effective in restoring valve competence. Although the repair and replacement groups were similar with respect to all relevant baseline characteristics, improved operative survival was observed after valve repair, as compared to replacement, both for the overall group (p = 0.03) and for acute papillary muscle dysfunction (p = 0.05). These data suggest that a policy of predominant mitral valve repair, when appropriately applied in patients with ischemic mitral regurgitation, offers the potential for improving therapeutic results.
- Published
- 1988
58. Accuracy of digital angiography for quantitation of normal coronary luminal segments in excised, perfused hearts
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Thomas N. Skelton, Thomas M. Bashore, Eileen M. Mikat, and Katherine B. Kisslo
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medicine.medical_specialty ,Coronary Angiography ,Digital image ,Dogs ,Internal medicine ,medicine ,Animals ,Humans ,Diagnosis, Computer-Assisted ,Fixation (histology) ,Luminal diameter ,business.industry ,Angiography ,Coronary Vessels ,Perfusion ,Standard error ,medicine.anatomical_structure ,Contrast injection ,Cardiology ,Radiology ,Cardiology and Cardiovascular Medicine ,Digital angiography ,business ,Nuclear medicine ,Artery - Abstract
The accuracy of coronary artery diameter determination by digital angiography was assessed by imaging 39 coronary segments of excised dog and human hearts and comparing these segments with pathologic sections 0.76 to 3.31 mm in luminal diameter. Digital images were obtained postmortem both during contrast injection using a fixed-pressure coronary perfusion system and after fixation when the coronary size was maintained by injection of a barium-gelatin casting mixture. Digital data were analyzed with commercially available, automated edge-detection software using a coronary catheter as the calibration standard. Coronary diameter measured during contrast injection was not significantly different from that measured after casting and fixation. Digital data from both methods correlated well with diameters from pathologic sections (injected, r = 0.85; fixed, r = 0.91). Linear regression parameters comparing pathologic diameters with the contrast injection method were slope = 0.82, intercept = 0.42 mm, and standard error of the estimate = 0.27 mm. Parameters for the comparison of pathology with casted coronary data were slope = 0.95, intercept = 0.16 mm, and standard error of the estimate = 0.23 mm. Intra- and interobserver variability were 3% (0.05 mm) and 4% (0.07 mm), respectively. These data indicate that when a coronary catheter as a calibration standard is used, coronary artery dimensions can be accurately measured by automated digital angiography techniques.
- Published
- 1987
59. Diastolic Myocardial Mechanics and the Regulation of Cardiac Performance
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J. William Gaynor, George W. Maier, J. Scott Rankin, C. O. Olsen, Donald D. Glower, G. S. Tyson, Michael P. Feneley, Thomas N. Skelton, Thomas M. Bashore, and J. A. Spratt
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medicine.medical_specialty ,Heart disease ,business.industry ,Volume overload ,Diastole ,Disease ,medicine.disease ,Ventricular geometry ,Myocardial mechanics ,Clinical investigation ,Internal medicine ,medicine ,Ventricular pressure ,Cardiology ,business - Abstract
Over the past 15 years, the primary goal of our physiology laboratory has been to improve the understanding of basic myocardial function in both normal and diseased hearts. Very early in our studies, it became evident that existing descriptors of myocardial performance were deficient, and initial efforts were expended to develop basic models of ventricular geometry, diastolic properties, and systolic function. Later work has been directed toward applying these models to the study of pathophysiology in ischemic heart disease and chronic volume overload. Although this investigation is still in progress, enough information is currently available to provide insight into basic aspects of diastolic myocardial function, to propose several hypotheses on how the heart adapts to clinical heart disease, and to provide direction for future clinical investigation of myocardial mechanics in humans. This chapter will review these topics primarily through publications from our laboratory, each of which contains full references.
- Published
- 1987
60. The risk for systemic embolization associated with percutaneous balloon valvuloplasty in adults. A prospective comprehensive evaluation
- Author
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Charles A. Simonton, Yihong Kong, Charles J. Davidson, Thomas N. Skelton, Harry R. Phillips, Victor S. Behar, Katherine B. Kisslo, Thomas M. Bashore, and Robert H. Peter
- Subjects
Aortic valve ,Adult ,Male ,Risk ,medicine.medical_specialty ,Percutaneous ,medicine.medical_treatment ,Embolism ,Catheterization ,Internal medicine ,Internal Medicine ,medicine ,Humans ,Mitral Valve Stenosis ,cardiovascular diseases ,Embolization ,Prospective Studies ,Cardiac catheterization ,Aged ,Aged, 80 and over ,medicine.diagnostic_test ,business.industry ,Cerebral infarction ,Calcinosis ,General Medicine ,Aortic Valve Stenosis ,Cerebral Infarction ,Middle Aged ,medicine.disease ,Aortic valvuloplasty ,Stenosis ,medicine.anatomical_structure ,cardiovascular system ,Cardiology ,Female ,business ,Tomography, X-Ray Computed ,Electrocardiography - Abstract
Study objective To prospectively investigate the evidence for embolic phenomena associated with percutaneous mitral and aortic valvuloplasty. Design Prospective, consecutive case series before and after balloon valvuloplasty. Setting Referral center hospital and cardiac catheterization laboratory. Patients Consecutive sample of 32 patients having balloon valvuloplasty for critical symptomatic stenosis of the mitral or aortic valve. Twenty-six patients had aortic stenosis; 6 had mitral stenosis. Intervention Computed tomography of the head, funduscopy, and electrocardiography were done in all patients before and after valvuloplasty. Cardiac isoenzymes were measured serially in 19 patients. Measurements and main results Previous cerebral infarction was seen in nine patients, with three showing a new abnormality after aortic valvuloplasty. In one of these patients a funduscopic hemorrhage was detected by photography. Total creatinine kinase and MB fraction were elevated in 1 of 19 patients. Serial electrocardiograms were unchanged in all patients. Conclusions The incidence of cerebral neurologic events and myocardial injury are acceptably low after balloon valvuloplasty of calcific aortic and mitral stenosis. Both episodes of symptomatic cerebral infarction occurred in patients with apparent bicuspid aortic valvular stenosis, suggesting that calcific bicuspid aortic stenosis may be associated with more neurologic events after aortic valvuloplasty.
- Published
- 1988
61. Echocardiographic guidance of cardiac catheterization for atrial septal defect in pregnancy
- Author
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Humberto Vidaillet, Katherine B. Kisslo, Thomas N. Skelton, Thomas M. Bashore, and Joseph Kisslo
- Subjects
Adult ,medicine.medical_specialty ,Cardiac Catheterization ,Heart disease ,medicine.medical_treatment ,Pregnancy Complications, Cardiovascular ,Hemodynamics ,Disease ,Heart Septal Defects, Atrial ,Pregnancy ,Internal medicine ,medicine ,Humans ,In patient ,Cardiac catheterization ,business.industry ,medicine.disease ,Echocardiography ,Anesthesia ,cardiovascular system ,Cardiology ,Gestation ,Maternal death ,Female ,Cardiology and Cardiovascular Medicine ,business - Abstract
Cardiac disease is the most important cause of non-obstetrical maternal death. 1 Atrial septal defect (ASD), which has a 2:1 female predominance, is the most common congenital heart disease during pregnancy. 1 Echocardiographically guided cardiac catheterization may be an option in patients in whom definitive hemodynamic data are needed for decision making. 224
- Published
- 1986
62. Comparison of coronary stenosis quantitation results from on-line digital and digitized cine film images
- Author
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Thomas M. Bashore, Katherine B. Kisslo, and Thomas N. Skelton
- Subjects
medicine.medical_specialty ,Motion Pictures ,Coronary Disease ,Coronary stenosis ,Constriction, Pathologic ,Coronary Angiography ,Electrocardiography ,Diagnostic angiography ,Internal medicine ,Linear regression ,medicine ,Image Processing, Computer-Assisted ,Image acquisition ,Humans ,business.industry ,Digital imaging ,Subtraction ,Angiography ,medicine.disease ,Stenosis ,Subtraction Technique ,Line (geometry) ,Cardiology ,Regression Analysis ,Television ,Cardiology and Cardiovascular Medicine ,business ,Densitometry - Abstract
To examine the effects of digital image acquisition mode and subtraction techniques on the results of coronary stenosis quantitation, 100 discrete lesions from 45 patients undergoing routine diagnostic angiography were analyzed in each of 3 image types: direct on-line digital, electrocardiogram-gated digital subtraction and digitized cine film images. For the geometric measurements (minimal lumen diameter and percent diameter stenosis) correlation coefficients for 2-way comparisons among the image types ranged from 0.90 to 0.96. Linear regression slopes ranged from 0.93 to 1.00, with intercepts from 0.03 to 0.07 mm for minimal diameter and −0.5 to 4.4% for percent diameter stenosis. For the videodensitometric percent area stenosis data, the correlation coefficients ranged from 0.80 to 0.89, with linear regression slopes from 0.84 to 0.89 and intercepts from 8.3 to 12.8%. Thus, the results of quantitative geometric measurements of coronary stenosis severity were not strongly affected by image acquisition mode (on-line versus cine film digitization) or by electrocardiogram-gated digital subtraction, while densitometric data correlated less well when on-line digital and digitized cine film acquisition methodology were compared.
- Published
- 1988
63. Exercise treadmill testing is a poor predictor of anatomic restenosis after angioplasty for acute myocardial infarction
- Author
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David S. Rendall, Tomoaki Hinohara, Mark A. Hlatky, Daniel B. Mark, Michael B. Honan, Richard S. Stack, Robert M. Califf, James R. Bengtson, David B. Pryor, and Thomas N. Skelton
- Subjects
Male ,medicine.medical_specialty ,Time Factors ,medicine.medical_treatment ,Population ,Myocardial Infarction ,Angina Pectoris ,Angina ,Electrocardiography ,Restenosis ,Predictive Value of Tests ,Recurrence ,Physiology (medical) ,Internal medicine ,Angioplasty ,medicine ,Humans ,Myocardial infarction ,Treadmill ,Angioplasty, Balloon, Coronary ,education ,Cardiac catheterization ,education.field_of_study ,business.industry ,Left bundle branch block ,Middle Aged ,medicine.disease ,Cardiology ,Exercise Test ,Regression Analysis ,Female ,Emergencies ,Cardiology and Cardiovascular Medicine ,business ,Follow-Up Studies - Abstract
This study evaluated whether an exercise treadmill test could predict restenosis in 289 patients 6 months after a successful emergency angioplasty of the infarct-related artery for acute myocardial infarction. After excluding those with interim interventions (64), medical events (36), or medical contraindications to follow-up testing (25), both a treadmill test and a cardiac catheterization were completed in 144 patients, 88% of those eligible for this assessment. Four patients with left bundle branch block or pacemaker rhythm at the time of treadmill testing were also excluded from analysis. Of six follow-up clinical and treadmill variables examined by multivariable logistic regression analysis, only exercise ST deviation was independently correlated with restenosis at follow-up (chi 2 = 5, p = 0.02). The clinical diagnosis of angina at follow-up, although marginally related to restenosis when considered by itself (p = 0.04), did not add significant information once ST deviation was known. The sensitivity of ST deviation of 0.10 mV or greater for detecting restenosis was only 24% (13 of 55 patients), and the specificity was 88% (75 of 85 patients). The sensitivity of exercise-induced ST deviation for detection of restenosis was not affected by extent or severity of wall motion abnormalities at follow-up, by the timing of thrombolytic therapy or of angioplasty, or by the presence of collateral blood flow at the time of acute angiography. A second multivariable analysis evaluating the association of the same variables with number of vessels with significant coronary disease at the 6-month catheterization found an association with both exercise ST deviation (p = 0.003) and exercise duration (p = 0.04). Angina symptoms and exercise treadmill test results in this population had limited value for predicting anatomic restenosis 6 months after emergency angioplasty for acute myocardial infarction.
- Published
- 1989
64. Rate-related left bundle branch block with chest pain and normal coronary arteriograms treated by exercise training
- Author
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Robert M. Califf, Thomas N. Skelton, and James A. Heinsimer
- Subjects
Thorax ,Chest Pain ,Activities of daily living ,Rehabilitation ,Bundle branch block ,Gauche effect ,Left bundle branch block ,business.industry ,medicine.medical_treatment ,Bundle-Branch Block ,General Medicine ,Middle Aged ,Chest pain ,medicine.disease ,Coronary Angiography ,Exercise Therapy ,Heart Rate ,Anesthesia ,Heart rate ,medicine ,Exercise Test ,Humans ,Female ,medicine.symptom ,business - Abstract
A clinical observation of chest pain associated with the onset of rate-related left bundle branch block has been described in patients with normal coronary arteriograms. The authors used standard cardiac rehabilitation techniques for exercise training in a 47- year-old woman with these manifestations. Serial treadmill tests revealed that during the course of 3 months of exercise training, the heart rate at onset of LBBB gradually rose from 133 to 175 beats per minute, and she no longer developed symptoms during her routine daily activities or exercises. Exercise training was a successful nonpharmacologic strategy that delayed the onset of rate-related LBBB and chest pain in this patient and avoided the need for beta blocker therapy.
- Published
- 1986
65. Comparison of m-mode echocardiographic left ventricular mass measured using digital and strip chart readings: The Atherosclerosis Risk in Communities (ARIC) study
- Author
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Thomas N. Skelton, Donna K. Arnett, Philip R. Liebson, Emelia J. Benjamin, and Richard G. Hutchinson
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Male ,lcsh:Diseases of the circulatory (Cardiovascular) system ,medicine.medical_specialty ,Comorbidity ,Risk Assessment ,Sensitivity and Specificity ,Cohort Studies ,Left ventricular mass ,Ventricular Dysfunction, Left ,Chart ,Risk Factors ,Internal medicine ,Image Interpretation, Computer-Assisted ,Prevalence ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Aric study ,Angiology ,Observer Variation ,business.industry ,Research ,Reproducibility of Results ,Signal Processing, Computer-Assisted ,Organ Size ,General Medicine ,Middle Aged ,United States ,Atherosclerosis Risk in Communities ,Echocardiography ,lcsh:RC666-701 ,Radiology Nuclear Medicine and imaging ,Cardiology ,Calipers ,Female ,Hypertrophy, Left Ventricular ,Radiology ,business ,Observer variation ,Cardiology and Cardiovascular Medicine - Abstract
Background Epidemiological and clinical studies frequently use echocardiography to measure LV wall thicknesses and chamber dimension for estimating quantitative measures of LV mass. While echocardiographic M-mode LV images have traditionally been measured using hand-held calipers and strip-chart paper tracings, digitized M-mode LV image measurements made directly on the computer screen using electronic calipers have become standard practice. We sought to determine if systematic differences in LV mass occur between the two methods by comparing LV mass measured from simultaneous M-mode strip chart recordings and digitized recordings. Methods The Atherosclerosis Risk in Communities study applied the latter method. To determine if systematic differences in LV mass occur between the two methods, LV mass was measured from simultaneous M-mode strip chart recordings and digitized recordings. Results We found no difference in LV mass (p > .25) and a strong correlation in LV mass between the two methods (r = 0.97). Neither age, sex, nor hypertension status affected the correlation of LV mass between the two methods. Conclusions We conclude that digital estimates of LV mass provide unbiased estimates comparable to the strip-chart method.
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66. Contrast Nephrotoxicity
- Author
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Thomas M. Bashore, Karen S. Pieper, Charles J. Davidson, Thomas N. Skelton, Mark A. Hlatky, Kenneth G. Morris, and Steve J. Schwab
- Subjects
Creatinine ,medicine.medical_specialty ,medicine.drug_class ,business.industry ,Radiographic Contrast Agent ,Urology ,Diatrizoate ,Liter ,General Medicine ,Urine ,medicine.disease ,Iopamidol ,Surgery ,Nephrotoxicity ,chemistry.chemical_compound ,chemistry ,Heart failure ,Toxicity ,medicine ,business ,medicine.drug - Abstract
Experimental studies have suggested that nonionic contrast agents are less nephrotoxic than ionic contrast agents. To examine the relative nephrotoxicity of the two types of agents, we randomly assigned 443 patients to receive either iopamidol (nonionic) or diatrizoate (ionic) for cardiac catheterization. The patients were stratified into low-risk (n = 283) or high-risk (n = 160) groups, on the basis of the presence of diabetes mellitus, heart failure, or preexisting renal insufficiency (base-line serum creatinine level, greater than 133 mumol per liter). Serum and urine analyses were performed at base line and 24 and 48 hours after the infusion of contrast material. Nephrotoxicity was defined as an increase in the serum creatinine level within 48 hours of at least 44 mumol per liter. The median maximal rise in the serum creatinine level was 18 mumol per liter in both the diatrizoate group (n = 235) and the iopamidol group (n = 208) (P not significant; power to detect a difference greater than 9 mumol per liter, greater than 90 percent). Creatinine levels increased by at least 44 mumol per liter (0.5 mg per deciliter) in 10.2 percent of the patients receiving diatrizoate and 8.2 percent of the patients receiving iopamidol (P not significant). Among the high-risk patients, creatinine levels increased by at least 44 mumol per liter in 17 percent of the patients in the diatrizoate group, as compared with 15 percent of the patients in the iopamidol group (P not significant). We were unable to demonstrate a difference in the incidence of nephrotoxicity between patients receiving a non-ionic contrast agent and those receiving an ionic contrast agent.
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- 1989
67. Cardiovascular and Renal Toxicity of a Nonionic Radiographic Contrast Agent after Cardiac Catheterization
- Author
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Steve J. Schwab, Karen S. Pieper, Thomas N. Skelton, Mark A. Hlatky, Kenneth G. Morris, Thomas M. Bashore, and Charles J. Davidson
- Subjects
Male ,Cardiac Catheterization ,medicine.medical_specialty ,medicine.medical_treatment ,Renal function ,Iopamidol ,Nephrotoxicity ,Nephropathy ,Diabetes Complications ,chemistry.chemical_compound ,Risk Factors ,Internal medicine ,Internal Medicine ,medicine ,Humans ,Prospective Studies ,Prospective cohort study ,Aged ,Cardiac catheterization ,Creatinine ,business.industry ,General Medicine ,Middle Aged ,medicine.disease ,chemistry ,Cardiovascular Diseases ,Heart failure ,Cardiology ,Female ,Kidney Diseases ,business ,medicine.drug - Abstract
Study objective To determine the incidence of cardiovascular and renal toxicity of a nonionic contrast agent when used for cardiac catheterization, and to assess the value of electrolytes and urinalysis results as predictors of nephropathy induced by a contrast agent. Study design Nonrandomized trial using a criterion standard and a cohort analytic study with a 48-hour follow-up. Setting Referral-based university hospital. Patients Convenience sample of patients having diagnostic cardiac catheterization. Renal function and clinical status were evaluated at baseline in 1,144 patients; at 24 hours in 1,077 (94%); and at 48 hours in 663 (57%). Interventions After patients received saline for hydration, coronary angiography and left ventriculography were done with iopamidol (average dose, 203 +/- 56 cc). Measurements and main results The definite and possible incidence of major acute cardiovascular complications from nonionic contrast media was 0.2% and 0.7%, respectively. The mean serum creatinine level increased 11.5 mumol/L from baseline at 24 hours (P less than 0.0001) and 16.8 mumol/L from baseline at 48 hours (P less than 0.0001). Results in a randomly selected training sample were studied to determine predictors of a rise in serum creatinine of 44.2 mumol/L or more. The baseline serum creatinine level and age were significant predictors of renal injury, but hypertension, diabetes mellitus, congestive heart failure, vascular disease, the volume of contrast agent injected or baseline values of urinary variables did not predict nephrotoxicity. In an independent validation sample, only the baseline serum creatinine level was confirmed as a predictor of nephrotoxicity, whereas age was not. A model that predicted contrast-induced nephropathy by the serum creatinine level showed an exponential increase in the risk for nephrotoxicity if the baseline level was 106.1 mumol/L or higher. Conclusions Patients have a small but significant rise in serum creatinine after cardiac catheterization with a nonionic contrast agent. Baseline renal insufficiency is the only confirmed predictor of nonionic contrast-induced nephrotoxicity.
- Published
- 1989
68. High dietary K+inhibits formation of restenosis lesion in the swine coronary artery
- Author
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Peter G. Anderson, M. Ge, David B. Young, Kerry Lyle, Thomas N. Skelton, Jianfang Luo, H. Lin, N.T. Srivastava, Andrew W. Grady, H.C. Waterer, and C. Hayes
- Subjects
Lesion ,medicine.medical_specialty ,medicine.anatomical_structure ,Restenosis ,business.industry ,Internal medicine ,Cardiology ,Medicine ,medicine.symptom ,business ,medicine.disease ,Cardiology and Cardiovascular Medicine ,Artery - Full Text
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