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Biomedical subjects

M A Alpert

Publications and source records attributed to M A Alpert.

At least 37 records · Page 2Linked to original sources
PubMed1998

Origin of angina pectoris in patients with high-grade single-vessel coronary artery stenosis undergoing percutaneous transluminal coronary angioplasty.

This study shows that in patients with subtotal (95% to 99%) coronary artery stenosis, the presence of myocardial ischemia is dictated primarily by the presence and degree of coronary collateral flow, with anterograde flow participating little, if at all, in the origin of myocardial ischemia and angina pectoris. Conversely, in patients with severe but not subtotal coronary artery stenosis (70% to 94%), both reduced anterograde flow and coronary collateralization contribute to the evolution of myocardial ischemia and angina pectoris.

Adult↗
PubMed1998

Coronary artery slow flow associated with angina pectoris and hypotension--a case report.

A 56-year-old woman with a history of angina pectoris developed substernal chest pressure and hypotension during coronary angiography. Her baseline coronary angiogram appeared normal. During this episode, injection of contrast medium into the left coronary artery demonstrated coronary artery slow flow in the left anterior descending artery and branches of the circumflex coronary artery, which normalized following the sublingual administration of nitroglycerin. There were no focal areas of coronary artery spasm. This phenomenon may represent a heretofore undescribed mechanism for myocardial ischemia and its sequelae.

Angina Pectoris↗
PubMed1998

Diminished short-term heart rate variability predicts inducible ventricular tachycardia.

PURPOSE: The purpose of this study is to determine whether short-term heart rate variability (HRV) can be used successfully to predict inducible ventricular tachycardia (VT). METHODS: A high-speed (300 mm/s) electrocardiographic recording was obtained in 32 patients in the supine position prior to programmed ventricular stimulation. Beat-to-beat RR intervals (in milliseconds) were derived from an 11-beat strip (10 RR intervals). Logistic regression was used to study the relationship between several variables and a dichotomous dependent variable (inducible, clinical, or electrocardiographic evidence of VT). RESULTS: Of 32 patients, 12 had inducible VT (inducible VT group) and 20 had no clinical or electrocardiographic evidence of VT (control group). Mean short-term HRV values were significantly lower in those with inducible VT than in the control group in all patients (25+/-15 ms, n=12 vs 67+/-22 ms, n=20; p<0.0001) and in patients with coronary artery disease or congestive heart failure or both (22+/-13 ms, n=11 vs 63+/-23 ms, n=11; p<0.0001). For the group as a whole, short-term HRV was < or =50 ms in 11 of 12 patients (92%) with inducible VT, but was < or =50 ms in only 3 of 20 control subjects (15%; p<0.001). As a result of a stepwise selection procedure conducted within the logistic regression, only the short-term HRV was found to be predictive of inducible VT (p<0.0001). CONCLUSION: Short-term HRV is significantly lower in subjects with inducible VT than in those without clinical or electrocardiographic evidence of VT. The probability of developing sudden death increases substantially when short-term HRV decreases below 50 ms.

Cardiac Pacing, Artificial↗
PubMed1997

Cardiac morphology and left ventricular function in normotensive morbidly obese patients with and without congestive heart failure, and effect of weight loss.

To assess cardiac morphology and left ventricular (LV) function in normotensive morbidly obese patients with and without congestive heart failure (CHF) we performed a physical examination and obtained a transthoracic echocardiogram and cardiac Doppler studies before and after substantial weight loss in patients whose actual body weight was initially equal to or more than twice their ideal body weight and who were free from systemic hypertension and underlying organic heart disease. There were 24 patients with CHF, 14 of whom were studied after weight loss. There were 50 patients without CHF, 39 of whom were studied after weight loss. Compared to patients without CHF, those with CHF had significantly greater mean LV internal dimension in diastole, LV end-systolic wall stress, LV mass/height index values, left atrial dimension and right ventricular internal dimension values, significantly lower mean LV fractional shortening, and transmitral Doppler E/A ratio values, and significantly longer mean transmitral E-wave deceleration time and duration of morbid obesity than patients without CHF. Substantial weight loss in those with and without CHF produced comparable reductions in mean LV internal dimension in diastole, LV end-systolic wall stress, LV mass/height index, transmitral Doppler E-wave deceleration time, and left atrial dimension, and comparable increases in LV fractional shortening and transmitral Doppler E/A ratio. Linear regression analysis identified duration of morbid obesity as the strongest predictor of CHF (p <0.00000002). Thus, LV mass is greater and LV systolic function and diastolic filling are more impaired in normotensive morbidly obese subjects with CHF than in those without CHF. Duration of morbid obesity is the strongest predictor of CHF among the variables studied. Substantial weight loss produces comparable changes in cardiac morphology and function in those with and without CHF.

Adult↗
PubMed1997

Symptomatic reinfarctation of a previously silent myocardial region four months after successful reperfusion--a case report.

Coronary collateral circulation helps to preserve myocardial perfusion distal to severely stenotic or totally obstructed coronary arteries. The presence or absence of angina pectoris and the state of myocardial function depend on the extent of collateralization and its functional contribution to myocardial blood flow. Clinical and experimental observations have suggested that newly developed collaterals usually remain even after successful revascularizaton. The authors present a case of a patient with extensive intercoronary collaterals and hibernating myocardium after an acute inferior wall myocardial infarction who underwent successful percutaneous transluminal coronary angioplasty of a totally obstructed, dominant right coronary artery and then experienced extensive reinfarction following reocclusion 4 months later. This case demonstrates failure of extensive collaterals to prevent acute myocardial infarction.

Adult↗
PubMed1996

Use of a national data base to assess perioperative risk, morbidity, mortality, and cost savings in coronary artery bypass grafting.

To show the usefulness of the Society of Thoracic Surgeons (STS) National Database in providing clinical and cost-related outcome data, we studied 297 consecutive patients who had isolated coronary artery bypass grafting (CABG) and who were assigned to either a "fast track" or traditional track. The observed overall mortality rate was 2.7%. The predicted mortality based on preoperative risk factors was 4.7%. Before the initiation of a "fast-track" protocol and critical pathways, the average length of stay was 8.2 days and the average cost of uncomplicated isolated CABG was $18,476. The length of postoperative stay and the cost decreased to 6.0 days and $12,427, respectively, with the application of a fast-track protocol (when appropriate) and critical pathways without affecting clinical outcomes. Use of the STS National Database provided rapid and reassessing evidence that survival and quality of care were not compromised with implementation of a cost-saving fast-track protocol and critical pathways.

Aged↗
PubMed1996

Cardiovascular factors influencing survival in dialysis patients.

Cardiovascular disease is the most common cause of death among dialysis patients. Cardiovascular abnormalities that predispose to mortality include acute myocardial infarction, chronic ischemic heart disease, atherosclerotic peripheral vascular disease, congestive heart failure, left ventricular hypertrophy, dilated cardiomyopathy, hypertrophic hyperkinetic heart disease, prior cardiac arrest, and possibly systemic hypertension. This review explores the influences of cardiovascular disease on survival in patients with end-stage renal disease treated with dialysis.

Cardiovascular Diseases↗
PubMed1995

Influence of left ventricular mass on left ventricular diastolic filling in normotensive morbid obesity.

To identify factors influencing left ventricular (LV) diastolic filling in patients with morbid obesity, we performed transthoracic and Doppler echocardiography on 50 subjects whose actual body weight was > or = twice their ideal body weight and on 50 normal lean control subjects. The transmitral Doppler E/A ratio and E wave deceleration half-time were used to assess LV diastolic filling. Significant negative correlations were seen between the E/A ratio and the LV internal dimension in diastole (r = 0.819, p = 0.0001), systolic blood pressure (r = 0.751, p = 0.0001), LV end-systolic wall stress (r = 0.782, p = 0.0001), and LV mass/height index (r = 0.901, p = 0.0001). Significant positive correlations were seen between the E wave deceleration half-time and the LV internal dimension in diastole (r = 0.743, p = 0.0001), systolic blood pressure (r = 0.789, p = 0.0001), LV end-systolic wall stress (r = 0.828, p = 0.0001), and LV mass/height index (r = 0.831, p = 0.0001). No correlation was seen between diastolic blood pressure and either index of LV diastolic filling. Thus increasing LV mass is associated with progressive impairment of LV diastolic filling in morbidly obese individuals. The aforementioned alterations in LV loading conditions may contribute to impairment of LV diastolic filling directly or by increasing LV mass.

Adult↗
PubMed1995

Pathogenesis, recognition, and management of common cardiac arrhythmias. Part I: Ventricular premature beats and tachyarrhythmias.

Cardiac arrhythmias are disorders of impulse formation, impulse conduction, or both. Part I of this two-part review discusses clinically relevant cardiac electrophysiology, as well as the pathogenesis, recognition, and management of ventricular premature beats and ventricular tachyarrhythmias. Part II will review the pathogenesis, recognition, and management of supraventricular premature beats and supraventricular tachyarrhythmias.

Anti-Arrhythmia Agents↗
PubMed1995

The prevalence of rheumatologic disorders in patients with chest pain and angiographically normal coronary arteries.

The purpose of this study was to determine the prevalence of musculoskeletal disorders in patients with chest pain and angiographically normal coronary arteries. The authors studied 40 consecutive patients with chest pain presenting at an Internal Medicine Clinic who had undergone coronary angiography and were found to have < 30% stenosis of all major coronary arteries. Patients with any known noncardiac cause of chest pain were excluded from the study. Each patient underwent a complete rheumatologic examination with x-rays and blood tests when indicated. The diagnosis of fibromyalgia was based on the presence of at least eight paired tender points. The diagnosis of costochondritis was made when palpation of the costal cartilages elicited tenderness. In the normal coronary artery group, 30% of the patients had fibromyalgia and 10% had costochondritis. In the control group of 40 patients with coronary artery disease, only 1 patient had fibromyalgia and none had costochondritis (P < 0.04). Other rheumatologic disorders were uncommon, with no statistical difference between the two groups. The authors conclude that many patients with chest pain and angiographically normal coronary arteries suffer from rheumatologic disorders with fibromyalgia being the most common.

Adult↗
PubMed1995

Interrelationship of left ventricular mass, systolic function and diastolic filling in normotensive morbidly obese patients.

OBJECTIVE: To determine the interrelationship of left ventricular (LV) mass, systolic function and diastolic relaxation in morbidly obese subjects. METHOD: We obtained echocardiograms (M-mode, two dimension) and cardiac Doppler studies (pulse wave, continuous wave colour flow) on 50 subjects whose actual body weight was > or = twice ideal body weight. LV mass/height index was calculated from echocardiographic data (Penn Convention). LV systolic function was assessed by calculating LV fractional shortening. LV diastolic filling was assessed by measuring the transmitral Doppler E/A ratio and the transmitral E wave deceleration time. RESULTS: There were significant positive correlations between LV mass/height index and the LV internal dimensions in diastole, systolic blood pressure, LV end-systolic wall wall stress and the transmitral E wave deceleration time. There were significant negative correlations between LV mass/height index and both LV fractional shortening and the transmitral Doppler E/A ratio. There were significant negative correlations between LV fractional shortening and the LV internal dimension in diastole, systolic blood pressure LV end-systolic wall stress and the transmitral E wave deceleration time. There was a significant positive correlation between LV fractional shortening and the transmitral Doppler E/A ratio. There were significant positive correlations between the transmitral E wave deceleration time and LV internal dimension in diastole, systolic blood pressure and LV end-systolic wall stress. There were significant negative correlations between the transmitral Doppler E/A ratio and the aforementioned variables. CONCLUSIONS: Unfavourable alterations in LV loading conditions contribute to the development of LV hypertrophy and impairment systolic dysfunction in morbidly obese subjects. Increasing LV mass and altered loading conditions may synergistically contribute to impairment of LV diastolic filling in such individuals.

Adult↗