摘要:

Digoxin (5 mg/mI) was added to 10-mg and 20-mg pellets of purified primary and secondary amyloid fibrils, a normal human liver and heart homogenate and a homogenate from the heart of a patient with amyloid cardiomyopathy who had not received digitalis. After centrifugation, the supernatants were recovered and assayed for digoxin concentrations. Aliquots from the sediments were studied for the presence of digoxin, using rabbit antidigoxin antiserum and an indirect immunofluorescent technique. The results showed that 0.11–0.13 ng/ml of digoxin bound per milligram of fibrils and could not be separated by repeated washings. elution with citrate or changes in the pH of the buffer. Immunofluorescent studies demonstrated diffusely bright immunofluorescence with the fibril preparation and amyloid heart homogenate when reacted with digoxin and digoxin-specific antiserum. These studies demonstrate that isolated amyloid fibrils bind digoxin and suggest that this interaction may play some role in the sensitivity to digitalis that has been observed in some patients with amyloid cardiomyopathy.

ISSN:0009-7322    

出版商:OVID    

年代:1981

数据来源: OVID

摘要:

Electron microscopic and statistical analyses of 66 right ventricular biopsies from 48 patients were undertaken to investigate whether quantitative differences exist between those patients with “ordinary” myocardial hypertrophy and those suffering from a form of cardiomyopathy.The electron microscopic changes were scored and correlated with hemodynamic variables such as ejection fraction (EF), left ventricular end-diastolic pressure (LVEDP) and length of history. The patients were followed for an average of 22.5 months, permitting an assessment of prognosis.The results show that the three diagnostic groups “ordinary” hypertrophy, hypertrophic cardiomyopathy (HOCM) and congestive cardiomyopathy (COCM) overlap, but crossover of sarcomeres is more frequent in patients in whom HOCM is diagnosed. Except for a tenuous relationship between EF, and the electron microscopy (EM) (r= −0.46,p< 0.1) and between LVEDP and EM score (r= 0.61,p< 0.01), in the COCM group, no correlation could be established between EF, LVEDP and length of history when the patients were grouped according to histologic or clinical diagnosis.This study shows that the various claims regarding relationships between morphologic changes and the functional status of patients or prognosis cannot be confirmed.

ISSN:0009-7322    

出版商:OVID    

年代:1981

数据来源: OVID

摘要:

The relation between quantitative ultrastructural changes of the left ventricular (LV) myocardium and contractile function was studied in patients with chronic aortic stenosis (AS). The volume fractions of myofibrils, sarcoplasm and mitochondria in myocardial cells were determined by electron microscopic morphometry in small LV tissue samples of 19 patients with AS. Interstitial fibrosis was measured by light microscopic morphometry. Transmural biopsies of the LV free wall perfused by the anterior descending branch of the left anterior descending coronary artery (LAD) were obtained during aortic valve replacement. LV function was analyzed from preoperative right- and left-heart catheterization and angiography. Group 1 consisted of seven patients with ejection fractions (EFs) greater than 55% and mean left atrial pressure (LAP) less than 15 mm Hg. Group 2 consisted of 12 patients with EFs less than 55% and mean LAP greater than 15 mm Hg. Patients in group 1 had lower LV end-diastolic volume (91.9 vs 145.3 ml/m2,p< 0.05) and lower LV muscle mass (148.3 vs 199.8 g/m2,p< 0.05) than patients in group 2. The volume fraction of myofibrils was higher in group 1 than in group 2 (48.4 vs 42.1%,p< 0.05), while volume fractions of sarcoplasm (31.7 vs 36.0%) and mitochondria (20.9 vs 22.0%) were comparable (p> 0.05). Interstitial myocardial fibrosis did not differ between groups (16.3 vs 14.7%,p> 0.05). Biopsies from the area perfused by the LAD in 10 additional surgical patients who had coronary artery disease with moderate LAD stenosis and normal wall motion in the area of LV free wall perfused by the LAD were taken as controls for morphometric data. No significant difference of ultrastructural data was found between group 1 and controls. The volume fraction of myofibrils was lower in group 2 than in controls (42.1 vs 52.9%,p< 0.001), and the volume fraction of sarcoplasm was higher (36.0 vs 21.1%,p< 0.001). Mitochondria and interstitial fibrosis did not differ in group 2 and controls (p> 0.05).Thus, intracellular reduction in the volume fraction of myofibrils was the major morphologic finding in LV biopsy samples of patients with decompensated pressure overload.

ISSN:0009-7322    

出版商:OVID    

年代:1981

数据来源: OVID

摘要:

In 18 patients who underwent coronary arteriography, aortic velocity and pressure data were obtained during a control state and during either isoproterenol infusion at 1, 2 and 3 pg/min or graded nitroprusside infusion (average peak dose 60 μg/min). Impedance moduli and phase angles were derived to 10 Hz for control states, isoproterenol at 2 μg/min, and at peak nitroprusside effect. Averaged control data included a mean resistance of 1460 dyn-sec-cm-' and a characteristic impedance of 88 dyn-sec-cm-5. The characteristic impedance did not correlate with age (r= 0.21), coronary artery disease score (r= 0.17) or mean aortic pressure (r− −0.01). In 11 patients, isoproterenol induced a 38% reduction in mean resistance and a 10% reduction in mean aortic pressure. There was slight reduction in characteristic impedance and phase angles became less negative, to 2 Hz. In seven patients, nitroprusside induced a 38% reduction in mean resistance and a 22% reduction in mean aortic pressure. Impedance moduli decreased to 1.8 Hz and phase angles became less negative, to 3 Hz. Based on the different cardiovascular actions of these two drugs, the data suggest that vasodilators do not induce significant changes in the aortic impedance spectrum when not associated with a decrease in mean aortic pressure.

ISSN:0009-7322    

出版商:OVID    

年代:1981

数据来源: OVID

摘要:

To assess left ventricular (LV) function in patients with atrial septal defect (ASD), we used radionuclide cineangiography at rest and during exercise in 11 patients (ages 16–59 years, mean 36 years) without other cardiac abnormalities. All patients had normal LV ejection fraction (EF) at rest (mean 59 ± 3% vs normal 57 ± 1%; NS); during exercise, four patients increased LVEF normally, four had no change in LVEF with exercise, and three decreased LVEF to 56%, 54%, and 44% (lower limit of normal 55%). These three patients had orthopnea and paroxysmal nocturnal dyspnea; the other eight were asymptomatic or mildly symptomatic. While the LVEF response to exercise did not correlate directly with hemodynamic or echo data, the two patients with the greatest decrease in LVEF during exercise had higher pulmonary-to-systemic flow ratios than the other nine patients (mean 4.8 vs 2.0,p< 0.001). All patients had abnormalities of ventricular septal motion on echocardiography with subnormal LV diastolic dimensions secondary to the right ventricular volume overload. Six months after operation, all 11 patients were asymptomatic and all had normal rest and exercise LVEFs (mean EF 58 2% rest, 65 3% exercise,p< 0.001), including the seven patients with abnormal preoperative LVEF responses to exercise. LV diastolic dimension by echocardiography, subnormal before operation in all 11 patients, increased into the normal range in all patients postoperatively. These data suggest that diminished LV functional reserve in adult patients with ASD is related, at least in part, to reversible mechanical factors related to right ventricular volume overload with abnormal diastolic-systolic relations of the interventricular septum, rather than to intrinsic, irreversible myocardial dysfunction.

ISSN:0009-7322    

出版商:OVID    

年代:1981

数据来源: OVID

摘要:

Cardiac tamponade that occurs late after cardiac surgery (7 days) is relatively uncommon but potentially fatal. We analyzed its incidence, clinical course and relationship to the postpericardiotomy syndrome in 1290 consecutive adult patients who survived surgery. Criteria for diagnosis of cardiac tamponade were (1) elevated jugular venous pressure, (2) hypotension or decreased cardiac index, (3) characteristic hemodynamics at cardiac catheterization, and (4) echocardiographic evidence of pericardial effusion.Ten of the 1290 patients (0.8%) developed cardiac tamponade. Surgery was for congenital heart disease in five patients, valvular heart disease in two patients, and coronary artery disease in three patients. The onset of hemodynamic compromise ranged from 15–180 days postoperatively (mean 49 days). All patients had echocardiographic evidence of pericardial fluid, eight had a pericardial friction rub at the time of cardiac tamponade, nine had pericardial pain, and all were considered to have a postpericardiotomy syndrome. One patient was receiving coumadin and two patients were receiving aspirin before the diagnosis of cardiac tamponade. Nine patients underwent pericardiocentesis (0.5–1 1 of fluid). There were no deaths in the group. The syndrome resolved in nine patients with conservative medical therapy and one patient required pericardial stripping for recurrent cardiac tamponade.In this study, cardiac tamponade occurred in 0.8% of patients who survived cardiac surgery; cardiac tamponade occurred in patients without prior anticoagulation, in marked contrast to previously reported cases; pericardiocentesis and conservative medical therapy were successful in treating the majority of patients; clear symptoms and signs of pericardial involvement were present before cardiac tamponade occurred.

ISSN:0009-7322    

出版商:OVID    

年代:1981

数据来源: OVID

摘要:

A multivariate risk function was developed on data from all 508 medical patients in the Veterans Administration (VA) randomized study of coronary bypass surgery. The variables, in order of importance, were ST-segment depression on resting ECG, history of myocardial infarction, history of hypertension and New York Heart Association functional classification III or IV. These noninvasive variables have been reported to be risk factors in natural-history studies of coronary heart disease (CHD). Applying the risk function to medical and surgical patients of the 1972–1974 cohort yielded a 5-year probability of dying for each patient. Investigation of treatment effects in approximate terciles obtained by collapsing the probability distribution into low-, middle- and high-risk groups showed that surgery was beneficial for patients in the high-risk tercile even after removal of patients with left main coronary artery disease (17% surgical vs 34% medical mortality at 5 years;p< 0.01). This finding was accentuated when patients in the 10 hospitals with the lowest operative mortality (3.3%) were compared. Mortality results in the low-risk tercile favored medical treatment (medical vs surgical mortality 7% vs 17%;p< 0.05).The risk function predicted mortality well not only for the VA medical group, but also for an independent symptomatic CHD population from the University of Alabama arteriography registry.This report further delineates the advantages and limitations of coronary bypass surgery in CHD patients with chronic stable angina.

ISSN:0009-7322    

出版商:OVID    

年代:1981

数据来源: OVID

摘要:

The arm-ankle systolic pressure gradient was measured in 165 male patients with intermittent claudication and was correlated with different combinations of known cardiovascular risk factors. The pressure gradient increased with increasing number of risk factors. We conclude that intermittent claudication may be used as a simple model for studies of arteriosclerosis, the arm-ankle systolic pressure gradient being a measure of the degree of arteriosclerosis between heart and ankle.

ISSN:0009-7322    

出版商:OVID    

年代:1981

数据来源: OVID

摘要:

The associations observed in the Coronary Drug Project between two baseline factors serum cholesterol level and number of cigarettes smoked per day and 5-year mortality in men who had a history of myocardial infarction are used to derive required sample sizes for future risk factor intervention trials in the secondary prevention of coronary heart disease. Consider a trial in which it is anticipated that the baseline cholesterol level will be 250 mg/dl in the control group and that a 20% reduction in this level to 200 mg/dl will be experienced by the treated group. Let it also be assumed that this reduction in cholesterol level will have the effect of immediately reducing the mortality risk to that corresponding to a patient with a baseline level of 200 mg/dl. Given a type I error rate, α, of 0.05 for a two-sided test, a type II error rate, β, of 0.10, and a follow-up period of 5 years, the required size of the trial would be over 10,000 patients. A similar sample size would be required for a single-factor trial focusing on cigarette smoking cessation. The sample size might be reduced to 6000 for a two-factor trial with intervention on cholesterol and cigarette smoking simultaneously. These numbers increase two- to threefold when dropout patients and “dropin” patients (i.e., those in the control group who decide on their own to begin the intervention therapy) are considered and when other assumptions are made concerning the anticipated time required for the treatment to achieve maximum benefit with respect to the mortality or morbidity end point.

ISSN:0009-7322    

出版商:OVID    

年代:1981

数据来源: OVID

摘要:

To define the prevalence, frequency and characteristics of premature ventricular complexes (PVCs) in adults free of recognizable heart disease, we performed 24-hour ambulatory electrocardiography on 101 subjects (51 men and 50 women, mean age 48.8 years) in whom physical examination, chest x-ray, ECG, echocardiogram, maximal exercise stress test, right- and left-heart catheterization and coronary arteriography were normal. Thirty-nine subjects had at least 1 PVC/24 hours, but only four had more than 100 PVCs/24 hours and fewer than five had more than five PVCs in any given hour. The probability of having at least 1 PVC/24 hours increased with age (chi square = 11.789,p= 0.019). The number of PVCs/24 hours was also positively associated with age (r− 0.33,p= 0.001). There was no consistent relationship between the presence or number of PVCs/24 hours and sex, blood pressure, weight, height, body mass index, serum potassium or calcium, cholesterol and triglyceride, hemoglobin, the ingestion of coffee, tea or alcohol, and cigarette smoking. Four subjects had multiform PVCs, two of whom had early PVCs.

ISSN:0009-7322    

出版商:OVID    

年代:1981

数据来源: OVID