ISSN:0009-7322    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

For half a century the systolic click and late systolic murmur lay dormant as innocent auscultatory curiosities. The thirteen years since Barlow related these phenomena to mitral leaflet prolapse have witnessed an astonishing information explosion. We have sought to bring together the accumulated data in this review.AnHistorical Perspectivetraces the evolution from the now abandoned “pericardial” or “extracardiac” phase, through the leafletchordal phase (redundancy), the myocardial phase (segmental left ventricular contraction abnormalities), to the anular phase (dilatation and faulty systolic contraction).Functional Anatomyis dealt with in terms of pathology, pathophysiology, hemodynamics, angiocardiography, echocardiography, and physical and pharmacological interventions.Clinical Manifestationsare concerned with prevalence, natural history, symptoms, physical signs, electrocardiographic abnormalities and roentgen findings. The fourMajor Complications- sudden death, infective endocarditis, spontaneous rupture of chordae tendineae, and progressive mitral regurgitation — are examined.Associated Cardiac Diseases, i.e., Marfan's syndrome, ostium secundum atrial septal defect and atherosclerotic coronary artery disease, are discussed, and a section onTreatmentdeals chiefly with prophylaxis for infective endocarditis and the management of arrhythmias and chest pain. A final section onEvolving Informationconsiders etiologic concepts, the nature of left ventricular contraction abnormalities, the cause of chest pain, the relationship to Marfan's syndrome and ostium secundum atrial septal defect, and the effect of aging and sex differences on leaflet-chordal redundancy.

ISSN:0009-7322    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

Intravenous perhexiline maleate in a canine preparation with fixed coronary flow increases coronary diastolic pressure. It also redistributes coronary flow so as to preserve endocardial flow. Myocardial oxygen consumption was reduced and lactate uptake enhanced by the drug. It had no effect upon the threshold for ischemic-induced left ventricular failure.

ISSN:0009-7322    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

The response patterns of plasma cortisol and plasma free cortisol have been studied in 20 consecutive patients undergoing cardiac surgery involving the use of heart-lung bypass. Sixteen consecutive patients undergoing closed mitral valvotomy have been used as controls. Total plasma cortisol levels fell at the onset of extracorporeal circulation (ECC) and did not rise significantly throughout the period of ECC. The peak cortisol level in the bypass patients occurred at 24 hours postoperatively with elevated levels still present at 48 hours. This pattern was significantly different from the control patients (P< 0.001) who exhibited the typical cortisol stress response pattern. Synthetic ACTH stimulation of the adrenal cortex during heart-lung bypass produced a positive response (i.e., a rise plasma cortisol > 7.5 μ/100 ml) in all six patients studied while six mitral valvotomy patients had no response to synthetic ACTH administration during operation (P< 0.01).Plasma free cortisol estimations indicate that a rapid and significant rise in % free cortisol occurred at the onset of ECC, but despite the rise in percentage free, the overall plasma free cortisol concentration (i.e., total plasma cortisol × % free) was significantly lower during ECC in the bypass patients when compared with control (P< 0.01). Twenty-four hours postoperatively these concentrations were significantly higher in the bypass patients (P< 0.001).

ISSN:0009-7322    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

We studied the changes which occurred in regional coronary blood flow after right ventriculotomy and the subsequent effects of hypertonic mannitol or isoproterenol infusion. Regional coronary flows were measured with radioactive microspheres (9 micron) in open-chest anesthetized dogs. Either hypertonic mannitol (25%) was infused at 3.2 ml/min or 7.6 ml/min for 30 minutes, or normal saline at 7.6 ml/min for 30 minutes followed by isoproterenol at 0.05–0.10 μg/kg/min. In the mannitol treated animals right ventricular, left atrial and aortic pressures, heart rate, and cardiac out- put did not change significantly following vertical ventriculotomy, whereas in the saline-isoproterenol treated animals aortic pressures fell significantly. Coronary flow to the peri-incisional area fell from 41 to 24 ml/min. 100g (P< 0.05) following ventriculotomy, increased by 34% (P< 0.05) when osmolality rose after mannitol by 37 mOsm, but was unchanged with isoproterenol. The data indicate that a vertical ventriculotomy reduces flow to adjacent myocardium and that subsequent infusion of hypertonic mannitol at moderate rates significantly increases coronary flow to this region.

ISSN:0009-7322    

出版商:OVID    

年代:1976

数据来源: OVID

ISSN:0009-7322    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

The relative benefits and risks of reserpine and guanethidine were compared in patients with thiazide-treated mild to moderate hypertension (diastolic pressure 95–115 mm Hg). Fortynine ambulant patients (30 men, 19 women) were treated throughout the study with hydrochlorothiazide, 50 mg/day. In this double blind crossover study each drug was added in graded increments until a predetermined therapeutic response was obtained, blood pressure measurements and side effect scores were evaluated biweekly. Major conclusions of the study were: 1) guanethidine, as well as reserpine, will reduce mild to moderate blood pressures to normal; 2) in most cases, side effects which did occur while taking guanethidine or reserpine were well tolerated and neither drug was clearly superior. Side effects associated with larger doses of guanethidine employed in severe hypertension were absent or only slightly bothersome. Thus, guanethidine appears to have a good benefit-to-risk ratio in the therapy of mild to moderate hypertension and offers a number of advantages over drugs commonly used in this syndrome. This study refutes the common belief that guanethidine must be reserved only for the treatment of more severe degrees of hypertension.

ISSN:0009-7322    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

The effects of glucose-insulin-potassium infusion (GIK) on atrial pacing-induced angina, ST depression, abnormal left ventricular end-diastolic pressure during pacing interruption (LVEDPi) and lactate metabolism (L), were studied in 18 patients: ten had angina during pacing = Ischemic group, and eight (5 normals and 3 with coronary artery disease) remained asymptomatic = Nonischemic group. The study consisted of 8–10 minute periods of control, pacing and recovery, before and after GIK. No untoward effects were observed. Comparison of the pacing responses (GIK vs pre-GIK states) showed that during GIK, angina occurred in only 4 patients, while significantly less severe changes were observed in ST depression (1.4 ± 0.5 vs 2.4 ± 0.4 mm) and LVEDPi (16 ± 3 vs 23 ± 3 mm Hg). Lactate extraction was also higher (8.1 ± 10.9 vs −5.2 ± 11.1%), but not significantly so, although L became normal in 4 subjects and improved in another. These results indicate that GIK infusion was well tolerated and had a beneficial effect on pacing-induced myocardial ischenia.

ISSN:0009-7322    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

The effect of timolol versus propranolol on hypertension, hemodynamics, and plasma renin activity was evaluated in 20 men. After two weeks of placebo, 11 men received timolol 30 to 60 mg daily, and nine men received propranolol, 240 to 480 mg daily, for five weeks in a double-blind randomized study. The 20 men then received placebo again for two weeks. Right heart catheterization was performed in all 20 patients after two weeks of the first placebo and after five weeks of timolol or propranolol. Equipotent doses of timolol and propranolol were equally effective in significantly lowering supine and upright systolic and diastolic blood pressure and heart rate recorded on an outpatient basis. Equipotent doses of timolol and propranolol caused similar hemodynamic effects including similar significant depression of cardiac index. Equipotent doses of timolol and propranolol caused similar marked depression of plasma renin activity. The hypotensive action of timolol and of propranolol was unrelated to their effect on plasma renin activity.

ISSN:0009-7322    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

The Western Collaborative Group Study is a prospective study of 3,154 employed men, aged 39–59 years. Coronary heart disease (CHD) occurred in 257 subjects during 8.5 years of follow-up. The multiple logistic risk model was used to assess the comparative strength of systolic, diastolic, mean arterial and pulse pressure for the prediction of CHD in two age decades after adjustment for age, serum cholesterol, cigarette smoking, behavior pattern and weight.The risk of CHD was more strongly associated with the systolic than the diastolic pressure. The general practice of assessing the importance of blood pressure based only on the diastolic component should be reassessed.

ISSN:0009-7322    

出版商:OVID    

年代:1976

数据来源: OVID