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Biomedical subjects

K Chatterjee

Publications and source records attributed to K Chatterjee.

322 records · Page 18Linked to original sources
PubMedDate not supplied

Captopril: clinical pharmacology and benefit-to-risk ratio in hypertension and congestive heart failure.

Captopril, a competitive antagonist of angiotensin converting enzyme, has been marketed in the United States for the treatment of resistant hypertension. Despite extensive study, its exact mechanism of action remains unclear; decreased renin-angiotensin-aldosterone and sympathoadrenal system activity as well as increased bradykinin and prostaglandin E and F activity have been postulated. The drug decreases peripheral vascular resistance. Controlled trials in resistant hypertension of various etiologies and chronic congestive heart failure have demonstrated sustained effectiveness and therapeutic benefits. Side effects include skin rash, loss of taste, proteinuria, and leukopenia; higher doses and concomitant renal dysfunction appear to be predisposing factors. The benefit-to-risk ratio for captopril clearly justifies its use in resistant cases of hypertension and congestive heart failure, but further experience is needed to evaluate its use in milder forms of these diseases.

Captopril↗
PubMedDate not supplied

The role of vasodilator therapy in heart failure.

This article has attempted to summarize the current status of the therapeutic use of vasodilator drugs in acute and chronic heart failure. It is apparent from the increasing number of publications in this area that this alternative to more standard forms of therapy is likely to find a permanent and important place in the management of patients with heart disease. It should also be apparent that ideal drugs for the therapy of chronic heart failure are not yet available. Nevertheless, it is probable that such drugs will emerge and become at least as important as the routine use of digitalis in such patients.

Animals↗
PubMedDate not supplied

Hypertrophic cardiomyopathy--therapy with slow channel inhibiting agents.

Slow channel inhibiting agents, particularly verapamil, appear to produce beneficial effects in relieving symptoms of dyspnea, chest pain, and syncope or presyncope in over 70% of patients with hypertrophic cardiomyopathy. Symptomatic relief occurs in patients with and without left ventricular outflow obstruction. Exercise hemodynamics, exercise tolerance, and cardiac performance during exercise tend to improve. The mechanisms for this symptomatic improvement, however, are not fully explained. Relief of symptoms is observed irrespective of any changes in the resting or provocable left ventricular outflow gradient. Similarly, changes in left ventricular systolic function, which in general remains unaffected, cannot be the basis for the beneficial response. Slow channel inhibiting agents, however, appear to improve left ventricular diastolic function, the mechanism of which is yet to be elucidated. Nevertheless, improved left ventricular diastolic function may provide an explanation for the relief of some symptoms in patients with hypertrophic cardiomyopathy. The influence of therapy with slow channel inhibiting agents on arrhythmias, sudden death, and on long-term prognosis of patients with hypertrophic cardiomyopathy remains uncertain at the present time and should be the subject of future investigations.

Angiocardiography↗
PubMedDate not supplied

Evaluation of thoracic aortic dissection using breath-holding cine MRI.

OBJECTIVE: Our goal was to determine if breath-hold cine MRI in transaxial planes can be used for the evaluation of thoracic aortic dissection instead of conventional cine MRI since rapid imaging is required in this clinical setting. MATERIALS AND METHODS: Twelve patients with thoracic aortic dissection were imaged using a 1.5 T imager. Breath-hold images were acquired with fast cine MR sequence (TR/TE = 9/2.8, 20 degrees flip angle) using segmented k-space data acquisition. Conventional non-breath-hold cine MR images (TR/TE = 22/7.5, 35 degrees flip angle, 2 averages) were taken with flow and respiratory compensation. RESULTS: Sharpness of edges of the vessels on fast cine MR images was better than that on conventional cine MR images in 34 (57%) of 60 images. Inhomogeneous blood signal in aortic lumen due to motion artifacts was found in 2 (3%) of fast cine MR images and in 15 (25%) of conventional cine MR images. The contrast-to-noise ratios of fast cine MR images were significantly better than those of conventional cine MR images (26.4 +/- 9.1 vs. 18.5 +/- 10.1; p < 0.05) when the region of interest for noise was placed to include ghosting artifacts. CONCLUSION: Breath-hold cine MRI is a rapid technique that gives high quality images of thoracic aortic dissection and can provide a diagnosis in < 10 min of imaging time.

Aged↗
PubMedDate not supplied

Surgical therapy in acute ischemic syndromes.

Despite increasing enthusiasm about the treatment of symptomatic angina pectoris by direct revascularization surgery, there appropriately continues to be concern about the effects of such therapy. While it is generally accepted that surgery is effective in relieving anginal pain in upwards of 80% of patients undergoing aortocoronary bypass, reservations focus on the possibilities that such therapy may increase the incidence of infarction (postoperative), accelerate the atherosclerotic process, and shorten longevity, primarily because of the increased early operative mortality. While these contentions may or may not be true for the majority of patients who undergo such therapy, there is accumulating experience that in certain well-defined subsets, surgery does favorably affect the prognosis of the disease. Patients with preinfarction angina constitute one such subset of patients with coronary atherosclerosis. The all-inclusive surgical mortality for 106 consecutive cases was 3.8%, and 86% of the survivors are asymptomatic. Actuarial analysis of follow-up data reveals that this survival rate is essentially constant through the first 36 months after surgery. On the basis of this experience we feel that patients with preinfarction angina present a therapeutic opportunity in which the ideal goal of preventive medical care can be achieved by early identification, study and surgery.

Adult↗
PubMedDate not supplied

Relationship between pacemaker fibrillation thresholds and electrode area.

Energy thresholds for electrical pacing of the heart are lower with small electrodes than with large. Because pacing of the heart during the vulnerable period may produce ventricular fibrillation, it is also pertinent to know if fibrillation threshold is affected by the electrode size. Electrodes of different surface area but of the same material were implanted in 40 dogs and the pacing thresholds were recorded. Ventricular fibrillation was electrically induced by discharging a 2-msec d.c. cathodal pulse of progressively increasing energy into the vulnerable period. It was found that small electrodes required more energy to produce ventricular fibrillation than large electrodes, and the ratio of fibrillation to stimulation threshold was higher for the small-surface-area electrode. The difference between the thresholds and ratios obtained with the various electrodes was statistically significant. A similar experiment was performed in animals with chronically implanted electrodes, producing comparable results. The results indicate that, in regard to pacing and fibrillation thresholds, small electrodes are preferable to large.

Animals↗
PubMedDate not supplied

Cyclosporine-induced hemolytic uremic syndrome in a heart transplant recipient.

We report a case of hemolytic uremic syndrome associated with the use of cyclosporine in a heart transplant recipient. The patient manifested many classic signs and symptoms of hemolytic uremic syndrome, and a diagnosis was confirmed by kidney biopsy. Treatment with plasma exchange was effective in halting the hemolysis, but renal function failed to improve. Rechallenge with cyclosporine caused recurrence of microangiopathic hemolysis. Because of concerns regarding allograft rejection, an experimental immunosuppressive agent, RS-61443, was used that was effective in controlling rejection and was not associated with recurrence of hemolytic uremic syndrome.

Cyclosporine↗