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Biomedical subjects

B C Pakrashi

Publications and source records attributed to B C Pakrashi.

At least 19 recordsLinked to original sources
PubMed1976

Hemodynamic effects of pacing-induced heart rate augmentation. A study in patients early after mitral and aortic valve operations.

Heart rate augmentation induced by atrial and ventricular pacing was carried out in 23 patients early after intracardiac valve operations. The series comprised two groups of patients: 11 with aortic and 12 with mitral valve surgery. A different pattern of hemodynamic responses emerged during heart rate augmentation in each group. Atrial pacing produced, in the aortic group, a significant increase in cardiac output and mean aortic pressure and a reduction in left atrial pressure. The changes in the mitral group were not significant. During ventricular pacing the left atrial pressure rose in both groups. Although there was a decrease in the mean cardiac output in the aortic group and an increase in the mitral group, these changes did not reach statistical significance. A similar distinction between the aortic and mitral groups was observed when comparing the results of atrial and ventricular pacing at the same heart rate. The hemodynamic benefit appeared to be confined to the aortic group. The different pattern of response in each group of patients was probably due to clinical, hemodynamic, and therapeutic factors related to the condition and management of patients with each type of valve surgery.

Adult↗
PubMed1976

Sequential hemodynamic studies following mitral fascia lata valve replacement.

Sequential hemodynamic studies were performed at mean intervals of 6 and 38 months following mitral valve replacement in 10 patients who had angiographically competent fascia lata valves and in whom preoperative hemodynamic studies were available. The cardiac index did not change significantly during postoperative studies as compared with the preoperative values, and its response in relation to oxygen uptake during exercise remained impaired. The mean pulmonary wedge and pulmonary artery pressures showed significant reduction at the first and the second postoperative studies, both at rest and during exercise. Progressive reduction in the pulmonary vascular resistance occurred in patients with high initial values, although the group mean did not alter significantly. The mean diastolic gradient across the mitral fascial valves averaged 8.1 +/- 1.3 mm Hg at rest rising to 22.5 +/- 2.4 mm Hg during exercise (P less than 0.001), and the calculated mitral valve area was 1.9 +/- 0.22 cm2 at rest and 2.36 +/- 0.3 cm2 during exercise (P less than 0.02). This study indicates that the insertion of stented mitral fascia lata valves results in significant hemodynamic improvement, which is maintained at least for 3 years after surgery, in patients with competent valves. However, a degree of obstruction to the forward flow is apparent especially during exercise, despite the central flow design of the valve.

Adult↗
PubMed1975

Tissue valves in the mitral position. Five years' experience.

Between April 1969 and November 1973 103 patients underwent isolated mitral replacement with three-cusp stented tissue valves. Autologous fascia lata was used in 50 patients, homologous fascia lata in 21, and heterologous pericardium in 32. The early mortality rate (14.6%) was influenced by age, the extent of preoperative cardiac disability, and low cardiac output. The survivors were followed up for periods varying from 8 to 60 months (average 37 months). In general, a factor in late death (13.6%) was high preoperative pulmonary artery pressure. In the autologous fascial series valve failure and infective endocarditis were significantly related to late mortality. The results with homologous fascia and pericardium were better than with autologous fascia valves. The incidence of postoperative mitral regurgitation was singificantly lower in the homologous fascial and pericardial series and none of these grafts had to be removed. The incidence of thromboembolism was low without anticoagulants. Actuarial analysis showed a survival rate at five years of 82.2 per cent. We no longer use autologous fascial valves. Though better results have been obtained with both homologous fascia and pericardium we prefer the physical characteristics of heterologous pericardium and it is easy to obtain.

Adolescent↗
PubMed1975

Clinical and hemodynamic results of mitral valve replacement with autologous fascia lata grafts. Studies in patients with competent prostheses.

Nine patients with severe mitral disease were studied before and six months after mitral valve replacement with a three-cusp stented prosthesis using fresh autologous fascia lata tissue. Only patients in whom there was no auscultatory and angiographic evidence of incompetence of the replaced valve were selected for restudy. All patients claimed a marked improvement in their exercise capacity after operation and there was a significant reduction in radiographic heart size. The cardiac output at rest and the response to exercise were both reduced before operation and were unchanged after valve replacement. The elevated pulmonary arterial and wedge pressures were significantly reduced after operation in all patients both at rest and during exercise, but in no instance were the postoperative exercise values within normal limits. Left ventricular end-diastolic pressure was within normal limits at rest and during exercise in all patients after valve replacement but the average pressure gradient across the fascia lata valve was 6+/-1 mm Hg at rest and 18+/-3 mm Hg during exercise. These findings indicate that altough replacement of the diseased mitral valve with a competent fascia lata prosthesis afforded substantial symptomatic relief, reduction of cardiac enlargement and a lowering of the pulmonary vascular pressures, this artificial valve offered a significant obstruction to left ventricular diastolic filling, particularly during exercise.

Adult↗