STUDIES ON ADVANCED RHEUMATIC MITRAL INSUFFICIENCY CLINICAL ASPECTS AND CIRCULATORY DYNAMICS WITH SPECIAL REFERENCE TO THEIR CORRELATIONS

The clinical and pathophysiological features of 41 patients with advanced pure mitral insufficiency of rheumatic origin, were investigated and statistical analysis of the hemodynamic parameters was made with special reference to their correlations. 1. A history compatible with acute rheumatic fever was obtained in 31 patients (75.6 per cent). The average age at the time of initial attack was 13.1 years and the asymptomatic intervals averaged 6.8 years. 2. Exertional dyspnea (95 per cent), palpitation (78 per cent) and excess fatigability (76 per cent) were the early and most common symptoms of the patients. 3. In addition to the loud apical pansystolic murmur constantly present, a middiastolic murmur was heard in 33 patients (.81 per cent). A third sound or diastolic gallop sound was present in over a half of the patients (56 per cent). 4. Auricular fibrillation was found in over two-thirds of the patients (68 per cent). Patients with auricular fibrillation was older and had longer duration of the disease in comparison with those of sinus rhythm. The average period since first attack of rheumatic fever or equivalents was 15 years in patients with auricular fibrillation. The majority of patients revealed electrocardiographic evidence of combined ventricular hyper-trophy (54 per cent) and right ventricular hypertrophy alone was observed in 5 per cent of patients. 5. The cardiac size as expressed by cardio-thoracic ratio ranged from 0.52 to 0.87 with an average of 0.70 and marked cardiomegaly (cardio-thoracic ratio exceeding 0.81) was noted in 7.5 per cent of the patients. Giant left atrium was present in 1 2.8 per cent of the cases. 6. The cardiac index ranged from 2.0 to 4.5 L/min/M2 BSA with an average of 3.1 and low cardiac index (less than 2.6 L/min/M2 BSA) was encountered in 37 per cent of patients. 7. The peak systolic pressure in the pulmonary artery ranged from 25 to 105 mmHg, averaging 55; the mean pressure varied from 14 to 65 with an average of 37. Moderately severe to severe pulmonary hypertension (pulmonary-systemic peak systolic ratio of over 0.7) was observed in 17 per cent of patients. The total pulmonary resistance ranged from 286 to 2, 329 dynes sec. cm-5 with an average of 81 5. The values in excess of 1, 300 dynes sec. cm-5 was noted in 17 per cent of patients. 8. The various hemodynamic parameters were analysed in relation to duration of the disease and degree of the mitral insufficiency, and factors influencing pulmonary vascular reactivity were assessed in addition. The pressure-volume relationships of the left side of the heart in rheumatic mitral insufficiency were complex. Myocardial malfunction secondary to the under-lying rheumatic process as well as to increased myocardial burden because of the presence of mitral insufficiency, size and compliance of the left atrium and presence or absence of auricular fibrillation might greatly influence and shape the total cardiac dynamics. The possible interrelationships between mitral regurgitant flow and pulmonary vascular reactivity were also discuss-ed. 9. The most reliable method for estimating the severity of mitral insufficiency was selective left ventriculography. With no exception, the severity could be graded as 3 plus or greater in a total of 30 patients in whom the diagnosis was confirmed at surgery. 10. Selected pathological findings obtained at surgery were reported and the status of rheumatic fever as well as the prevalence of cardiac involvement in this subtropical or tropical zone was sepculated.