DIAGNOSIS AND TREATMENT OF TRICUSPID STENOSIS

Abstract

The diagno-sis, circulatory effects, and surgical treatment of rheumatic tricuspid stenosis associated with mitral stenosis is discussed in relation to 17 patients subjected to combined valvotomy. The diagnosis of tricuspid stenosis may be difficult and is frequently overlooked. Although a large flicking "a" wave in the venous pulse, a tricuspid diastolic murmur, right atrial enlargement in the radiograph, right atrial hypertrophy in the electrocardiogram, and a pressure gradient across the tricuspid valve in diastole, offer presumptive evidence for tricuspid 6tenosis, each of these features may occur in other conditions. Large "a" waves occur in pulmonary stenosis, in pulmonary hypertension, including that of mitral stenosis, and in organic tricuspid incompetence. There is, however, a particular pattern of a "flicking" "a" wave unaccompanied by a systolic wave which is characteristic of severe tricuspid stenosis. Tricuspid diastolic murmurs may occur in dominant tricuspid incompetence. They indicate organic tricuspid disease but are no guide to the severity of the stenosis. Tall P waves in the electrocardiogram and right atrial enlargement in the radiograph though present in tricuspid stenosis are common findings in tricuspid incompetence and in right ventricular hypertrophy with a normal tricuspid valve. Enlargement of the pulmonary artery, congestion of the lung fields, and right ventricular hypertrophy do not exclude severe tricuspid stenosis. A pressure gradient in diastole across the tricuspid valve occurs both in dominant stenosis and in dominant organic incompetence and is unreliable as a guide to tricuspid stenosis of a severity requiring operation. Valve area calculations are similarly unreliable if incompetence is present. Atrial fibrillation increases the difficulty of diagnosis. When tricuspid disease is present with fibrillation, a prominent systolic wave in the venous pulse may be associated with severe stenosis and only minor regurgita-tion. The presence of any one of these features should raise the suspicion of severe tricuspid stenosis, and a combination is strongly suggestive. The most consistent confirmatory evidence of severe stenosis in the presence of a tricuspid pressure gradient proved to be the dissociation of right atrial and right ventricular diastolic pressures during respiration. The relation of tricuspid murmurs to respiration is discussed, and it is pointed out that in severe tricuspid stenosis a systolic murmur from associated tricuspid incompetence tends to decrease on inspiration. The explanation for this is discussed in detail. Tricuspid stenosis causes a disability similar to that in mitral stenosis but which may be unrelieved by mitral valvotomy. The cardiac output is severely restricted both at rest and on exercise. When atrial fibrillation occurs the venous pressure remains permanently raised. Symptoms were relieved in 12 patients after operation. Cardiac catheterization was repeated after operation in 5, and showed a reduction but not complete abolition of the valve gradient. Right atrial size did not decrease. Regression of the P pulmonale pattern in the electrocardiogram was usual but not always complete. Three patients died during the operation, but no death was considered to be due to the tricuspid valvotomy itself. Traumatic, i.e. operative valvular incompetence of significant degree, only resulted in one case. Two patients subsequently died, after 1 and 2 years respectively, and this was considered to be due to the over-all effects of severe rheumatic heart disease. Eleven of the 12 remaining survivors have remained well 2 to 6 years later: one had only a fair result.