Rheumatic tricuspid stenosis
Rheumatic tricuspid stenosis is often associated with mitral valve disease. As in rheumatic mitral stenosis, there is commissural fusion in rheumatic tricuspid stenosis. Anteroseptal commissure between the anterior and septal leaflets of the tricuspid valve is the one which is most commonly involved. Tricuspid valve being the largest valve in the body, a gradient of 2 mm Hg across it will qualify for tricuspid stenosis. A gradient of 5 mm Hg would mean severe tricuspid stenosis where as the corresponding gradient in severe mitral stenosis is 20 mm Hg.
Severe tricuspid stenosis causes right atrial hypertrophy and prominent a waves in the jugular venous pulse (giant a waves). Slow y descent is another feature as right atrial emptying into the right ventricle is impeded. A presystolic hepatic pulsation may also be felt in severe tricuspid stenosis. Tricuspid opening snap increases with inspiration and is heard in the lower left sternal border. A mid diastolic murmur in the tricuspid area is heard in tricuspid stenosis. Ascites disproportionate to pedal edema (ascites precox) can occur in tricuspid stenosis/regurgitation. Hepatomegaly may be noted secondary to high right atrial pressure with dilated inferior vena cava. This can lead on to liver dysfunction as well.
Balloon tricuspid valvotomy, a catheter based technique, is sometimes used to relieve tricuspid valve obstruction. Unlike balloon mitral valvotomy, tricuspid valvotomy does not require puncture of the interatrial septum. The venous access is usually through the right femoral vein. The procedure is often done along with balloon mitral valvotomy as tricuspid stenosis is almost invariably associated with mitral stenosis. Surgical treatment of tricuspid stenosis is opted for when there is need for concomitant mitral or aortic valve surgery. Surgical treatment is also needed when tricuspid stenosis is associated with significant tricuspid regurgitation, which is often the case. Chance for thrombosis of the prosthetic tricuspid valve is higher because of the low flow velocity across it, being a right sided valve.