A 56-year-old man presented with anasarca, severe groin and sacral hidadenitis in the setting of a known tricuspid valve anomaly, a 2-year history of permanent atrial fibrillation, iron-deficiency anemia, and benign hypertrophy of the prostate. His current medications included digoxin 250 μg once daily, ferrous sulfate 325 mg once daily, torsemide 40 mg once daily, thyroxine 100 μg once daily, tamsulosin 0.4 mg once daily, and warfarin (intended to achieve an international normalized ratio [INR] of between 2 and 3, with regular testing). His physical examination was remarkable for anasarca and bilateral crepitations. His initial laboratory results revealed microcytic anemia with hemoglobin of 9.7 g/dL, bilirubin of 2.5 mg/dL, aspartate aminotransferase of 65 U/L, and an INR of 2.7.
Transthoracic echocardiography revealed severe right atrial dilation associated with a diastolic tricuspid gradient that originated at the level of a large muscle bundle just beneath the tricuspid valve (mean gradient, 8 mmHg). The tricuspid valve displayed normal leaflet motion, but there was mild tricuspid regurgitation ().
Fig. 1 Transthoracic echocardiogram (modified apical view) shows a massively dilated right atrium. Also visible is a muscular shelf at the right ventricular inflow tract, distal to the septal leaflet of the tricuspid valve.
Fig. 2 Transthoracic color-flow Doppler interrogation from a window similar to that in shows Doppler artifact at the level of the vena contracta (that is, at the narrow orifice below the muscular shelf).
Fig. 3 Continuous-wave Doppler shows a diastolic right ventricular inflow gradient.
Cardiac catheterization revealed normal coronary arteries. The right-sided heart study showed a central venous pressure of 20 mmHg with a large V wave of 22 mmHg, a right ventricular pressure of 28/8 mmHg, and a pulmonary artery pressure of 28/18 mmHg. The pulmonary capillary wedge pressure was 11 mmHg with a pulmonary vascular resistance of 144 (dyne · sec)/cm5. The mean tricuspid valve gradient was 8.89 mmHg ().
Fig. 4 Simultaneous recording of right ventricular and right atrial pressures shows the presence of a right ventricular inflow gradient (shaded area).
Magnetic resonance imaging confirmed subvalvular tricuspid stenosis and insufficiency, with a hypoplastic but normally contracting RV.
The patient was taken to the operating room for definitive surgical treatment. At operation, the right atrium was seen to be massively dilated and the RV to be small with normal contractility. The tricuspid valve was stenotic: the septal and anterior leaflets were mobile, but the posterior leaflet was fused to the subvalvular structures. There was a large band of muscle beneath the anterior and posterior leaflets, extending 3 cm into the RV cavity and causing severe inflow obstruction ().
Fig. 5 Intraoperative photograph shows a large band of muscle beneath the anterior and posterior leaflets, which had been causing severe right ventricular inflow obstruction.
A complete left- and right-sided bipolar radiofrequency maze procedure was performed, and the left atrial appendage was transected and oversewn. The muscle band beneath the tricuspid annulus was found to be heavily calcified and to encase the undersurface of the valve. The inflow obstruction was completely resected, and the valve was replaced with a 29-mm porcine bio-prosthesis ().
Fig. 6 Intraoperative photograph shows completed tricuspid valve replacement with a 29-mm porcine bioprosthesis. The inflow obstruction was completely resected.
Postoperatively, the patient remained in sinus rhythm. When a follow-up echocardiogram was performed after surgery, the mean gradient observed across the tricuspid valve was 2 mmHg.