Dynamic tricuspid valve stenosis induced with a pacemaker lead: a case report.

Isolated severe tricuspid valve stenosis due to an endocardial pacemaker lead is extremely rare, and is usually caused by either fibrosis of a perforated or lacerated leaflet, or fibrotic adherence between the lead and the valvular apparatus. Reported cases typically include clinical manifestations of both systemic venous stasis and low cardiac output. The case is presented of a 20-year-old female with a surgically repaired congenital heart disease who developed severe tricuspid stenosis at six years after the implantation of a DDD pacemaker. Unexpectedly, the patient had no signs of venous stasis and suffered only from exercise intolerance. Right heart catheterization under fluoroscopic guidance revealed an atrial lead forming a loop at the level of the tricuspid valve. A paradoxical inspiratory decrease in the transvalvular diastolic gradient, caused by the caudal heart motion and straightening of the loop during inspiration, was noted. Such a dynamic nature with a temporary inspiratory relief of the obstruction may explain the partial clinical presentation of tricuspid stenosis in this case. The lead was removed and the tricuspid valve repaired surgically, after which the patient's recovery was uneventful with normalization of exercise tolerance.