Metal through metal: pacing lead across a mechanical tricuspid valve
A 41-year-old man with triple mechanical valve replacement due to rheumatic heart disease (ball-in-cage aortic and bileaflet mitral and tricuspid prostheses) required pacemaker implantation for symptomatic complete atrioventricular block. A transvenous pacing lead was erroneously inserted, at another institution, across the mechanical tricuspid valve (MTV) into the right ventricle. Six months later a routine echocardiogram showed that the tricuspid disc pertaining to the orifice through which the lead crosses was immobile in a semi-open position, with evidence of obstruction to flow and tricuspid regurgitation (Fig. 1). The patient was asymptomatic and the international normalized ratio was subtherapeutic at 1.5. He was treated with intravenous streptokinase for suspicion of MTV thrombosis.1 This led to resumption of disc mobility, but still the lead prevented full disc closure. He refused any interventions including lead extraction.
Insertion of leads across mechanical valves is contraindicated due to risk of prosthesis malfunction and/or thrombosis. Options for pacing in patients with MTV include surgically implanted epicardial leads or transvenously inserted leads through the coronary sinus.