Contralateral transvenous left ventricular lead placement of implantable devices with pre-sternal tunnelling in chronically obstructed subclavian veins.

Cardiac resynchronisation therapy (CRT) is a recognised therapy for the management of severe left ventricular dysfunction, advanced congestive cardiac failure (NYHA III or IV), ventricular dyssynchrony (either broad LBBB or mechanical dyssynchrony on echocardiography) and failure of optimal medical therapy to achieve improvement in clinical status. Upgrading right ventricular pacemakers or defibrillators to biventricular devices is common and we describe here, 2 such cases of biventricular upgrade with blocked venous access on the ipsilateral side and successful placement of left ventricular leads following pre-sternal tunnelling from the contralateral side.