Interventional approach to CRT in a patient with drainage of the superior vena cava into the coronary sinus.

A persistent left superior vena cava markedly increases the size of the coronary sinus (CS), which can increase the difficulty of left ventricular (LV) lead placement in patients receiving cardiac resynchronization therapy (CRT). We present a case where the entire superior vena cava drains into the coronary sinus, creating a massive CS. We also describe an interventional approach to LV lead implantation utilizing a combination of delivery systems from different vendors.