CCI Registered Cardiovascular Invasive Specialist (RCIS) Practice Exam

In CRT, the left ventricular pacing lead is placed through the coronary venous system. After gaining venous access (often via the subclavian or axillary vein), the lead is advanced into the coronary sinus and then into a lateral or posterolateral vein of the left ventricle. The coronary sinus is a large vein that runs in the posterior atrioventricular groove and drains into the right atrium, providing a direct route to epicardial LV veins for stable LV pacing. The other structures listed aren’t the path for the LV lead: the superior vena cava is part of the drainage pathway to reach the right atrium but isn’t the route into LV veins; the left subclavian vein is an access site, not the LV lead’s final path; the pulmonary veins are in the left atrium and have no role in LV pacing lead delivery.