Delivery of cardiac resynchronization therapy via the left inferior phrenic vein: A case report

Abstract

Background: The successful implantation of cardiac resynchronization therapy (CRT) may be prevented by anatomical variations that preclude the delivery of clinically effective left ventricular (LV) pacing from within the coronary sinus (CS) or its tributaries. Failure of lead delivery, suboptimal LV capture thresholds, or intractable phrenic nerve capture with accompanying diaphragmatic twitch is often encountered. Commonly employed alternative approaches to LV lead delivery, including epicardial, trans-septal, or transapical pacing are associated with significant morbidity. Case summary: A 74-year-old man with ischaemic heart disease, prior mitral valve repair, long-standing atrial fibrillation, and severe symptomatic LV systolic dysfunction, underwent single chamber pacemaker upgrade to a CRT defibrillator. It was found not to be possible to place a CS lead during the procedure. Biventricular pacing was accomplished by the delivery of a pacing lead through the left inferior phrenic vein (LIPV). Satisfactory LV capture thresholds were obtained with the avoidance of clinically significant diaphragmatic stimulation. Following implantation, a marked clinical response to treatment was observed with improvement in both heart failure symptoms and LV ejection fraction. Discussion: The LIPV is known to drain into the inferior vena cava in around one-third of examined subjects. In these individuals, LV lead delivery through the LIPV may provide an alternate route for the delivery of resynchronization therapy. This approach to the implantation of CRT may be considered when pacing via the CS or its branches are not achievable.