The Impact Of Different Left Ventricular Pacing Sites On Clinical Outcome Of Cardiac Resynchronization Therapy

ObjectiveTo explore the impact of different left ventricular (LV) lead pacing sites on clinical outcome of cardiac resynchronization therapy (CRT) or the device with defibrillator (CRT-D).MethodsThe location of the LV lead was assessed by means of coronary venograms in right and left anterior oblique views which were recorded at the time of device implantation in41patients of CRT with a pacemaker or a defibrillator from January2008to May2011in our study. The LV lead location was classified along the short axis into anterior (n=9), anterolateral (n=10), lateral (n=12), posterolateral (n=10), or posterior position(n=0) and along the long axis into a basal(n=15), midventricular (n=26), or apical region (n=0).All patients were evaluated at baseline,7days,3months,6months,12months,18months and24months after the implementation by such indices as left ventricular ejection fraction (LVEF), left ventricular end-diastolic dimension (LVEDD), New York Heart Association (NYHA) class,6min walking distance, quality of life (QOL), CRT parameters and the incidence rate of adverse events. Results①Improvement in LVEF, LVEDD, NYHA class,6min walking distance and QOL were found in all groups (P<0.05).②Improvement in LVEF, NYHA class,6min walking distance and QOL were significantly greater in non-anterior location than anterior location after a follow-up of3months (P<0.05). The extent of cardiac resynchronization therapy benefit was similar for leads in the anterolateral, lateral and posterolateral position (P<0.05).③The extent of cardiac resynchronization therapy benefit was similar for leads in the basal and midventricular position (P<0.05).④There were no presentation of abnormal CRT parameters, readmission of heart failure, lead dislocation, phrenic nerve stimulation, CRT associated infection and other events.Conclusions①Cardiac resynchronization therapy recipients are profiting by two years’follow-up.②LV lead was difficult to place in the apical and posterior position.③LV lead placed in anterolateral, lateral or posterolateral position is more preferential for achieving optimal CRT benefit than ones placed in the anterior position. And the benefit from CRT was similar for LV leads positioned along the anterolateral, lateral or posterolateral wall and for lead position along the basal and midventricular wall.