Should stimulation site be tailored in the individual heart failure patient?

Right ventricular pacing at various sites and shortened atrioventricular (A V) delay has foiled to demonstrate a convincing short-term and long-term im provement of left ventricular function. Left-ventricular-based stimulation offers a new therapeutic option for patients with symptomatic congestive he art failure and conduction disturbances, especially of left bundle-branch b lock configuration. Left ventricular mechanical improvement seems mainly de pendent on the pacing site, in addition to optimizing the AV delay. Predomi nantly retrospective data suggest that pacing the posterolateral free wall results in the greatest hemodynamic improvement. Based on the evaluation of different pacing sites in 2 patients, we noted that site is of major impor tance for maximal improvement of left ventricular function, and pacing at a suboptimal site can even deteriorate left ventricular contractility. Moreo ver, lead technology has advanced rapidly and different areas of the left v entricle can now be reached transvenously for acute and chronic placement. Therefore, ongoing trials will help to identify the optimal pacing site and might indicate whether invasive testing will be required in the future. (C ) 2000 by Excerpta Medica, Inc.