EVALUATION OF DIFFERENT VENTRICULAR PACING SITES IN PATIENTS WITH SEVERE HEART-FAILURE - RESULTS OF AN ACUTE HEMODYNAMIC-STUDY

Background Multisite ventricular pacing has recently been proposed as an additional treatment for patients with severe congestive heart fail ure. To further assess the potential value of this technique, we compa red the acute hemodynamic changes associated with pacing the right ven tricular apex (RVA) or outflow tract (RVOT) alone, the left ventricle (LV) alone, or biventricular (BIV) pacing of the RVA and LV together. Methods and Results Acute hemodynamic findings were measured in 27 pat ients with severe heart failure despite optimal therapy and either fir st-degree AV block and/or an intraventricular conduction defect. In th e 23 patients with a high pulmonary capillary wedge pressure (PCWP) (> 15 mm Hg), data were collected after transvenous pacing at different ventricular sites in either the VDD mode (AV delay = 100 ms) or the VV I mode in patients with atrial fibrillation (n = 6). The mean baseline cardiac index was 1.82 L.min(-1).m(-2). Mean +/- SD baseline systolic blood pressure (SEP) (118.5 +/- 15.2 mm Hg), PCWP (26.4 +/- 6.6 mm Hg ), and V-wave amplitude (39.1 +/- 14.6 mm Hg) were similar before and after either RVA or RVOT pacing. In contrast, LV-based pacing (either LV alone or BIV pacing) resulted in higher SEP (P < .03) and lower PCW P (P < .01) and V-wave amplitude (P < .001) than either baseline or RV pacing measurements. With LV pacing alone, SEP, PCWP, and V waves wer e 126.5 +/- 15.1, 20.7 +/- 5.9, and 25.5 +/- 8.1 mm Hg, respectively. The results with LV pacing alone were similar to those obtained with B IV pacing. Conclusions In patients with severe congestive heart failur e, both LV pacing alone and BIV pacing resulted in a similar and signi ficant acute improvement in SEP, PCWP, and V-wave amplitude compared w ith baseline measurements and RV pacing alone. These results provide a strong basis for initiating long-term studies examining the chronic e ffects of LV-based pacing in patients with medically refractory conges tive heart failure.