Comparison of chronic biventricular pacing between epicardial and endocardial left ventricular stimulation using Doppler tissue imaging in patients with heart failure

In patients Vith a wide QRS, drug-resistant heart failure, and a coronary s inus that is unsuitable for transvenous biventricular pacing (BVP), a trans septal approach from the right to left atrium can allow endocardial left ve ntricular (LV) pacing (with permanent anticoagulant therapy) instead of epi cardial pacing via the coronary sinus branches. We sought to compare the ef fects of endocardial pacing with those of epicardial LV pacing on regional LV electromechanical delay (EMD) and contractility. Twenty-three patients ( 68 +/- 8 years) with severe heart failure and QRS greater than or equal to 130 ms received a pacemaker for BVP. Fifteen patients underwent epicardial LV pacing, and 8 underwent endocardial LV pacing because of an unsuitable c oronary sinus. All LV leads were placed at the anterolateral LV wall. Six m onths after implant, echocardiography and Doppler tissue imaging were perfo rmed. LV wall velocities and regional EMDs (time interval between the onset of the QRS and local ventricular systolic motion) were calculated for the 4 LV walls and compared for each patient between right ventricular (RV) and BVP. The amplitude of regional LV contractility was also assessed. Epicard ial BVP reduced the septal wall EMD by 11% versus RV pacing (p = 0.05) and the lateral wall EMD by 41% versus PV pacing (p <0.01). With endocardial BV P, the septal and lateral EMDs were 21.3% and 54%, respectively (p <0.01, c ompared with epicardial BVP). The mitral time-velocity integral increased b y 40% with endocardial BVP versus 2% with epicardial BVP (p <0.01). The amp litude of the lateral LV wall systolic motion increased by 14% with epicard ial BVP versus 31% with endocardial BVP (p = 0.01). This resulted in a LV s horterning fraction increase of 25% in patients with endocardial BVP (p = 0 .05). However, all patients were clinically improved at the end of followup . Thus, in heart failure patients with BVP, endocardial BVP provides more h omogenous intraventricular resynchronization than epicardial BVP and is ass ociated with better LV filling and systolic performance. (C) 2001 by Excerp ta Medica, Inc.