Author + information
- Received September 28, 2004
- Revision received January 26, 2005
- Accepted February 1, 2005
- Published online December 20, 2005.
- Berry M. van Gelder, PhD⁎ (, )
- Frank A. Bracke, MD, PhD,
- Albert Meijer, MD, PhD and
- Nico H.J. Pijls, MD, PhD
- ↵⁎Reprint requests and correspondence:
Dr. Berry M. van Gelder, Department of Cardiology, Catharina Hospital, Michelangelolaan 2, 5623 EJ Eindhoven, the Netherlands
Objectives We sought to investigate the effect of intrinsic conduction over the right bundle on the maximum rate of left ventricular pressure rise (LVdP/dtmax) during left ventricular (LV) pacing compared to biventricular (BiV) pacing.
Background Simultaneous BiV pacing and LV pacing both improve LV function in patients with heart failure and LV asynchrony. We studied the hemodynamic effect of intrinsic conduction leading to ventricular fusion during LV pacing.
Methods In 34 patients with New York Heart Association functional class III or IV, sinus rhythm with normal atrioventricular (AV) conduction, left bundle branch block, QRS >130 ms, and optimal medical therapy, LVdP/dtmaxwas measured invasively during LV and simultaneous BiV pacing. The AV interval was varied in four steps starting (AV1) with an AV interval 40 ms shorter than the intrinsic PQ time and decreased with 25% for each step.
Results At AV1, LVdP/dtmaxwas 996 ± 194 mm Hg/s for LV pacing and 960 ± 200 mm Hg/s for BiV pacing (p = 0.0009), with all patients showing ventricular fusion during LV pacing. At AV2, 21 patients had ventricular fusion with a LVdP/dtmaxof 983 ± 213 mm Hg/s and 957 ± 202 mm Hg/s for LV and BiV pacing, respectively. In the remaining 13 patients without fusion these values were 919 ± 164 mm Hg/s and 957 ± 174 mm Hg/s, respectively. The difference between LV and BiV at AV2 is significantly higher when fusion is present (p = 0.01).
Conclusions The LVdP/dtmaxis higher in LV than in BiV pacing provided that LV pacing is associated with ventricular fusion caused by intrinsic activation.
- Received September 28, 2004.
- Revision received January 26, 2005.
- Accepted February 1, 2005.
- American College of Cardiology Foundation