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Intramural dyssynchrony from acute right ventricular apical pacing in human subjects with normal left ventricular
Alan J Bank1, David S Schwartzman, Kevin V Burns
1St. Paul Heart Clinic, 225 N. Smith Ave, Suite 400, St. Paul, MN 55102, USA. abank@stphc.com
Journal of Cardiovascular Translational Research
|June 19, 2010
Summary
Right ventricular apical pacing impairs cardiac function and increases dyssynchrony in patients with normal left ventricular function. Pacing from the left ventricular free wall alone is a more optimal strategy for maintaining systolic function.
Area of Science:
- Cardiology
- Electrophysiology
- Cardiac Physiology
Background:
- Ventricular pacing can lead to inefficient myocardial contraction patterns.
- This inefficiency may negatively impact overall cardiac function.
Purpose of the Study:
- To evaluate the acute effects of right ventricular apical (RV(a)) pacing on left ventricular (LV) systolic function and intramural dyssynchrony.
- To compare these effects with pacing from alternate ventricular sites in patients with normal LV function.
Main Methods:
- Twenty-six patients with normal LV function underwent electrophysiology evaluation.
- Atrial pacing (AAI), RV(a) pacing, left ventricular free wall (LV(fw)) pacing, and biventricular (BiV) pacing were performed.
- Tissue Doppler imaging assessed intramural dyssynchrony using the cross-correlation synchrony index (CCSI).
Main Results:
- RV(a) and BiV pacing significantly reduced systolic function (SCA(long), VTI) compared to AAI and LV(fw) pacing.
- RV(a) and BiV pacing induced significant septal and lateral intramural dyssynchrony (lower CCSI) versus AAI.
- RV(a) pacing resulted in worse CCSI than LV(fw) pacing.
Conclusions:
- Acute RV(a) pacing, alone or with BiV, impairs regional and global LV systolic function in patients with normal LV function.
- RV(a) pacing causes significant intramural dyssynchrony compared to LV(fw) pacing.
- LV(fw) pacing appears to be a more favorable strategy for maintaining systolic function during ventricular pacing.
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