Cited 22 times since 2009 (1.5 per year) source: EuropePMC American heart journal, Volume 158, Issue 5, 1 1 2009, Pages 769-776 Cardiac resynchronization therapy in patients with ischemic versus non-ischemic heart failure: Differential effect of optimizing interventricular pacing interval. Marsan NA, Bleeker GB, Van Bommel RJ, Borleffs C, Bertini M, Holman ER, van der Wall EE, Schalij MJ, Bax JJ
Background
Whether sequential biventricular pacing provides substantial benefits over conventional simultaneous stimulation remains unclear, particularly regarding the differences between ischemic and non-ischemic patients. The purpose of this study was to evaluate the acute effect of interventricular pacing interval (V-V) optimization on left ventricular (LV) systolic performance and dyssynchrony in ischemic versus non-ischemic patients.
Methods
Sixty-nine consecutive patients underwent cardiac resynchronization therapy. Within 3 days after implantation, V-V was optimized by measuring (every 20-millisecond interval) LV systolic performance (LV outflow-tract velocity-time-integral, LVOT VTI) and LV dyssynchrony (using tissue Doppler imaging). Optimal pacing configuration was the one achieving maximal increase in LVOT VTI.
Results
Optimized sequential pacing provided a significant improvement in LVOT VTI compared to simultaneous stimulation (from 138 +/- 42 to 163 +/- 38 mm, P < .001) and was associated with a significant reduction in LV dyssynchrony (from 33 +/- 31 to 19 +/- 24 milliseconds, P < .001). The increase in LVOT VTI and LV ejection fraction after implantation was greater in non-ischemic as compared to ischemic patients (P < .001). However, V-V optimization yielded a larger improvement in LV systolic performance in ischemic patients (P = .03). Consequently, the 2 groups showed comparable response after V-V optimization. A significant correlation was observed between LV scar tissue and optimal V-V interval (r = 0.58, P < .001), with a larger extent of scar related to a larger level of LV preactivation, probably reflecting slow intra-LV conduction.
Conclusions
Optimized sequential biventricular pacing further increased LV systolic performance as compared to simultaneous stimulation, particularly in ischemic patients where the presence of a large scar was correlated with a larger LV preactivation.
