Abstract

ABSTRACT:
BACKGROUND:
Right ventricular apical pacing is associated with alterations of left ventricular contraction sequence and dilatation and may have a deleterious effect on left ventricular function.
OBJECTIVE:
The study investigates the correlation between left ventricular function and long term right ventricular pacing.
METHODS:
In this study, 80 patients with permanent right ventricular apical pacing (VDD and DDD) randomized to assess left ventricular systolic function particularly LVEF% .primary end point was LVEF% after 1 year of pacing.
RESULTS:
In this study, the mean LVEF% was reduced after 1year of right ventricular pacing from (67.47±2.94 to 55.89±8.41, p value 0.0001), with absolute reduction of about 12%.
Patients with LV systolic dysfunction (EF% less than or equal to 45%) which constitute 10 patients (12.5%) have mean baseline LVEF% (66.70±4.03 reduced to 37.50±6.38, P value 0.0001). Cumulative percentage of RV pacing and duration are predictors of LVEF% reduction.
CONCLUSION:
Conventional right ventricular apical pacing resulted in a significant reduction in the left ventricular ejection fraction, particularly in patients with high percentage of right ventricular pacing and should be suspected in any patients after long term pacing of right ventricular. Functional rather than topographic criterion should be considered for optimal pacing.