Background: Much information is available regarding the possible negative effects of long-term right ventricular (RV) apical pacing, which may cause worsening of heart failure. However, very limited data are available regarding the effects of RV pacing in patients with a previous myocardial infarction (MI).
Methods and results: We screened 115 consecutive post-MI patients and matched a group of 29 pacemaker (PM) recipients with a group of 49 unpaced patients, for age, left ventricular (LV) ejection fraction, and site of MI. During a median follow-up of 54 months, echocardiograms showed a decrease in LV ejection fraction in the paced group, from 51 +/- 10 to 39 +/- 11 (P < 0.01), and a minimal change in the unpaced group, from 57 +/- 8 to 56 +/- 7 (P = 0.98). Similar change was observed in systolic and diastolic diameters and volumes.
Conclusions: The study showed that, in post-MI patients, RV apical pacing was associated with a worsening of LV function, suggesting that, among MI survivors, the need for a PM is a marker of worse outcome.