Purpose: To assess right and left ventricular function during RV apical stimulation.
Methods: We included 53 consecutive patients. LV and RV function were assessed with 2D echocardiography, TDI and STE. The patients were divided according to the percentage of cumulative ventricular pacing <40% (Group 1) n=20 (38%) or >40% (Group 2) n = 33 (62%).
Results. After a mean follow-up of 8 months in Group 1 patients there was decline in GLS-RV -22.00% to -18.58% (p = .009) and RVFWS -21.66% to -19.11% (p = .034) but no significant change in GLS LV and LVEF. In Group 2 we observed significant decline in GLS LV strain -20.37% to -17.49% (p = .027), GLS-RV -20.01% to -18.34% (p = .048) and RVFWS -22.73% to -19.04% (p = .049), without worsening of LVEF (p=.104). In Group1 the ratio of E/e`m increased from 10.68 to 14.31 (p=.002) and in Group2 increased from 13.5 to 16.6 (p=.014), without significant increase of the RV filling pressures. There was a significant decline in TAPSE (21.65mm to 19.12mm, p=.001) and S` (17.88cm/s to 12.33cm/s, p=.007) in patients from Group 1. The results in Group 2 were similar. We found significant decrease in TAPSE (21.7mm to 19.5mm, p=.004) and S` (13.6cm/s to 12.1cm/s, p=.029). There was no significant correlation between parameters at baseline and follow-up in Group 1 except for a negative correlation between LVEF and GLS LV in Group 2 patients (r=-.767; p=.000).
Conclusion: Permanent pacing caused subclinical worsening of LV and RV function during 8 months of follow-up.