Ventricular pacing is an accepted therapy for congenital complete atrioventricular block (CCAVB). Electromechanical dyssynchrony may play a role in the development of cardiomyopathy.
Objetive: To determine the effect of ventricular pacing in cardiac function and synchrony in paced patients with CCAVB.
Methods: We compared 25 patients with CCAVB with 30 healthy children with conventional echocardiography, TDI, TSI, strain, strain rate, maximal difference in 12 LV segments for Ts and Ts-SD.
Results: The median age at pacemaker implatation was 30 months with a median length of follow-up of 63 months. Our report compares findings between the paced and control groups. LV, RV and LA sizes were similar. A difference was not found in systolic and diastolic LV function. A significant difference was observed in tricuspid tissue Doppler : e’ 0.13 v/s 0.15 m/s ( p=0.021) , E/e’ 5.8 v/s 4.3 (p < 0.001) and s’ 0.08 v/s 0.12 m/s ( p<0.001). Maximal difference in 12 LV segments was 109 v/s 89m/s (p=0.004) for Ts and 36 v/s 30 m/s Ts-SD (p>0.05). Strain was similar in both groups. A significant difference (p<0.001) was found between septum and LV, septum and RV, and RV and LV when evaluating synchrony with TDI y TSI.
Conclusion: Conventional echocardiography did not find differences between groups. However, tissue Doppler demonstrated abnormalities in RV function and LV synchrony. These findings could play a role in the development of late cardiomyopathy. Doppler and strain rate imaging may become useful in the long term follow-up of CCAVB patients.