Effects of chronic Right Ventricular Apical Pacing (RVAP) on Left Ventricular function with a normal baseline Left Ventricular function a descriptive study

Author(s):

J V Balasubramaniyan , R H Lakshmi , J S Satyanarayana Murthy

Background: A common treatment option for cardiac rhythm abnormalities like sick sinus syndrome or atrioventricular block is ventricular pacing over the Right Ventricular (RV) Apex. Though several sites have come recently for ventricular pacing, RV apical pacing still holds the gold standard especially in patients with heart failure and atrial fibrillation. Limited studies exist on the long-term effects on cardiac outcome parameters following RV apical pacing. Aim: Asses the effects of long-term RV Apical Pacing on Left Ventricular (LV) function in patients with baseline normal LV Function. Materials and Methods: A descriptive study involving 51 study participants on RV apical pacing selected randomly from among those registered at the Cardiology Clinic, Chennai, India between 2009 to 2019. LV function was assessed by 2-D echocardiography at the time of pacemaker implantation and during follow-up. Only those patients with ventricular pacing of more than 90% from the time of implantation were included. Echocardiographic assessment of LV systolic and diastolic function, LV dimensions and severity of mitral regurgitation at the time of pacemaker implantation and subsequent follow-up was done for all patients. Statistical analysis was done using Statistical Package for Social Sciences ver 16.0. Results: Complete Heart Block was the most common (74.5%) indication for pacemaker implantation in the study population. Amongst the various pacing modes employed, VVI was the most common amounting to 52.94% followed by VVD in 31.3%. There was a significant change in Left Ventricular End systolic diameter (ESD) and End diastolic diameter (EDD) before and after pacing reflecting a change in LV dimensions following RV apical pacing (> 90%) for the given indications. Conclusions: RV apical pacing will not cause adverse effects in all the patients. The amount of LV dyssynchrony depends on LV function at baseline and accompanying conduction disease at baseline. Though changes in LV dimensions were noted, LV dysfunction was not commonly noted in our patients undergoing RV apical pacing.