It is known that right ventricular apical pacing can result in deterioration of left ventricular systolic function in the long run due to dyssynchrony of left ventricular contraction. The BLOCK-HF study  evaluated the role of biventricular pacing compared to RV pacing for those with AV block and left ventricular ejection fraction of 50% or less and in NYHA classes I to III. The study documented that the composite endpoint of death, heart failure-related urgent care, and adverse left ventricular remodeling were lower in biventricular pacing group compared to right ventricular pacing. This further translated into improved quality of life and heart failure status at one year. The study could be sufficient reason for recommending biventricular pacing in those with reduced left ventricular function and atrioventricular block with indication for permanent pacing.
- Curtis AB et al. Improvement in Clinical Outcomes With Biventricular Versus Right Ventricular Pacing. The BLOCK HF Study. Am Coll Cardiol. 2016;67(18):2148-2157.