Trade-off between elimination of premature ventricular complexes and loss of synchronized left ventricular pacing improved cardiac function in a patient with heart failure.

Synchronized left ventricular pacing (sLVP) via adaptive cardiac resynchronization therapy (aCRT) algorithm might enhance the efficacy of CRT. A 71-year-old female was admitted with the diagnosis of heart failure. Electrocardiograms revealed left bundle branch block with QRS width of 144 ms, and frequent premature ventricular complexes (PVCs). A CRT device was implanted, and sLVP via a CRT algorithm was provided. Frequent PVCs arising from the His-bundle suppressed effective sLVP percentage. Radiofrequency application at the His-bundle successfully eliminated the PVCs, but induced complete atrioventricular (AV) block, leading to loss of sLVP. These procedures remarkably improved the patient's cardiac function, suggesting the advantage of PVC elimination overweighed the disadvantage of loss of sLVP.