Cardiac resynchronization therapy for patients with heart failure and nonspecific intraventricular conduction delay.

The efficacy of cardiac resynchronization therapy (CRT) in heart failure patients with left bundle branch block (LBBB) is well established with Class I or IIa recommendation according to 2021 ESC Guidelines on cardiac pacing and CRT, whereas non-LBBB morphology is less recommended. There is insufficient evidence that proves patients with NICD could benefit from CRT. As patients with NICD are characterized by heterogeneity, the effect of CRT on these patients is still controversial. Although the proportion of NICD in the population is lower than that of LBBB patients, it is still worth investigating the effects of CRT on patients with NICD in an era of His-Purkinje conduction system pacing (HPCSP).