Cardiac resynchronization therapy (CRT) is an effective treatment for dyssynchronous heart failure; however, 30–50% of patients fail to improve after implant. Endocardial left ventricular (LV) pacing is an alternative therapy for patients who do not respond to conventional CRT or in whom placement of a lead via the coronary sinus is not possible. It enables pacing at a wide variety of sites, without restrictions due to coronary sinus anatomy, and there is evidence of superior electrical resynchronization and hemodynamic response compared with conventional epicardial CRT. In this article, we discuss the potential advantages and disadvantages of endocardial LV pacing compared with conventional CRT, review the evidence for the delivery of endocardial LV pacing using both lead-based and leadless systems, and explore possible future directions of this novel technology.

心脏再同步化治疗（CRT）是治疗不同步性心力衰竭的有效方法；然而，30-50% 的患者在植入后未能改善。心内膜左心室 (LV) 起搏是对常规 CRT 无反应或无法通过冠状窦放置导线的患者的替代疗法。它可以在多种部位起搏，不受冠状窦解剖结构的限制，并且与传统的心外膜 CRT 相比，有证据表明其电再同步和血流动力学反应更好。在本文中，我们讨论了心内膜左室起搏与传统 CRT 相比的潜在优势和劣势，回顾了使用基于引线和无引线系统进行心内膜左室起搏的证据，