Alternative left ventricular pacing approaches for optimal cardiac resynchronization therapy.

Cardiac resynchronization therapy (CRT) improves mortality, morbidity, and quality of life in selected heart failure patients with severe left ventricular (LV) ejection fraction impairment. However, between 20% and 40% of device recipients do not benefit clinically from CRT. Indeed, some anatomic and technical difficulties are related to the coronary venous implantation site via the coronary sinus (CS). Additionally, electrical constraints have been described, and CS does not always correspond to the optimal LV lead position. In the last decade, engineers and physicians have worked together to overcome the challenging LV lead implantation, and various biventricular pacing alternatives have been developed to improve CRT response. In this review, we discuss the evolution from CS pacing to wireless LV stimulation and His-bundle pacing.