This review summarizes the evolution of cardiac resynchronization therapy and emerging conduction system pacing modalities for heart failure, highlighting the need for future randomized trials.
This review summarizes the evolution of cardiac resynchronization therapy and highlights conduction system pacing as a promising emerging technique requiring further randomized trial evaluation.
Cardiac resynchronization therapy (CRT) was proposed in the 1990s as a new therapy for patients with heart failure and wide QRS with depressed left ventricular ejection fraction despite optimal medical treatment. This review is aimed first to describe the rationale and the physiologic effects of CRT. The journey of the landmark randomized trials leading to the adoption of CRT in the guidelines since 2005 is also reported showing the high level of evidence for CRT. Different alternative pacing modalities of CRT to conventional left ventricular pacing through the coronary sinus have been proposed to increase the response rate to CRT such as multisite pacing and endocardial pacing. A new emerging alternative technique to conventional biventricular pacing, conduction system pacing (CSP), is a promising therapy. The different modalities of CSP are described (Hirs pacing and left bundle branch area pacing). This new technique has to be evaluated in clinical randomized trials before implementation in the guidelines with a high level of evidence.
Ellenbogen et al. (Tue,) conducted a review in Heart failure with wide QRS and depressed left ventricular ejection fraction. Cardiac resynchronization therapy (CRT) and conduction system pacing (CSP) was evaluated. This review summarizes the evolution of cardiac resynchronization therapy and emerging conduction system pacing modalities for heart failure, highlighting the need for future randomized trials.