Cardiac Resynchronization Therapy

Congestive heart failure (HF) continues to be a major source of morbidity, mortality, and healthcare spending in society. In the past 20 years, device-based therapies such as implantable cardiac defibrillators (ICDs), cardiac resynchronization therapy (CRT), and left ventricular assist devices have been developed and demonstrated to improve outcomes in patients with CHF and/or systolic dysfunction. These therapies treat two of the major causes of death associated with CHF, namely, sudden cardiac death and pump failure. This chapter focuses on the application of CRT to HF treatment, with a focus on the therapeutic mechanisms, historical development, evolution of the technology, implant techniques and patient follow-up, clinical trials, evolving indications, approaches for optimizing therapy, and future directions including physiologic pacing.