Advances in Devices for Cardiac Resynchronization in Heart Failure

Patients with advanced heart failure have a high mortality and morbidity despite medical therapy. Depending on the underlying heart disease and severity of heart failure, 3.7 to 52.8% of patients have a QRS complex ≥120 ms who may have interventricular and intraventricular dyssynchrony correctible by cardiac resynchronization therapy (CRT). The latter is usually achieved with biventiricular pacing, with the left ventricular lead placed in a tributary of the coronary sinus (CS), with a reported success rate between 88–92%. The technical advances for implantation include preformed guide sheaths to canulate the CS, over the wire leads with passive fixation mechanism, and surgical placement methods.