Cardiac resynchronization therapy reduces morbidity and mortality in patients with NYHA class III/IV heart failure, reduced ejection fraction, and electrical dyssynchrony.
Does cardiac resynchronization therapy (CRT-P or CRT-D) reduce morbidity and mortality in patients with symptomatic heart failure, reduced LVEF, and electrical dyssynchrony?
CRT is an established and effective therapy for symptomatic heart failure with reduced LVEF and wide QRS, but further evidence is needed to refine patient selection (e.g., narrow QRS, atrial fibrillation) and clarify the incremental benefit of adding defibrillator therapy.
Cardiac resynchronization therapy (CRT) is recommended to reduce morbidity and mortality in patients with New York Heart Association class III/IV, who are symptomatic despite optimal medical therapy, and who had a reduced left ventricle (LV) ejection fraction and electrical dyssynchrony. The effects of CRT are reflected mainly by the degree and location of dyssynchrony and by working in insertion of optimal LV lead site. Echocardiography and Doppler echocardiography are considered to be good tools to measure LV dyssynchrony directly. However, the large randomized trials have shown that no single echocardiographic measure of dyssynchrony is recommended to improve patient selection for CRT beyond current guidelines. There were several unsolved issues on CRT, such as patient selection, electrical or electromechanical dyssynchrony criteria to patients for CRT, indication of patients with a narrow or slightly prolonged QRS width, indication of patients with atrial fibrillation, and indication of patients with mild heart failure or asymptomatic LV dysfunction, and device selection; CRT alone (CRT-P) or CRT in combination with implantable cardioverter therapy (CRT-D). This review paper summarized the concept of therapy, the current evidence regarding the indications, effectiveness and safety of CRT-P and CRT-D in patients with LV dysfunction, and unsolved issues.
Akihiko Shimizu (2009) conducted a review in Heart failure with left ventricular systolic dysfunction. Cardiac resynchronization therapy (CRT-P and CRT-D) vs. Optimal medical therapy was evaluated. Cardiac resynchronization therapy reduces morbidity and mortality in patients with NYHA class III/IV heart failure, reduced ejection fraction, and electrical dyssynchrony.