Fragmented QRS and Ventricular Dyssynchrony in a Patient Treated with Cardiac Resynchronization Therapy

Cardiac resynchronization is an established treatment modality in patients with heart failure NYHA class III-IV on optimal medical treatment, QRS duration of at least 120-130 ms and ejection fraction <35%. Nevertheless, a proportion of patients, up to 20-30%, are considered non-responders as they are not improved by cardiac resynchronization therapy (CRT). This report describes a 63-year-old patient with ischemic cardiomyopathy, severe mitral regurgitation, and fragmented QRS complex in several leads. The patient had LV dyssynchrony identified by echocardiographic tissue Doppler imaging. A biventricular pacemaker was implanted successfully, and resulted in improvement in LV dyssynchrony, LV dimensions, mitral regurgitation and symptoms. Fragmented QRS complex as a marker of ventricular dyssynchrony may play a role in identifying patients who may benefit from cardiac resynchronization therapy.