Doppler Echocardiography-Guided Heart Rate Modulation Therapy Using Ivabradine in a Patient with Systolic Heart Failure.

Heart rate reduction using ivabradine, a selective I channel blocker that purely decreases heart rate without affecting hemodynamics, improves clinical outcomes in patients with systolic heart failure. However, the ideal heart rate that should be a target remains unknown. Our team recently proposed a methodology using Doppler echocardiography to estimate ideal heart rate, at which E-wave and A-wave stand adjacent without overlap. However, the implication of Doppler echocardiography-guided heart rate modulation therapy using ivabradine remains uncertain. We had a 72-year-old man with systolic heart failure and sinus tachycardia who initiated ivabradine therapy. Ivabradine dose was adjusted between 5.0 mg/day and 10.0 mg/day and continued for 12 weeks to minimize the overlap between the two echocardiography waves, accompanying improvement in cardiac output, left ventricular ejection fraction, plasma B-type natriuretic peptide, and six-minute walk distance. Doppler echocardiography-guided heart rate regulation therapy using ivabradine may be a promising strategy to improve cardiac function and clinical outcomes in patients with systolic heart failure, although further studies are required to validate this hypothesis.