Beneficial effect of ivabradine in dilated cardiomyopathy from Becker muscular dystrophy

The I(f) blocker ivabradine reduces heart rate and improves systolic function without causing arterial hypotension. Ivabradine has not been reported to improve cardiac involvement in Becker muscular dystrophy (BMD).

In a 22-year-old Vietnamese male with BMD, cardiac involvement became apparent at age 19 years with reduced systolic function, which was treated with ramipril. At the age of 20 years, he developed sinus tachycardia, leg edema, coughing, and arterial hypotension. Dilated cardiomyopathy was diagnosed and ramipril was successfully replaced by candesartan, ivabradine, and furosemide. An attempt to discontinue ivabradine and increase candesartan was followed by recurrence of sinus tachycardia and reduction of blood pressure. Under ivabradine, candesartan, and spironolactone, which replaced furosemide, he achieved heart rates between 60 and 80 beats/min and systolic blood pressure values between 85 and 105 mmHg without heart failure.

Ivabradine normalizes sinus tachycardia and resolves heart failure in patients with dilated cardiomyopathy from BMD. In addition to normalization of the heart rate and remodeling of the left ventricle, ivabradine seems to also have a positive inotropic effect in dilated cardiomyopathy of BMD patients.