Mitral Regurgitation in HOCM
A 47-year-old man with hypertension, hyperlipidemia, and hypertrophic obstructive cardiomyopathy (HOCM) treated with atenolol and verapamil to maximally tolerated doses reports worsening dyspnea on exertion. He has a history of mild-to-moderate mitral regurgitation (MR) with a resting left ventricular outflow tract (LVOT) peak gradient of 49 mmHg (Figure 1), provokable to 60 mmHg with exercise. On exam, his blood pressure is 125/80 mmHg with a resting heart rate of 53 bpm. He has a III/VI harsh mid-systolic murmur at the left lower sternal border and a II/VI mid-systolic murmur at the apex. Disopyramide therapy is aborted due to excessive QT prolongation. An echocardiogram demonstrates a septal thickness of 2.0 cm, a normal ejection fraction of 66%, and systolic anterior motion of the mitral leaflets with 4+ severe MR and 1+ mild aortic regurgitation (Figure 2, Videos 1-3). Cardiac magnetic resonance imaging confirms these findings along with severe left atrial enlargement and anterior displacement of the anterior papillary muscle (Figure 3, Video 4).
What should you recommend to this patient to best treat his MR?