Peak Performance In Hypertrophic Cardiomyopathy

Abstract

<h3>Background</h3> Progressive symptoms with exertion despite optimal medical therapy is common among patient with hypertrophic obstructive cardiomyopathy (HOCM). However, little is known about the exercise tolerance in this subset of patients. <h3>Case Description</h3> A 55 year old Caucasian male with long standing history of HOCM was referred for progressively worsening NYHA Class 3b symptoms. He denied any syncope or significant family history of sudden cardiac death. Baseline echocardiogram revealed normal LV systolic function with severe asymmetric septal hypertrophy to 21 mm, resting LVOT gradient of 27 mmHg, and severe pulmonary hypertension with right ventricular systolic pressure (RVSP) of 72 mmHg. He subsequently underwent stress echocardiography with resting LVOT gradient of 63 mmHg which markedly worsened with exertion to peak gradient of 218 mmHg. (Image 1A) He exercised for a total of 7 minutes and 37 seconds. The test was stopped due to dyspnea and 10 mmHg drop in blood pressure. Subsequent right and left heart catheterization which showed angiographically normal coronary arteries and normal cardiac outputs. The peak to peak gradient measured across the aortic valve was 79 mmHg. (Image 1B) After discussion with the heart team, the decision was made to pursue septal myectomy. Intraoperative transesophageal echocardiography prior to septal myectomy showed severe LVOT obstruction with mean gradient of 45 mmHg and peak gradient of 89 mmHg with associated moderate eccentric mitral regurgitation secondary to systolic anterior motion. Following myectomy, the LVOT gradient improved to a mean of 2 mmHg and peak of 5 mmHg. Patient was successfully discharged home within 4 days following surgery. <h3>Conclusion</h3> In patients with long standing HOCM, elevated gradients up to 218 mmHg may be well tolerated without syncope or ventricular arrythmias. Septal myectomy can provide dramatic improvement of LVOT gradient and long-lasting symptomatic relief.