Surgery of Hypertrophic Obstructive Cardiomyopathy in Patients With Severe Hypertrophy, Myocardial Fibrosis, and Ventricular Tachycardia.

BACKGROUND: In patients with hypertrophic obstructive cardiomyopathy (HOCM) myocardial fibrosis is an independent predictor of adverse outcome. A new technique of HOCM surgical correction in patients with severe hypertrophy and septal myocardial fibrosis has been proposed.

METHODS: The excision of the asymmetrical hypertrophied area of the interventricular septum causing obstruction was performed from the conal part of the right ventricle corresponding to the zone of obstruction of the left ventricle (LV). The areas of septal myocardial fibrosis were removed corresponding to the zone of delayed enhancement imaging. Myocardial fibrosis was detected by cardiovascular magnetic resonance. Eleven patients with HOCM with severe hypertrophy, myocardial fibrosis, and episodes of ventricular tachycardia underwent this procedure. Five patients had biventricular obstruction. The follow-up period was 39 ± 9 months.

RESULTS: Ten patients were free of symptoms (New York Heart Association class I) and 1 patient had only mild limitations. The mean echocardiographic gradient in the LV decreased from 88.9 ± 10.0 to 9.7 ± 2.1 mm Hg, the mean value of gradient in the right ventricular outflow tract was reduced from 45.2 ± 4.7 to 3.8 ± 1.3 mm Hg. Echocardiographically determined septal thickness was reduced from 34.5 ± 3.8 to 15.5 ± 1.6 mm. Sinus rhythm without block of His bundle right branch was noted in all patients after the operation. Ventricular tachycardia was not registered.

CONCLUSIONS: The benefits of applying the technique include effective surgical treatment of patients with HOCM with severe hypertrophy and biventricular obstruction. It may be an appropriate choice for patients with HOCM with septal myocardial fibrosis.