Surgical Treatment of the Patients With Restrictive Phenotype of the Hypertrophic Cardiomyopathy Without LVOT Obstruction

Hypertrophic cardiomyopathy - is an inherited disease characterized by pronounced genetic and phenotypic heterogeneity. There are two most common anatomic variants of cardiac hypertrophy: subaortic and submitral phenotypes. Subaortic phenotype is characterized by hypertrophy of the basal parts of the heart, mainly in the interventricular septum (IVS), manifesting by a high pressure gradient in the LVOT. Submitral phenotype is characterized by localization of hypertrophic zone downward to the apex and apical phenotype is without a pressure gradient in the LVOT.

The morphology, nature of hemodynamic abnormalities not well studied in patients with apical phenotype of HCM, and surgical treatment are controversial, and for those patients with advanced stage of the HF the orthotopic heart transplantations (HTx) is usually considered.

One of the surgical techniques available for this category of patients is apical myectomy. The main goal of this intervention is increasing the left ventricular volume and improving of the LV compliance with an increase of the diastolic relaxation. Limited data of such procedures in HCM patients were already published but it still requires further investigation on larger cohort of patients.

In this study, the investigators hypothesize that along with left ventricular septal hypertrophy, a small cavity is formed in patients with submittal-apical phenotype due to an increased number of hypertrophied papillary muscles. They are displaced to the apex and tightly fixed both among themselves and to the left ventricular walls. This causes a significant reduction in diastolic volume and left ventricular relaxation capacity. The present study will analyze the experience of performing resection of hypertrophied trabeculae and mobilization of papillary muscles performed through the aorta. Throw this approach procedure can be done without the need for traumatic access and suturing in the apex of the left ventricle.