MYH7 Rare Variant in a Family With Double-Chambered Left Ventricle.

Abstract

An 11-year-old boy was admitted to hospital with symptoms of nausea, edema, fatigability, and inability to lie down, which slowly developed over the past 4 months. Transthoracic echocardiography and an ECG were performed and showed the diagnosis of double-chambered left ventricle (DCLV). A physical examination showed protrusion of the precordium, soft heart sounds, cardiomegaly, a grade 3/6 systolic murmur at the cardiac apex, and enlargement of the liver to 3 cm below the right costal margin. ECG showed a sinus rhythm with left ventricular hypertrophy. Transthoracic echocardiography demonstrated that the left ventricle was divided into basal and apical chambers by an incomplete fibromuscular septum (Figure 1A). The basal chamber, which communicated with the left atrium and the normally positioned aorta, was severely enlarged with an end-diastolic diameter of 80.7 mm. This chamber was abnormally configured to the shape of a ball. The basal and midventricular septum expanded toward the right ventricle. The left ventricular wall and septum had impaired contraction with severe reduction of the left ventricular ejection fraction to 35%. Systolic pressure of the 2 chambers was similar, and the diameter of communication between them was 16.0 mm. There was thinning of the wall of the apical chamber. A DCLV was also shown by cardiac magnetic resonance imaging (Figure 1B). The patient’s ECG showed sinus rhythm, T-wave changes, and enlargement of the left ventricle and left atrium (Figure 1C). Figure 1. Clinical feathers of the DCLV proband. A , Apical 4-chamber view of transthoracic echocardiography of the proband. B , Cardiac magnetic resonance imaging shows the diagnosis. C , ECG result of the proband. white arrow, fibromuscular septum. LA indicates left atrium; LV1, basal chamber of the left ventricle; LV2, apical chamber of the left ventricle; RA, right atrium; …