2021 Volume 70 Issue 4 Pages 803-809
The sigmoid-shaped interventricular septum is the sigmoid-shaped basal septum protruding into the LV cavity. The AS angle (aortoseptal angle: the angle between the anterior aortic wall and the interventricular septum) in patients with the sigmoid-shaped interventricular septum is smaller than that in normal subjects. The causes of the sigmoid-shaped interventricular septum are aging and left ventricular outflow tract obstruction (LVOTO), which is rare. We report the case of a patient with the sigmoid-shaped interventricular septum with LVOTO and exertional dyspnea. In this patient, cibenzoline administration improved LVOTO markedly. In our 370 consecutive patients, six (1.6%) showed significant pressure gradients (PG) > 30 mmHg. Patients with PG > 30 mmHg showed significant narrowing of LVOT. Echocardiographic examination including Valsava maneuver is useful for symptomatic patients with LVOT and narrowing of the sigmoid-shaped interventricular septum.
