What are typical echocardiographic features of hypertrophic cardiomyopathy?

Hypertrophic cardiomyopathy (HCM) is characterized by the abnormal thickening of the heart muscle, particularly affecting the ventricular septum and the left ventricular walls. The hallmark echocardiographic feature of HCM is asymmetric ventricular septal hypertrophy, where the septal wall becomes significantly thicker than other walls of the heart. This asymmetrical thickening can lead to a dynamic outflow tract obstruction, particularly during systole, when the thickened septum impinges on the left ventricular outflow tract (LVOT), causing a narrowing that can lead to symptoms of obstruction such as dyspnea or syncope.

In contrast, thinning of the ventricular walls and uniform thickening of all heart chambers are not features of HCM. Instead, thinning of the walls is more typically seen in conditions like dilated cardiomyopathy. Bilateral ventricular dilation is also not characteristic of HCM, as it typically presents with preserved or increased ventricular wall thickness without global dilation. Therefore, the presence of asymmetric septal hypertrophy and the potential for dynamic left ventricular outflow tract obstruction accurately reflects the key echocardiographic features of hypertrophic cardiomyopathy.