The interventricular septum in health and disease.

The interventricular septum constitutes a major part of the heart and contributes to both left and right ventricular function. It is directly affected in certain disease states which can be diagnosed by echocardiographic examination of the septum. The septum also demonstrates characteristic patterns in cardiac conditions that do not directly affect it. These abnormal patterns have physiologic and diagnostic value. As a general rule, no matter what the diastolic configuration of the interventricular septum, it tries to assume its characteristic concave shape in systole. The significant exception is the presence of right ventricular pressure overload. The introduction of echocardiography has greatly increased our understanding of the interventricular septum in both health and disease.