[Functional abnormality due to a deformation of the left ventricle: dynamic anatomy revealed using echocardiography]

A deformation of the left ventricular cavity is commonly observed in myocardial infarction, which directly influences the ventricular function. Even in cases without ischemia, a deformation of the left ventricle during systole or diastole is presumed to affect its function. Inward bending of the left ventricular posterobasal wall in giant left atrium is an example of the unfavourable effects of such a deformation. Systolic flattening of the left ventricle is atrial septal defect complicated by pulmonary hypertension is an example of the favourable influences by such a deformation. A regional wall motion abnormality observed in these cases is explained by the deformation attributed to the relationship between the left ventricle and left atrium or between the left and right ventricles. The relationship between the deformation and the function of the left ventricle in ventricular aneurysm can be explained well by the mode of blood turnover within the left ventricle. Contrast studies via the left atrium revealed that blood flow into the left ventricle did not reach the cardiac apex with an aneurysm, but immediately turned upwards towards the outflow tract. These results indicate that, although the left ventricle is anatomically a single cavity, it consists of functioning and non-functioning portions for blood turnover. A morphological abnormality of the left ventricle influences its function even without myocardial ischemia. It is necessary to relate all morphological changes of the left ventricle to cardiac function, regardless of the causes of a deformation.