[Sigmoid shaped ventricular septum causing hemodynamic deterioration during lumbar anesthesia: a case report].

: A 73-year-old woman with a left femoral neck fracture underwent an operation for femoral caput replacement. Twenty-five minutes after induction of spinal anesthesia, ST depression emerged followed by shock. Although the ST depression indicated an ischemic event, Levine grade IV systolic murmur was noticed at the aortic valve area. Echocardiography revealed narrowing of the left ventricular outflow tract with a pressure gradient of 170 mmHg. Rapid fluid infusion (1,000 ml) stabilized her blood pressure and the patient recovered without adverse sequelae. Echocardiography and magnetic resonance imaging suggested the presence of sigmoid shaped ventricular septum rather than obstructive hypertrophic cardiomyopathy. There was no significant pressure gradient at rest. Sigmoid shaped ventricular septum is usually considered as a normal aging process and has little clinical importance, but several cases associated with outflow obstruction have been reported. As the patient had no abnormal findings on electrocardiography or chest radiography and had no abnormal symptom on physical examination, the sequelae were impossible to predict.