A new syndrome in hypovolemic shock: Systolic murmur and intraventricular pressure gradient

Abstract

A grade 5 6 systolic murmur appeared in a patient with severe shock produced by gram-negative bacteremia. Cardiac catheterization demonstrated a systolic pressure difference of 70 mm. Hg between the left ventricle and the aorta. “Infundibular” pressure was recorded while the catheter was withdrawn from the left ventricle into the aorta. Left ventricular systolic pressure increased, and arterial systolic pressure fell in postextrasystolic beats. Immediately after the administration of propranolol, blood and phenylephrine, the systolic pressure difference between the left ventricle and the aorta and the systolic murmur disappeared. Autopsy revealed a normal heart. We believe this is the first reported case with clinical and hemodynamic evidence of an intracavitary left ventricular systolic pressure difference in a man with shock and without severe left ventricular hypertrophy. The sudden occurrence of a loud murmur when left ventricular systolic pressure greatly exceeded aortic systolic pressure and the disappearance of the murmur when these two pressures were equal suggests that outflow tract obstruction may develop in shock. However, the severity of the patient's clinical condition prevented us from obtaining measurements crucial to the determination of the mechanism of the systolic pressure difference.