Hemodynamic failure caused by adrenaline administration for anaphylaxis reaction in a patient at risk for systolic anterior motion of mitral valve (SAM)

SAM is the abnormal anterior motion of the mitral valve toward left ventricular outflow tract during sys-Tole. The anterior mitral leaflet abuts the thickened septum, causing left ventricular outflow tract (LVOT) obstruction and mitral regurgitation (MR) transiently. A 71-year-old male patient was scheduled to undergo mitral valve plasty for the treatment of MR. Preoperative echocardiography revealed thickened basal interventricular septum. Intraoperatively, the patient developed severe hypotension resulting from anaphylaxis probably induced by platelet transfusioa which was not responding well to adrenaline adminis-Tratioa Afterward, transesophageal echocardiography (TEE) revealed that SAM and LVOT obstruction became clinically evident followed by severe MR. Hemodynamic change associated with intraoperative anaphylaxis and adrenaline administration worsened SAM as follows ; (1) decreasing afterload due to vasodilation caused by anaphylaxis, (2) decreasing preload due to plasma leakage, (3) increasing contractile force caused by adrenaline therapy, and decreasing diastolic filling by tachycardia Adrenaline is the first and most important treatment for anaphylaxis, but potentially caused SAM and LVOT obstructioa The preoperative assessment of the risk for SAM is useful to respond quickly to unexpected intraoperative hemodynamic change. Management by using intraoperative TEE is important if hemodynamic change occurs in a patient at risk for SAM.