Manifestation of latent left ventricular outflow tract obstruction caused by acute myocardial infarction: An important complication of acute myocardial infarction

Background: Although transient left ventricular outflow tract (LVOT) obstruction is reported as a complication with acute myocardial infarction (AMI), the mechanisms and features of LVOT obstruction in AMI are unclear.

Methods and results: Herein, we present two cases of transient LVOT obstruction with anteroseptal AMI. The features of these two cases were one-vessel disease (1-VD) of the left anterior descending artery (LAD) and maintenance of blood flow to the major septal branch (SB). Moreover, LVOT obstruction was revealed after dobutamine infusion in the chronic phase and the aorto-septal angle was low in these two cases, meaning that latent LVOT obstruction was due to sigmoid-shaped septum.

Conclusions: Latent LVOT obstruction would be manifested in the acute phase of AMI. 1-VD of LAD and the maintenance of major SB blood flow are important factors with respect to the manifestation of latent LVOT obstruction.