This study describes a dynamic left ventricular outflow tract gradient complicating an acute anterior myocardial infarction in two patients. In both cases, hyperdynamic contraction of the non-infarcted segments were noted in addition to large antero-apical a- or dyskinesia. Both patients had evidence of mitral annular calcifications, and the occurrence of dynamic outflow tract obstruction preceded sudden death. Early recognition of the underlying pathophysiological mechanism might have major therapeutic implications and could decrease the risk of myocardial rupture.