Causes of Transient Dilatation of the Left Ventricle During Myocardial Perfusion Imaging

1349 eginning with Stolzenberg [1] in 1980 and later popularized by Weiss et al. [2] in 1987, the apparent dilatation of the left ventricular cavity on myocardial perfusion imaging in the presence of extensive epicardial vessel stenoses has been referred to as transient ischemic dilation. Iskandrian et al. [3] provided evidence that the mechanism of this apparent dilatation may involve subendocardial ischemia by revealing increased wall thickness on the delay images when cavity dilatation with myocardial thinning was seen during stress. The severely ischemic, count-poor subendocardium at stress appears as part of the left ventricular cavity with an external rim of slightly better perfused epicardium. The result is a relatively dilated left ventricular cavity during stress imaging. Transient ischemic left ventricular cavity dilatation during stress myocardial perfusion imaging has become a generally accepted marker of severe, Causes of Transient Dilatation of the Left Ventricle During Myocardial Perfusion Imaging Vincent J. B. Robinson 1,2 , James H. Corley 2 , David S. Marks 1,3 , Linton W. Eberhardt 2 , Casimir Eubig 2 , George J. Burke 2 , L. Michael Prisant 1