Why is transient left ventricular cavity dilation on SMPI a poor prognostic sign?
Transient left ventricular cavity dilation refers to the cavity appearing larger on stress images than on resting images. This is in contrast to fixed cavity dilation, which may be associated with cardiomyopathy that could be related to a number of causes including CAD, alcoholic cardiomyopathy, valvular disease, or viral or autoimmune processes. Transient left ventricular cavity dilation suggests that during stress, CAD results in worsening myocardial function such that the heart cannot maintain its usual contractile state and then dilates. Another explanation is stress-induced subendocardial ischemia that resolves at rest. Transient left ventricular cavity dilation is a poor prognostic sign because significant cardiac function and structure are at risk for an ischemic event.