The Characteristics and Distribution of the Scar Tissue Predict Ventricular Tachycardia in Patients with Advanced Heart Failure

BACKGROUND: Contrast-enhanced magnetic resonance imaging (CMR) identifies scar tissue as hyperenhanced areas. We sought to clarify the relationship between the scar characteristics and occurrence of sustained ventricular tachycardia (VT) in patients with advanced heart failure. METHODS: CMR was performed in 29 patients with dilated cardiomyopathy (DCM group) and 18 patients with ischemic cardiomyopathy (ICM group). The characteristics, volume, and distribution of the hyperenhanced areas were analyzed by CMR. The CMR parameters and clinical arrhythmic events were compared between the two groups. RESULTS: In the DCM group, almost all hyperenhanced areas were nontransmural, and presented frequently in the midwall layer. The volume of the hyperenhanced areas and total number of hyperenhanced segments were greater in patients with sustained VT than in those without. On the other hand, in the ICM group, transmural or subendocardial hyperenhanced areas were detected in the territory of the coronary arteries. The volume of the hyperenhanced areas and total number of transmural hyperenhanced segments in patients with sustained VT were unexpectedly smaller than in those without. However, the percentage of nontransmural hyperenhanced segments was greater in patients with sustained VT than in those without. CONCLUSIONS: The presence and magnitude of the nontransmural scar tissue may predict sustained VT in patients with advanced heart failure. There was the possibility that a recruitment bias was responsible for the finding of the smaller scars in the ICM patients with sustained VT.