In patients with nonischemic cardiomyopathy, two typical scar patterns (anteroseptal and inferolateral) accounted for 89% of arrhythmogenic substrates, guiding specific ablation approaches.
Observational (n=19)
What are the typical arrhythmogenic substrates and associated ventricular tachycardias in patients with nonischemic cardiomyopathy?
In patients with nonischemic cardiomyopathy, contrast-enhanced MRI identifies two predominant scar patterns (anteroseptal and inferolateral) that correlate with distinct VT morphologies and dictate specific endocardial or epicardial ablation strategies.
BACKGROUND: There are limited data on typical arrhythmogenic substrates and associated ventricular tachycardias (VT) in patients with nonischemic cardiomyopathy. The substrate location may have implications for the ablation strategy. METHODS AND RESULTS: Nineteen consecutive patients with nonischemic cardiomyopathy (age 58±14 years, 79% men, left ventricular ejection fraction 41±11%) who underwent contrast-enhanced MRI and VT ablation were included. On the basis of 3-dimensional contrast-enhanced MRI-derived scar reconstructions, 8 patients (42%) had predominant basal anteroseptal scar, 9 patients (47%) had predominant inferolateral scar, and 2 patients (11%) had other scar types. Three distinct VT morphologies (≥1 of 3 inducible in 16/19 patients) were associated with underlying scar type. In 9 patients with anteroseptal scar-related VT (8/9 predominant scar, 1/9 nonpredominant), ablation target sites (defined as sites with ≥11/12 pacemap, concealed entrainment or VT termination during ablation) were located in the aortic root and/or anteroseptal left ventricular endocardium in 8 patients (89%) and in the anterior cardiac vein in 1 patient (11%), with additional target sites at the right ventricular septum in 2 patients (22%) and at the epicardium in 1 patient (11%). In contrast, in 8 patients with predominant inferolateral scar-related VT, target sites were located at the epicardium in 5 patients (63%) and in the endocardial inferolateral left ventricle in 3 patients (37%). CONCLUSIONS: Two typical scar patterns (anteroseptal and inferolateral) account for 89% of arrhythmogenic substrates in patients with nonischemic cardiomyopathy. Three distinct VT morphologies are highly suggestive of the presence of these scars. Anteroseptal scars were, in general, most effectively approached from the aortic root or anteroseptal left ventricular endocardium, whereas inferolateral scars frequently required an epicardial approach.
Piers et al. (2013) conducted an observational in Nonischemic cardiomyopathy with ventricular tachycardia (n=19). Contrast-enhanced MRI and VT ablation was evaluated on Scar patterns and associated VT morphologies/ablation target sites. In patients with nonischemic cardiomyopathy, two typical scar patterns (anteroseptal and inferolateral) accounted for 89% of arrhythmogenic substrates, guiding specific ablation approaches.
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