Epicardial Ablation for Ventricular Tachycardia in Chronic Chagas Heart Disease

Catheter Ablation of Sustained VT in Chagas Heart Disease

The main mechanism of SVT of chronic Chagas Heart Disease is the reentry located in a left ventricle inferolateral and baseline scar in more than 70% of the cases^,. The reentrant circuit of SVT may involve subendocardial, intramyocardial and subepicardial fibers. In some patients, the reentrant circuits have their genesis in places with very thin walls and, on account of that, conventional pulses of RF, emitted from the endocardium, may cause transmural injury and reach all the structures potentially involved in the circuit. Nevertheless, in others, the segmental injury is intramural and the circuit is predominantly kept by subepicardial fibers. Insofar as the contralateral subendocardial tissue is very thick, it may prevent RF applications from reaching the causative intramyocardial and subepicardial fibers and be the reason for an unsuccessful procedure. This was the initial hypothesis for resorting to the transthoracic subxiphoid percutaneous approach to explore the pericardial space and identify patients with possible subepicardial circuits.

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