Surgical treatment of ventricular tachycardia. Regional cryoablation guided by computerized epicardial and endocardial mapping

Extended cryoablation as a single method of myocardial ablation was used for surgical treatment of 33 patients with ventricular tachycardia associated with coronary artery disease. Surgery was guided by roving-probe mapping in 14 patients and by computerized epicardial and computerized, left ventricular, endocardial, multielectrode mapping in 19 patients. In the latter group, the anatomic correlation between sites of the earliest epicardial activation (EA-EPI) and those of the earliest endocardial activation (EA-ENDO) was found to be consistent in the apical region. In contrast, the EA-ENDO corresponding to the EA-EPI localized in the left anterolateral and posterobasal free-wall regions could be localized either in an underlying area or on the septum. All tachycardias with EA-EPI in anterior and posterior right ventricular regions had their corresponding EA-ENDOs in the interventricular septum. EA-ENDO preceded EA-EPI in 33 of 41 tachycardias studied. The converse was observed in the remaining eight tachycardias. Cryoablation was applied regionally in areas corresponding to EA-ENDO, along with standard aneurysmectomy and coronary artery bypass grafting when indicated. Among the entire group of 33 patients, there were two (6%) operative deaths. Ventricular tachycardias recurred spontaneously in two (6%) patients and remained inducible in four (13%), of whom one (3%) died suddenly. After hospital deaths were taken into account, actuarial survival was 74 +/- 9% (mean +/- SD) at 48 months after operation. Among the 10 patients who had an EA-EPI on the right ventricle and an EA-ENDO on the interventricular septum, deep septal involvement was suspected, and arrhythmic failure occurred in five patients; in contrast, complete surgical success was obtained in all nine patients who did not display this pattern during intraoperative investigation. We conclude that regional cryoablation alone in areas of the earliest left ventricular activation is highly effective for treatment of ventricular tachycardia, except in a subset of patients with specific markers of deep septal involvement, which can be detected by computerized epicardial and endocardial mapping.