Stevenson, W. G. et al. Irrigated radiofrequency catheter ablation guided by electroanatomic mapping for recurrent ventricular tachycardia after myocardial infarction: the multicenter thermocool ventricular tachycardia ablation trial. Circulation 118, 2773–2782 (2009).

Catheter ablation guided by electroanatomic mapping is now a viable treatment option to reduce episodes of recurrent ventricular tachycardia (VT) in patients who have experienced myocardial infarction. A multicenter study by William Stevenson et al. has shown that patients can be free of VT 6 months after ablation.

VT episodes can be terminated, but not prevented, using an implantable cardioverter-defibrillator. In patients with these devices, antiarrhythmic drug therapy is often administered to prevent VT; however, these agents have adverse effects and relatively poor efficacy.

Stevenson and colleagues evaluated 231 patients with recurrent episodes of monomorphic VT (median 11 in the preceding 6 months) caused by previous myocardial infarction. Ablation was carried out in all patients by means of a saline-irrigated catheter combined with electroanatomic mapping system to assist substrate mapping during sinus rhythm.

At the 6-month follow-up, 53% of patients were free of VT, and the 6-month frequency of VT episodes was reduced from a median of 11.5 to 0 in the 142 patients who had an implantable cardioverter-defibrillator before ablation. A total of 7 deaths were recorded within 7 days of the procedure and the 1-year mortality rate was 18%.

“The dramatic reduction of VT episodes after catheter ablation would likely be associated with an improved quality of life in the high-risk patients assessed in this study,” says Hugh Calkins from the Johns Hopkins Hospital in the USA.