Aims: The prognostic significance of multiple ventricular tachycardia (VT) morphologies, whether spontaneous or induced, was investigated in patients who underwent radiofrequency catheter ablation (RFCA) for postinfarction ventricular tachycardia.
Methods and results: We studied 137 patients with postinfarction ventricular tachycardia. Catheter ablation of all induced ventricular tachycardias was attempted. A single ventricular tachycardia morphology was documented in 102/137 patients (MONO group); 35 patients had spontaneous pleomorphism (PLEO group). Multiple VT morphologies were induced in 58/102 (57%) MONO patients and in all PLEO patients. A higher rate of arrhythmia suppression was obtained in MONO as compared to PLEO patients (162/212 [76%] vs. 43/110 [39%]). Clinical presentation (VT pleomorphism) (OR: 0.22, CI: 0.08-0.62) and the induced VT cycle (mean PLEO/MONO: 338/385 ms, OR: 1.06) were independent predictors of acute RFCA success. Among MONO patients, the procedure was successful in 75% of the patients with a single induced ventricular tachycardia compared to 64% of those with multiple tachycardias. The acute success rate was lower in PLEO patients (23%). PLEO patients had a significantly higher 3- and 5-year arrhythmia recurrence rate than MONO patients. RFCA acute success was the only independent predictor of long-term outcome in multivariate analysis.
Conclusions: Spontaneous, but not induced, VT pleomorphism in patients with prior myocardial infarction adversely affects the acute and long-term success rate of RFCA.