Results of catheter ablation of sustained monomorphic ventricular tachycardia (SMVT) in patients with structural heart disease are presented.
Methods: Catheter ablation was performed in 34 patients (5 females), aged 63 +/- 11 years. One (3%) patient had a permanent SMVT resistant to electric cardioversion, 13 (38%) patients had incessant SMVT, 4 (12%) patients had SMVT at least once a day, 9 (26%) patients at least once a week, and 7 (21%) patients at least once a month. Twenty-nine (85%) patients were treated with amiodarone. Twenty-seven (79%) patients had a history of remote myocardial infarction, 2 (6%) patients presented with dilated cardimyopathy, 4 (12%) patients had arrhythmogenic right ventricular cardimyopathy, and 1 (3%) patient was after surgery for tetralogy of Fallot. Left ventricular ejection fraction was 35 +/- 13%. Ablation was mostly performed as a palliative approach with the purpose to eliminate clinically significant forms of SMVT leading to frequent ICD discharges, respectively to the worsening of heart failure. Less frequently, ablation was accomplished as a curative therapy. For the SMVT ablation, electroanatomic mapping was used, and, target or substrate mapping and ablation or their combinations were employed.
Results: Clinical form of SMVT was successfully eliminated in 33 (97%) patients, all inducible ventricular tachyarrhythmias were eliminated in 14 (41%) patients. Any ventricular tachycardia did not recur in 29 (85%) patients during 22 +/- 17 months follow-up. Twenty-three (68 %) patients had eventually implanted ICD. Ablation was performed as a curative procedure in 11 (32 %) patients. Average procedure duration was 213 +/- 56 minutes, fluoroscopy time was 18 +/- 9 minutes, and number of radiofrequency applications was 23 +/- 13.
Conclusion: Catheter ablation in patients with structural heart disease offers a highly effective method in elimination of clinical forms of SMVT. In long-term perspective, it is associated with low recurrence of any ventricular tachyarrhythmia. Efficacy of the ablation in elimination of all inducible forms of ventricular tachyarrhythmia is lower and therefore it should be mostly viewed as a palliative method, particularly in patients with left ventricular dysfunction and incomplete revascularization.