CATHETER ABLATION OF VENTRICULAR TACHYCARDIA - LONG-TERM RESULTS

Abstract

Ventricular tachycardia represents life-threatening cardiac rhythm disturbance and catheter ablation using radiofrequency current provides powerful means for definitive cure of almost all monomorphic tachyarrhythmias. Presence and extent of underlying structural heart disease is important for further prognosis of the patients, who undergo catheter ablation of ventricular tachycardia. Long-term results of catheter ablation for ventricular tachycarida in patients with and without structural heart disease are presented. Patients and results: Twenty three patients (9 females) aged 49.1 ± 15.6 (18–72) years underwent catheter ablation for monomorphic (resp. polymorphic in one patient) ventricular tqachycardia in 30 ablation procedures. Patients with structural heart disease: Seven patients (2 females) aged 54.2 ± 19.8 (21–72) years had structural heart disease (5 patients – post myocardial infarction, 1 patient – arrhythmogenic right ventricular dysplasia, 1 patient – surgically corrected transposition of great arteries). All sustained monomorphic ventricular tachycardias were eliminated during the catheter ablation and no ventricular tachycardia recurred during the follow-up period in 4 patients. In two patients sustained monomorphic ventricular tachycardia was not eliminated with radiofrequency current. One of the patients remains free of ventricular tachycardia and one patient experienced one recurrence of slowed ventricular tachycardia. Thus long-term clinical success was achieved in 4 patients and some clinical benefit probably also in the latter two patients. A different ablation strategy targeting large arrhythmogenic area at the border of postmyocardial infarction scar was employed in the last patient with frequent ICD discharges for polymorphic ventricular tachycardia associated with hemodynamic deterioration. This procedure brought immediate and long-term significant reduction of ICD shocks and rehospitalizations and probably was life-saving. Patients without structural heart disease: In sixteen patients (7 females) aged 44.2 ± 12.8 (18–66) years no structural heart disease was found. These patients presented with documented ventricular ectopy in different forms from incessant ventricular premature beats through repetitive nonsustained ventricular tachycardia to paroxysmal sustained ventricular tachycardia. The arrhythmia originated in the right ventricle in 11 patients (right ventricular outflow tract in 10 patients and basolateral wall in 1 patient) and in the left ventricle in 5 patients (inferoapicoseptal region in 4 patients and basoinferoseptal region in 1 patient). Eleven patients (68.7 %) had the arrhythmia eliminated or markedly suppressed during the ablation procedure and remain free of palpitations and antiarrhythmic drugs. Two patients with partial suppression of the ectopic rhythm are less symptomatic and the antiarrhythmic drugs could be reduced. In one patient one ventricular tachycardia morphology from the right ventricular outflow tract was eliminated while the second ventricular tachycardia morphology was not targeted (and was suppressed by antiarrhythmic drug) for close vicinity of the arrhythmogenic focus to the left anterior descending artery. Thus the clinical benefit of the ablation procedure is enhanced to 14 (87.5 %) patients. Ablation completely failed in two patients. Conclusion: Radiofrequency catheter ablation of ventricular tachycardia is highly effective and safe and results in long-term arrhythmia elimination. In patients with underlying structural heart disease it should be currently viewed as a adjunctive therapy to a complex management of the patient, while in otherwise healthy patients it can be considered a method for permanent cure.