Short- and long-term success of substrate-based mapping and ablation of ventricular tachycardia in arrhythmogenic right ventricular dysplasia

Background - Multiple morphologies, hemodynamic instability, or noninducibility may limit ventricular tachycardia ( VT) ablation in patients with arrhythmogenic right ventricular dysplasia ( ARVD). Substrate- based mapping and ablation may overcome these limitations. We report the results and success of substrate- based VT ablation in ARVD. Methods and Results - Twenty- two patients with ARVD were studied. Traditional mapping for VT was limited because of multiple/ changing VT morphologies ( n = 14), nonsustained VT ( n = 10), or hemodynamic intolerance ( n = 5). Sinus rhythm CARTO mapping was performed to define areas of "scar" ( < 0.5 mV) and "abnormal" myocardium ( 0.5 to 1.5 mV). Ablation was performed in "abnormal" regions, targeting sites with good pace maps compared with the induced VT( s). Linear lesions were created in these areas to ( 1) connect the scar/ abnormal region to a valve continuity or other scar or ( 2) encircle the scar/ abnormal region. Eighteen patients had implanted cardioverter defibrillators, 15 had implanted cardioverter defibrillator therapies, and 7 had sustained VT ( 6 with syncope). VTs ( 3 +/- 2 per patient) were induced ( cycle length, 339 +/- 94 ms), and scar was identified in all patients. Scar areas were related to the tricuspid annulus, proximal right ventricular outflow tract, and anterior/ inferior- apical walls. Lesions connected abnormal regions to the annulus ( n = 12) or other scars ( n = 4) and/ or encircled abnormal regions ( n = 13). Per patient, a mean of 38 +/- 22 radiofrequency lesions was applied. Short- term success was achieved in 18 patients ( 82%). VT recurred in 23%, 27%, and 47% of patients after 1, 2, and 3 years' follow- up, respectively. Conclusions - Substrate- based ablation of VT in ARVD can achieve a good short- term success rate. However, recurrences become increasingly common during long- term follow- up.