Abstract 3877: Three-dimensional Electroanatomic Voltage Mapping Predicts the Outcome of Patients With Arrhythmias of Right Ventricular Origin
Background Endocardial voltage mapping (EVM) by CARTO system offers the potential to identify the presence, location and extent of right ventricular (RV) electroanatomic scars (EAS), i.e. low-voltage regions with bipolar electrogram <0.5 mV, which may represent the substrate of life-threatening RV tachyarrhythmias. This study prospectively evaluated the prognostic value of RV EAS in a cohort of patients presenting clinically with arrhythmias of RV origin.
Methods The study population comprised 109 consecutive patients (73 men and 36 women; mean age 36±14 years) with a left bundle branch block pattern ventricular arrhythmia, such as sustained ventricular tachycardia (VT) in 21, non sustained VT in 64, frequent and/or ripetitive premature ventricular beats in 94 patients. All patients underwent detailed clinical evaluation and EVM by sampling multiregional RV bipolar electrograms (197±23) to identify EAS
Results EAS were found in 54 patients (49%), affecting 20.4%±13 (range 2.6% to 49.8%) of the RV free wall. The presence of EAS significantly correlated with a positive family history (p<0.001), late potentials on SAECG (p<0.001), and RV dilatation/dysfunction (p<0.001). During a mean follow-up of 49±13 months, 25 of 109 patients (23 %) experienced malignant arrhythmic events such as sudden death in 2, cardiac arrest due to ventricular fibrillation in 4, appropriate ICD intervention in 7, and instable VT leading to syncope in 12. Unexplained syncope (p<0.001) and EAS (p<0.001) were significantly associated with arrhythmic events. Among patients with an abnormal RV EVM, those who experienced arrhythmic events during follow-up had a significantly greater extent of EAS (27.4±10.5% vs 16±12.3%, p<0.001). After adjustement for age, family history, VT, and RV dilatation/dysfunction, unexplained syncope (OR=15.9, 95% CI 4.1– 61.8; p<0.001) and EAS (OR=9.28, 95% CI. 2.0 – 42.7; p=0.004) remained independent predictors of malignant arrhythmic outcome.
Conclusions EAS were found in approximately half of patients with arrhythmias of RV origin. There was a significant correlation between EAS extent and incidence of arrhythmic events during follow-up. EAS, but no RV dilatation/dysfunction, was an independent predictor of malignant arrhythmic outcome.