Electrophysiology and Ablation
Electrocardiographic algorithm to identify the optimal target ablation site for idiopathic right ventricular outflow tract ventricular premature contraction
1 Cardiovascular Medical Center of Jiangsu, First Affiliated Hospital of Nanjing Medical University, Nanjing, China; 2 Cardiology Division, Department of Medicine, University of Hong Kong, Hong Kong SAR, China; 3 Research Centre of Heart, Brain, Hormone and Healthy Aging, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong SAR, China
Aims: Several electrocardiographic (ECG) algorithms have been developed to identify the site of origin of ventricular premature contractions (VPCs) from right ventricular outflow tract (RVOT) based on pacemapping; however, their accuracy remains unclear.
Methods and results: We evaluated the accuracy of these algorithms in 52 consecutive patients (31 female, mean age 42.6 ± 14.6 years) with successful radiofrequency ablation of RVOT-VPC as guided by 3D electroanatomical non-contact mapping (Ensite, St Jude Medical, USA) and compared with a newly proposed ECG algorithm. As guided by 3D electroanatomical mapping, the successful ablation sites of RVOT-VPC were RVOT septum (n = 31), RVOT free wall (n = 19), and His region (n = 2). Retrospective evaluation in the initial 39 patients shows that the overall positive prediction value to identify a successful ablation site of this newly proposed ECG algorithm is 77.3% and is higher than the 73.3% by Ito et al., 73.3% by Joshi et al., and 53.8% by Dixit et al. (P > 0.05). Prospective evaluation in the subsequent 13 patients also demonstrate similar high overall sensitivity (79.0%), specificity (92.7%), and positive prediction value (88.2%) to identify a successful ablation site with this newly proposed ECG algorithm.
Conclusion: On the basis of detail 3D electroanatomical mapping of successful ablation sites, a newly proposed ECG algorithm was developed to improve the sensitivity, specificity, and positive prediction value in identification of targeted ablation sites for RVOT-VPC.
Key Words: Electrocardiogram, Ventricular premature contraction, Right ventricular outflow tract
* Corresponding authors. Fax: +86 25 8371 7168 (K.C.)/+86 852 2818 6304 (H.-F.T.). Email: kjcao{at}njmu.edu.cn (K.C.)/hftse{at}hkucc.hku.hk (H.-F.T.)
The first two authors contributed equally to the study.
Manuscript submitted 26 May 2009. Accepted after revision 29 July 2009.