Review of Outcomes of Eighty-two cases of Typical AVNRT after Radiofrequency Ablation at Madras Medical Mission, India

Context: Diagnoses of supraventricular arrhythmias often depend on combination of varied features of baseline electrophysiology, tachycardia and responses to pacing manoeuvres. These investigations are carried out regularly at the Cardiac Catheterization Laboratory of Madras Medical Mission, India.Aims: The purpose of this study was to describe the initial outcome following cardiac electrophysiologic studies and radiofrequency ablation of typical atrio-ventricular nodal re-entrant tachycardia (AVNRT).Settings and Design: This retrospective study was carried out in the Cardiac Electrophysiology Department, of the Institute of Cardiovascular Diseases, Madras Medical Mission, India.Subjects and Methods: Records of consecutive cases of typical AVNRT following cardiac electrophysiologic studies and radiofrequency ablation carried out between May 2013 to April 2014 were reviewed. Eighty-two cases were chosen for analysis.Statistical analysis used: The data obtained were analysed using SPSS statistical software version 15.Results: The 82 patients comprised 24 males and 58 females. Dual nodal physiology was documented in 79 (96.3%), A simultaneous V and A (VA interval <20 ms) was documented in 66 (80.5%). The presence of ventricular-atrial dissociation (VAD) during ventricular overdrive pacing (VOP), post-VOP V-A-V response, termination of tachycardia by VOP without advancing A, absence of VA linking and failure of His-refractory premature ventricular complex (PVC) to advance A were other characteristics used in differential diagnosis. The slow pathway was successfully ablated in 52 (63.4%), successfully modified in 29 (35.4%). The overall success rate was 98.8% while radiofrequency ablation was unsuccessful in 1 (1.2%). There was a very low incidence of complications.Conclusions: Treatment of typical AVNRT by radiofrequency cardiac catheter ablation at the Madras Medical Mission is highly effective and safe.