Recurrent A V block following ablation for AVNRT.

Slow pathway modification has become the mainstay for the treatment of atrio-ventricular nodal re-entrant tachycardia (AVNRT) ablation because of high success rate and low incidence of complications. Our patient had a rare complication of slow pathway modification by radiofrequency ablation (RFA) in form of delayed complete heart block, occurring 10 days after the procedure and resolving in 6 weeks to normal conduction. Complete AV block is a rare immediate complication of RFA but can present weeks later. Transient atrio-ventricular (AV) block during the procedure is seen in all patients who develop delayed AV block and these patients should be monitored closely.