Background: Pericicatricial right intra-atrial reentrant tachycardias occur frequently in patients who have undergone surgical correction of an interatrial defect.
Aim: To characterize the tachycardia circuits using three-dimensional electroanatomical mapping.
Methods: Twelve tachycardias were analysed in 11 patients who had undergone surgical correction of an interatrial defect. Patients were divided into two groups: atrial flutter with typical sawtooth flutter waves in inferior leads, atrial tachycardia with clearly delimited P waves separated by an isoelectric line.
Results: Seven tachycardias were classified as atrial flutter; three-dimensional mapping identified a peritricuspid circuit with inferior vena cava-tricuspid annulus isthmus involvement in all cases. All atrial flutters were terminated by linear ablation of this isthmus. Five tachycardias were classified as atrial tachycardia; three-dimensional mapping identified periatriotomy loops. All atrial tachycardias were ablated successfully between two scars or between a scar and an anatomical barrier.
Conclusion: Periatriotomy loops were always associated with an atrial tachycardia electrocardiogram pattern. Three-dimensional electroanatomical mapping appeared to be particularly useful for circuit identification and for ablation of these complex arrhythmias.