Atrial tachycardia originating from a right atrial free wall diverticulum: case report.

Background: Atrial tachycardia (AT) is an arrhythmic disorder originating from the atrium, independent of the atrioventricular node, and includes various types based on different mechanisms such as abnormal automaticity, triggered activity, and re-entry. These mechanisms are often related to specific anatomical structures. Focal AT, though relatively rare, typically arises from well-known locations in the left and right atria, such as the pulmonary veins, mitral valve annulus, crista terminalis, and coronary sinus ostium.

Case summary: We report a rare case of AT originating from a diverticulum in the right atrial free wall. The patient experienced recurrent AT episodes resistant to standard treatments. Detailed electrophysiological mapping identified the unusual origin of the tachycardia from a right atrial free wall diverticulum. Catheter ablation was successfully performed, leading to the resolution of the arrhythmia, with the patient remaining symptom-free during follow-up.

Discussion: This case expands the understanding of AT origins, highlighting the right atrial free wall diverticulum as a potential, though rare, source of tachycardia. The case emphasizes the importance of comprehensive electrophysiological mapping, especially in atypical presentations of AT. Successful ablation in this instance underscores the potential for targeted interventions even in uncommon anatomical sites. Further studies are needed to assess the prevalence and clinical significance of AT arising from such rare locations.