Right Atrial Appendage Aneurysm Resection to Cure Aneurysm-Related Atrial Tachyarrhythmia

Congenital right atrial appendage aneurysm (RAAA) is an extremely rare malformation that can coexist with atrial tachyarrhythmia. There is no consensus on treatment for this condition. This research aimed to investigate the clinical characteristics and efficacy of surgical resection to treat atrial tachyarrhythmia originating from RAAA in children. Four RAAA children diagnosed with atrial tachyarrhythmia at the age of 1-5.25 years weighing 8.3-17.1 kg were discussed in this retrospective study. Patients underwent various treatments, included electrocardiogram (ECG) and echocardiography, antiarrhythmic medication therapy, radiofrequency catheter ablation (RFCA), surgical resection of RAAA and pathological examinations. The results from these treatments along with clinical features of patients were analyzed. The incidence of RAAA in patients with atrial tachycardia originating from the right or left atrial appendages (RAA or LAA) was 7.3% (4/55). The prevalence of RAAA in the RAA was 12.5% (4/32). Atrial tachyarrhythmia was identified both prenatally (26 and 36 weeks of gestational age) and postnatally (1 and 4 months after birth), with two patients per group, respectively. The RAAAs condition in two patients with atrial tachycardia (AT), concomitant atrial flutter (AF) and atrial fibrillation (Af) was identified using echocardiogram. Although, RAAA in two patients with mono AT was unidentified in echocardiogram and failed to be identified in the procedure of RFCA, RAAA was confirmed during surgical resection of the RAA. Multiple pre-surgical antiarrhythmic medications combined therapy used to treat all four patients showed either no effect at all or was only partially effective. The original atrial tachyarrhythmia was successfully abolished after RAAA surgical resection in four patients. AT originating from new foci was established in two patients post-surgically. The conditions of these two patients were successfully reverted and normal sinus rhythm maintained in the application of antiarrhythmic medications. These results confirmed the efficacy of RAAA surgical resection. The pathology study showed cystic dilation in parts of the atrial cavity, fibrosis of the cyst wall, generalized fibrosis of atrial myocardium with myocardium atrophy and cystic dilation. RAAA is prone to misdiagnosis by echocardiogram. Atrial tachyarrhythmia in patients with RAAA is usually resistant to antiarrhythmic medication therapy and RFCA. Surgical resection of RAAA is a safe and effective option that is minimally invasive.