Supraventricular Tachycardia in Patients with Coronary Sinus Stenosis/Atresia: Prevalence, Anatomical Features, and Ablation Outcomes.

BACKGROUND Supraventricular tachycardia (SVT) with coronary sinus (CS) ostial atresia (CSA) or coronary sinus stenosis (CSS) causes difficulty in electrophysiological procedures, but its characteristics are poorly understood. OBJECTIVE Study the anatomical and clinical features of SVT patients with CSA/CSS. METHODS Of 6128 patients with SVT undergoing electrophysiological procedures, consecutive patients with CSA/CSS were enrolled, and the baseline characteristics, imaging materials, intraoperative data, and follow-up outcomes were analyzed. RESULTS Thirteen patients, seven with CSA and six with CSS, underwent the electrophysiological procedure. Decapolar catheters were placed into the proximal CS in three cases, while the rest were placed at the free wall of the right atrium. Fourteen arrhythmias were confirmed: four atrioventricular nodal reentrant tachycardias, five left-sided accessory pathways, three paroxysmal atrial fibrillations, and two atrial flutters (AFLs). In addition to three patients who underwent only an electrophysiological study, the acute ablation success rate was 100% in 10 cases, with no procedure-related complications. After a median follow-up period of 59.6 months, only one case of atypical AFL recurred. For those cases (seven CSA and two CSS) with a total of 10 anomalous types of CS drainage, three types were classified: from the CS to the persistent left superior vena cava (n = 3), from an unroofed CS (n = 3), and from the CS to the small cardiac vein (n = 3) or Thebesian vein (n = 1). CONCLUSION Patients with CSA/CSS may develop different kinds of SVT. Electrophysiological procedures for such patients are feasible and effective. An individualized mapping strategy based on the three types of CS drainage will be helpful.