Abstract 1734: Focal Atrial Tachycardia Arising From the Non-Coronary Aortic Sinus
Introduction: The majority of focal atrial tachycardias (FAT’s) arise either in the right atrium (preferably crista terminals, coronary sinus ostium) or in the left atrium (pulmonary veins, close to mitral annulus ). We describe 6 patients with a FAT that arised from the non-coronary aortic sinus.
Methods: 6 patients (p.) ( 2 females, age 54 ± 12, 29 to 63 yrs) have been referred for electrophysiological study (EPS) because of paroxysmal palpitations. In 3 of them a regular narrow-QRS complex tachycardia had been documented. 2 p. had already an EPS and unsuccessful ablation attempt elsewhere. A long-standing hypertension was known in one p., otherwise the individuals were healthy.
Results: During the EPS a FAT (CL 418±57 ms) could easily be induced by atrial burst in all p.. During tachycardia earliest activation site was distal His. Proximal His, coronary sinus ostium and high right atrium were activated 7±2, 25 ±12 and 44 ± 20 ms after distal His activation. Activation of the coronary sinus occured from proximal to distal. Mapping of the left atrium in 4 p. showed earliest activation at the septal region ( 22 ± 10 ms later than distal His). No ablation was attempted at His side. The ablation catheter was retrogradely introduced in the aorta ascendens and detailed activation mapping was performed in the aortic root. Both right and left coronary aortic sinus (AS) were activated almost simultaneously to distal His ( left AS-distal His: 4 ± 9 ms, right AS-distal His: 5 ±7ms). Activation of non coronary aortic sinus was 33 ±9 ms earlier than at distal His. RF-application (30 Watt, 40 ±12 sec) at this side terminated the FAT in less than 2 sec in 5 p. and in less than 6 sec in all p. After successful ablation FAT could not be induced in any of the p. A coronary angiogram after ablation excluded coronary spasm or thrombosis. No acute or late complication occured in any of the p.. During a follow-up of 6 ±2 months all p. remained free of symptoms.
Conclusion: In case of FAT with earliest atrial activation at His site, a detailed activation mapping in the aortic root and especially non-coronary aortic sinus should be performed. Radiofrequency ablation at this side is safe and effective in permanently eliminating the tachycardia.