Electrophysiological characteristics of atrial tachycardia originating from the coronary sinus

A 22-year-old girl was admitted to our cardiology institute with Permanent tachycardia in last 6 years for diagnostic assessment and therapy. Doppler echocardiography show structural of heart is normal, ECG revealed a varied resting rate from 120 to 140 bpm, 1:1 AV ratio and long RP interval. P wave morphology was negative on leads I, II, III, aVF, and V4 to V6, positive on lead V1, and diphasic 1 /2 on lead aVL. Electrophysiology (EP) study was performed, Although the exactly mapping was performed in left inferior pulmonary vein and mitral annulus, however, no target point was found ahead of CS1-2, the tried discharge was invalid. The ablation catheter was entered the coronary sinus to guide electrical isolation, curing the tachycardia. The ECG returned to normal sinus rhythm. Through three years follow up, no AT recurrence.