Background:—Sometime, it’s difficult to distinguish the electrophysiological mechanism of some tachycardia, and so, influencing the efficacy and safety of ablation operation. Therefore, it’s helpful to analysis some tachycardia in particular mechanism, as in this case. Methods and results:—A 49 years old Chinese male patient had a history of paroxysmal palpitation for 25 years, and recurred more frequently in the month before admission. Electrocardiogram (ECG) showed no abnormity under sinus rhythm, and showed no specific sign to distinguish its reentrant mechanism when tachycardia running. Electrophysiological examination and the result of successful ablation showed that the retrograde pathway of its reentry was in slow conduction, and from which the reentry started; moreover, after partially ablating, the reentry started from antegrade slow conduction. Conclusion:—Careful cardiac electrophysiological examination and paying more attention to inducing conditions of tachycardia are critical to accurately determining the tachycardia mechanism.
Key words: Radiofrequency Catheter Ablation (RFCA), Atrioventricular Nodal Reentrant Tachycardia (AVNRT), Atrioventricular Reentrant Tachycardia (AVRT) A 49