摘要篇首： Atrioventricular nodal reentrant tachycardia (AVNRT) is one of the most common types of paroxysmal supraventricular tachycardia. The mechanism of AVNRT is reentry associated with dual or multiple atrioventricular nodal (AVN) pathways. Typical AVNRT pathways,including fast and slow pathways, are confined in the right atrium. Radiofrequency catheter ablation of the slow pathway, and occasionally the fast pathway, has become the definitive treatment of choice for most symptomatic patients. Besides typical AVNRT, there exists some atypical AVNRT with various manifestations. Several groups have reported successful ablation of the leftward dual AVN pathway from the left side of the heart.1-3 We present one case of left-sided AVN as well as dual AVN pathway. The tachycardia was successfully eliminated by ablation of the slow pathway deep in the coronary sinus.