"Left-variant" adenosine-sensitive atrial reentrant tachycardia ablated from the left coronary aortic sinus.

Adenosine-sensitive reentrant atrial tachycardia (AT) is usually amenable to ablation at the right superoseptum near the His bundle. We report a case with "left-variant" adenosine-sensitive reentrant AT. The AT was reproducibly induced by atrial extrastimulation with negative correlation between the coupling interval and return cycle, and was terminated by atrial extrastimulation and bolus of 2 mg of adenosine 5'-triphosphate. Ablations at the right superoseptum were unsuccessful; however, the AT was successfully ablated from the left coronary aortic sinus (LCAS) where the earliest atrial activation was recorded. Ablation at the LCAS might be effective in this entity resistant to right-sided ablation.