A 54 year-old man was referred with a history of recurrent attacks of paroxysmal atiral fibrillation (AF) for several years.
No regular tachycardia was ever documented. The attacks were refractory to multiple anti-arrhythmic drugs.
Pulmonary isolation with NavX 3D mapping system was scheduled. Baseline electrophysiologic studies were performed at the onset of the study.
There was no ventriculo-atrial (VA) conduction at first.
However, after isoproterenol infusion a VA conduction through atrioventricular (AV) node was demonstrable.
Surpisingly, Atrioventricular Nodal Reentrant Tachycardia (AVNRT) was easily inducible by right atrial (RA) bursts.
And it converted rapidly to atrial fibrillation.
And had to be cardioverted.
Slow pathway ablation was, therefore, planned. But it proved more difficult than AF ablation itself. Burns had to be stopped with blocked junctional beats.
Even transient AV block was observed during burns.
And atrio-hisian (AH) interval prolonged.
AH returned to normal.
But it did not prevent the induciblity of AVNRT and conversion to AF.
A coronary sinus (CS) catheter was inserted a this point and showed earliest retrograde atrial activation at proximal CS.
Transseptal puncture was performed.
And slow pathway ablation was tried from the left side.
A nice accelerated junctional rhythm without block was induced by the first burn on the left side.
No tachycardia, AVNRT or AF, was inducible ever afterwards despite repeated bursts during isoproterenol infusion.
He has remained asymptomatic during the last year without any medications.