PS-R02-9: A PATIENT HAS THE ONLY CONNECTION BETWEEN THE ATRIUM AND VENTRICLE IS AN ACCESSORY PATHWAY

Abstract

Case report: A 62-year-old woman without cardiovascular risk factors such as hypertension, diabetes, smoking and hyperlipidemia was admitted to our cardiology outpatient clinic with palpitations and syncope history. Her electrocardiography showed preexcitation possible posteroseptal accessory pathway. We performed electrophysiological study and found posteroseptal accessory pathway. Tachycardia was not induced in inductions. ERP detected below 240 msn. The area where the shortest V-A interval was detected. His signal was not detected in this region. We determined that it was anatomically far from the AV node. We started radiofrequency ablation and in the 5. second of ablation, we saw that the patient entered 3. degree AV block. Ablation was immediately stopped then sinus rhythm restored in patients qucikly. We search his signal with ablation catheter in right atrium but could not find the signal. We detected that the AV block and accessory pathway were found together in the patient. Since the patient had a history of syncope and ERP < 250 ms was detected, we planned ablation after pacemaker implantation in the patient. We implant DDDR pacemaker and 2 weeks later we make successfully accessory pathway ablation. Discussion: In these patients, atrioventricular conduction is done only, and entirely, via the accessory route. A complete block, nodal or sub-Hissian, underlying, will only be visible on the ECG if there is concomitant blockage of the atrioventricular conduction through the accessory pathway. The appearance of atrioventricular conductive disorders after radiofrequency ablation of an accessory pathway, located at a distance from the atrioventricular junction, is not considered by some authors to be a real complication of this procedure. It would rather be a prior conductive disorder having been unmasked following the blockage of the accessory pathway thanks to ablation. It is therefore logical to review the indication for the removal of the accessory pathway in these cases, especially in asymptomatic patients who have never reported a history of palpitation attacks. The only possible tachycardia remains atrial fibrillation on WPW. Only the study of anterograde refractory periods makes it possible to specify the correct indication for ablative treatment. The indication for the implantation of a pacemaker is still appropriate given the risk of progressive and subsequent degeneration of the accessory pathway. In addition, conduction via the accessory pathway, whether continuous or intermittent, would help prolong the longevity of the pacemaker by inhibiting ventricular pacing in the event of atrioventricular conduction through the accessory pathway.