Atypical atrioventricular nodal reentry tachycardia with eccentric retrograde left-sided activation of coronary sinus.

BACKGROUND: Recent anatomical and electrophysiological studies have demonstrated that in the human atrioventricular node there are two main extensions, the rightward and leftward posterior nodal extension (LPNE). The occurrence of eccentric retrograde atrial activation has been demonstrated in several previous reports to be from 6 to 8% in patients with AVNRT. OBJECTIVES: The study was performed to confirm that standard right atrium ablation is effective and successful for atrioventricular node reentry tachycardia (AVNRT) with eccentric retrograde left-sided activation, masquerading as a tachycardia which looks like a tachycardia, using the left accessory pathway. METHODS AND RESULTS: During a 7 years period (from 2002 to 2008), 865 consecutive patients underwent electrophysiological study. In the group with atrioventricular node reentry tachycardia (AVNRT) there were 178 patients. In the group with typical fast-slow AVNRT (162 pts) there was concentric retrograde activation of both the atria. The 16 patients had atypical AVNRT (10 pts with slow-slow AVNRT and 6 pts with LPNE). The ablation was performed, in all patients in the Koch's triangle on the slow pathway of the atrioventricular node. The successful rate of ablation was 99.4% (177/178 pts). The incidence of AVNRT with eccentric retrograde activation was 3.4%. In the follow-up period (16±12 months), there was no recurrence of AVNRT in the group with LPNE. CONCLUSIONS: This study demonstrated the different electrophysiologic characteristics between the AVNRT patients with eccentric and concentric retrograde atrial activation. Standard ablation, but a little bit higher in the Koch's triangle, closer to the fast pathway, in the right atrium is effective and successful for AVNRT with retrograde left eccentric conduction in the coronary sinus.

Cardiac memory (t-wave memory) after ablation of posteroseptal accessory pathway.

BACKGROUND: Cardiac memory is a phenomenon characterized by transient T-wave abnormalities occurring during normal sinus rhythm, after a period of altered ventricular depolarization, where the T-wave vector has the same direction as the vector of the previously altered QRS complex (T-wave inversion). It is a form of electrical remodelling of the ventricular, where the T-wave follows ("remembers") a previously altered QRS vector. METHODS AND RESULTS: Over a 5-year period (2002-2006), 525 consecutive patients underwent electrophysiological study. One hundred and one patients underwent ablation of the atrioventricular reentry tachycardia (AVRT) with an accessory pathway (AP). Forty-two of them were without delta wave on the electrocardiogram (concealed accessory pathway), and 58 patients had an open form of accessory pathways, with delta wave on EKG (Wolff-Parkinson-White syndrome) and only one patient had an accessory pathway between the right atrium and right bundle branch (Mahaim form). According to the location of the accessory pathway, 17 patients (29.3 %) had an accessory pathway in the right posteroseptal region. There was the highest percentage of the appearance of inversion of the T-wave in patients with this position of accessory pathway. T-wave changes were followed in the frontal plane (leads II, III, and aVF). Electrocardiogram (ECG) signs of cardiac memory were present in 16 of 17 (94.1 %) patients within one day after the ablation. The post-ablation T-wave vector had the same direction as the vector of the pre-excited QRS complex (and delta wave) creating inferior T-wave inversions. There was no correlation between the number or duration of energy applications and the extent of cardiac memory post ablation. A majority (90% of cases) of ECGs recorded 3 months after the procedure showed complete or almost complete normalization. None of the patients with T-wave inversion after ablation had a recurrence of preexcitation or tachycardia during the follow-up period of 12 +/- 4 months. CONCLUSIONS: T-wave inversion in leads II, III and aVF with the disappearance of the delta wave after ablation of the accessory pathway in patients with Wolff-Parkinson-White syndrome (accessory pathway in the right posteroseptal region of the heart), is the most powerful marker of successful ablation.

Radiofrequency current catheter ablation of accessory atrioventricular pathways.

BACKGROUND: The purpose of this study was to evaluate the safety and efficacy of a radiofrequency catheter ablation in the patients with the Wolff-Parkinson-White syndrome or paroxysmal supraventricular tachycardia involving a concealed accessory atrio ventricular connection. METHODS AND RESULTS: During a 45 month period (1st January 2002 until 30th September 2005) 373 consecutive patients underwent electrophysiological study in our electrophysiological lab at the Institute for Heart Diseases. Of all the patients 171 (45.8%) were ablated for junction depend tachycardia. Ninety-five patients had undergone ablation of atrioventricular nodal reentrant tachycardia (AVNRT), atrioventricular reentry tachycardia (AVRT) with accessory pathway (AP) 76 patients. Ablation of the atrioventricular node (AVN) was performed in 59 patients, because of uncontrolled atrial fibrillation with implantation of pacemakers. Ablation was successful in 206 patients (89.3%), partial successful was achieved in 21 patient (9.4%), and no successful only in 3 patients (1.3%). Ablation successful outcome rate was 98.7% (without clinical supraventricular arrhythmia in the follow up period until September 2005). There was a need for performing a re-do ablation in 11 patients (4.8%). A complication occurred in 8 patients, 4.9% (only one major complication, complete atrioventricular block with narrow QRS complex in the AVNRT group). In the group with accessory pathways (atrio ventricular reentry tachycardia (AVRT), there were 76 patients, 28 without delta way on the electrocardiogram (concealed accessory pathways), 47 patients were with open form of accessory pathways, with delta way on EKG (Wolff-Parkinson-White syndrome) and only in one patient with accessory pathway between right atrio and right bundle branch (Mahaim form of concealed accessory pathway). In two patients with AVRT, another circle movement tachycardia was found after the ablation of the accessory pathways, bystander arrhythmia of AVNRT: CONCLUSIONS: The success and safety of catheter accessory pathway ablation is so great that we recommend this nonpharmacological approach as an initial option to any patient with AVRT who has recurrent symptomatic arrhythmias.