Periprocedural, early, and long-term risks of pacemaker implantation after atrioventricular nodal re-entry tachycardia ablation: a French nationwide cohort

AIMS

Pacemaker implantation (PI) after atrioventricular nodal re-entry tachycardia (AVNRT) ablation is a dreadful complication. We aimed to assess periprocedural, early, and late risks for PI.

METHODS AND RESULTS

All 27 022 patients who underwent latest AVNRT ablation in France from 2009 to 2017, were identified in the nationwide medicalization database. A control group of 305 152 patients hospitalized for arm, leg, or skin injuries with no history of AVNRT or supraventricular tachycardia were selected. After propensity score matching, both groups had mean age of 53 ± 18 years and were predominantly female (64%). During this 9-year period, 822 of 27 022 (3.0%) AVNRT patients underwent PI, with significant higher risk in propensity-matched AVNRT patients compared to propensity-matched controls [2.9% vs. 0.9%; hazard ratio 3.4 (2.9-3.9), P < 0.0001]. This excess risk was significant during all follow-up, including periprocedural (1st month), early (1-6 months), and late (>6 months) risk periods. Annualized late risk per 100 AVNRT patients was 0.2%. In comparison to controls, excess risk was 0.2% in <30-year-old AVNRT patients; 0.7% in 30-50-year-old; 1.1% in 50-70-year-old and 6.5% over 70-year-olds. Risk for PI was also significantly different according to three procedural factors: centres, experience, and ablation date, with a 30% decrease since 2015.

CONCLUSION

Periprocedural, early, and late risks for PI were higher after AVNRT ablation compared to propensity-matched controls. Longer follow-up is needed as the excess risk seems to persist late after AVNRT ablation.

The HAV pattern in pediatric patients with atrioventricular node reentrant tachycardia

Objectives

The purpose of this study is to assess the prevalence of a His-Atrial-Ventricular (HAV) pattern, i.e. the atrial electrogram following the His bundle -HB- electrogram and preceding the ventricular one, on the catheter placed in the His position in pediatric patients during typical atrioventricular node reentry (AVNRT).

Materials and methods

The pediatric electrophysiology databases of two separate institutions were queried for patients with a diagnosis of AVNRT. Demographic, clinical data and the electrophysiology study (EPS) information were assessed.

Results

Thirty-nine consecutive patients were included. Twenty-five were female. The average age at the time of the EPS was 12 ± 3.7 years. Induction was achieved with atrial pacing in 23, with a single atrial extra stimulus in 8 and with dual atrial extra stimuli in 8. Isoproterenol was needed to induce tachycardia in 21. Tachycardia cycle length averaged 320 ± 50 ms. An HAV pattern was present in 35 (74%) of the patients, and in 100% of the patients younger than 8.

Conclusions

An HAV pattern on the catheter placed in the His position, is common in pediatric patients with AVNRT, occurring in up to 74% of the patients in this population, being more common in younger patients.

Coronary sinus morphology in pediatric patients with supraventricular tachycardia

PURPOSE

The anatomic basis of atrioventricular node reentrant tachycardia (AVNRT) remains incompletely characterized in children. Differences in coronary sinus (CS) size and morphology have been observed in adults with AVNRT but have not been well characterized in children.

METHODS

Children (< 18 years) brought to the EP lab with supraventricular tachycardia for ablation underwent CS venography. A blinded pediatric interventional cardiologist performed CS measurements, which were indexed to body surface area. Patients were excluded if they were < 25 kg or had significant congenital heart disease.

RESULTS

Forty-six patients (age 14.2 ± 3.3 years) met inclusion criteria, 17 with AVNRT and 32 with an accessory pathway (AP). CS ostium (LAO projection, end-systole) was 7.8 ± 2.9 mm/m² for the AVNRT group versus 6.0 ± 2.5 mm/m² for the AP group (p = 0.04). CS "windsock" morphology was more prevalent in the AVNRT group (16/17, 94.1%) than the AP group (11/32, 34.3%) (p < 0.001). Within the AVNRT group, there was no correlation between CS ostium size and tachycardia cycle length (R = 0.01, p = 0.96), fast-pathway ERP (FPERP) (R = 0.42, p = 0.12), or A2-H2 at the FPERP (R = 0.25, p = 0.39).

CONCLUSIONS

Children with AVNRT have larger CS ostia and more prevalent windsock morphology. CS size/morphology did not correlate with EP properties of the AVNRT substrate. These features may explain the basis for the development of the electrophysiologic substrate for dual AV node physiology in children.

Efficacy and Safety of Radiofrequency Catheter Ablation of Tachyarrhythmias in 123 Children Under 3 Years of Age

BACKGROUND

The risk-benefit ratio of radiofrequency catheter ablation (RFCA) in infants and toddlers remains controversial. Experience with RFCA in these patients is limited. This work is intended to describe the efficacy and safety of RFCA in children under 3 years of age with tachycardia complicated by drug resistance, drug intolerance, or tachycardia-induced cardiomyopathy.

METHODS

We retrospectively reviewed data from 123 consecutive children under 3 years of age (mean, 2.3 ± 0.8 years; weight, 13.6 ± 2.8 kg) with tachycardia complicated by drug resistance, drug intolerance, or tachycardia-induced cardiomyopathy; the children underwent an electrophysiology study between 1994 and 2014 at our center. Fifteen children had congenital heart disease, and 27 children were under 1 year of age. Among the 109 children who underwent RFCA, acute success rate (no inducible arrhythmia before procedure completion), 2-year rate of symptomatic tachyarrhythmia recurrence, and complication rate were assessed.

RESULTS

Among the 123 children studied, 76.4% had atrioventricular reentrant tachycardia, 5.7% had atrioventricular nodal reentrant tachycardia, 2.4% had focal atrial tachycardia, 6.5% had atrial flutter, and 4.1% had idiopathic left ventricular tachycardia. For RFCA, the acute success rate was 94.5%, and the 2-year recurrence rate was 6.8%, without any major complications.

CONCLUSION

RFCA appears to be an effective and safe therapeutic option in selected small children with tachycardia resistant to conventional medical management, tachycardia complicated by drug intolerance, or tachycardia-induced cardiomyopathy.

Clinical and electrophysiological characteristics of typical atrioventricular nodal reentrant tachycardia in the elderly - changing of slow pathway location with aging

BACKGROUND

The aim of this study was to retrospectively evaluate the clinical and electrophysiological characteristics of elderly patients with typical atrioventricular nodal reentrant tachycardia (AVNRT), and to assess the acute safety and efficacy of slow-pathway radiofrequency (RF) ablation in this specific group of patients.

METHODS AND RESULTS

The present study retrospectively included a total of 1,290 patients receiving successful slow-pathway RF ablation for typical slow-fast AVNRT. Patients were divided into 2 groups: group I included 1,148 patients aged <65 years and group II included 142 patients aged >65 years. The required total procedure duration and total fluoroscopy exposure time were significantly higher in group II vs. group I (P=0.005 and P=0.0001, respectively). The number of RF pulses needed for a successful procedural end-point was significantly higher in group II than in group I (4.4 vs. 7.2, P=0.005). While the ratio of the anterior location near to the His-bundle region was significantly higher in group II, the ratio of posterior and midseptal locations were significantly higher in group I (P=0.0001). The overall procedure success rates were similar. There was no significant difference between the 2 groups in respect of the complications rates.

CONCLUSIONS

This experience demonstrates that RF catheter ablation, targeting the slow pathway, could be considered as first-line therapy for typical AVNRT patients older than 65 years as well as younger patients, as it is very safe and effective in the acute period of treatment.

Permanent pacemaker implantation for late atrioventricular block in patients receiving catheter ablation for atrioventricular nodal reentrant tachycardia

The present study investigated the incidence and predictors of permanent pacemaker (PPM) implantation for late atrioventricular block (AVB) in patients with atrioventricular nodal reentrant tachycardia (AVNRT) who received ablation. The data from 3,442 patients with AVNRT who received ablation were analyzed. Those who developed late AVB (>1 month after ablation) and received a PPM were identified. The incidence of PPM implantation in 1,148 matched patients with Wolff-Parkinson-White syndrome and in the whole population of Taiwan were compared. Of the patients with AVNRT receiving ablation (mean follow-up duration 128.3 ± 62.5 months), 15 (0.4%) received PPM implantation for late AVB (mean interval after catheter ablation 95.4 ± 55.0 months). Only age (odds ratio 1.05, p = 0.02) and transient AVB (odds ratio 8.55, p = 0.01) during the procedure were independently associated with PPM implantation for late AVB. The patients with AVNRT had a greater incidence of PPM implantation due to late AVB compared to the matched patients with Wolff-Parkinson-White syndrome. The annual incidence of PPM implantation for AVB was also greater in the patients with AVNRT than in the general population. In conclusion, the incidence of PPM implantation for late AVB in patients with AVNRT who received catheter ablation was low but still greater than that in patients with Wolff-Parkinson-White syndrome and the general population in Taiwan.

Effects of slow pathway ablation on fast pathway function in patients with atrioventricular nodal reentrant tachycardia: cryo- vs. radiofrequency ablation

BACKGROUND

In typical atrioventricular nodal reentrant tachycardia, radiofrequency (RF) ablation of the slow pathway (SP) is known to change the effective refractory period of the fast pathway (ERP(FP)) after successful RF ablation of the SP. The purpose of this study was to ascertain the mechanism of the ERP(FP) changes after SP ablation by comparing the results of both cryo- and RF ablation.

METHODS AND RESULTS

A total of 112 patients were enrolled prospectively and their electrophysiological properties analyzed before and after successful SP ablation. Patients were grouped into cryoablation (n=54) and RF ablation (n=58) groups and each group was subdivided into complete ablation (CG) and modification (MG) based on the presence of the SP after successful ablation. CG was performed in 64 patients: 30 by cryoablation and 34 by RF ablation. In patients who underwent complete SP ablation, the ERP(FP) was shortened significantly after cryoablation (375 ± 74 vs. 281 ± 39 ms, P<0.01), without significant change in the atrio-His (AH) or sinus cycle length (SCL) interval. Similarly, the ERP(FP) was shortened significantly (358 ± 106 vs. 289 ± 84 ms, P=0.01) also after RF ablation without change in AH or SCL interval.

CONCLUSIONS

ERP(FP) shortening was observed after complete SP ablation with both cryo- and RF ablation without significant changes in indices of autonomic activity.