Slow pathway ablation in children with documented reentrant supraventricular tachycardia not inducible during invasive electrophysiologic study

Long-Term Follow-Up of Empirical Slow Pathway Ablation in Pediatric and Adult Patients with Suspected AV Nodal Reentrant Tachycardia

BACKGROUND

The aim of this study was to assess long-term efficacy and safety of empirical slow pathway (ESP) ablation in pediatric and adult patients with a special interest in patients without dual AV nodal physiology (DAVNP).

METHODS

A retrospective single-center review of patients who underwent ESP ablation between December 2014 and September 2022 was performed. Follow-up included telephone communication, letter questionnaire and outpatient presentation. Recurrence was based on typical symptoms.

RESULTS

115 patients aged 6-81 years (median age 36.3 years, 59.1% female; 26 pts < 18 years) were included. A typical history was present in all patients (100%), an ECG documentation of narrow complex tachycardia in 97 patients (84%). Patients were divided into three groups: Group 1 without DAVNP (n = 23), Group 2 with AH jump (n = 30) and Group 3 with AH jump and at least one AV nodal echo beat (n = 62). No permanent AV block was observed. During a median follow-up of 23.6 ± 22.7 months, symptom recurrence occurred in 7/115 patients (6.1%) with no significant difference between the groups (p = 0.73, log-rank test). Symptom recurrence occurred significantly more often in patients without (5/18 patients; 27%) as compared to patients with ECG documentation (2/97 patients; 2.1%; p = 0.025). No correlation between age and success rate was found (p > 0.1).

CONCLUSIONS

ESP ablation is effective and safe in patients with non-inducible AVNRT. Overall, recurrence of symptoms during long-term follow-up is low, even if no DAVNP is present. Tachycardia documentation before the EP study leads to a significantly lower recurrence rate following ESP ablation.

Empiric slow-pathway ablation results for presumed atrioventricular nodal reentrant tachycardia in pediatric patients

BACKGROUND

In pediatric patients with documented narrow QRS tachycardia that is suggestive of atrioventricular nodal reentrant tachycardia (AVNRT) and not inducible in electrophysiological study (EPS), empiric slowpathway ablation (ESPA) may be considered. There is limited data in children about this topic.

METHODS

Seventy-nine patients who underwent cryoablation and/or radiofrequency ablation (RFA) for presumed AVNRT between January 2010 and January 2020, with no inducible tachycardia and no other tachycardia mechanisms during EPS, were included in this study.

RESULTS

The age was between 6 and 18 years. All patients had no structural heart disease. Preablation exhibited sustained SP conduction for all patients. In all cases, the ablation end points were prolongation in wenckebach cycle length (WBCL) with loss of cross and/or jump, and/or echo beat. The end points were not achieved in two patients. Overall, the mean basal WBCL increased to 351 ms (240-500 ms) from 301.3 ms (180-420 ms), evident in the non-recurrence group. Nine patients had a transient AV block that improved. We followed the patients without medication for about 46.9 months (8 months to 10 years). Palpitations occurred again in 9 of 77 patients (clinical recurrence rate 9/79 - 11.3%). The documented ECG recurrence rate was 1.2% (1/79). In the non-recurrence group, WBCL prolongation was higher and mean age was lower than in the recurrence group (13.075 vs. 15.33 years).

CONCLUSION

In cases with presumed AVNRT, ESPA seems to be a reasonable and safe way. In our study, we found our procedural success rate as 97.4% and follow-up recurrence rate as 12.6% (9+1/79).

Deep sedation in patients undergoing atrioventricular nodal reentry tachycardia ablation

BACKGROUND

General anesthesia and deep sedation can be used during cardiac EPS to relief pain and provide comfort and immobility, but many electrophysiologists avoid sedation for better arrhythmia induction.

OBJECTIVE

To determine anesthesia effects in ablation procedures in adults, we used intravenous anesthetic agents in patients who underwent slow pathway ablation.

PATIENTS AND METHODS

One hundred patients who were to undergo radiofrequency catheter ablation were randomly assigned to with and without intravenous anesthesia groups. All patients had palpitation with a documented electrocardiography (ECG) compatible with atrio-ventricular nodal reentrant tachycardia (AVNRT). We used propofol, fentanyl and midazolam for intravenous sedation. Electrophysiological parameters were checked for the two groups and compared before and after the ablation.

RESULTS

Electrophysiological parameters were not significantly different in the two groups. In the anesthetic group, patients were more satisfied with the procedure (P value < 0. 001).

CONCLUSIONS

Intravenous anesthesia could be done safely in patients who underwent electrophysiological procedures. It had no effect on arrhythmia induction or slow pathway ablation in patients with documented AVNRT.

Approaches to empiric ablation of slow pathway: results from the Canadian EP web survey

AIM

Dual atrioventricular nodal physiology (DAVNP) is a frequent finding in patients with suspected or documented supraventricular tachycardia (SVT). Empiric slow pathway ablation (ESPA) is sometimes performed in patients with DAVNP without inducible SVT at the time of electrophysiological study. Evidence to guide this practice in the adult population is limited. This study was aimed to assess the practice of ESPA by adult electrophysiologists in Canada.

METHODS

All Canadian interventional electrophysiologists (n = 81) were invited to complete a web-based questionnaire assessing their practice of ESPA in patients with suspected and documented SVT. Operator experience, reimbursement models, diagnostic, and treatment decisions regarding ESPA were assessed with case scenarios.

RESULTS

Forty-one responses (50 %) were obtained. Ninety-five percent of the responders stated that the evidence for ESPA is lacking or limited. Responders were more likely to perform ESPA in the setting of non-inducible SVT when there was documentation of the clinical arrhythmia (64 vs. 31 % (p = 0.017)). The threshold to perform ESPA was highly variable. Longer time in practice (r = 0.38, p = 0.017) and less perceived complications with ESPA (r = 0.31, p = 0.05) were correlated with the practice of ESPA, whereas length of ablation waiting lists (r = -0.15, p = 0.38), number of procedures performed per day (r = 0.11, p = 0.51) and type of reimbursement (p = 0.24) were not associated with the practice of ESPA. The perceived complication rate with ESPA was <1 %.

CONCLUSION

Variability in the practice of ESPA in cases of non-inducible SVT exists. Documentation of the clinical arrhythmia, operator experience, and perceived low complication rates positively influence this practice.

Documented narrow QRS tachycardia not inducible during electrophysiology study: should we modify the AV node or not

Ablation therapy is the widely accepted definitive therapy for atrioventricular reentry tachycardia. Noninducibility of the tachycardia is the targeted end point of the procedure. We report on 21 patients with documented narrow QRS tachycardia, in whom the clinical tachycardia could not be induced during the electrophysiologic study. After exclusion of an accessory pathway, we could treat them by slow pathway ablation, either with radiofrequency energy or with cryoenergy, successfully.

[Electrical heart diseases--therapy during childhood and adolescence]

With increasing experience, radiofrequency catheter ablation of tachyarrhythmia substrates has become first choice therapy for children >4 years of age with recurrent tachyarrhythmia. In younger patients, the risks associated with the procedure (typically procedure-related AV block or possible coronary artery damage) have to be weighed against the natural history of the tachyarrhythmia substrate, and the degree of control achieved with pharmacologic agents. Ablation for postoperative arrhythmias is more complicated, and associated with lower success rates and a higher rate of recurrence (of the same or a new tachyarrhythmia) despite acute procedural success. In this setting, catheter ablation has to be considered in conjunction with further surgery or the use of a defibrillator as a backup device to prevent arrhythmia-related sudden death. Also in inherited arrhythmias as in long QT syndrome and Brugada syndrome, implantable defibrillators have to be considered as a possible therapeutic option for patients with a higher risk for sudden cardiac death, irrespective of age.