Deep sedation in patients undergoing atrioventricular nodal reentry tachycardia 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).

Outcomes of deep sedation for catheter ablation of paroxysmal supraventricular tachycardia, with adaptive servo ventilation

BACKGROUND

Catheter ablation for paroxysmal supraventricular tachycardia (PSVT) is an established treatment, but the effect of deep sedation on PSVT inducibility remains unclear.

AIM

We sought to examine PSVT inducibility and outcomes of catheter ablation under deep sedation using adaptive servo ventilation (ASV).

METHODS

We retrospectively evaluated consecutive patients who underwent catheter ablation for PSVT under deep sedation (Propofol + Dexmedetomidine) with use of ASV. Anesthetic depth was controlled with BIS™ monitoring, and phenylephrine was administered to prevent anesthesia-induced hypotension. PSVT induction was attempted in all patients using extrastimuli at baseline, and after isoproterenol (ISP) infusion when necessary.

RESULTS

PSVT was successfully induced in 145 of 147 patients, although ISP infusion was required in the majority (89%). The PSVT was atrioventricular nodal reentrant tachycardia (AVNRT) in 77 (53%), atrioventricular reciprocating tachycardia (AVRT) in 51 (35%), and atrial tachycardia (AT) in 17 (12%). A higher ISP dose was required for AT compared to other PSVT (AVNRT: 0.06 (IQR 0.03-0.06) vs AVRT: 0.03 (0.02-0.06) vs AT: 0.06 (0.03-0.12) mg/h, P = .013). More than half (51%) of the patients developed hypotension requiring phenylephrine; these patients were older. Acute success was obtained in 99% (patients with AVNRT had endpoints with single echo on ISP in 46%). Long-term success rate was 136 of 144 (94%) (AVNRT 96%, AVRT 92%, and AT 93%). There were no complications related to deep sedation.

CONCLUSIONS

Deep sedation with use of ASV is a feasible anesthesia strategy for catheter ablation of PSVT with good long-term outcome. PSVT remains inducible if ISP is used.

Arrhythmia induction using isoproterenol or epinephrine during electrophysiology study for supraventricular tachycardia

BACKGROUND

Electrophysiology study (EPS) is an important part of the diagnosis and workup for supraventricular tachycardia (SVT). Provocative medications are used to induce arrhythmias, when they are not inducible at baseline. The most common medication is the β1-specific agonist, isoproterenol, but recent price increases have resulted in a shift toward the nonspecific agonist, epinephrine.

OBJECTIVE

We hypothesize that isoproterenol is a better induction agent for SVT during EPS than epinephrine.

METHODS

We created a retrospective cohort of 131 patients, who underwent EPS and required medication infusion with either isoproterenol or epinephrine for SVT induction. The primary outcome was arrhythmia induction.

RESULTS

Successful induction was achieved in 71% of isoproterenol cases and 53% of epinephrine cases (P = 0.020). Isoproterenol was significantly better than epinephrine for SVT induction during EPS (odds ratio [OR], 2.35; 95% confidence interval [CI], 1.14-4.85; P = 0.021). There was no difference in baseline variables or complications between the two groups. Other variables associated with successful arrhythmia induction included a longer procedure duration and atrioventricular nodal re-entry tachycardia as the clinical arrhythmia. In a multivariable model, isoproterenol remained significantly associated with successful induction (OR, 2.57; 95% CI, 1.002-6.59; P = 0.05).

CONCLUSIONS

Isoproterenol was significantly better than epinephrine for SVT arrhythmia induction. However, epinephrine was safe and successfully induced arrhythmias in the majority of patients who received it. Furthermore, when atropine was added in epinephrine-refractory cases, in a post hoc analysis there was no difference in arrhythmia induction between medications. Cost savings could thus be significant without compromising safety.