Congenital Heart And Pediatric Electrophysiology

Arrhythmias Requiring ECMO in Infants Without Structural Congenital Heart Disease Andrew Well1,2 · Arnold Fenrich1,3 · Daniel Shmorhun1,3 · Daniel Stromberg1,3 · Preston Lavinghousez1,3 · Ziv Beckerman1,2 · Charles D. Fraser Jr.1,2 · Carlos M. Mery1,2 Received: 9 July 2021 / Accepted: 6 December 2021 / Published online: 17 January 2022   Commentary by Dr. Daniel Cortez (Sacramento, CA, USA), Congenital and Pediatric Cardiac EP section editor. Introduction Discussion of incidence of pediatric arrhythmias in emergency room notes a fairly low number of 55/100000, however the next line is slightly misleading, to clarify, the quoted abstract (reference 1) discusses that sinus tachycardia makes up most of the arrhythmia emergency room visits, while SVT is diagnosed 13% of the time in the pediatric emergency room visits. Two smaller studies have demonstrated 6/6 infants survived to discharge after ECMO for SVT, while in those under 21 years ofg age, with ECMO due to SVT, only 65% survived, with decreased survival in congenital structural heart disease. The need exists to further evaluate ECMO survival for neonatal SVT.   Methods Fairly sound methods here with congenital heart disease patients not included (this might be worth a second thought, however, but perhaps they are planning a second manuscript). Data is from the Extracorporal Life Support Organization Registry from 2008 through 2019 of patients less than 1 year of age using ICD-9 and ICD-10 codes. Appropriate statistical analyses were employed.   Results One hundred and forty patients were evaluated including based on ICD codes for SVT, unspecified arrhythmia (23.6%) and cardiac arrest. Sixty two percent had SVT, 12.5% had VT, and unspecified arrhythmias noted in 22.5%, with VF in3.3% and atrial flutter/fibrillation in 1.7% (2 patients) with “neonatal tachycardia” noted in 1.7% as well and one patient (0.8%) with supraventricular premature beats. Most patients were Caucasian and none were black.   One hundred and twenty survived (85.7%). Median time on ECMO support was 94 hours (interquartile range 69 to 158.5). Inotropic support prior to ECMO (12.1% vs 37.7%, p-value 0.005) and narcotic use (30.3% vs 57.5%, p-value -0.006) were associated with incidence of ECMO complication. Of those that did not survive, 65% (13/20) occurred while on ECMO and the other 7 (35%) were successfully separated but did not survive to discharge. Interestingly enough all VF patients survived and 10/15 (66.7%) of the VT patients survived and one of the two atrial fibrillation/flutter patients survived. Increased narcotic use (and neuromuscular blockade were associated with non-survival, as well as potentially use of norepinephrine (but small numbers used).   Central cannulation complications occurred in 12.9% of patients (36.9%) in non-survivors. Central ECMO cannulation had a high odds ratio for in-hospital mortality of 50.2 (95% CI 2.96 to 1,651.93). Out of patients with just SVT pacemaker pre-operatively, bicarb administration and central ECMO cannulation were associated with non-survival.   Overall, this paper discusses Infant ECMO survival in the setting of arrhythmias and looks partially at those with SVT. And although the driving point of the manuscript is that survival of 85.7% is better than prior reports of ECMO in older patients in the setting of SVT, I think there are a few points that would have been helpful, that are likely limited due to the nature of the study (registry study). The first is that the demographics of the SVT population (and how they differ from all comers with arrhythmias) would have been helpful. Secondly, what was used to control the arrhythmias and was urgent ablation performed in any of these patients? With smaller catheters available such as 5F Livewire mapping and with the advent of Cryoablation and it’s proven safety in smaller patients, were any of these modalities attempted to prevent or curb ECMO time. The answer is likely no, but perhaps type of antiarrhythmic used would help determine most effective to limit ECMO time (especially with IV sotalol now at more centers).