Association between survival and number of shocks for pulseless ventricular arrhythmias during pediatric in-hospital cardiac arrest in a national registry.

BACKGROUND: Annually 15,200 children suffer an in-hospital cardiac arrest (IHCA) in the US. Ventricular fibrillation or pulseless ventricular tachycardia (VF/pVT) is the initial rhythm in 10-15% of these arrests. We sought to evaluate the association of number of shocks and early dose escalation with survival for initial VF/pVT in pediatric IHCA. METHODS: Using 2000-2020 data from the American Heart Association's (AHA) Get with the Guidelines®-Resuscitation (GWTG-R) registry, we identified children >48 hours of life and ≤18 years who had an IHCA from initial VF/pVT and received defibrillation. RESULTS: There were 251 subjects (37.7%) who received a single shock and 415 subjects (62.3%) who received multiple shocks. Baseline and cardiac arrest characteristics did not differ between those who received a single shock versus multiple shocks except for duration of arrest and calendar year. The median first shock dose was consistent with AHA dosing recommendations and not different between those who received a single shock versus multiple shocks. Survival was improved for those who received a single shock compared to multiple shocks. However, no difference in survival was noted between those who received 2, 3, or ≥4 shocks. Of those receiving multiple shocks, no difference was observed with early dose escalation. CONCLUSIONS: In pediatric IHCA, most patients with initial VF/pVT require more than one shock. No distinctions in patient or pre-arrest characteristics were identified between those who received a single shock versus multiple shocks. Subjects who received a single shock were more likely to survive to hospital discharge even after adjusting for duration of resuscitation.

A Prolonged QTc Interval Leads to the Diagnosis of Hyperthyroidism in an Adolescent Boy.

BACKGROUND: Syncope is a common cause of pediatric emergency department visits and carries a broad differential diagnosis, which includes a few rare but critical cardiac conditions. CASE REPORT: We review the case of an adolescent boy who presented to the emergency department after a syncopal event. He was found to have a prolonged QTc interval on electrocardiogram (ECG), without personal or family history or known risk factors. He was screened for thyroid dysfunction on a second ED visit for presyncope and was subsequently diagnosed with hyperthyroidism. The patient was treated with methimazole for 2 weeks and a repeat ECG showed normalization of the QTc interval with a QTc reduction of more than 100 ms; routine thyroid studies showed correction of thyroid stimulating hormone and free thyroxine levels shortly thereafter. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: This case and review of the medical literature should raise awareness for the emergency physician to consider evaluation of thyroid function in pediatric patients with QT interval prolongation and vice versa, potentially averting dangerous dysrhythmias.

Improved survival to hospital discharge in pediatric in-hospital cardiac arrest using 2 Joules/kilogram as first defibrillation dose for initial pulseless ventricular arrhythmia.

The American Heart Association (AHA) recommends first defibrillation energy dose of 2 Joules/kilogram (J/kg) for pediatric cardiac arrest with ventricular fibrillation (VF) or pulseless ventricular tachycardia (pVT). However, optimal first energy dose remains unclear. METHODS: Using AHA Get With the Guidelines-Resuscitation® (GWTG-R) database, we identified children ≤12 years with IHCA due to VF/pVT. Primary exposure was energy dose in J/kg. We categorized energy doses: 1.7-2.5 J/kg as reference (reflecting 2 J/kg intended dose), <1.7 J/kg and >2.5 J/kg. We compared survival for reference doses to all other doses. We constructed models to test association of energy dose with survival; adjusting for age, location, illness category, initial rhythm and vasoactive medications. RESULTS: We identified 301 patients ≤12 years with index IHCA and initial VF/pVT. Survival to discharge was significantly lower with energy doses other than 1.7-2.5 J/kg. Individual dose categories of <1.7 J/kg or >2.5 J/kg were not associated with differences in survival. For patients with initial VF, doses >2.5 J/kg had worse survival compared to reference. For all patients ≤18 years (n = 422), there were no differences in survival between dosing categories. However, all ≤18 with initial VF receiving >2.5 J/kg had worse survival. CONCLUSIONS: First energy doses other than 1.7-2.5 J/kg are associated with lower rate of survival to hospital discharge in patients ≤12 years old with initial VF/pVT, and first doses >2.5 J/kg had lower survival rates in all patients ≤18 years old with initial VF. These results support current AHA guidelines for first pediatric defibrillation energy dose of 2 J/kg.

Junctional ectopic tachycardia in infants and children.

Tachyarrhythmias originating in the atrioventricular (AV) node and AV junction including the bundle of His complex (BH) are called junctional tachycardia (JT) or junctional ectopic tachycardia (JET). Congenital JET (CJET) is a rare arrhythmia that occurs in patients without a preceding cardiac surgery and can be refractory to medical therapy and associated with high morbidity and mortality. CJET has a high rate of morbidity and mortality with death occurring in 35% of cases. JET occurring within 72 hours after cardiac surgery is referred to as postoperative JET (POJET) and caused by direct trauma, ischemic, or stretch injury to the AV conduction tissues during surgical repair of congenital heart defects. Focal junctional tachycardia (FJT) is also known as automatic junctional tachycardia and includes paroxysmal or non-paroxysmal forms. We discuss a staged approach to therapy with improved pharmacological therapies and the use of catheter-based therapies.

Permanent junctional reciprocating tachycardia in infants and Children.

Permanent junctional reciprocating tachycardia (PJRT) is a rare form of supraventricular tachycardia (SVT). It generally presents in infants but can be difficult to diagnose. The characteristic EKG findings, response to Adenosine and persistence or frequent recurrences are helpful in making the diagnosis. It is usually difficult to manage with the initial and single medications used in SVT. Many patients are misdiagnosed and not treated effectively and end up having end stage cardiomyopathy and are diagnosed in patients referred for transplant. Hence all patients referred for a cardiac transplant with dilated cardiomyopathy need to be evaluated for this arrhythmia. If appropriate treatment is started early in the course, the failure can be ameliorated, and the cardiomyopathy can be resolved.

Cardiopulmonary Resuscitation in Infants and Children With Cardiac Disease: A Scientific Statement From the American Heart Association.

Cardiac arrest occurs at a higher rate in children with heart disease than in healthy children. Pediatric basic life support and advanced life support guidelines focus on delivering high-quality resuscitation in children with normal hearts. The complexity and variability in pediatric heart disease pose unique challenges during resuscitation. A writing group appointed by the American Heart Association reviewed the literature addressing resuscitation in children with heart disease. MEDLINE and Google Scholar databases were searched from 1966 to 2015, cross-referencing pediatric heart disease with pertinent resuscitation search terms. The American College of Cardiology/American Heart Association classification of recommendations and levels of evidence for practice guidelines were used. The recommendations in this statement concur with the critical components of the 2015 American Heart Association pediatric basic life support and pediatric advanced life support guidelines and are meant to serve as a resuscitation supplement. This statement is meant for caregivers of children with heart disease in the prehospital and in-hospital settings. Understanding the anatomy and physiology of the high-risk pediatric cardiac population will promote early recognition and treatment of decompensation to prevent cardiac arrest, increase survival from cardiac arrest by providing high-quality resuscitations, and improve outcomes with postresuscitation care.

2017 American Heart Association Focused Update on Pediatric Basic Life Support and Cardiopulmonary Resuscitation Quality: An Update to the American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care.

This focused update to the American Heart Association guidelines for cardiopulmonary resuscitation (CPR) and emergency cardiovascular care follows the Pediatric Task Force of the International Liaison Committee on Resuscitation evidence review. It aligns with the International Liaison Committee on Resuscitation's continuous evidence review process, and updates are published when the International Liaison Committee on Resuscitation completes a literature review based on new science. This update provides the evidence review and treatment recommendation for chest compression-only CPR versus CPR using chest compressions with rescue breaths for children <18 years of age. Four large database studies were available for review, including 2 published after the "2015 American Heart Association Guidelines Update for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care." Two demonstrated worse 30-day outcomes with chest compression-only CPR for children 1 through 18 years of age, whereas 2 studies documented no difference between chest compression-only CPR and CPR using chest compressions with rescue breaths. When the results were analyzed for infants <1 year of age, CPR using chest compressions with rescue breaths was better than no CPR but was no different from chest compression-only CPR in 1 study, whereas another study observed no differences among chest compression-only CPR, CPR using chest compressions with rescue breaths, and no CPR. CPR using chest compressions with rescue breaths should be provided for infants and children in cardiac arrest. If bystanders are unwilling or unable to deliver rescue breaths, we recommend that rescuers provide chest compressions for infants and children.

Neonatal complex arrhythmias possibly related to a TTN mutation.

We describe a neonate born with complex arrhythmias that included concurrent atrial and ventricular tachycardias. Genetic testing demonstrated a mutation in the TTN gene, which codes for titin, a large protein found in striated muscle sarcomeres. The complex arrhythmias were successfully treated with amiodarone and flecainide. The patient remains asymptomatic with normal biventricular function. We speculate that the complex arrhythmias and TTN gene mutation may be related.

Epinephrine dosing interval and survival outcomes during pediatric in-hospital cardiac arrest.

BACKGROUND: Current guidelines recommend epinephrine every 3-5min during cardiopulmonary resuscitation. For adults with in-hospital cardiac arrest (IHCA), longer dosing intervals are associated with improved survival to discharge. This study investigates whether longer epinephrine dosing intervals were associated with improved survival to discharge during pediatric IHCA. METHODS: Retrospective review of AHA Get With The Guidelines-Resuscitation registry identified 1630 pediatric IHCAs that met inclusion criteria. Average epinephrine dosing interval was defined by dividing duration of resuscitation after first dose of epinephrine by total doses. Average dosing intervals were categorized as 1-5min, >5 to <8min, and 8 to <10min/dose. Primary outcome was survival to hospital discharge. Multivariable logistic regression models controlled for age, gender, illness category, location of arrest, arrest duration, time of day, and time to first epinephrine dose. Secondary analysis separated patients on vasoactive infusion at the time of arrest from those without an infusion in place. RESULTS: Odds ratios (OR) calculated using 1-5min/dose interval as reference. For the total cohort, adjusted OR for survival to hospital discharge for >5 to <8min was 1.81 (95% CI 1.26-2.59), and 8 to <10min 2.64 (95% CI 1.53-4.55). For patients not receiving vasoactive infusion, adjusted OR for survival to discharge for >5 to <8min was 1.99 (95% CI 1.29-3.06) and 8 to <10min 2.67 (95% CI 1.14-5.04). CONCLUSIONS: Longer average dosing intervals than currently recommended for epinephrine administration during pediatric IHCA were associated with improved survival to hospital discharge.

Decreased false-positive adolescent pre-athletic screening with Seattle Criteria-interpreted electrocardiograms.

Sudden cardiac arrest is a rare but devastating cause of death in young adults. Electrocardiograms may detect many causes of sudden cardiac arrest, but are not routinely included in pre-athletic screening in the United States of America partly because of high rates of false-positive interpretation. To improve electrocardiogram specificity for identifying cardiac conditions associated with sudden cardiac arrest, an expert panel developed refined criteria known as the Seattle Criteria. Ours is the first study to compare standard electrocardiogram criteria with Seattle Criteria in 11- to 13-year-olds. In total, 1424 students completed the pre-athletic screening and electrocardiogram; those with a positive screen or abnormal electrocardiogram interpreted by a paediatric electrophysiologist completed further work-up. Electrocardiograms referred for additional evaluation were re-interpreted by a paediatric electrophysiologist using Seattle Criteria. Electrocardiogram abnormalities were identified in 98 (6.9%); Seattle Criteria identified 28 (2.0%). Formal evaluation confirmed four students at risk for sudden cardiac arrest (0.3%): long QT syndrome (n=2), Wolff-Parkinson-White (n=1), and pulmonary hypertension (n=1). All students with at-risk phenotypes for sudden cardiac arrest were identified by both standard electrophysiologist and Seattle Criteria. The false-positive interpretation rate decreased from 6.6 to 1.7% with Seattle Criteria. Downstream costs associated with screening using standard paediatric electrocardiogram interpretations and Seattle Criteria were projected at $24 versus $7, respectively. In conclusion, using Seattle Criteria for electrocardiogram interpretation decreases the rate of false-positive results compared with standard interpretation without omitting true-positive electrocardiogram findings. This may decrease unnecessary referrals and costs associated with formal cardiology evaluation.

The KCNJ8-S422L variant previously associated with J-wave syndromes is found at an increased frequency in Ashkenazi Jews.

J-wave syndromes have been associated with increased risk of ventricular fibrillation and sudden cardiac death. Previous studies have identified the KCNJ8-S422L variant in heterozygous form in individuals with J-wave syndromes. Its absence in over 1500 controls, coupled with in vitro analysis, have led to the conclusion that S422L is pathogenic. We previously performed whole-genome sequencing in a family quartet of Ashkenazi Jewish decent with no history of J-wave syndrome. Re-examination of these data reveals that both parents are heterozygous for the S422L variant, while the 12-year old son carries two copies--thus representing the first reported case of a S422L homozygote. In order to examine whether the S422L mutation might segregate at appreciable frequencies in specific populations, we genotyped the variant in a panel consisting of 722 individuals from 22 European, Middle Eastern non-Jewish, Ashkenazi Jewish, and non-Ashkenazi Jewish populations. We found that the S422L allele was at a significantly higher frequency in Ashkenazi Jews (~4%) compared with other populations in our survey, which have frequencies <0.25%. We also performed ECGs in both male members of the family quartet. The homozygous boy demonstrated no clinically significant ECG abnormalities, while the heterozygous father presented with a subtle J-wave point elevation. Our results suggest that either (a) previous studies implicating S422L as pathogenic for J-wave syndromes failed to appropriately account for European population structure and the variant is likely benign, or (b) Ashkenazi Jews may be at significantly increased risk of J-wave syndromes and ultimately sudden cardiac death.

Outcomes associated with amiodarone and lidocaine in the treatment of in-hospital pediatric cardiac arrest with pulseless ventricular tachycardia or ventricular fibrillation.

AIM: To determine the association between amiodarone and lidocaine and outcomes in children with cardiac arrest with pulseless ventricular tachycardia (pVT) and ventricular fibrillation (VF). BACKGROUND: Current AHA guidelines for CPR and emergency cardiovascular care recommend amiodarone for cardiac arrest in children associated with shock refractory pVT/VF, based on a single pediatric study and extrapolation from adult data. METHODS: Retrospective cohort study from the Get With the Guidelines-Resuscitation database for in-patient cardiac arrest. Patients<18 years old with pVT/VF cardiac arrest were included. Patients receiving amiodarone or lidocaine prior to arrest or whose initial arrest rhythm was unknown were excluded. Univariate analysis was performed to assess the association between patient and event factors and clinical outcomes. Multivariate analysis was performed to address independent association between lidocaine and amiodarone use and outcomes. RESULTS: Of 889 patients, 171 (19%) received amiodarone, 295 (33%) received lidocaine, and 82 (10%) received both. Return of spontaneous circulation (ROSC) occurred in 484/889 (54%), 24-h survival in 342/874 (39%), and survival to hospital discharge in 194/889 (22%). Lidocaine was associated with improved ROSC (adjusted OR 2.02, 95% CI 1.36-3), and 24-h survival (adjusted OR 1.66, 95% CI 1.11-2.49), but not hospital discharge. Amiodarone use was not associated with ROSC, 24h survival, or survival to discharge. CONCLUSIONS: For children with in-hospital pVT/VF, lidocaine use was independently associated with improved ROSC and 24-h survival. Amiodarone use was not associated with superior rates of ROSC, survival at 24h. Neither drug was associated with survival to hospital discharge.