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.

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.

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.

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.

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.

Part 6: electrical therapies: automated external defibrillators, defibrillation, cardioversion, and pacing: 2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care.

The recommendations for electrical therapies described in this section are designed to improve survival from SCA and life-threatening arrhythmias. Whenever defibrillation is attempted, rescuers must coordinate high-quality CPR with defibrillation to minimize interruptions in chest compressions and to ensure immediate resumption of chest compressions after shock delivery. The high first-shock efficacy of newer biphasic defibrillators led to the recommendation of single shocks plus immediate CPR instead of 3-shock sequences that were recommended prior to 2005 to treat VF. Further data are needed to refine recommendations for energy levels for defibrillation and cardioversion using biphasic waveforms.

Part 1: executive summary: 2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care.

The goal of therapy for bradycardia or tachycardia is to rapidly identify and treat patients who are hemodynamically unstable or symptomatic due to the arrhythmia. Drugs or, when appropriate, pacing may be used to control unstable or symptomatic bradycardia. Cardioversion or drugs or both may be used to control unstable or symptomatic tachycardia. ACLS providers should closely monitor stable patients pending expert consultation and should be prepared to aggressively treat those with evidence of decompensation.

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.

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.

Outcomes of in-hospital ventricular fibrillation in children.

BACKGROUND: Ventricular fibrillation and ventricular tachycardia are less common causes of cardiac arrest in children than in adults. These tachyarrhythmias can also begin during cardiopulmonary resuscitation (CPR), presumably as reperfusion arrhythmias. We determined whether the outcome is better for initial than for subsequent ventricular fibrillation or tachycardia. METHODS: All cardiac arrests in persons under 18 years of age were identified from a large, multicenter, in-hospital cardiac-arrest registry. The results from children with initial ventricular fibrillation or tachycardia, children in whom ventricular fibrillation or tachycardia developed during CPR, and children with no ventricular fibrillation or tachycardia were compared by chi-square and multivariable logistic-regression analysis. RESULTS: Of 1005 index patients with in-hospital cardiac arrest, 272 (27 percent) had documented ventricular fibrillation or tachycardia during the arrest. In 104 patients (10 percent), ventricular fibrillation or tachycardia was the initial pulseless rhythm; in 149 patients (15 percent), it developed during the arrest. The time of initiation of ventricular fibrillation or tachycardia was not documented in 19 patients. Thirty-five percent of patients with initial ventricular fibrillation or tachycardia survived to hospital discharge, as compared with 11 percent of patients with subsequent ventricular fibrillation or tachycardia (odds ratio, 2.6; 95 percent confidence interval, 1.2 to 5.8). Twenty-seven percent of patients with no ventricular fibrillation or tachycardia survived to hospital discharge, as compared with 11 percent of patients with subsequent ventricular fibrillation or tachycardia (odds ratio, 3.8; 95 percent confidence interval, 1.8 to 7.6). CONCLUSIONS: In pediatric patients with in-hospital cardiac arrests, survival outcomes were highest among patients in whom ventricular fibrillation or tachycardia was present initially than among those in whom it developed subsequently. The outcomes for patients with subsequent ventricular fibrillation or tachycardia were substantially worse than those for patients with asystole or pulseless electrical activity.

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.

Immediate post-shock chest compressions improve outcome from prolonged ventricular fibrillation.

AIM: This study was designed to test the hypothesis that immediate post-shock chest compressions improve outcome from prolonged ventricular fibrillation (VF) compared with typical "hands off" period (i.e., delayed post-shock compressions) associated with AED use. MATERIALS AND METHODS: After 7.5 min of untreated VF, 36 domestic swine (26+/-1 kg) were treated with 200 J biphasic shocks and randomly assigned to: (1) 1 min of immediate post-shock chest compressions or (2) simulated pre-hospital automated external defibrillator (AED) care with delays in post-shock chest compressions. Return of spontaneous circulation (ROSC) occurred in 7/18 immediate chest compressions animals within 2 min of the first shock versus 0/18 AED animals (P<0.01). Ten of 18 immediate chest compressions animals attained ROSC compared with 3/18 AED animals (P<0.05). Nine of 18 immediate chest compressions swine were alive at 24 and 48 h compared with 3/18 AED swine (P<0.05). All 48-h survivors had good neurologic outcomes. Among the 21 animals that defibrillated with the first shock, ROSC was attained in 7/10 immediate chest compressions animals within 2 min of the first shock compared with 0/11 AED animals (P=0.001), and 48-h survival was attained in 8/10 versus 3/11, respectively (P<0.05). CONCLUSIONS: Immediate post-shock chest compressions can substantially improve outcome from prolonged VF compared with simulated pre-hospital AED care.

Attenuating the defibrillation dosage decreases postresuscitation myocardial dysfunction in a swine model of pediatric ventricular fibrillation.

OBJECTIVE: The optimal biphasic defibrillation dose for children is unknown. Postresuscitation myocardial dysfunction is common and may be worsened by higher defibrillation doses. Adult-dose automated external defibrillators are commonly available; pediatric doses can be delivered by attenuating the adult defibrillation dose through a pediatric pads/cable system. The objective was to investigate whether unattenuated (adult) dose biphasic defibrillation results in greater postresuscitation myocardial dysfunction and damage than attenuated (pediatric) defibrillation. DESIGN: Laboratory animal experiment. SETTING: University animal laboratory. SUBJECTS: Domestic swine weighing 19 +/- 3.6 kg. INTERVENTIONS: Fifty-two piglets were randomized to receive biphasic defibrillation using either adult-dose shocks of 200, 300, and 360 J or pediatric-dose shocks of approximately 50, 75, and 85 J after 7 mins of untreated ventricular fibrillation. Contrast left ventriculograms were obtained at baseline and then at 1, 2, 3, and 4 hrs postresuscitation. Postresuscitation left ventricular ejection fraction and cardiac troponins were evaluated. MEASUREMENTS AND MAIN RESULTS: By design, piglets in the adult-dose group received shocks with more energy (261 +/- 65 J vs. 72 +/- 12 J, p < .001) and higher peak current (37 +/- 8 A vs. 13 +/- 2 A, p < .001) at the largest defibrillation dose needed. In both groups, left ventricular ejection fraction was reduced significantly at 1, 2, and 4 hrs from baseline and improved during the 4 hrs postresuscitation. The decrease in left ventricular ejection fraction from baseline was greater after adult-dose defibrillation. Plasma cardiac troponin levels were elevated 4 hrs postresuscitation in 11 of 19 adult-dose piglets vs. four of 20 pediatric-dose piglets (p = .02). CONCLUSIONS: Unattenuated adult-dose defibrillation results in a greater frequency of myocardial damage and worse postresuscitation myocardial function than pediatric doses in a swine model of prolonged out-of-hospital pediatric ventricular fibrillation cardiac arrest. These data support the use of pediatric attenuating electrodes with adult biphasic automated external defibrillators to defibrillate children.

Tachyarrhythmias and defibrillation.

Although cardiac arrhythmias less commonly cause hemodynamic compromise in children than in adults, prompt recognition and treatment of arrhythmias remain an important part of pediatric resuscitation because of the availability of specific, effective therapies. This article summarizes the 2005 American Heart Association Guidelines for Pediatric Advanced Life Support regarding tachyarrhythmias, including treatment with antiarrhythmics and direct current countershock therapy, and provides an update of recent literature since the guidelines were published.

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.