Adenosine in the management of supraventricular tachycardia in children

Arrhythmias Requiring ECMO in Infants Without Structural Congenital Heart Disease

Arrhythmias account for 55 per 100,000 patient evaluations in pediatric emergency departments. Most arrhythmias in children are amenable to medical management or cardioversion. Rarely, arrhythmias lead to significant hemodynamic instability requiring extracorporeal membrane oxygenation (ECMO) support. This study seeks to evaluate children under 1 year of age with a structurally normal heart requiring ECMO for an arrhythmia. This is a retrospective review of the Extracorporeal Life Support Organization Registry. All patients less than 1 year of age between 2009 and 2019 with a diagnosis of arrhythmia and without a diagnosis of structural heart malformation were included. Demographics, clinical characteristics, and outcomes were assessed with descriptive statistics and univariate and multivariable analyses. A total of 140 eligible patients were identified from the dataset. The most common arrhythmia was supraventricular tachycardia (SVT) in 70 (50%) patients. ECMO complications occurred in 106 (76.3%) patients and survival to discharge was achieved in 120 (85.7%) patients. In-hospital mortality was associated with neuromuscular blockade prior to ECMO [aOR 10.0 (95% CI 2.95-41.56), p < 0.001], neurologic ECMO complication [aOR 28.1 (95% CI 6.6-155.1), p < 0.001], and race with white race being protective [aOR 0.13, (95% CI 0.02-0.21), p = 0.002]. Similar survival and complication rates were found in subgroup analysis of SVT arrhythmias alone. Arrhythmias necessitating ECMO support in infants without structural congenital heart disease is a rare occurrence. However, survival to hospital discharge is favorable at greater than 85%. Given the favorable survival, earlier and more aggressive utilization of ECMO may result in improved outcomes.

Acute Management of Refractory and Unstable Pediatric Supraventricular Tachycardia

OBJECTIVE

To characterize the management of acute pediatric supraventricular tachycardia (SVT), placing special emphasis on infants, patients refractory to adenosine (refractory SVT), and patients with hypotension, poor perfusion, or altered mental status (unstable SVT).

STUDY DESIGN

Retrospective cohort study of patients 0-18 years of age without congenital heart disease who presented to our pediatric hospital from January 2003 to December 2012 for the treatment of acute SVT. Multiple logistic regression was applied to identify whether age was a risk factor for different SVT therapies. Model fit and residuals also were examined.

RESULTS

We identified 179 episodes for SVT. First dose of adenosine was effective in 72 (56%) episodes, and a second dose was effective in 27 of 54 (50%) episodes, leaving 27 (15%) episodes with refractory SVT. The response to the first dose of adenosine increased proportionally with age (OR 1.13, 95% CI 1.05-1.2). Only 1 of 17 episodes in infants responded to the first dose of adenosine. Refractory SVT was more frequent in infants vs older children (χ² = 5.9 [1 df], P = .01). Unstable SVT was present in 13 episodes and was treated with adenosine and antiarrhythmics. Synchronized cardioversion was performed on 3 patients, 2 patients with unstable SVT, and 1 with refractory SVT.

CONCLUSION

In children with SVT, young age is associated with decreased response to the first dose of adenosine and increased odds of adenosine-refractory SVT. In the treatment of unstable SVT, medical management with various antiarrhythmics before cardioversion may have a role in a subset of patients. Synchronized cardioversion rarely is performed for acute SVT.

Use of adenosine in the treatment of supraventricular tachycardia in a pediatric emergency department

OBJECTIVE

Supraventricular tachycardia (SVT) is the most frequent arrhythmia requiring treatment in childhood, with an estimated incidence of 1/100 to 1/250 children. The treatment of choice of the acute event is intravenous adenosine. This study aimed to determine if doses of adenosine higher than previously described are needed to successfully revert SVT in children.

METHODS

This is a retrospective study of SVT cases in a tertiary hospital from January 2007 to December 2011.

RESULTS

A total of 44 episodes of SVT were recorded in 26 patients. Mean age was 3.1 years. In 39 patients (89%), adenosine was administered, reverting to stable sinus rhythm in 29 episodes, which represents an effectiveness of 75%. In relation to the number of doses administered, 12 patients (30%) received a single dose, with a mean (SD) response dose of 112 (35) µg/kg; 16 (41%) received 2 doses, with a mean (SD) response dose of 188 (55) µg/kg; and 9 (24%) received 3 doses, with a mean (SD) response dose of 249 (108) µg/kg. Finally, in 2 patients (4%), 4 doses of adenosine were administered, with only 1 of them responding to a dose of 300 µg/kg. The mean (SD) dose that reverted the SVT to normal sinus rhythm was 173 (84) µg/kg, and the mean (SD) number of doses administered was 1.7 (0.8) (range, 1-4). Sixty-six percent were discharged home, without the need to be transferred to pediatric intensive care unit or pediatric ward.

CONCLUSIONS

Most of the patients with SVT episodes require treatment with more than 1 dose of adenosine. Doses higher than the usually described in the guidelines are necessary to revert SVT. Most patients can be discharged home from the emergency department, without the need of hospital admission.

Part 10: Pediatric basic and advanced life support: 2010 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations

Note From the Writing Group: Throughout this article, the reader will notice combinations of superscripted letters and numbers (eg, “Family Presence During ResuscitationPeds-003”). These callouts are hyperlinked to evidence-based worksheets, which were used in the development of this article. An appendix of worksheets, applicable to this article, is located at the end of the text. The worksheets are available in PDF format and are open access.

Supraventricular tachycardia as a presenting feature of volvulus in a 15-month-old boy

A 15-month-old boy presented in shock with a supraventricular tachycardia following a 12-h history of worsening abdominal pain and vomiting. The supraventricular tachycardia reverted to sinus tachycardia with fluid resuscitation and adenosine. He was noted to have a distended and firm abdomen. A presumptive diagnosis of intestinal ischaemia was subsequently confirmed at laparotomy when an internal hernia with a distal small bowel volvulus and necrosis was found. Intestinal ischaemia presenting with a life-threatening cardiac dysrhythmia in a child appears not to have been reported previously.

Neonatal tachyarrhythmias

CARDIAC ARRHYTHMIAS CAN BE found in the fetus and the neonate. Arrhythmias that are seen in the neonate include sinus bradycardia and tachycardia, premature atrial and ventricular contractions, supraventricular tachycardia, atrial flutter, ventricular arrhythmias, and heart block. Although infants with structural or functional anomalies can have arrhythmias, many arrhythmias result from noncardiac causes, such as hypoxemia and acidosis.1

Supraventricular tachycardia in the neonate and infant

Supraventricular tachycardia (SVT) is the most common sustained arrhythmia to present in the neonatal and infancy age group. Predisposing factors (congenital heart disease, drug administration, illness and fever) occur only in 15% of infants. The presentation of SVT in the neonate is frequently subtle, and may include pallor, cyanosis, restlessness, irritability, feeding difficulty, tachypnea, diaphoresis and grunting. Congestive heart failure is more common in infants under 4 months of age (35% incidence). Age-related differences in the distribution of SVT mechanisms occur in different age groups. In infants under 1 year of age, the mechanisms underlying SVT are atrial tachycardia (15%), AV nodal re-entry tachycardia (5%), and AV reciprocating tachycardia (80%). Options for acute management include: use of the diving reflex, intravenous adenosine, transesophageal pacing, and cardioversion. Intravenous administration of verapamil should be avoided. Data regarding freedom from recurrence of untreated SVT in the first year of life are limited, and may be in the range of 25-60%. Chronic therapy with digoxin, beta-blockers, flecainide, sotalol and amiodarone has proved effective in controlling recurrent episodes of SVT. Radiofrequency ablation can be employed successfully in medically refractory cases, but should be avoided in this age group (increased complication rate).