A Crashing 2-Week-Old

Educational Objectives

The goals of this program are to improve recognition and management of supraventricular tachycardia in infants. After hearing and assimilating this program, the clinician will be better able to:

1. Choose appropriate techniques for the management of refractory supraventricular tachycardia.

Summary

History and physical examination: 2-wk-old female infant presents with 12-hr history of increased sleepiness, changes in breathing, and refusal to feed; prior to presentation, noted to be limp and lethargic with purple appearance of hands and feet; vital signs — patient hypothermic, tachycardic, and hypoxemic

Differential diagnosis: sepsis — most common etiology for age group; administer antibiotics as soon as possible (cerebrospinal fluid cultures not immediately affected by antibiotics); administer ampicillin and cefotaxime (ceftriaxone if >4 mo of age); give drugs intramuscularly if intravenous (IV) access not established

Other etiologies: undiagnosed congenital heart disease — ductal-dependent lesions may present as patent ductus arteriosus (PDA) closes; check O2 saturations on right upper extremity (preductal) and on either leg (postductal); order chest x-ray and electrocardiography (ECG); check blood pressure (BP) in all extremities; administer prostaglandin if infant crashing; echocardiography often unreliable; congenital adrenal hyperplasia — results of newborn screening may not be available or known at time of presentation; laboratory results would show profound metabolic acidosis, hyperkalemia, and hyponatremia; administer hydrocortisone (25 mg IV); treat hyperkalemia with calcium, insulin, glucose, albuterol, and sodium polystyrene sulfonate (Kalexate, Kayexalate, Kionex); nonaccidental trauma — perform thorough physical examination

Management: correct hypoxemia — provide blow-by oxygen within 2 in of face; establish IV access — in sick children <6 yr of age, use intraosseous (IO) infusion if peripheral access not obtained within 90 sec or 3 attempts; select appropriately sized needle (pink [15 mm] for babies <40 kg) to avoid advancing through bone; use stabilizer to keep IO in place; preferred location medial aspect of proximal tibia 2 fingers below patella; use gentle touch and expect push-back; release trigger when lack of resistance noted; alternate sites include distal femur (1 cm above patella and 1 cm medial) or proximal humerus for children >6 yr of age

History and physical examination (continued): history — unable to obtain IV access; infant spontaneously improved; vital signs stabilized; infant transferred to Dartmouth emergency department from outside hospital; examination — alert; slightly hypothermic; normal heart rate and respiratory rate; normal O2 saturation; normal BP; normal fingerstick glucose level

Management: urinalysis normal; single view chest x-ray read as pneumonia (no antibiotics administered); lumbar puncture performed to complete sepsis workup; consider scalp veins for peripheral access in stable infant

Physical examination: heart rate increased >300 bpm but otherwise stable

Management: ECG showed narrow complex tachycardia (supraventricular tachycardia [SVT]); uniform (nonsinus) P-waves visualized; vagal maneuver (ice to face) slowed heart rate from 340 to 171 bpm; transitioned to pediatric intensive care unit; tachycardia returned and unresponsive to 3 doses of adenosine; 2 attempts at cardioversion unsuccessful; no response to another trial of adenosine; returned to sinus rhythm after 15 min on IV amiodarone; echocardiography showed moderate atrial septal defect; transitioned to oral sotalol and discharged

Discussion: refractory SVTs include AV node-dependent SVT and AV node-independent SVT (eg, atrial tachycardias); prevalence of SVT in children 1 in 200 to 400; atrial tachycardias comprise 14% of SVT

Ectopic atrial tachycardia: caused by abnormal electrical focus in atrium; primarily affects infants and children; typically responsive to medical therapy and resolves within 1 yr in children <3 yr of age; more refractory to medical treatment in children >3 yr of age; in infants, presentation similar to that of heart failure (ie, tachycardia-induced cardiomyopathy); signs and symptoms include failure to thrive, sweating, and tachypnea with feeding; treatment — not responsive to cardioversion; use class III antiarrhythmic drugs that prolong depolarization phase (eg, amiodarone, sotalol), class II antiarrhythmic drugs (eg, esmolol), and class I antiarrhythmic drugs that block sodium channel

Take-home points: consider SVT for infant heart rate >220 bpm; initiate vagal maneuvers (eg, ice to face) and adenosine for SVT; attempt cardioversion; consider amiodarone and esmolol for refractory SVT

Readings

Ge H et al: Predictors of pharmacological therapy of ectopic atrial tachycardia in children. Pediatr Cardiol, 2017 Feb;38(2):289-95; Lewis J et al: Acute management of refractory and unstable pediatric supraventricular tachycardia. J Pediatr, 2017 Feb;181:177-82; L’Italien K et al: Usefulness of echocardiography in children with new-onset supraventricular tachycardia. J Am Soc Echocardiogr, 2018 Oct;31(10):1146-50; Li X et al: Efficacy of intravenous sotalol for treatment of incessant tachyarrhythmias in children. Am J Cardiol, 2017 May 1;119(9):1366-70; Sohinki D, Obel OA: Current trends in supraventricular tachycardia management. Ochsner J, 2014 Winter;14(4):586-95; Vignati G, Annoni G: Characterization of supraventricular tachycardia in infants: clinical and instrumental diagnosis. Curr Pharm Des, 2008;14(8):729-35.

Disclosures

For this program, Dr. Rutman and members of the faculty and planning committee reported nothing to disclose.

Acknowledgements

Dr. Rutman was recorded at Managing Medical Emergencies, held May 16-18, 2018, in Lebanon, NH, and presented by Dartmouth-Hitchcock. For more information about upcoming CME activities presented by Dartmouth-Hitchcock, visit: med.dartmouth-hitchcock.org. The Audio Digest Foundation thanks Dr. Rozycki, Dr. Namias, Dr. Rutman, and the sponsors for their cooperation in the production of this program.

CME/CE INFO

Accreditation:

Lecture ID:

EM360803

Qualifies for:

Expiration:

This CME course qualifies for AMA PRA Category 1 Credits™ for 3 years from the date of publication.

Instructions:

To earn CME/CE credit for this course, you must complete all the following components in the order recommended: (1) Review introductory course content, including Educational Objectives and Faculty/Planner Disclosures; (2) Listen to the audio program and review accompanying learning materials; (3) Complete posttest (only after completing Step 2) and earn a passing score of at least 80%. Taking the course Pretest and completing the Evaluation Survey are strongly recommended (but not mandatory) components of completing this CME/CE course.

Estimated time to complete this CME/CE course:

Approximately 2x the length of the recorded lecture to account for time spent studying accompanying learning materials and completing tests.