Tachycardia-Induced Cardiomyopathy in a 1-Month-Old Infant

Abstract

Supraventricular tachycardia (SVT) is the most common arrhythmia in children and is especially common in infants. SVT is typically thought of as an acute condition; however, if unrecognized, a persistent tachyarrhythmia can progress to a state of cardiac contractile dysfunction known as tachycardia-induced cardiomyopathy. A high index of suspicion for an underlying arrhythmia is needed in the workup of any patient with new onset heart failure, and the 12-lead electrocardiogram can aid in the diagnosis. While this may be a rare cause of dilated cardiomyopathy and heart failure in children, the condition is usually reversible and should be considered in infants and young children.

Application of Neonatologist Performed Echocardiography in the Assessment and Management of Neonatal Heart Failure unrelated to Congenital Heart Disease

“…Fetal and early persistent neonatal arrhythmias can cause a transient DCM phenomenon, referred to as arrhythmia-induced neonatal cardiomyopathy (AINC). In neonates, all tachyarrhythmia (even supraventricular and ventricular ectopy) could potentially cause AINC, 96 but atrial ectopic tachycardia (AET) is the most common of AINC. 97 In older infants and children, the etiologies of cardiomyopathy also include re-entry tachycardia (i.e.…”

“…This is probably an under-appreciated etiology of dilated cardiomyopathy and myocardial dysfunction in children. 96 The sustained tachycardia in AINC may lead to abnormal cellular remodeling, diminishing the number of microtubules in the cardiac myocyte and contributing to contractile dysfunction. 99 Chronic tachycardia may lead to a depletion of high-energy phosphates and cellular reduction in sarcolemmal sodium/potassium ATPase activity and enzyme distribution that may affect calcium handling.…”

“… 100 Neonates will therefore have more rapid deterioration in function due to lower intracellular calcium reserves. 96 …”

“…Even a single, sustained episode of typical supraventricular tachycardia may be unrecognized until HF symptoms emerge; thus, neonates may present with clinical signs of shock. 96 , 99 If the arrhythmia is first recognized after birth, the infant may still be asymptomatic, but left untreated or unrecognized after a few days to weeks of accelerated ventricular rates, signs of congestive heart failure and a state of cardiac contractile dysfunction can evolve because of the DCM. 96 AINC can also present with tachycardia interspersed with periods of sinus rhythm, and therefore the responsible tachycardia may also not be evident at presentation.…”

“… 96 , 99 If the arrhythmia is first recognized after birth, the infant may still be asymptomatic, but left untreated or unrecognized after a few days to weeks of accelerated ventricular rates, signs of congestive heart failure and a state of cardiac contractile dysfunction can evolve because of the DCM. 96 AINC can also present with tachycardia interspersed with periods of sinus rhythm, and therefore the responsible tachycardia may also not be evident at presentation. 96 , 97 The neonate cannot verbalize the common symptoms of palpitations, further complicating the early identification of heart failure.…”