Prescription Amphetamine Use Associated With Acute Cardiomyopathy

Abstract

An 18-year-old male with a past medical history significant for Attention Deficit Hyperactivity disorder (ADHD) presented with chest pain and shortness of breath. He reportedly took four times the amount of lisdexamphetamine as normally prescribed, 160 mg total. He had no other history of illicit drug, tobacco, or alcohol abuse. On physical examination he was anxious appearing and his blood pressure was 188/98 mmHg, HR 65 bpm, and saturating 99% on room air. Urinary drug screen was positive for amphetamines. Due to overdose protocol, he was admitted to the ICU where his respiratory status acutely decompensated necessitating emergent intubation. Chest radiograph revealed diffuse bilateral interstitial opacities. Sinus tachycardia with inferior-lateral ST depressions were noted on his ECG. Troponin I peaked at 0.481 ng/mL. An emergent transthoracic echocardiogram revealed an EF of 15-20% with mid-ventricular severe hypokinesis, basal inferior/lateral dyskinesis, and sparing of the apex. Diastology was consistent with grade II dysfunction. A diagnosis of stress-induced cardiomyopathy secondary to prescription amphetamine overdose was made. Repeat transthoracic echocardiogram at 48 hours revealed a recovering ejection fraction of 45-50% with mild global hypokinesis. He was discharged and lost to follow up thereafter. Amphetamine use associated cardiomyopathy, which has also been described as Amphetamine Type Stimulant Associated Cardiomyopathy (ATSAC), should be considered in patients prescribed amphetamines presenting with clinical features of heart failure. Several cases have reported a link between illicit amphetamines and reversible stress induced cardiomyopathy, however, few have shown an association with prescription amphetamines. In the setting of a hyper-catecholamine state, proposed mechanisms of cardiotoxicity have included oxidative stress, perfusion defects, cardiomyocyte necrosis, and defects in intracellular calcium homeostasis, among others. Additional cardiovascular complications linked to these medications include acute coronary syndromes, myopericarditis, and arrhythmias. Our patient's echocardiogram was suggestive of atypical basal variant of Takotsubo's that significantly improved on subsequent echocardiographic evaluation. This case highlights the importance of recognizing the potential cardiotoxicities associated with commonly prescribed amphetamine type stimulants. Frequently, as depicted in our case, the acute cardiomyopathy may be transient. Prompt diagnosis and withdrawal of the offending agent may lead to recovery of cardiac function and improved patient outcomes.