A Case of Amitriptyline-induced Myocarditis.

Area of Science:

• Cardiology
• Toxicology
• Pharmacology

Background:

• Tricyclic antidepressants (TCAs), like amitriptyline, are widely prescribed but possess a significant cardiotoxicity profile that is under-discussed in medical literature.
• Amitriptyline overdose presents a serious risk, necessitating prompt recognition and management of potential cardiac complications.

Observation:

• A 21-year-old male with no prior cardiac history presented with decreased consciousness following an amitriptyline overdose.
• Initial EKG revealed sinus tachycardia, prolonged QRS, prolonged QTc, and non-specific ST-T wave changes, prompting aggressive management with fluid resuscitation and sodium bicarbonate.
• Despite clinical improvement, subsequent troponin elevation, fever, leukocytosis, and inflammatory markers indicated cardiac involvement.

Findings:

• Transthoracic echocardiography (TTE) showed reduced ejection fraction (45%-50%) and mild-to-moderate pericardial effusion.
• Cardiac magnetic resonance (CMR) confirmed acute myocarditis, moderate pericardial effusion, moderate left ventricular dilation, and preserved coronary arteries.
• The constellation of clinical presentation, EKG findings, and advanced cardiac imaging in the context of amitriptyline overdose strongly suggests direct drug-induced cardiotoxicity.

Implications:

• This case underscores the potential for amitriptyline to induce direct myocardial and pericardial toxicity, leading to myocarditis and effusion.
• Clinicians should maintain a high index of suspicion for cardiac involvement in amitriptyline overdose, even in young patients without prior cardiac history.
• Further research into the specific mechanisms of TCA cardiotoxicity is warranted to improve patient outcomes and treatment strategies.