Early Recognition of Giant Cell Myocarditis in a Patient With Fascicular Ventricular Tachycardia

BACKGROUND: Giant cell myocarditis (GCM) is a rare, rapidly progressive inflammatory cardiomyopathy, often manifesting with ventricular arrhythmias or heart failure. Early recognition and immunosuppressive therapy are crucial for improving outcomes. CASE SUMMARY: A 65-year-old man undergoing preoperative evaluation for hip surgery was found to have a wide complex tachycardia. He reported palpitations and dizziness but denied chest pain. Troponin was significantly elevated (5,206 ng/L, peaking at 5,647 ng/L). Transthoracic echocardiography showed reduced left ventricular ejection fraction (35%-40%), and cardiac magnetic resonance suggested myocarditis. Endomyocardial biopsy confirmed GCM. The patient was started on pulse-dose steroids, tacrolimus, and mycophenolate mofetil, resulting in swift improvement as indicated by rapidly downtrending troponin levels. He was ultimately listed for heart transplantation. DISCUSSION: GCM often manifests with ventricular arrhythmias and rapid clinical deterioration. This case underscores the importance of recognizing myocarditis as a cause of ventricular tachycardia, particularly in patients with elevated troponins and nonobstructive coronary artery disease. Early diagnosis and immunosuppression are key to improving prognosis. TAKE-HOME MESSAGES: Consider myocarditis in patients with ventricular tachycardia and high troponins and nonobstructive coronary artery disease. Early recognition and immunosuppressive therapy are critical for management of GCM. Cardiac magnetic resonance and biopsy are essential for diagnosis. Orthotopic heart transplantation should be considered in all cases of GCM owing to the associated high mortality rates.