Sustained monomorphic ventricular tachycardia as the first manifestation of probable cardiac sarcoidosis: A case report

Cardiac sarcoidosis is an inflammatory heart disease that can cause conduction block, ventricular arrhythmias, and cardiomyopathy. Sustained monomorphic ventricular tachycardia is a high-risk presentation and may be the first sign of disease. A 69-year-old man with paroxysmal atrial fibrillation and chronic diastolic heart failure presented with palpitations, dizziness, and shortness of breath after a physical-therapy session. In the emergency department, he was found to be in atrial fibrillation with rapid ventricular response and frequent sustained runs of monomorphic ventricular tachycardia at rates >200 beats/min. Intravenous amiodarone was started. Echocardiography showed mildly reduced left ventricular ejection fraction (46%) and apical hypokinesis. Coronary angiography revealed only minimal nonobstructive coronary artery disease. Cardiac magnetic resonance imaging demonstrated mildly reduced left ventricular function (45%) and a nonischemic pattern of late gadolinium enhancement in the basal anteroseptal, basal inferoseptal, mid-inferoseptal, and inferior segments, highly suggestive of cardiac sarcoidosis. Endomyocardial biopsy was not pursued because of its low sensitivity and invasive risk, and the patient met contemporary criteria for “probable” cardiac sarcoidosis based on imaging and clinical findings. A targeted evaluation for extracardiac disease and infiltrative mimics was unremarkable. Further testing, including positron emission tomography, was planned as outpatient testing. He underwent implantation of a single-chamber implantable cardioverter–defibrillator for secondary prevention and was discharged in stable condition. This case highlights cardiac sarcoidosis as an important cause of sustained ventricular tachycardia in patients with non-ischemic scar on cardiac magnetic resonance and minimal coronary disease. Modern guidelines allow a working diagnosis without biopsy, relying instead on cardiac magnetic resonance and positron emission tomography.