Clinically Proven Cardiac Sarcoidosis Presenting as Recurrent Ventricular Tachycardia With Severely Reduced Left Ventricular Function: A Case Report

Cardiac sarcoidosis is a rare but life-threatening manifestation of systemic sarcoidosis, frequently presenting with ventricular arrhythmias, heart block, or sudden cardiac death. It remains underdiagnosed owing to its diverse clinical presentation and rarity and the limitations of conventional diagnostic modalities. We report a case of a 42-year-old man with no prior cardiac history who presented with a three-day history of recurrent palpitations and three to four syncopal episodes. Electrocardiography during syncope demonstrated self-terminating ventricular tachycardia (VT), with one episode lasting five hours, requiring pharmacological cardioversion. Coronary angiography revealed entirely normal coronary arteries. Cardiac magnetic resonance imaging (CMR) with late gadolinium enhancement (LGE) identified a non-ischemic, epicardial-to-mid-myocardial enhancement pattern involving the interventricular septum, inferior wall, and lateral wall, accompanied by mediastinal and hilar lymphadenopathy. Two-dimensional echocardiography revealed severe left ventricular (LV) dysfunction with an ejection fraction of 15%. Serum angiotensin-converting enzyme levels were markedly elevated at 90 U/L (reference: 12-66 U/L). The patient was commenced on systemic corticosteroids (prednisolone), antiarrhythmic therapy (amiodarone), anticoagulation, and guideline-directed heart failure therapy. This case underscores the diagnostic utility of CMR-LGE in identifying non-ischemic infiltrative cardiomyopathy and highlights the importance of considering cardiac sarcoidosis in patients presenting with unexplained VT and severely reduced LV function. Early immunosuppressive therapy and multidisciplinary management are pivotal in improving clinical outcomes.