Ventricular Tachycardia as a Manifestation of Cardiac Metastasis Mimicking Acute Coronary Syndrome: A Case Report

We report the case of a 64-year-old male patient with a history of heart failure with midrange ejection fraction (EF), confirmed by cardiac MRI, and a coronary angiography performed three years earlier showing only mild coronary lesions. His past medical history also included a pulmonary embolism and lingual squamous cell carcinoma treated with radiotherapy, which remained in remission for three years. He presented to the emergency department with syncope, which was found to be secondary to ventricular tachycardia with a left bundle branch block morphology and a negative QRS morphology in the inferior leads, as well as in lead I and aVL, consistent with a midseptal origin of the tachycardia. Intravenous amiodarone was administered, successfully restoring sinus rhythm. Transthoracic echocardiography revealed no significant structural abnormalities aside from a midrange EF. On the following day, coronary angiography revealed a long 60% stenotic lesion in the mid left anterior descending artery (LAD), which could represent either an atherosclerotic lesion or a parietal hematoma. A similar irregular lesion was observed in the first diagonal branch. A cardiac MRI was performed and revealed a septal myocardial mass with radiological features suggestive of a secondary (metastatic) lesion, potentially explaining the arrhythmic event and the stenotic lesion. A whole-body CT scan showed multiple secondary lesions in the liver, kidneys, adrenal glands, peritoneum, gluteal muscle, and lungs, as well as a pulmonary embolism. Unfortunately, the patient died one month after discharge. This case highlights how a cardiac mass, likely metastatic, may present with ventricular arrhythmias and mimic an acute coronary syndrome, with a coronary angiography that can also be misleading. It also underscores the pivotal role of cardiac MRI in establishing the correct diagnosis when echocardiography and angiography yield inconclusive or atypical findings.