Right Ventricular Thrombus Following an LAD Infarction: A Rare Case Report of a Common Culprit

Abstract Background Right ventricular (RV) thrombus is a rare complication of myocardial infarction, most often associated with inferior infarcts or pulmonary embolism. This case highlights a unique presentation of RV thrombus following an anterior ST-elevation myocardial infarction (STEMI), expanding our understanding of infarct extension patterns in left coronary dominance and underscoring the diagnostic value of advanced cardiac imaging. Case summary A 39-year-old male presented with chest pain and dyspnea. Electrocardiography and cardiac biomarkers confirmed an anterior STEMI. Coronary angiography revealed a thrombotic occlusion of the mid-left anterior descending artery (LAD) in a left-dominant system, treated with stenting. Four days later, transthoracic echocardiography detected a RV thrombus, which was confirmed on cardiac MRI. Imaging revealed extensive myocardial infarction in the LAD territory including the apex of both ventricles with transmural necrosis and significant microvascular obstruction. The patient was anticoagulated and subsequently received a two-chamber ICD due to episodes of ventricular fibrillation. Follow-up imaging showed thrombus resolution. Conclusion This case demonstrates that anterior infarctions due to wraparound LAD occlusion can extend into the right ventricle and result in thrombus formation, even with preserved RV function. It reinforces the importance of cardiac MRI for comprehensive assessment and highlights the need for awareness of atypical infarct complications.