(128) Right Ventricular Thrombus as a Complication of Inferior ST Segment Elevation Myocardial Infarction

Introduction: Ventricular thrombi are rare complications following ST elevation myocardial infarction (STEMI). Mechanisms typically involve endothelial injury from MI, blood stasis from ventricular dysfunction, and hypercoagulability due to inflammation. Current guidelines recommend treatment with heparin followed by vitamin K antagonists over direct oral anticoagulants for left ventricular thrombus. However, there are no definitive guidelines for right ventricular thrombus (RVT) management which can be associated with life threatening complications such as pulmonary embolism and paradoxical stroke.

Description: We present a case of a 68-year-old male who developed right ventricular thrombus following an inferior STEMI due to total occlusion of the right coronary artery. The patient initially presented with dyspnea and experienced a cardiac arrest due to ventricular fibrillation en route to the hospital. After successful resuscitation, emergent coronary angiography revealed a 100% thrombotic occlusion of the mid-right coronary artery, which was treated with aspiration thrombectomy and drug-eluting stent placement. The patient developed reperfusion arrhythmias and cardiogenic shock at SCAI stage C, necessitating inotropic support with dobutamine without mechanical circulatory support. An echocardiogram revealed left ventricular ejection fraction of 35-40%, moderately enlarged RV with reduced systolic function, and a 2.69 cm x 1.54 cm RV thrombus attached to the posterior wall. Heparin infusion was initiated, later bridged to warfarin targeting an INR of 2-3. Follow-up echocardiography showed no evidence of the RV thrombus. Bilateral lower extremity venous dopplers were negative for deep vein thrombosis. CT angiography was deferred due to acute kidney injury and low suspicion for PE. He was subsequently discharged on oral warfarin.

Discussion: This unique case underscores the importance of prompt intervention with reperfusion therapy to restore RV function. Patients who have severe RV dysfunction from MI and stunned myocardium should be evaluated for presence of RVT and initiated on anticoagulation if indicated to prevent embolic complications. Further studies are warranted to establish standardized treatment protocols and to explore the role of newer anticoagulants in the management of RVT.