(146) A Rare Case of Primary Cardiac Lymphoma Presenting as Out-of-Hospital Cardiac Arrest

Introduction: Ventricular tachycardia (VT) and ventricular fibrillation (VF) are responsible for most cases of sudden cardiac arrest (SCA) in the United States. Etiologic determination can help impact survival. Coronary and structural heart disease are responsible for the majority of cases of SCA. Patients under 40 years of age present a unique challenge as etiologies of SCA can be more varied. We present a young patient with SCA due to VF/VT who was found to have primary cardiac lymphoma after initial work-up was unrevealing.

Description: A 34-year-old was brought to our emergency department after collapsing in the parking lot at Target. She received immediate bystander CPR and was found to be in VF upon arrival of EMS. She underwent two defibrillations for VF and one synchronized cardioversion for VT and regained normal sinus rhythm. Upon arrival, she sustained several additional episodes of VT requiring initiation of amiodarone and lidocaine. Upon further questioning, she denied any prior medical conditions, episodes of syncope or palpitations, alcohol or illicit drug use, or recent illness. She was adopted, and unable to share any relevant family history. Initial workup was remarkable only for a mildly dilated right ventricle (RV) on transthoracic echocardiogram. Cardiac MRI revealed a cardiac tumor infiltrating the RV free wall near the atrioventricular groove, felt to be the cause of her malignant arrythmias. Unfortunately, the mass was not accessible by minimally invasive biopsy and the patient underwent hemi sternotomy with open cardiac biopsy approximately two weeks after her admission. Pathology revealed diffuse large B cell lymphoma. The patient had an ICD implanted and was discharged on amiodarone. Over the ensuing months, she underwent 6 cycles of chemotherapy and is now in remission.

Discussion: Primary cardiac lymphoma is exceedingly rare and cardiac arrest from VT due to primary cardiac lymphoma is not previously well-described in the literature. Interestingly, our patient had a follow-up MRI five days following the identification of her mass and it had already progressed to encase the right coronary artery. Our case highlights the importance of a thorough work-up and maintaining a high index of suspicion for less common causes of cardiac pathology underlying malignant arrythmias.