Abstract Title Atrial Fibrillation Presenting as Renal Infarction Background Renal infarction is caused by occlusion of renal artery or its branches, due to emboli from cardiac sources or in situ thrombosis. It presents as sudden flank or abdominal pain, with labs showing elevated LDH, hematuria, proteinuria. Prompt diagnosis is crucial to initiate timely revascularization therapies.

Case Presentation A 78-year-old male with past medical history of hypertension, diabetes mellitus, hyperlipidemia, COPD, meningioma presented to the emergency department with complaints of pain in the left flank and umbilical region which started gradually over the past few days and was described as dull and non-radiating. Physical evaluation revealed stable vital signs with hypertension, chronic normocytic anemia, irregularly irregular pulse, Left costovertebral angle (CVA) tenderness, bilateral chronic hand tremors. No focal neurological deficits. Denies fever, nausea, vomiting, diarrhea, constipation, anorexia, alcohol use, changes with meal, similar pain, incontinence, dysuria, hematuria, changes with urine output, urinary frequency, chest pains, palpitations, syncope, orthopnea, PND, edema. Initial Diagnostic workup included negative troponin, COVID-19/flu/RSV tests, and a chest X-ray showing mediastinal widening. Further investigations with a CT angiography chest ruled out aortic aneurysm or dissection but noted a region of low density in the left kidney parenchyma suggestive of multiple cortical infarcts. Urinalysis was positive for microscopic blood and 1 RBC. An EKG demonstrated new-onset atrial fibrillation (Afib). Cardiology consulted recommended to start anticoagulation therapy for atrial fibrillation and electrophysiology with no immediate plan for cardioversion. Later, CTAP with and without contrast show findings consistent with multiple acute renal infarcts (ARI) in the left kidney. Urology was consulted and determined no surgical intervention was indicated, recommending anticoagulation to prevent further complications from kidney infarcts. The patient was educated about his condition and discharged with appropriate outpatient follow-up.

Discussion ARI is potentially serious medical condition but its clinical presentation of is often nonspecific, leading to delays in diagnosis and treatment. Autopsy studies suggest the incidence of renal infarction is 14 per 1000, or 1.4%. Other retrospective studies of ER admissions found an incidence of 0.004% to 0.007%. In our case, the patient's abdominal pain with no previous history of arrhythmias prompted further evaluation, revealing new-onset AFib on EKG and subsequent diagnosis of renal infarction on imaging. Afib can cause thrombotic complication to any body part, most commonly being ischemic stroke. Clinicians should suspect other systemic embolization phenomena in patients with Afib.