Pediatric Dilated Cardiomyopathy With Suspected Hereditary Protein C/S and Antithrombin III Deficiency Presenting as Ischemic Stroke—A Rare Case Report

Objective To report a rare case of pediatric dilated cardiomyopathy (DCM) with suspected hereditary protein C, protein S, and antithrombin III deficiency presenting as ischemic stroke. Background Children with DCM are at increased risk of thromboembolism. Inherited thrombophilias are an uncommon but important cause of pediatric stroke and may coexist with cardiac disease. Case Presentation An 8‐year‐old female presented with heart failure and was diagnosed with severe DCM (LVEF ∼24%). Despite medical therapy and antiplatelet prophylaxis, she developed acute right‐sided hemiparesis. MRI confirmed a left hemispheric ischemic stroke. Thrombophilia workup revealed reduced protein C (41.5%), protein S (50.7%), and antithrombin III (65.1%) levels, suggestive of a suspected inherited thrombophilic disorder, while PT/aPTT/INR remained normal. She was managed conservatively with antiplatelets and rehabilitation, showing partial neurological recovery. Follow‐up demonstrated improved cardiac function (LVEF ∼50%). Conclusion The coexistence of DCM and suspected inherited thrombophilia can predispose to ischemic stroke in children. Normal routine coagulation tests do not exclude thrombophilia; targeted screening should be considered in high‐risk cases.