From sudden stroke to heart transplant: unmasking restrictive cardiomyopathy in an adolescent: a case report.

Background: Paediatric acute ischaemic stroke (AIS) is a challenging diagnostic entity. A comprehensive cardiac evaluation is essential in all paediatric AIS cases to rule out cardioembolic sources. We present the case of a teenage female with AIS who was found to have restrictive cardiomyopathy (RCM). Case summary: A 15-year-old female presented to the emergency department with left-sided paresis, hemi-neglect, and facial paralysis. Neuroimaging demonstrated a right middle cerebral artery infarct and mechanical thrombectomy was performed. Chest radiography revealed cardiomegaly and pulmonary oedema, and electrocardiogram (ECG) showed biatrial enlargement with repolarization abnormalities. Echocardiography revealed RCM, which was subsequently confirmed by cardiac magnetic resonance imaging, providing support for a cardioembolic source, and she received a heart transplant. Genetic testing ultimately identified a heterozygous pathogenic variant in Discussion: Paediatric AIS is uncommon and frequently idiopathic, with cardioembolism accounting for ∼15% of adolescent cases. Restrictive cardiomyopathy, although rare, should be considered in the differential, as thromboembolic complications occur in up to one-third of patients, with nearly half of these involving the cerebral circulation. Importantly, stroke may be the first manifestation of the disease. Early cardiac screening, including ECG, chest radiography, N-terminal pro-B-type natriuretic peptide (NT-proBNP), and echocardiography, is crucial in the early diagnostic work-up of paediatric AIS. Prompt recognition of diastolic dysfunction and atrial enlargement may accelerate diagnosis and inform timely referral for heart transplantation. In short, paediatric AIS, though rare, requires thorough diagnostic evaluation to identify potential cardioembolic sources.