Misdiagnosis of restrictive cardiomyopathy averted by a stethoscope: a case report

Iatrogenic arteriovenous (AV) fistula is a rare but treatable cause of high-output heart failure that can mimic restrictive cardiomyopathy and may lead to inappropriate listing for heart transplantation.

A 37-year-old man presented with 7 months of progressive pedal oedema, tense ascites, and exertional dyspnoea. The baseline ECG showed sinus tachycardia with right axis deviation, and chest radiograph revealed cardiomegaly with right pleural effusion. Transthoracic echocardiography and cardiac MRI demonstrated right atrial and ventricular enlargement and severe functional tricuspid regurgitation with preserved biventricular systolic function. A provisional diagnosis of restrictive cardiomyopathy was considered, and the patient was referred for transplant evaluation. Bedside examination identified a continuous murmur loudest over the left iliac fossa. Contrast CT aortogram confirmed a large iliocaval communication between the left common iliac artery and the inferior vena cava. Surgical closure with vascular grafting was performed. At 1-month follow-up, the symptoms resolved and echocardiography showed normalization of right heart size with disappearance of tricuspid regurgitation.

This case highlights the enduring value of focused history and physical examination in detecting extracardiac, reversible causes of heart failure.