LAUSR

In the absence of cardiac pathology, the presence of a dilated inferior vena cava (IVC) is considered idiopathic. To date, this phenomenon has only been described in athletic individuals as an adaptation to chronically augmented venous return. This is the largest prospective cohort study, following ten individuals with idiopathic dilated IVC against an age‐matched control group with annual echocardiograms and cardiac magnetic resonance (CMR) imaging for a median of 55 months. No significant difference was found between echocardiography and CMR measurements in IVC diameter assessment both at baseline and at follow‐up. Over the study period, there was no significant progression of the IVC in diameter as measured either by echocardiography or CMR. None of the patients suffered any cardiovascular events, and there were no hospitalizations. Our findings indicate the benign nature of this condition and provide reassurance with regard to future clinical implications.