Idiopathic Renal Infarction

Background Renal infarction may be an underrecognized disorder. Classical teaching holds that cardioemboli, notably in the setting of arterial fibrillation, are responsible. The expanding use of contrast enhanced computed tomography (CT) in patients with acute abdomen may change the spectrum of renal infarction. Methods Twenty-seven consecutive patients presenting to a single university hospital with nontraumatic CT-documented acute renal infarction were studied and stratified according to the presence or absence of cardiac disease, either obvious at presentation or detected during work-up. Results Eleven patients (41%) had obvious cardiac disease, including atrial fibrillation in all but one. Sixteen patients (59%) had no discernible structural or arrhythmic cardiac disease and were classified as idiopathic group. Patients in the idiopathic group were significantly younger (median age in years [interquartile range]: 48 [41-53] versus 75 [53-82] years, P = .003) and, besides smoking, had fewer traditional cardiovascular risk factors. Conclusion Acute renal infarction may occur in individuals of middle age without risk factors for cardioembolism. In patients with renal colic without lithiasis the diagnosis of renal infarction should be considered especially if serum lactate dehydrogenase is elevated, even in the absence of atrial fibrillation.