Aortic valve lesion in a dialysis patient
A pleasant elderly patient on dialysis presented with fever, chills, and dizziness. No obvious signs of dialysis access infection but found to have gram positive bacteremia. Following are the focused echocardiogram clips demonstrating an echogenic mass-like structure adherent to aortic valve (non-coronary cusp) prolapsing into LV outflow tract. It is relatively regular and doesn’t seem to move independent of the valve unlike our recent case of tricuspid endocarditis. LV systolic function appears to be reduced but no known valvular heart disease. There was some aortic regurgitation on color flow images. The patient does have paroxysmal atrial fibrillation.
Magnetic resonance imaging (MRI) of the brain demonstrated multiple tiny infarcts in the cortical and subcortical regions suggestive of an embolic stroke. Based on transthoracic echocardiogram, it is difficult to say if this is a vegetation or an old, calcified thrombus and/or there is a hidden thrombus somewhere else in the setting of atrial fibrillation.
A transesophageal echocardiogram (TEE) is usually needed to establish the diagnosis and look for complications such as peri-aortic abscess because it allows closer evaluation of the values with a higher resolution. Unfortunately, our patient expired before TEE was performed. *Patient kindly consented to share these unidentified images for educational purposes when we performed FoCUS study.
Apart from vegetation and thrombus, differential of aortic mass also includes Lambl’s excrescence and fibroelastoma. Lambl’s excrescences are fine filamentous lesions of valvular leaflets considered as a degenerative change due to mechanical wear and tear. Papillary fibroelastoma is a benign avascular tumor arising from the normal endocardium. It can occur anywhere in the heart, but more commonly arises from valvular endocardium. Following table summarizes the important differences between a vegetation and these two benign abnormalities.
Additional good-to-know point: In a patient with sinus rhythm, the occurrence of a first-degree AV block in this scenario is strongly suggestive perivalvular extension of an aortic abscess. This is due to the anatomical proximity of the aortic valve to the bundle of His. The inferior aspect of the noncoronary cusp of the aortic valve overlies interventricular septum along which the bundle branches run. Direct perivalvular extension of infection into this area disrupts the conduction system and can lead to AV or bundle branch blocks. These disruptions increase mortality and confer worse prognosis.