Investigations
A transthoracic echocardiogram (TTE) revealed a moderately to severely
reduced left ventricular systolic function with an estimated ejection
fraction of 30-35%, moderate transvalvular aortic regurgitation, with
increased transprothetic pressure gradients. Prosthetic transvalvular
velocities (Vmax 3.55m/s) were increased with peak gradient of 51 mmHg
and mean gradient of 32 mmHg [Figure 1]. A transesophageal
echocardiogram (TEE) revealed an abnormally functioning mechanical valve
with transvalvular peak gradient of 49 mmHg, mean gradient of 29 mmHg,
Doppler velocity index of 0.21 and acceleration time of 114msec,
consistent with prosthetic aortic valve stenosis [video 1, Figure
2]. Leaflet mobility and sub valvular structures could not be
evaluated because of acoustic shadowing on esophageal views. Valve
fluoroscopy revealed an immobile disc without any obvious obstructive
lesions [video 2]. A Multi detector computed tomography (MDCT) was
performed to help in assessing the etiology of valve dysfunction. It
revealed a low-density lesion (40HU), consistent with thrombus,
measuring 8 x 5 mm interfering with the mobility of the posterior disc
of the Prosthetic Aortic Valve [Figure 3].