APICTURE IS WORTH A THOUSAND WORDS

PROSTHETIC MITRAL VALVE THROMBOSIS

A 41-year-old male was referred for echocardiogram because of dyspnea on exertion and fever. A St. Jude prosthetic valve had been implanted in the mitral position in 1994. A mobile mass was noted in the LVOT on TTE and a TEE was performed. Fig. 1A. TEE study in the midesophageal level in the 4-chamber-zoomed view shows a large well-organized thrombus (red arrows), measuring 20 mm x 10 mm occluding the orifice of the bileaflet mitral prosthesis and preventing the anterior prosthesis leaflet from opening. The posterior leaflet motion was also restricted. Fig. 1B. Scanning at 106 degree reveals part of the thrombus (white arrows) protruding into the left ventricular outflow tract.

Fig. 2A. Doppler mitral inflow showed a mean diastolic pressure gradient across the prosthesis of 25 mmHg and MVA of 0.6 cm2. The RVSP was 76 mmHg. The INR was 1.4. The patient was in NYHA class II failure. The patient underwent emergency redo mitral valve replacement. Fig. 2B. Intraoperative Doppler mitral inflow after mitral valve replacement shows remarkable decrease in diastolic gradient to 5mmHg with rapid early filling phase. Effective MVA was 2.9 cm2.

Fig. 3. Surgically excised prosthesis showing large organized thrombus (arrows), which measured 25 mm x 15 mm. The thrombus is shown occupying more than half the prosthesis orifice. Operative finding showed a bileaflet prosthesis placed in almost a transverse position in it's opening axis. The anterior cusp was completely covered by a sheet-like cast of thrombus on both atrial and ventricular sides. The posterior cusp was free, but it's movement was restricted by the thrombus. There was no obvious sign of infection

Abbreviations: LA = left atrium; RA = right atrium; AoV = aortic valve; MV pr = mitral valve prosthesis. RVSP = right ventricular systolic pressure; TTE = transthoracic echocardiography; TEE = transesophageal echocardiography 

From the Echocardiography Laboratory and Cardiothoracic Surgery, Department of Cardiology and Cardiovascular Surgery, Hamad Medical Corporation, Doha, Qatar.

*Director, Non-Invasive Cardiac Laboratory, Cardiology & Cardiovascular Surgery Department, Hamad Medical Corporation, Doha, Qatar. Email:rachel@hmc.org.qa