Echocardiographic Assessment of Prosthetic Valves

Figures

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  Fig. 1.. Maximal opening of a 21 mm SJM Regent Mechanical Heart Valve in the aortic position with normal valve function. Fluoroscopy demonstrated brisk and complete opening and closing of the leaflets. Note the leaflets are not quite 90 degrees perpendicular to the annular plane at the time of maximal opening which still is within normal limits.

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  Fig. 2.. An image of a prosthetic aortic valve with subvalvular pannus ingrowth leading to significant obstruction and stenosis after valve explant. The orifice area of the surgical specimen showed excellent correlation with calculated orifice area via Doppler echocardiography.

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  Fig. 3.. Parasternal long axis view of a four year old 21 mm St Jude Trifecta pericardial aortic valve in a patient who presented with progressive exertional dyspnea and presyncope and was found to have severe prosthetic obstruction. Note the highly echogenic aortic bioprosthesis, suggesting a heavily calcified valve with stenotic orifice, which was confirmed during valve replacement.

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  Fig. 4.. Continuous Wave Doppler of a normally functioning aortic prosthesis with functionally obstructive hemodynamics. Note the triangular contour of the Doppler jet with a rapid acceleration time (AT) of 70 msec.

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  Fig. 5.. Continuous Wave Doppler of an aortic prosthesis with structurally obstructive hemodynamics. Note the rounded contour of the Doppler jet, with an acceleration time (AT) of 160 msec.

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  Fig. 6.. Correct and Incorrect method of measuring the TVI of the LVOT. Top Images: Pulse Wave Doppler with sample volume placed immediately proximal to the zone of flow acceleration within the LVOT, with an accurate TVI of 27 cm. Bottom images: Pulse Wave Doppler with sample volume placed within the zone of flow acceleration leading to a spuriously elevated TVI of 38 cm. This can lead to an elevated DVI in a patient with an obstructive prosthesis, and care should be taken to avoid this error.

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  Fig. 7.. Echocardiographic imaging of a patient with a mitral bioprosthesis and heart failure symptoms found to have prosthetic thrombosis. Top Left: Continuous Wave Doppler in a patient with a 31 mm Hancock porcine mitral bioprosthesis who presented with dyspnea on exertion and lightheadedness. The mean gradient was 12 mmHg with a heart rate of 51 and a pressure halftime of 280 msec. The DVI was 5.7, with an EOAi of 0.44 cm2/m2 all consistent with severe obstruction. Top Right: This is confirmed on transesophageal echo which shows an echogenic mass on the anterior leaflet that is highly mobile and independent of the prosthetic leaflets; additionally there is increased leaflet thickness and mobility on the live images. Bottom Left: Color Doppler demonstrates turbulence during diastole with transmitral flow due to the obstruction. Because of suspicion for mitral prosthetic thrombosis, the patient was initiated on warfarin therapy. Bottom Right: Transesophageal echo image of the mitral valve after 6 weeks of warfarin therapy showing complete resolution of the thrombosis. This case highlights the importance of recognizing bioprosthetic valve thrombosis on one’s differential with an incidence…

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  Fig. 8.. Echocardiographic imaging of a patient with a mitral bioprosthesis and prosthetic dehiscence. Top Left and Right: Continuous Wave Doppler of a male with a Biocor porcine mitral bioprosthesis just 5 months previously. The mean gradient was 11 mmHg with a heart rate of 51. The DVI was 4.0, with an EOAi of 0.48 cm2/m2 which may mislead towards a diagnosis of obstruction. However, the pressure half time was 120 msec, which is too short to be seen in severe structural obstruction. Bottom Left: Transesophageal 2-D image showed rocking of the mitral prosthesis with evidence of a paravalvular gap. Bottom Right: Color Doppler shows torrential MR secondary to a paravalvular leak with an eccentric jet. This was confirmed as prosthetic dehiscence during surgical correction.

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  Fig. 9.. A mitral pressure half time of ≥130 msec associated with a TVI𝐌𝐕𝐑/TVI𝐋𝐕𝐎𝐓 ratio of >2.2 for mechanical mitral prostheses with an increased mean pressure gradient is consistent with structural obstruction such as with thrombosis, pannus ingrowth, or occluder disc immobility. With a TVIMVR/TVILVOT ratio of >2.2 with a PHT of <130 msec, functional stenosis due to mitral regurgitant inflow volume (reflected by increased TVIMVR) crossing the mitral prosthesis is likely. In high cardiac output states or with tachycardia, the flows across the mitral prosthesis and LVOT would both be increased as reflected by a TVI ratio of <2.2 and a mitral EOAi of ≥1.2 cm2/m2. Mitral prosthesis patient mismatch is likely if the EOAi is <1.2 cm2/m2 with a PHT of <130 msec and a TVIMVR/TVILVOT ratio <2.2. Modified and adapted after reference [22].