July 2024 Issue
ISSN 2689-291X
ISSN 2689-291X
Mechanical Valve M-Mode Contour:
A Disk Excursion Tip!
Description
Mechanical heart valves are often not well visualized by transthoracic 2-dimensional (2-D) echocardiography (TTE) and require transesophageal echocardiography (TEE) and/or fluoroscopy for better evaluation of valve structure and function. The above 2-D TTE and TEE images demonstrate the crucial role of m-mode echocardiography in the assessment of the function of mechanical valves.
In a normally functioning mechanical bileaflet tilting disk mitral valve prosthesis, shown in figure A, there is brisk opening (left yellow arrow) and closure (right yellow arrow) of the prosthetic disks, seen as sharp demarcation of the m-mode opening and closure contour, indicative of unobstructed disk excursion.
When there is obstruction to disk excursion as shown in figure B, the opening and closure m-mode TTE contours (left and right red arrows) become blunted and rounded, rather than sharp and brisk, providing a clue that disk movement is pathological impeded and need to be further evaluated. This can be a valuable tool in TTE imaging given the high temporal resolution of m-mode echocardiography.
Mid-esophageal TEE image shown in figure C, of the case in figure B, clearly demonstrates vegetations along the struts of the mechanical mitral prosthesis; with further vegetations identified along the disks in other images not shown, providing explanation to the abnormal m-mode contour on TTE.
Discussion
The limitations of TTE in the evaluation of prosthetic valves have long been recognized, with TEE providing higher specificity and sensitivity in detecting valvular abnormalities [1]. With evolving technology, a comprehensive multimodality imaging is often required for the complete assessment of prosthetic heart valve function [2].
Technology is in continuous and exponential evolution. As the incremental value of 2-D over m-mode echocardiography was questioned in 1979 [3], there was an obviously limited discussion of m-mode echocardiography in the American Society of Echocardiography recommendations for quality echocardiography laboratory operations document in 2011 [4], prompting expert criticism [5].
M-mode echocardiography remains a valuable tool in echocardiography enjoying a higher temporal resolution than 2-D echocardiography [6]. It remains of great value in assessing prosthetic valve function, as demonstrated in the above discussed images, providing clues which can prompt further assessment when the 2-D images are limited.
References
Mechanical heart valves are often not well visualized by transthoracic 2-dimensional (2-D) echocardiography (TTE) and require transesophageal echocardiography (TEE) and/or fluoroscopy for better evaluation of valve structure and function. The above 2-D TTE and TEE images demonstrate the crucial role of m-mode echocardiography in the assessment of the function of mechanical valves.
In a normally functioning mechanical bileaflet tilting disk mitral valve prosthesis, shown in figure A, there is brisk opening (left yellow arrow) and closure (right yellow arrow) of the prosthetic disks, seen as sharp demarcation of the m-mode opening and closure contour, indicative of unobstructed disk excursion.
When there is obstruction to disk excursion as shown in figure B, the opening and closure m-mode TTE contours (left and right red arrows) become blunted and rounded, rather than sharp and brisk, providing a clue that disk movement is pathological impeded and need to be further evaluated. This can be a valuable tool in TTE imaging given the high temporal resolution of m-mode echocardiography.
Mid-esophageal TEE image shown in figure C, of the case in figure B, clearly demonstrates vegetations along the struts of the mechanical mitral prosthesis; with further vegetations identified along the disks in other images not shown, providing explanation to the abnormal m-mode contour on TTE.
Discussion
The limitations of TTE in the evaluation of prosthetic valves have long been recognized, with TEE providing higher specificity and sensitivity in detecting valvular abnormalities [1]. With evolving technology, a comprehensive multimodality imaging is often required for the complete assessment of prosthetic heart valve function [2].
Technology is in continuous and exponential evolution. As the incremental value of 2-D over m-mode echocardiography was questioned in 1979 [3], there was an obviously limited discussion of m-mode echocardiography in the American Society of Echocardiography recommendations for quality echocardiography laboratory operations document in 2011 [4], prompting expert criticism [5].
M-mode echocardiography remains a valuable tool in echocardiography enjoying a higher temporal resolution than 2-D echocardiography [6]. It remains of great value in assessing prosthetic valve function, as demonstrated in the above discussed images, providing clues which can prompt further assessment when the 2-D images are limited.
References
- Daniel WG, Mügge A, Grote J, Hausmann D, et al. Comparison of transthoracic and transesophageal echocardiography for detection of abnormalities of prosthetic and bioprosthetic valves in the mitral and aortic positions. Am J Cardiol. 1993 Jan 15;71(2):210-5.
- Zoghbi WA, Jone PN, Chamsi-Pasha MA, et al. Guidelines for the Evaluation of Prosthetic Valve Function With Cardiovascular Imaging: A Report From the American Society of Echocardiography Developed in Collaboration With the Society for Cardiovascular Magnetic Resonance and the Society of Cardiovascular Computed Tomography. J Am Soc Echocardiogr. 2024 Jan;37(1):2-63,
- Kisslo J. Comparison of M-mode and two-dimensional echocardiography. Circulation. 1979 Oct;60(4):734-6.
- Picard MH, Adams D, Bierig SM, et al; American Society of Echocardiography. American Society of Echocardiography recommendations for quality echocardiography laboratory operations. J Am Soc Echocardiogr. 2011 Jan;24(1):1-10.
- Feigenbaum H. Re: "American Society of Echocardiography recommendations for quality echocardiography laboratory operations". J Am Soc Echocardiogr. 2011 Aug;24(8):930; author reply 930.
- Feigenbaum H. Role of M-mode technique in today's echocardiography. J Am Soc Echocardiogr. 2010 Mar;23(3):240-57; 335-7.
Authors:
Mariam Riad, M.D.
Cardiology Fellow
University of South Alabama
Mobile, AL
Mustafeez Ur Rahman, M.D.
Cardiology Fellow
University of South Alabama
Mobile, AL
Celestine Odigwe, M.D.
Cardiology Fellow
University of South Alabama
Mobile, AL
Brent Ruiz, M.D.
Cardiology Fellow
University of South Alabama
Mobile, AL
Hajira Malik, M.D.
Cardiology Fellow
University of South Alabama
Mobile, AL
Bassam Omar, M.D., Ph.D.
Professor of Cardiology
University of South Alabama
Mobile, AL
Christopher Malozzi, D.O.
Associate Professor of Cardiology
University of South Alabama
Mobile, AL
Mariam Riad, M.D.
Cardiology Fellow
University of South Alabama
Mobile, AL
Mustafeez Ur Rahman, M.D.
Cardiology Fellow
University of South Alabama
Mobile, AL
Celestine Odigwe, M.D.
Cardiology Fellow
University of South Alabama
Mobile, AL
Brent Ruiz, M.D.
Cardiology Fellow
University of South Alabama
Mobile, AL
Hajira Malik, M.D.
Cardiology Fellow
University of South Alabama
Mobile, AL
Bassam Omar, M.D., Ph.D.
Professor of Cardiology
University of South Alabama
Mobile, AL
Christopher Malozzi, D.O.
Associate Professor of Cardiology
University of South Alabama
Mobile, AL