|Year : 2019 | Volume
| Issue : 1 | Page : 38-39
Left atrial myxomas: M-mode echocardiography characteristics – A forgotten modality
Rohit Tandon, Neelesh Pandey
Department of Cardiology, Hero DMC Heart Institute, Ludhiana, Punjab, India
|Date of Web Publication||15-Mar-2019|
Hero DMC Heart Institute, Ludhiana, Punjab
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Tandon R, Pandey N. Left atrial myxomas: M-mode echocardiography characteristics – A forgotten modality. J Indian Acad Echocardiogr Cardiovasc Imaging 2019;3:38-9
|How to cite this URL:|
Tandon R, Pandey N. Left atrial myxomas: M-mode echocardiography characteristics – A forgotten modality. J Indian Acad Echocardiogr Cardiovasc Imaging [serial online] 2019 [cited 2019 Mar 19];3:38-9. Available from: http://www.jiaecho.org/text.asp?2019/3/1/38/254254
M-mode echocardiographic scan [Figure 1] showing echoes from a myxoma within the mitral valve orifice. M-mode echocardiogram shows characteristic findings of multiple linear echoes (disorganized echoes) within the mitral orifice and within the left atrium in the vicinity of the anterior mitral valve leaflet.,, Furthermore, there is a time gap between the opening of the mitral valve and prolapse of the myxoma into the valve orifice (as shown by arrows). The systolic position of the myxoma could not be identified.
|Figure 1: M-mode echocardiogram shows characteristic findings of multiple linear echoes (disorganized echoes) within the mitral orifice and within the left atrium in the vicinity of the anterior mitral valve leaflet. (as shown by horizontal arrow). In addition, there is a time gap between opening of the mitral valve and prolapse of the myxoma into the valve orifice (as shown by vertical arrow)|
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Careful scanning of the left atrium at different transducer angles to catch the edge of the tumor which moves in and out during cardiac cycle is mandatory.
Dense linear or punctate echoes behind the thin anterior mitral leaflet in diastole but not in systole are the hallmark of the left atrial myxoma. Echo-free interval between the opening of anterior mitral leaflet and the appearance of tumor echoes (inertia of the tumor) is often seen.
At times, systolic and diastolic tumor echoes are seen when the tumor is attached very near the mitral valve, to the atrial wall or when a large tumor is attached to the septum. The E-F slope is reduced to varying degrees depending on the size of the tumor and the degree of obstruction. The “a” wave is diminished in amplitude or is absent. Dense echoes inside the left atrium in systole and less obviously in diastole are seen.
Sessile myxomas that remain within the atrium throughout the cardiac cycle are particularly prone to escape detection with the use of M-mode echocardiography. Since nonprolapsing myxomas do not produce the characteristic alterations of the mitral valve echogram associated with such neoplastic tumors, the correct diagnosis depends on the recording of abnormal echoes within the atrial cavity. Due to the spatial limitations of M-mode echocardiography, however, the ultrasonic beam may fail to traverse the mass - particularly if it is small - or may produce atypical intraatrial echoes which are frequently difficult to differentiate from artifact or other cardiac structures.,,,
It has been hypothesized that inadequate reflection of ultrasound from a myxoma will occur if the acoustic impedance characteristics of the myxoma are similar to that of blood or cardiac structures adjacent to the mass.,, Thus, myxomas composed of relatively homogeneous tissue or those with large areas of vascularity may not produce the multiple array of echoes behind the mitral valve or within the left atrium on the M-mode echogram. Thus inferring that absence of linear echoes on M-mode denotes a myxoma having echolucent characteristics and if such tumors are found near the mitral orifice, their embolic potential is low.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
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Conflicts of interest
There are no conflicts of interest.
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