What is M-mode echocardiography?

What is M-mode echocardiography?

Echocardiography is ultrasound imaging of the heart. M-mode echocardiography is time-motion mode in echocardiography and is a graphical representation of the movements of structures of the heart along a single scan line with time on the X-axis and movements on the Y-axis. It is a single dimensional imaging of the heart compared to the two dimensional echocardiograms which are easier to interpret. M-mode is an older modality compared to two dimensional echocardiogram, currently used mainly to take measurements of the left ventricle.

M-mode echocardiogram in mitral stenosis (narrowing of the valve between left atrium and left ventricle)