Much useful information can be obtained from cardiac ultrasound recordings. This safe, non-invasive technique allows direct visualisation of many cardiac abnormalities. Contraction, relaxation and heart valve operation can be observed in real time. The first of three video clips starts with the left side of a healthy heart. This is followed by a video of the patient's heart for comparison.
Blood velocity and pumping efficiency can be calculated from the Doppler frequency shifts in the reflected sound. The ultrasound equipment generates a false colour display where blood moving towards the observer is shaded blue and receding blood is shaded red. The third clip shows how this technique can demonstrate mitral valve leakage in the patient's heart.
 Left side orientation: Locate the aortic and the mitral valves. Note the differences in heart rate and chamber dimensions, and the duration of diastole in the two examples. Drag the slider bar to replay a video. Mitral regurgitation is visible on the third clip. |
The valve leaflets are restrained by the cordae tendineae which are attached to the ventricular wall via the papillary muscles. The greatly enlarged ventricles in the myopathic heart prevent the mitral and tricuspid valves from closing properly, and allow blood to escape back into the atria during systole. This reduces the efficiency of cardiac pumping and increases the work load on the already failing heart. It is possible to observe the valve operation with the ultrasound equipment:
 Mitral valve orientation: We are looking up the left ventricle from the apex (pointed end) towards the mitral valve. Notice the difference in heart rates and that the patient's valve doesn't close properly. Drag the slider bar to replay the video. |
It is possible to position the probe to show all four heart chambers simultaneously. This can give a slightly misleading impression of the shape of the heart, since there is only one unique orientation producing this view:
 Four chamber orientation: The difference in chamber dimensions is particularly obvious in this view. Notice the lack of contractility in the patient's heart, and the absence of effective pumping. Drag the slider bar to replay a video. |
The sounds produced by the heart can also be analysed by computer. This can yield additional diagnostic information beyond that available from an ordinary stethoscope.
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