What is the meaning of hypokinesia, dyskinesia and akinesia?
These terms are used in connection with the heart muscle. Akinesia means lack of movement or contraction of a region of the heart muscle. Dyskinesia means an abnormal movement – instead of contracting in systole, that segment of myocardium bulges out in systole. Hypokinesia means reduced movement or contraction of a segment of the heart muscle. Another term which is sometimes used is hyperkinesia, meaning increased contraction of heart muscle. Hyperkinesia can occur as a compensatory mechanism by which normal heart muscle does a little bit of extra work instead of the heart muscle which is defective with akinesia, hypokinesia or dyskinesia. These abnormalities of motion of the heart muscle when they involve regions and not the whole of the heart muscle, it is known as regional wall motion abnormality. Most commonly it occurs when blood supply to that region is low as when the blood vessel supplying that region is blocked.
These terms are commonly used in echocardiography (ultrasound imaging of the heart). But they can be used in any real time imaging of the heart like cine cardiac magnetic resonance (CMR) imaging, cine cardiac computed tomography (cardiac CT) or nuclear cardiology imaging which can display the movements of myocardial segments.