Q. What is Regional wall motion abnormality?
Ans.
A critical occlusion of a coronary artery leads to myocardial ischemia which is manifested as regional wall motion abnormality (Abnormal motion and loss of systolic thickening) where is readily identified by 2D echocardiography. Decreased or cessation of myocardial contractility (systolic thickening) to the immediate manifestation of myocardial ischemia, even before occurrence of ST changes or development of symptoms.
Normally LV free wall thickness increases more than 1.5 times of the diastolic dimensions during systole. Ischemic muscle shows 3 discrete patterns of movement.
1) Hypokinesis: When the muscle shows systolic inward motion, however the amplitude of movement is less as compared to normal adjoining areas i.e. systolic wall thickness 1.2- 1.5 times the diastolic thickness.
2) Akinesis: When the muscle shows no perceptible systolic motion and systolic thickness is less than 1.1 times the diastolic dimensions.
3) Dyskinesis: Dyskinesis is defined as a myocardial segment moving'outward - during systole, usually in association with systolic wall thinning.
In order to assess the wall motion, we have to concentrate on not only the movement of muscle but also the thickening during systole. This increases the specificity of wall motion study considerably.