Hypokinesis is a heart wall movement impairment. An artifact is structual change from a chemical or it can be a transient signal picked up by the EKG, etc.
If there is some wall movement disorder, and it is a structual abnormality (real) due to damaged heart cells, it is minor and basically insignificant due to location and/or degree. Normal EF (amount of blood pumped out with each heartbeat) is about 55 to 75%. An EF is an estimate and the margin of error can be 5 to 10%.