The initial 0.04 second polar vector of the QRS loop as an aid in the detection of a myocardial infarction.
D000328:Adult; D000368:Aged; D004562:Electrocardiography; D006801:Humans; D008433:Mathematics; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis*; D014672:Vectorcardiography