how is amplitude or duration of EKG determines
1 The R Wave is the first positive defection in the QRS Complex. 2  The S Wave is the first negative deflection that extends below the baseline in the QRS Complex that follows the R Wave. 3  The DURATION of the QRS Complex is 0.06 to 0.10 seconds in adults and 0.08 or less in children.ften the onset and end of the T Wave are difficult to determine with certainty. 1  The DURATION of the T Wave is 0.10 to 0.25 seconds or greater. 2  The AMPLITUDE of the T Wave is less than 5 mm. 3  The SHAPE of the T Wave is sharply or bluntly rounded and slightly asymmetrical.