P wave: atrial depolarization, 0.06-0.10 sec; - I, II, aVF, aVL, V4, V5, V6; - aVR
PR interval: 0.12 - 0.22 sec, AV conduction
QRS: ventricular depolarization; 0.05 - 0.10 sec; - I, II, V5, V6; - aVR, V1; transition zone - V3; or - aVL, aVF, III; left chest leads height < 27mm
Abnormal Q: >=0.04 sec., > 25% of height of following R; any Q in V1, V2, V3
T wave: ventricular repolarization; - I, II, V4, V5, V6; - aVR; maybe inverted - III, aVF, aVL, VI Abnormal T's: LVH - V6, LBBB, ischemia, subendocardial MI; Peaked T's: hyperkalemia, ischemia, CVA, antipsychotic meds
QT Interval:(ventricular depolarization and repolar.):0.34 - 0.42 sec or 40% of RR interval; HR shorter QT interval (100/min - 0.31+- 0.04 sec, 90/min - 0.32+-0.04 sec, 80/min - 0.33+-0.04 sec, 70/min - 0.36+- 0.05 sec, 60/min - 0.38 +- 0.05 sec); QT = QTc (square root of)RR(sec)
EKG Paper: (25 mm/sec); Small box: = 0.04 sec = 1 mm; Dark large box: = 0.20 sec = 5 mm