EKG midterm review

EKG midterm review [1-3] |

1. meaning of all EKG waves P = atrial depolarization

Q = initial negative deflection
from ven- tricular depolarization

R = huge positive deflection
from ven- tricular depolarization

S = 2nd negative deflection from
ventric- ular depolarization

T wave = ventricular repolarization




2. meaning of all EKG segments segment = straight line between
waves
("end of _ before _")

PR segment:
-after P until before Q
-delay of AV node to allow filling
of ven- tricles before
depolarization

ST segment:
-after S until before T
-time between ventricular
depolariza- tion & repolarization






, EKG midterm review [1-3] |

3. meaning of all EKG intervals interval = includes waves

PR interval:
-beginning of P until before Q
-time between atrial
depolarization & ventricular
depolarization

QT interval:
-beginning of Q until end of T
-time from ventricular
depolarization through
repolarization
-entire ventricular contraction
-normal < 1/2 of cardiac cycle (R-
R)




4. limb leads bipolar:
I
II (rhythm
strip) III

augmented (unipolar):
-aVF (lead II, III, left foot +)
-aVL (left arm, +)
-aVR (right arm, +)

5. chest leads always

positive right

leads:


, EKG midterm review [1-3] |

V1
V2

interventricular
septum: V3