Guyton Phys 11: The Normal Ecg

Front 1

atrial T wave

Back 1

occurs about 0.15-0.2 seconds after P wave termination (usually obscured by ventricular depolarization (QRS complex))

Front 2

time range of repolarization in ventricular fibers

Back 2

0.20 to 0.35 seconds

Front 3

Voltage of QRS vs T

Back 3

T is much less due to prolonged length

Front 4

10 small divisions up and down in EKG

Back 4

1 millivolt

Front 5

25 mm horizontal direction in EKG

Back 5

1 seond (divided into five 0.2 seond intervals which is broken into five 0.04 second intervals)

Front 6

Voltge of EKG

Back 6

varies on electrode placement (can be up to 3-4 mV)

Front 7

between arms and legs mV range

Back 7

1-1.5 mV from top of R to bottom of S

Front 8

PQ or PR interval Beginning of P and Q)

Back 8

time between atria excitation and ventricular excitation (0.16 s)

Front 9

QT interval (beginning of Q, end of T)

Back 9

contration of ventricles (0.35 s)

Front 10

Determining Heart rate from EKG

Back 10

60/(time interval between heartbeats)

Front 11

averge current flow in heart

Back 11

negativity toward base and positivity toward apex

Front 12

Why does current flow reverse for 0.1 s immediately before depolarization ends

Back 12

last part of heart to depolarize is the outer walls near base of heart

Front 13

electrode with positive reading

Back 13

lead connected to positive terminal is more positive

Front 14

EKG lead

Back 14

combination of two wires and their electrodes making a complete circuit between body and EKG

Front 15

Lead I

Back 15

neg terminal R arm, positive terminal L arm

Front 16

Lead II

Back 16

neg terminal R arm, positive terminal L leg

Front 17

Lead III

Back 17

neg terminal L arm, positive terminal L leg

Front 18

Eithoven's Law

Back 18

If two leads are known, can find 3rd by adding the two known leads

Front 19

Diagnosing arrhythmias

Back 19

Doesn't matter which lead you use, diagnosed by distance between peaks

Front 20

Diagnosing abnormalities of muscle contration or impulse conduction

Back 20

change patterns of some leads and doesn't affect others

Front 21

chest leads (V1-V6)

Back 21

records relatively minute abnormalities in ventricles (V1-V6 are positive; indifferent electrode (arms, L leg) are negative)

Front 22

V1 and V2

Back 22

record negative because they are nearer the base of heart

Front 23

Augmented unipolar limb leads

Back 23

Two limb leads connected to negative and one to positive (names after limb connected to positive)