Rapid EKG I

Question 1

SA node

Answer 1

sinus node
-pacemaking automaticity

upper posterior wall of right atrium

Question 2

contraction

Answer 2

wave of Na ions

Question 3

AV node

Answer 3

between tricuspid and mitral valve
-only way electricity from atrium to ventricles

-conduction is slowed - to allow ventricular filling

Question 4

slow conduction through AV node

Answer 4

calcium ions

Question 5

purkinje fibers

Answer 5

His bundle
R and L bundle branches

-conduction Na ions

Question 6

terminal purkinje fibers

Answer 6

spread out beneath endocardium

-go toward epicardium

Question 7

Q wave

Answer 7

first downward deflection

Question 8

R wave

Answer 8

upward deflection

Question 9

S wave

Answer 9

downward deflection following R wave

Question 10

QS wave

Answer 10

no R wave (no upward)

Question 11

ST segment

Answer 11

end of QRS to beginning of T

Question 12

ventricular repolarization

Answer 12

occurs ST segment and S wave

Question 13

QT interval

Answer 13

beginning of QRS to end of T

-indicator of repolarization

Question 14

myocyte contraction

Answer 14

Ca ion inflow

Question 15

repolarization of myocytes

Answer 15

K outflow

Question 16

cell-to-cell fast conduction

Answer 16

Na ion movement

Question 17

AV node slow conduction

Answer 17

Ca ions

Question 18

small square

Answer 18

0.04s

Question 19

large square

Answer 19

0.2s

Question 20

lead I

Answer 20

0 degrees

Question 21

lead II

Answer 21

+60 degrees

Question 22

lead III

Answer 22

+ 120 degrees

Question 23

lead AVF

Answer 23

+90 degrees

Question 24

lead AVL

Answer 24

-30 degrees

Question 25

lead AVR

Answer 25

-150 degrees

Question 26

inferior limb leads

Answer 26

II, III, AVF

Question 27

lateral limb leads

Answer 27

I, AVL

Question 28

center of horizontal plane

Answer 28

chest leads - from AV node

Question 29

right chest leads

Answer 29

V1 and V2

Question 30

left chest leads

Answer 30

V5 and V6

Question 31

IV septum leads

Answer 31

V3 and V4

Question 32

symapthetics

Answer 32

NE to beta1 adrenergic - increased SA node pacing - increased conduction rate - increased inotrophy - increased irritability of foci**

Question 33

parasympathetics

Answer 33

ACh to cholinergic receptors - decreased SA node pacing - decreased conduction rate - decreased inotropy - decreased irritability of atrial and junctional foci**

Question 34

decreased irritability of atrial and junctional foci

Answer 34

PS innervation

Question 35

constriction of arteries

Answer 35

sympathetic to alpha1

Question 36

syncope

Answer 36

severe vagus response - dilated arteries and bradycardia - loss of consciousness vaso-vagal syncope

Question 37

vagal maneuvers

Answer 37

gag or carotid massage - increase PS - inhibit irritable foci - inhibit AV node (longer refractory)

Question 38

standing

Answer 38

sympathetic response - baroreceptors sense low BP - vasoconstriction - and SA node stimulation

Question 39

orthostatic hypotension

Answer 39

failure of compensatory sympathetic response when standing

Question 40

neuro-cardiogenic syncope

Answer 40

in elderly - prolonged standing - stimulates sinus pacing - vasoconstriction falls - paradoxical PS reflex - slows SA node and causes vasodilation