Cardio ECG #1

Question 1

Which node initiates a current of depolarization that moves as a wave, between resting and activated tissue?

Answer 1

SA node

Surface electrodes detect electrical activity = ECG

Question 2

P wave

Answer 2

atrial muscle depolarization

Question 3

PR interval

Answer 3

conduction of SA through AV node

Question 4

QRS

Answer 4

Ventricular muscle depolarization

Question 5

ST and T

Answer 5

Ventricular muscle re polarization

Question 6

Lead II

Answer 6

Assess this one.
neg –> pos (LV) due to bigger muscle mass of LV

KNOW LEAD II QRS IS POSITIVE IN DOG AND CAT

Question 7

ECG is best for evaluating what

Answer 7

HR
Heart rhythm and conduction

Can tell you about cardiac chamber enlargement– specific, but NOT VERY SENSITIVE (use echo)

NOT for- presence of CHF or quality of cardiac mucle contraction.

Question 8

Standard calibration

Answer 8

1cm = 10 mm =1mV, so each small box = .1mV

Question 9

with paper speed 50mm/second, one small box = how many seconds

Answer 9

0.2 seconds

Question 10

what artifacts make ECG uninrepretable

Answer 10

Purring
Resp movement
Motion
Muscle twitches

Question 11

At 50 mm/second paper speed ___ boxes is 3 seconds

At 25 mm/second paper speed ___ is 3 seconds

Answer 11

30

15

Question 12

normal horse HR

Answer 12

28-40

Question 13

normal cow HR

Answer 13

70-90

Question 14

normal feline HR

Answer 14

140-220 (as low as 120 in home environment)

Question 15

normal canine HR

Answer 15

60-160 (if sleeping, mid 20s-30s)

Question 16

Cardiac rhythms- two common ones

Answer 16

Sinus rhythm

Sinus arrhythmia

Question 17

Sinus rhythm

Answer 17

Normal P wave
Normal HR, normal similar shaped P wave for every QRS
and normal similar shaped QRS for every P wave

very little variation in PP interval

Question 18

Sinus arrhythmia - what is it? what do you see? relation with vagal tone?

Answer 18

Irregular rhythm originating from SA node, but normal in many species.

Defined by: Normal HR, P waves, QRS for every P wave

PRONOUNCED VAGAL TONE may lead to increasing and decreasing HR pattern/ sometimes associated with respiration

Question 19

Varying P height means what

Answer 19

“wandering” pacemaker of vagal tone

Question 20

Sinus rhythm and arrhythmia in dogs vs cats

Answer 20

both normal in dogs

cats- just the sinus rhythm is the normal rhythm

Question 21

Sinus rhythm and arrhythmia in bovine vs equine

Answer 21

bovine- can have one normal rhythm, the sinus rhythm (but may see sinus bradycardia with less food intake)

equine- normal sinus rhythm and sinus arrhythmia, also normal 2nd degree AV block (vagal tone species?)

Question 22

Normal P, Deep S wave

Answer 22

Rule out RV enlargement and HIS bundle branch block (RV enlargement because going towards NEGATIVE end)

Question 23

Tall P, Tall R

Answer 23

Lead II QRS is positive but VERY positive (more than 3 mV)

Question 24

Tall P (P pulmonale)

Answer 24

R atrial enlargement- dogs
Left or R atrial enlargment - cats
Sinus tachycardia- dogs

Question 25

Wide P (P mitrale)

Answer 25

LA enlargement- dogs and cats

“Pseudo” abnormality, look for P waves in other leads

Question 26

Absent P

Answer 26

Hyperkalemia, atrial standstill, silent atrium or a fib (look for bumpy baseline)

Question 27

P height variation

Answer 27

Wandering pacemaker (normal with sinus arrhythmia), atrial or junctional premature beats

Question 28

PR/PQ interval shortened vs prolonged

Answer 28

High symp tone vs First degree AV block

Question 29

Deep Q wave

Answer 29

Normal variation in deep chested dogs

Biventricular enlargement

Question 30

Tall R wave

Answer 30

LV enlargement

Question 31

Wide QRS

Answer 31

Ventricular enlargement, intraventricular conduction disturbance

Question 32

Small QRS

Answer 32

Normal variation, PC or pleural effusion, pneumothorax, hypothyroidism, obesity

Question 33

Deep S wave

Answer 33

Normal variation; RV enlargement, LV hypertrophy (leads 2, 3, aVF ONLY)

Question 34

ST elevation vs depression

Answer 34

both- myocardial hypoxia, digoxin toxicity
elevation- PC effsion, pericarditis, transmural myocardial infarction
depression- potassium imbalance, subendocardial MC infarction

Question 35

QT segment prolonged vs shortened

Answer 35

HYPO (K, Ca, Thermia); bradycardia, quinidine therapy, conduction distrubance
shortening- hyperKalemia or calcemia, digoxin

Question 36

T wave large

Answer 36

myocardial hypoxia, interventricular conduction distrubance, bradycardia, ventricular enlargement, HyperK

Question 37

t wave small

Answer 37

same as for small QRS

normal in cats

Question 38

Ectopic beats

Answer 38

A complex with an abnormal shape may come from a different location of the heart (NOT sinus node)

can come from atria or ventricle

Question 39

Ectopic beats - premature vs escape

Answer 39

Earlier than expected vx later than expected

Question 40

Escape beats- when do they occur

Answer 40

Occur after long pause

May “rescue” the patient if the pause in the rhythm becomes too long

Question 41

escape and premature beats look same, but differentiated by what

Answer 41

Timing- early or late , as compared to preceding complexes

Question 42

Ventricular ectopic beats

Answer 42

Abnormal QRS morphology “wide and bizzare”