ECG

Question 1

The p wave is?

Answer 1

Atrial depolarization

Question 2

The PR interval is?

Answer 2

conduction from SA to AV node

Question 3

QRS interval is

Answer 3

ventricular muscle depolarization

Question 4

T wave is

Answer 4

ventricular muscle repolarization

Question 5

Which lead is used for amplitude measurements?

Answer 5

Lead II- right shoulder to left leg

Question 6

Positive waves are?

Answer 6

waves traveling toward the positive electrode

Question 7

ECG is best to evaluate?

Answer 7

Heart rate, heart rhythm, and conduction

Question 8

What are the 4 steps to evaluate and ECG?

Answer 8

1. Evaluate for artifacts, quality, and calibrations
2. Determine the heart rate
3. Name the cardiac rhythm
4. Evaluate the P-QRS-T complex configurations and morphologies

Question 9

What does amplitude increase indicate?

Answer 9

Chamber enlargement

Question 10

What is standard calibration for ECG?

Answer 10

Gain: 10mm/mV = 1cm/mV

- each small box is 1mm

Question 11

at 50mm/sec, 1 small box =?

Answer 11

0.02 seconds

Question 12

Name some artifacts that can render ECG uninterpretable?

Answer 12

purring, respiration movememt, motion, muscle twitches

Question 13

Normal feline heart rate

Answer 13

140-220

Question 14

Normal canine heart rate

Answer 14

60-160

Question 15

What are the two most common cardiac rhythms?

Answer 15

Sinus rhythm and sinus arrhythmia

Question 16

What is a sinus rhythm?

Answer 16

normal P wave with similar shaped QRS and similar P-P interval

Question 17

What is sinus arrhythmia?

Answer 17

irregular rhythm originated from the SA node, normal in many species, normal QRS for every P with varying normal heart rate because of high vagal tone, may see varying P height

Question 18

What is a wandering pacemaker?

Answer 18

varying P height, seen with sinus arrhythmia

Question 19

How tall should the T wave be

Answer 19

< 1/3 QRS, can even be negative or biphasic

Question 20

When may you see a sinus bradycardia in cattle?

Answer 20

Lack of food intake

Question 21

What are the normal cardiac rhythms of horses?

Answer 21

sinus rhythm
sinus arrhythmia
first or second degree AV block

Question 22

What is the difference between a premature and and escape ectopic beat?

Answer 22

PVC occurs earlier than expected and escape beats occur later than expected

Question 23

What is an atrial ectopic beat (atrial premature contraction)?

Answer 23

Has P wave that is too early, may be on top of T wave or not visible, normal QRS

Question 24

What is sinus bradycardia/bradyarrhythmia?

Answer 24

Normal p with every QRS, but at a slow rate

Question 25

Treatment for sinus bradycardia?

Answer 25

Identify and address underlying cause, can give atropine if because of anesthetic complications

Question 26

What is sick sinus syndrome?

Answer 26

abnormal rhythm disturbance in older small breed dogs, combo of: - sinus bradycardia - sinus arrest (pause with no P) - AV block - Supraventricular tachycardia- after a long pause

Question 27

What are first, second, and third degree AV block?

Answer 27

1st: prolonged PR 2nd: intermittent blocked P wave 3rd: P and QRS unrelated

Question 28

How do you differentiate pathologic 2nd degree AV block from high vagal tone?

Answer 28

Give atropine- if block disappears, high vagal tone

Question 29

What is the only treatment fr 3rd degree AV block?

Answer 29

Pacemaker

Question 30

What are the 3 types of tachycardia?

Answer 30

- sinus - supraventricular - ventricular

Question 31

Describe sinus tachycardia

Answer 31

Normal p, normal qrs

Question 32

Describe supraventricular tachycardia:

Answer 32

abnormal p, normal QRS | *3 or mor APCs or SVPCs in a row

Question 33

Describe ventricular tachycardia:

Answer 33

no associated p, wide/bizarre QRS

Question 34

What are the causes of sinus tachycardia?

Answer 34

Response to systemic issue, pain, excitement, hypotension

Question 35

What are causes of supraventricular tachycardia?

Answer 35

Atrial enlargement (most common in small animals) Enlarged hilar lymph nodes Thoracic masses Pulmonary inflammation Electrolyte disturbances *can occur in horses without structural heart disease

Question 36

T/F: Atrial fibrillation is not a type of supraventricular tachycardia

Answer 36

False- no clear p-waves, but QRS are normal

Question 37

T/F: All cases with atrial fibrillation will show bumpy baseline

Answer 37

False- small patients may not show bumpy baseline

Question 38

What are the most common causes of atrial fibrillation in small animals?

Answer 38

Severe atrial enlargement caused by dilated cardiomyopathy or chronic valvular disease

Question 39

T/F: Atrial fibrillation is uncommon in cats

Answer 39

T

Question 40

What is the treatment goal for SVT or A fib?

Answer 40

Decrease heart rate to normal range

Question 41

What drugs could be used to decrease heart rate in patients with SVT or A fib?

Answer 41

Digoxin, Calcium Channel Blockers (Diltiazem) Beta blockers (Atenolol)

Question 42

T/F: "Lone a-fib" occurs in horses, humans.

Answer 42

True- | lone a-fib means there is no underlying heart disease

Question 43

T/F: The most common cause of bovine a-fib is primary GI disease

Answer 43

True

Question 44

T/F: Equine lone fib can successfully be converted with medical treatment (quinidine + digoxin or amiodarone)

Answer 44

True

Question 45

T/F: Recurrence of a-fib in converted horses is uncommon.

Answer 45

False

Question 46

T/F: V-tach can result in sudden death.

Answer 46

True

Question 47

T/F: Anti-arrhythmics can have pro-arrhythmic effects, potentially making arrhythmias worse.

Answer 47

True: you must make sure you have reason to treat arrhythmias

Question 48

Name some indications to treat arrhythmias:

Answer 48

1. Paroxysms or sustained VT > 140-160bpm 2. > 20 VPCs per minute 3. Multiform VPCs 4. Arrhythmias with myocardial failure present 5. Breeds at risk for sudden death (dobys and boxers) 6. Clinical hypotension 7. VPCs close to the T wave of the proceeding complex 8. Critically ill patients

Question 49

What is the acute/emergency treatment for arrhythmias?

Answer 49

Lidocaine- IV in a bolus | - side effects can include seizures and vomiting

Question 50

What are chronic treatments for arrhythmias available orally?

Answer 50

``` Mexilitine (similar to lidocaine) Sotalol (B blocker and class 3) Atenolol (B blocker) ```

Question 51

T/F: V-fib is fatal unless electrical defribrillation is done in time.

Answer 51

True- no pulses, antiarrhythmics inneffective