ECG

Question 1

What is an electrocardiograph?

Answer 1

Machine/device that does an ECG

Question 2

What is an electrocardiography?

Answer 2

Process of performing an ECG

Question 3

What is an electrocardiogram?

Answer 3

Visual recording/graph produced by the machine

Question 4

What is the Hierarchy of conduction in the cardiac conduction system?

Answer 4

Sinoatrial node
Bachmans bundle
Atrioventricular node
Bundle of His
Right and left bundle branches
Purkinje fibres

Question 5

What are the intrinsic rates of conduction?

Answer 5

SA node
AV node
Bundle of His
Purkinje fibres

Question 6

What are the waves of an electrocardiogram?

Answer 6

P wave
QRS complex
T wave

Question 7

What are the intervals in an electrocardiogram?

Answer 7

PR interval
QT interval

Question 8

What are the segments of an electrocardiogram?

Answer 8

PR segment
ST segment

Question 9

What is a P wave?

Answer 9

Atrial depolarisation

Question 10

What is the PR interval?

Answer 10

Delay of conduction from SA node to AV node

Question 11

What is the QRS complex?

Answer 11

Ventricular depolarisation

Question 12

What is the QT interval?

Answer 12

Ventricles contracting

Question 13

What is a T wave?

Answer 13

Ventricular repolarisation

Question 14

What is the process of cardiac contraction?

Answer 14

Isovolumic relaxation (ventricular diastole)
>
Ventricular filing (ventricular diastole)
>
Atrial contraction (atrial systole begins)
>
Ventricular systole:
Isovolumic contraction, ventricular contraction, ventricular ejection

Question 15

What are the colours of electrodes for British machines?

Answer 15

Right forelimbs - red
Left forelimb - yellow
Left hindlimb - green
Right hindlimb - black

Question 16

What are the standard leads for an ECG?

Answer 16

I, II, III

They are bipolar

Question 17

What are the augmented leads for an ECG?

Answer 17

aVR, aVL, aVF

They are unipolar

Question 18

What are the precordial leads of an ECG?

Answer 18

V1-V6

They are unipolar

Question 19

What is the normal canine heart rate?

Answer 19

70-160bpm

Can drop to 30-40bpm when sleeping
Can rise to low 200s when stressed/excited

Question 20

What is the normal feline heart rate?

Answer 20

140-240bpm

Below 140 in a hospital setting is abnormal

Question 21

What is arrhythmias?

Answer 21

Abnormal heart rhythm

Tachycardia/bradycardia

Question 22

What is Tachycardia?

Answer 22

Increased HR

Dogs: 160+ bpm (220+ in puppies)
Cats: 220+ bpm

Tachycardic arrhythmias

Question 23

What is bradycardia?

Answer 23

Decreased HR

Dogs: below 70bpm
Cats: below 120bpm

bradycardic arrhythmias

Question 24

What is sinus bradycardia?

Answer 24

Normal appearance but slow conductance

Question 25

What diseases have a normal appearance but have a slow conductance?

Answer 25

Systemic disease Endocrine disturbance Hypothermia Hypertension

Question 26

What is atrioventricular block: 1st degree heart block ?

Answer 26

Prolonged PR internal >0.2s Block at AV node or bundle of his Delay in conduction Early sign of cardiac disease Often no clinical signs

Question 27

What is atrioventricular block: 2nd degree heart block: Mobitz I?

Answer 27

Progressive lengthening of PR interval, until P wave is completely blocked Greater ratio of P waves to QRS complexes Block in AV node Normally temporary and benign No clinical signs

Question 28

What is atrioventricular block: 2nd degree heart block: Mobitz II?

Answer 28

PR interval constant Greater ratio of P waves to QRS complex Block in Bundle of His Atria contract, blood sits in ventricles Usually indicates serous heart disease, can progress to 3rd degree block

Question 29

What is atrioventricular block: 3rd degree heart block?

Answer 29

No relation between P waves and QRS complexes P>QRS Block at AV node or lower Ventricles generate lifesaving bradycardiac escape rhythm Atria contract at 60-100bpm Atria and ventricles controlled by separate intrinsic pacemakers (AV dissociation)

Question 30

What is sick sinus syndrome?

Answer 30

Abnormal SA node conduction Periods of asystole Syncope

Question 31

What is the treatment for sick sinus syndrome?

Answer 31

Pacemaker implant

Question 32

What is atrial standstill?

Answer 32

No atrial electrical activity Ventricular escape rhythm Hyperkalaemia at a concentration high enough to lead to atrial standstill (Usually >8.5mmol/l) is an emergency

Question 33

What is Ventricular Premature Complexes (VPCs)?

Answer 33

Common in cats and dogs Arise from an ectopic focus within ventricular myocardium Depolarisation - abnormal detection QRS complexes are wide and bizarre and not associated with P waves T waves often large and opposite direction of QRS Cardiac or non cardiac (drugs, pain, excitement) causes Infrequent VPCs don’t generally compose cardiac output and often don’t require treatment

Question 34

What is sinus tachycardia?

Answer 34

Regular cardiac rhythm in which heart beats faster than normal Physiological responses to: Exercise Excitement Stree/fear Pain Disease

Question 35

What is ventricular tachycardia?

Answer 35

Three of more consecutive VPCs Indicates cardiac disease or systemic disease Signs of haemodynamic compromise (exercise intolerance, weakness, syncope, collapse) Weak apical beat, weak arterial pulses, pulse deficits

Question 36

What is ventricular fibrillation?

Answer 36

Chaotically irregular ventricular depolarisations Absence of coordination ventricular activity Produces very little cardiac output Requires immediate veterinary attention

Question 37

What is atrial fibrillation(AF)?

Answer 37

Rapid and irregular rhythm, narrow QRS complexes without P waves present Spontaneous AF is usually associated with significant heart disease Treated with diltiazem, atenolol or digoxin

Question 38

What are the three types of arrhythmia?

Answer 38

Bradyarrhythmia Tachyarrhythmia Premature beats