Class 1

Question 1

Properties of heart cells

Answer 1

1. Automaticity
To spontaneously initiate an action potential
SA node: 60/100/min
AV node: 40-60/min
Purkinjes: 20-40/min

2. Excitability
   To respond to an impulse and then generate it’s own action potential
3. Conductivity
   To conduct impulses

Question 2

Depolarization wave

Answer 2

From the SA node to the AV node & over to the LA = P wave
Thru the AV node, Bundle of His, bundle branches and perkinjes = PR interval
Thru the ventricular wall = QRS

Question 3

Repolarization wave

Answer 3

Of the atria = hidden
Of the ventricles = T wave
Of the perkinjes? = U wave (sometimes)

Question 4

SA node arrhythmias

Answer 4

Sinus bradycardia
Sinus tachycardia
Sinus arrest
Sick sinus syndrome
Premature atrial complexes (PAC)
Paroxysmal supraventricular tachycardia (PSVT)
Atrial flutter
Atrial fibrillation

Question 5

Sinus bradycardia

Question 6

Sinus tachycardia

Answer 6

>100
Normal with exertion/fever
Ischemia, hypoxemia (low blood volume)
Increases myocardial workload
Decreases coronary artery perfusion

Question 7

Sinus arrest

Answer 7

Failure of SA node, usually intermittent

Question 8

Sick sinus syndrome

Answer 8

D/t SA node injury

Question 9

Premature atrial complexes (PAC)

Answer 9

Early depolarization originating in the atria (not SA node)

Common

Question 10

Paroxysmal supraventricular tachycardia (PSVT)

Answer 10

140-240/min
Sudden onset and cessation
D/t ischemia, reentry
Wolff parkinson white syndrome (heart rate goes very fast and can go for days)

Question 11

Atrial flutter

Answer 11

Ectopic atrial tachycardia 240-450/min

D/t reentry

Question 12

Atrial fibrillation

Answer 12

Chaotic depolarization with only occasional contraction
Paroxysmal/chronic
D/t MI, HF

Question 13

Atrial fibrillation

Answer 13

What is happening in the heart?
Quivering muscle
Poor emptying of atria
Poor filling of ventricle = decreased CO

How will your patient present?
Heart rate will be irregularly irregular
Pulses will be irregular with varying strength
BP will be low

Question 14

AV conduction arrhythmias

Answer 14

Blocks (1st, 2nd and 3rd degree)

AV node/bundle of his/bundle branch issue

Question 15

1st degree AV block

Answer 15

Consistent long PR interval, followed by a QRS

Question 16

2nd degree AV block

Answer 16

Mobitz type 1/wenckebach 
Increasing PR until QRS dropped
Mobitz type 2
Occasional dropped QRS
PR stable

Question 17

3rd degree AV block

Answer 17

No electrical communication between atria and ventricles

Question 18

Ventricular arrhythmias

Answer 18

Premature ventricular complexes (PVC)

D/t irritability (ischemia/necrosis)

Question 19

Ventricular fibrillation

Answer 19

Ventricle is vibrating

No blood will be pumped

Question 20

Asystole

Answer 20

Heart is not doing anything at all

Cannot be fixed

Question 21

Cardiac conduction diagnosis

Answer 21

ECG (12 lead or 16 lead)
Holter monitor (send people home with electrodes on for 24 hours and keep a diary about what they are doing and it shows what the heart is doing at the same time)
Exercise stress test
Electrophysiologic studies

Question 22

Treatments for conduction disorders

Answer 22

Cardioversion (someone is still conscious, awake and in rhythm you don’t want)
Debrillation (lethal rhythm so electrical zapping)
Pacemaker
Surgical

Question 23

Cardioversion

Answer 23

Pharmacological (meds)
Physiologic (bare down or cough to stun heart to go back into proper rhythm)
Electrical

Question 24

Defibrillation

Answer 24

Electrical

Lethal rhythm so electrical zapping

Question 25

Pacemaker

Answer 25

Increases HR if heart is going too slow

Question 26

Surgical

Answer 26

Ablation (go in with tiny zapper and kill off bad part of conduction)
Pacemaker
Defibrillator