Pharmacology of rhythm control

Question 1

Phases of the cardiac myocyte AP:

Answer 1

4
0
1
2
3

Question 2

Phase 4 =

Answer 2

Resting membrane potential, K+ open

Question 3

Phase 0 =

Answer 3

Rapid depolarisation, Na+ open

Question 4

Phase 1 =

Answer 4

K+ open, small repolarisation

Question 5

Phase 2 =

Answer 5

Plateau phase. K+ and Ca2+ open

Question 6

Phase 3 =

Answer 6

Repolarisation. K+ open.

Question 7

ERP =

Answer 7

Effective refractory period

Question 8

Phases of nodal AP =

Answer 8

4
0
3

Question 9

Can tetanus occur in cardiac myocytes?

Answer 9

No

Question 10

RRP

Answer 10

Relative refractory period.

Question 11

When can cardioversion cause VF?

Answer 11

If shocked during relative refractory period.

Question 12

Phase 4 (nodal) =

Answer 12

T-type Ca2+ and Na+ open

Question 13

Phase 0 nodal =

Answer 13

L-type Ca2+ channels

Question 14

Phase 3 nodal =

Answer 14

voltage gated K+ open

Question 15

Intrinsic rate of SAN

Answer 15

60-100 bpm

Question 16

Intrinsic rate of AVN

Answer 16

40 bpm

Question 17

What is the HR in complete heart block?

Answer 17

40 bpm

Question 18

Where is the SAN?

Answer 18

Junction of SVC and RA

Question 19

Where is the AV node?

Answer 19

Inter-atrial septum

Question 20

What part of the heart conducts the fastest?

Answer 20

His-purkinje system

Question 21

Conduction rate of His-purkinje system

Answer 21

2-3 m/sec

Question 22

Conduction rate of ventricular and atrial muscles

Answer 22

1 m/sec

Question 23

Which part of the heart conducts the slowest?

Answer 23

AVN

Question 24

Conduction velocity of AVN

Answer 24

0.05 m/sec

Question 25

Which kind of heart block is asymptomatic?

Answer 25

Type 1 | Mobitz I

Question 26

Treatment of Mobitz 2

Answer 26

Close monitoring | Pacing

Question 27

Why is monitoring of mobitz 2 important

Answer 27

Can progress to complete heart block

Question 28

Treatment of complete heart block =

Answer 28

Atropine Isoprenaline Pacing

Question 29

Symptoms of 2nd and 3rd degree heart block =

Answer 29

``` Dizziness Syncope SOB Pain Fatigue ```

Question 30

Atrial rate in atrial flutter is usually =

Answer 30

300/min

Question 31

What can be given to see atrial flutter?

Answer 31

Adenosine

Question 32

Torsdaes de pointes is a type of

Answer 32

Ventricular tachycardia

Question 33

Causes of trosades de pointes =

Answer 33

- Congenital long QT - Heart block/bradycardia - Hypokalaemia or hypomagnaemia - Drugs (Type III antiarrthymics)

Question 34

Treatment of Vfib =

Answer 34

Direct current shock

Question 35

How to manage arrthymias:

Answer 35

- Treat causes - Vagotonic manoeuvres - DC cardioversion - Pacing - Surgery/ablation - Drugs

Question 36

How to treat bradycardia due to beta-blocker OD

Answer 36

Glucagon

Question 37

How to treat bradycardia due to Ca2+ blocker OD

Answer 37

Glucagon

Question 38

How to treat bradycardia due to acute digoxin toxicity

Answer 38

Digoxin-specific antibodies | Ca2+ blocker

Question 39

MoA atropine =

Answer 39

Antimuscarinic

Question 40

What to not give to cardiac transplant patient

Answer 40

Atropine

Question 41

If atropine fails, how should you treat bradycardia?

Answer 41

External pacing

Question 42

Hs and Ts describe =

Answer 42

Reversible causes of cardiac death

Question 43

Hs + Ts =

Answer 43

``` Hypovolemia Hypothermia Hypo/Hyperkalaemia Hypoxia Throbosis Toxins Tension pneumothorax Cardiac tamponade ```

Question 44

name a classification of antiarrthymics =

Answer 44

Vaughan Williams

Question 45

Class I

Answer 45

Na+ blockers

Question 46

Class II

Answer 46

Beta blockers

Question 47

Class III

Answer 47

K+ blockers

Question 48

Class IV

Answer 48

Ca2+ blockers

Question 49

MoA of Na+ blockers

Answer 49

Increase duration of depolarisation

Question 50

MoA of betablockers

Answer 50

Reduce sympathetic activity on SAN

Question 51

MoA of K+ blockers

Answer 51

Prolong repolarisation

Question 52

MoA of Ca2+ blockers

Answer 52

Prolong refractory period (nodal)

Question 53

Disopyramide

Answer 53

Na+ blockers

Question 54

Lidocaine

Answer 54

Na+ blockers

Question 55

Flecainide

Answer 55

Na+ blockers

Question 56

Antenolol

Answer 56

beta blockers

Question 57

Amiodarone

Answer 57

K+ blocker

Question 58

Verapamil

Answer 58

Ca2+ blocker

Question 59

Diltiazem

Answer 59

Ca2+ blocker

Question 60

MoA of adenosine

Answer 60

K+ channel activation - slows conduction through AV

Question 61

Use of adenosine

Answer 61

SVT

Question 62

MoA of digoxin

Answer 62

K+, Na+ ATPase inhibition

Question 63

Uses of digoxin =

Answer 63

AF Atrial flutter CHF

Question 64

What is digoxins ionotrophic effect?

Answer 64

+ve ionotrophy

Question 65

Low therapeutic index =

Answer 65

Dosing between therapeutic and lethal dose narrow

Question 66

What should you reduce digoxin dose in?

Answer 66

Elderly Renal impairment Hypokalaemia, hypomagnesia, hyperclacaemia

Question 67

Side effects of digoxin =

Answer 67

- Arrythmias, AF - GI - Blurring of vision - Gynaecomastia - CNS effects

Question 68

First line drug in ICU for SVT and VT =

Answer 68

Amiodarone

Question 69

Side effects of amiodarone

Answer 69

- Bradycardia, heart block, arrhythmia - Hypo/hyper thyroidism - Photosensitivity - Blue-grey skin - Lung fibrosis - Abnormal LFTs

Question 70

Why can amiodarone cause hyper/hypothyroidism

Answer 70

Contains iodine

Question 71

What is used in VT when amiodarne is contraindicated?

Answer 71

Lidocaine

Question 72

Class of lidocaine =

Answer 72

Class ib

Question 73

Contraindications of Ca2+ blockers =

Answer 73

Pregnancy Cardiogenic shock Severe bradycardia Heart failure