Antiarrhythmics

Question 0

Class 2 antiarrhythmics

Answer 0

Beta blockers

Question 1

Class 1 antiarrhythmics

Answer 1

Sodium channel blockers

Question 2

Class 3 antiarrhythmics

Answer 2

Potassium channel blockers

Question 3

Class 4 antiarrhythmics

Answer 3

Calcium channel blockers

Question 4

Class 1a antiarrhythmics effect on heart

Answer 4

Sodium channel blockers
Decrease conduction
Increase refractory period
Decrease automaticity - decrease slope of phase 4, fast potentials 
Increase threshold
Quinidine has anticholinergic properties

Question 5

Class 1a antiarrhythmics effect on ECG

Answer 5

Longer QRS, with or without long PR and long QT

Question 6

Class 1a antiarrhythmics uses

Answer 6

Quinidine - maintain sinus rhythm in AF and flutter, to prevent recurrent tachycardia and AF
Procainamide - acute treatment of SV and ventricular arrhythmias

Question 7

Quinidine

Answer 7

Class 1a antiarrhythmic
Oral or IV
Anticholinergic effect

Question 8

Procainamide

Answer 8

Class 1a antiarrhythmic

Question 9

Class 1a antiarrhythmics ADRs

Answer 9

Reduced CO
Torsades de Points 
Dizziness, confusion, insomnia, seizure
Lupus like syndrome
GI

Question 10

Class 1B antiarrhythmics effects on heart

Answer 10

Fast binding offset kinetics
No change in phase 0 in normal tissue (no tonic block), no ECG changes in these tissues
APD slightly decreases
Reduced phase 0 conductance in ischaemic or fast beating tissue
Increased QRS in these tissues

Question 11

Class 1B antiarrhythmics uses

Answer 11

Acute VT and VF, especially during ischaemia

Not atrial or AV junctional arrhythmias

Question 12

Lidocaine

Answer 12

Sodium channel blocker
Class 1B antiarrhythmic - IV only
Local anaesthetic

Question 13

Phenytoin

Answer 13

Sodium channel blocker
Class 1B antiarrhythmic - oral
Anti epileptic

Question 14

Class 1B antiarrhythmics ADRs

Answer 14

CNS- dizziness, drowsiness

Question 15

Class 1c antiarrhythmic effects

Answer 15

Slow binding offset kinetics (>10s)
Decreases phase 0 in normal tissue 
Decreases automaticity
Increased threshold
Increased APD
Increased refractory period, especially in rapidly depolarising atrial tissue

Question 16

Class 1c antiarrhythmic effects on ECG

Answer 16

Longer PR, long QRS, long QT

Question 17

Class 1c antiarrhythmic uses

Answer 17

Super ventricular arrhythmias (fib and flutter)
Premature ventricular contraction
Wollf-Parkenson White

Question 18

Flecainide

Answer 18

Class 1c antiarrhythmic

IV or oral

Question 19

Propafenone

Answer 19

Class 1c antiarrhythmic

IV or oral

Question 20

Class 1c antiarrhythmic ADRs

Answer 20

Proarrhythmic
Sudden death with chronic use
Increased ventricular response to supraventricular arrhythmias
CNS and GI

Question 21

Class 2 antiarrhythmics effect

Answer 21

Beta blockers

Increase APD and refractory period in AVN, reduced AV conduction velocity

Question 22

Class 2 antiarrhythmics effect on ECG

Answer 22

Longer PR interval

Lower HR

Question 23

Class 2 antiarrhythmics uses

Answer 23

Sinus and catecholamine dependent tachyarrhythmias
Converting re entrant arrhythmias in AV
Protecting ventricles from high atrial rates

Question 24

Propanolol

Answer 24

Beta blocker Non selective Oral or IV

Question 25

Esmolol

Answer 25

Beta blocker | IV only

Question 26

Class 2 antiarrhythmics ADRs

Answer 26

Bronchospasm | Hypotension

Question 27

Class 2 antiarrhythmics contraindications

Answer 27

Ventricular failure | Partial AV block

Question 28

Class 3 antiarrhythmics effects

Answer 28

Potassium channel blockers

Question 29

Amiodarone

Answer 29

Potassium channel blocker

Question 30

Amiodarone pharmacokinetics

Answer 30

Oral or IV T1/2 3 months Very lipid soluble - large volume of distribution

Question 31

Amiodarone effects on heart

Answer 31

``` Increased refractory period Increased action potential duration Increased threshold Decreases phase 4 Decreased AV conduction speed ```

Question 32

Amiodarone uses

Answer 32

Effective in most arrhythmias | Wolff Parkenson White

Question 33

Amiodarone ADRs

Answer 33

``` Hepatic injury Pulmonary fibrosis Thyroid disease Increased LDLs Photosensitivity leading to sunburn Crystals laid down in eyes ```

Question 34

Sotalol

Answer 34

Potassium channel blocker

Question 35

Sotalol administration

Answer 35

Oral

Question 36

Sotalol effects

Answer 36

Slow phase 4 Increased APD, refractory period in atrial and ventricular tissue Slows AV conduction Lengthens QT, decreases HR

Question 37

Sotalol uses

Answer 37

Wide spectrum SVT VT

Question 38

Sotalol ADRs

Answer 38

Insomnia Fatigue Proarrhythmic

Question 39

Class 4 antiarrhythmics effects

Answer 39

Slow AV conduction Increase refractory time in AVN Increase slope of phase 4 in SA to slow HR ECG shows longer PR, heart rate up or down depending on baroreceptor reflex

Question 40

Class 4 anti arrhythmics uses

Answer 40

``` Control ventricles during SVT Convert SVT (reentry around AV) ```

Question 41

Class 4 anti arrhythmics ADRs

Answer 41

GI | Caution in hypertension, low CO or sick sinus

Question 42

Diltiazem

Answer 42

Class 4 anti arrhythmics | Oral

Question 43

Adenosine mechanism

Answer 43

Binds A1 receptor Activates potassium currents in AVN and SAN, causing hyperpolarisation Reduces APD Decreases calcium currents, slowing AV conduction

Question 44

Adenosine pharmacokinetics

Answer 44

Short T1/2 (few seconds) | Rapid IV bolus

Question 45

Atropine mechanism

Answer 45

Muscarinic antagonist | Blocks vagal activity, increasing heart rate

Question 46

Atropine uses

Answer 46

Vagal bradycardia

Question 47

Digoxin mechanism in antiarrhythmics

Answer 47

Enhances vagal activity | Slows AV conduction and HR

Question 48

Magnesium antiarrhythmic

Answer 48

Treatment of tachycardia resulting from long QT

Question 49

Atenolol

Answer 49

Beta 1 selective beta blocker

Question 50

Bisoprolol

Answer 50

Beta 1 selective beta blocker

Question 51

Carvedilol

Answer 51

Mixed beta 1 alpha1 antagonist

Question 52

Digoxin used

Answer 52

Rapid atrial fibrillation