Arrhythmias

Question 1

Positive inotropic effect

Answer 1

Depolarisation effect
Makes your heart muscle contractions stronger
Increased cardiac output to a normal level
Increases the amount of blood our heart can pump out
Examples: dopamine, digoxin, adrenaline

Question 2

Negative inotropic effect

Answer 2

Hyperpolarisation effect
Weaken the heart’s contractions
Slow heart rate
Treat high blood pressure, heart failure, angina
Examples: beta blockers, flecainide, RL-CCB, digoxin

Question 3

Treatment for ectopic beats

Answer 3

Beta blockers - rarely used as these are spontaneous and resolve without treatment

Question 4

Types of atrial fibrillation

Answer 4

Paroxysmal - occurs intermittently and stops on its own within 7 days
Non-paroxysmal - persistent and lasts longer than 7 days
Long-standing persistent - lasts longer than a year

Question 5

Treatment of acute AF with life-threatening haemodynamic instability

Answer 5

Emergency electrical cardioversion without delay to achieve anticoagulation

Question 6

Treatment of acute AF without life-threatening haemodynamic instability if onset <48 hours

Answer 6

Rate or rhythm control

Question 7

Treatment of acute AF without life-threatening haemodynamic instability if onset >48 hours

Answer 7

Rate control only

Question 8

Examples of drugs for cardioversion (rhythm control) in acute AF without life-threatening haemodynamic instability if onset <48 hours

Answer 8

Flecainide, amiodarone

Question 9

Maintenance treatment of non-paroxysmal AF

Answer 9

1st: Monotherapy rate control with beta blocker, RL-CCB or digoxin
2nd: Dual therapy with two of the first line drugs
3rd: Rhythm control with sotalol, propafenone, amiodarone, flecainide or dronedarone

Question 10

Treatment if onset non-paroxysmal AF is >48 hours and what is required before initiating this treatment

Answer 10

Electrical cardioversion
Patient must be fully anticoagulated for at least 3 weeks before and 4 weeks after

Question 11

Treatment of paroxysmal AF with symptomatic episodes

Answer 11

Pill in pocket approach with flecainide
I seen in practice atenolol being used for this

Question 12

When would digoxin be used as first line for non-paroxysmal AF?

Answer 12

In predominately sedentary patients where beta blocker or RL-CCB doesn’t control symptoms

Question 13

Drug treatment that may be required post electrical cardioversion

Answer 13

Standard beta blocker
Sotalol, propafenone, amiodarone, or flecainide

Question 14

When should amiodarone be started and for how long should it be continued after electrical cardioversion?

Answer 14

4 week before and continued for up to 12 months after

Question 15

Treatment of paroxysmal AF

Answer 15

1st: Standard beta blocker
2nd: Sotalol, Propafenone, Amiodarone or Flecainide

Question 16

How to assess risk of stroke? What is the score that required anticoagulation therapy?

Answer 16

CHADsVASc
Men = >1
Women = >2

Question 17

Treatment of atrial flutter

Answer 17

Reacts less effectively to drug treatment so treat with direct current cardioversion or catheter ablation

Temporary rate control with beta blocker or RL-CCB until sinus rhythm restored

Question 18

When would direct current cardioversion be used to restore sinus rhythm in atrial flutter?

Answer 18

When haemodynamic instability is present

Question 19

When would catheter ablation be used to restore sinus rhythm in atrial flutter? What must you ensure before treatment?

Answer 19

Recurrent atrial flutter
Patient has been anticoagulated for 3 weeks if flutter lasts longer than 48 hours

Question 20

Treatment of paroxysmal supraventricular tachycardia

Answer 20

1st: Usually terminates spontaneously by itself
2nd: Reflex vagal stimulation e.g., immerse face in ice-cold water or carotid sinus massage with ECG monitoring
3rd: IV adenosine
4th: IV verapamil but should be avoided if recently treated with beta-blocker

Question 21

Treatment of recurrent symptoms of paroxysmal supraventricular tachycardia

Answer 21

Catheter ablation

Question 22

Prevention of further episodes of paroxysmal supraventricular tachycardi

Answer 22

Beta blockers, Flecainide, Propafenone, or RL-CCB

Question 23

Treatment of arrhythmias post-MI

Answer 23

Tachycardia
Best not to administer anti-arrhythmic until ECG record

Bradycardia
1st: IV atropine
2nd: IVI adrenaline

Question 24

Treatment of Pulseless Ventricular Tachycardia or Ventricular Fibrillation

Answer 24

Resuscitation

Question 25

Treatment of unstable sustained ventricular tachycardia

Answer 25

Direct current cardioversion followed by IV amiodarone Repeat current cardioversion if necessary

Question 26

Treatment of stable ventricular tachycardia

Answer 26

Amiodarone Flecainide, propafenone, lidocaine (less so)

Question 27

Treatment of stable ventricular tachycardia if sinus rhythm not restored

Answer 27

Direct current cardioversion or catheter ablation

Question 28

Treatment of non-sustained ventricular tachycardia

Answer 28

Beta blocker

Question 29

Maintenance treatment for patients with ventricular tachycardia

Answer 29

Only used if high risk of cardiac arrest Implantable cardioverter defibrillator Can add beta blocker / amiodarone

Question 30

Treatment of Torsade's de Pointes

Answer 30

Usually self-limiting IV magnesium sulphate Beta blocker and atrial / ventricular pacing NOT AN ANTI-ARRHYTHMIC (can cause QT prolongation)

Question 31

Drugs that can cause Torsade's de Pointes

Answer 31

Amiodarone Sotalol Macrolides Haloperidol SSRIs TCAs Antifungals Lithium

Question 32

Treatment of Supraventricular Arrhythmias

Answer 32

IV Adenosine IV Verapamil followed by oral treatment is preferred if asthmatic Oral digoxin (IV not effective for rapid control of ventricular rate) IV beta blocker can achieve rapid control

Question 33

When would verapamil be contraindicated?

Answer 33

AF or atrial flutter WITH Wolff-Parkinson White Syndrome

Question 34

Drugs used for both Supraventricular and Ventricular Arrhythmias

Answer 34

Amiodarone Beta blockers Disopyramide Flecainide Procainamide Propafenone

Question 35

How many anti-arrhythmic drug classifications are there?

Answer 35

4

Question 36

How are the anti-arrhythmic drugs classified?

Answer 36

According to the primary mechanism of action

Question 37

Class I anti-arrhythmic

Answer 37

Membrane stabilising drugs - block sodium channels (sodium influx inhibited) Rapid inhibition: Lidocaine Slow inhibition: Flecainide, propafenone

Question 38

Class II anti-arrhythmic

Answer 38

Beta blockers

Question 39

Class III anti-arrhythmic

Answer 39

Prolong the cardiac action potential by inhibiting potassium efflux Amiodarone, sotalol

Question 40

Class IV anti-arrhythmic

Answer 40

Inhibit calcium influx RL-CCB

Question 41

Why isn't sotalol used as rate control?

Answer 41

Can prolong the QT interval which can occasionally lead to life threatening ventricular arrhythmias

Question 42

Sotalol monitoring requirements

Answer 42

ECG and measurement of corrected QT interval Serum electrolytes (K+ , Mg2+, Ca2+) (electrolyte disturbance i.e. hypokalaemia, hypomagnesaemia, and hypercalcaemia, should be corrected before starting sotalol and during its use)