arrythmias

Question 1

shockable cardiac arrest rhythms

Answer 1

ventricular tachycardia
ventricular fibrillation

Question 2

non-shockable cardiac arrest rhythms

Answer 2

pulseless electrical activity
asystole

Question 3

what makes a narrow complex tachycardia

Answer 3

fast heart with a QRS complex duration less than 0.12s (3 small squares)

Question 4

differentials for narrow complex tachycardia

Answer 4

sinus tachycardia
supraventricular tachycardia
atrial fibrillation
atrial flutter

Question 5

treatment of supraventricular tachycardia

Answer 5

vagal manoeuvres and adenosine

Question 6

treatment of atrial fibrillation

Answer 6

rate control: beta blocker (bisoprolol)
rhythm control:
anticoagulation: DOAC

Question 7

what does a supraventricular tachycardia look like on ECG

Answer 7

narrow QRS followed by T wave
- P wave are present but often buried in T wave
- regular rhythm

Question 8

atrial fibrillation on ECG

Answer 8

absent P waves
irregularly irregular ventricular rhythm

Question 9

atrial flutter on ECG

Answer 9

atrial rate usually around 300 (P
saw-tooth pattern

Question 10

treatment of atrial flutter

Answer 10

similar to AF (including anticoag)
radiofrequency ablation of the tricuspid valve isthmus is curative
patients with life threatening atrial flutter treated with synchronised DC cardioversion

Question 11

what is broad complex tachycardia

Answer 11

fast heart rate with a QRS complex duration more than 0.12s (3 small squares)

Question 12

breakdown of broad complex tachycardias (resus guidelines)

Answer 12

ventricular tachycardia or unclear cause
polymorphic ventricular tachycardia (example: torsades de pointes)
atrial fibrillation with bundle branch block
supraventricular tachycardia with bundle branch block

Question 13

describe atrial flutter

Answer 13

re-entrant rhythm in either atrium
electrical signal re-circulates in a self perpetuating loop (why the atria rate is 300 bpm)

Question 14

what makes a prolonged QT interval

Answer 14

> 440 milliseconds in men
460 milliseconds in women

Question 15

management of ventricular tachycardia

Answer 15

adverse signs: immediate cardioversion
otherwise:
- amiodarone
- lidocaine
- procainamide
if these fail -> electrical cardioversion

Question 16

causes of prolonged QT interval

Answer 16

long QT syndrome
medications: antipsychotics, citalopram, erythromycin
electrolyte imbalances: hypokalaemia, hypomagnesaemia, hypocalcaemia
subarachnoid haemorrhage
hypothermia

Question 17

acute management of torsades de pointes

Answer 17

correct the underlying cause
magnesium infusion
defibrillation if ventricular tachycardia occurs

Question 18

what are ventricular ectopics

Answer 18

premature ventricular beats caused by random electrical discharges outside the atria

Question 19

how do ventricular ectopics appears on ECG

Answer 19

isolated, random broad QRS complexes on a normal ECG

Question 20

what is bigeminy

Answer 20

when every other beat is a ventricular ectopic

Question 21

management of bigeminy

Answer 21

reassure and no treatment in healthy people
beta blockers sometimes

Question 22

what is first degree heart block

Answer 22

delayed conduction through AV node
Prolonged PR interval >0.2 s

Question 23

what is second degree heart block

Answer 23

atrial impulses do not make it through the AV node to the ventricles
some p waves not followed by QRS complexes

Question 24

what are the two types of second degree heart block

Answer 24

mobitz type 1
mobitz type 2

Question 25

what is mobitz type 1

Answer 25

conduction through AV node takes progressively longer until it finally fails ECG: increasing PR interval until P wave is not followed by QRS complex

Question 26

what is mobitz type 2

Answer 26

intermittent failure of conduction through the AV node with an absence of QRS complexes following p waves ECG: PR interval remains normal RISK OF ASYSTOLE

Question 27

what is third degree heart block (complete heart block)

Answer 27

no relationship between p waves and QRS complexes significant risk of asystole

Question 28

what conditions have a risk of asystole

Answer 28

mobitz type 2 third degree heart block previous asystole ventricular pauses longer than 3 seconds

Question 29

management of unstable patients and those at risk of asystole with bradycardia

Answer 29

IV atropine inotropes (isoprenaline or adrenaline) temporary cardiac pacing permanent implantable pacemaker

Question 30

what is atropine

Answer 30

antimuscarinic medication and works by inhibiting the parasympathetic nervous system (pupil dilation, dry mouth, urinary retention and constipation)

Question 31

common causes of atrial fibrillation

Answer 31

SMITH sepsis mitral valve pathology ischaemic heart disease thyrotoxicosis hypertension

Question 32

presentation of atrial fibrillation

Answer 32

asymptomatic palpitations shortness of breath dizziness or syncope

Question 33

what is paroxysmal atrial fibrillation

Answer 33

episodes of atrial fibrillation that reoccur and spontaneously resolve back to sinus rhythm can last 30s- 48hrs

Question 34

investigations for patients with suspected paroxysmal atrial fibrillation

Answer 34

24 hours ambulatory ECG cardiac event recorder

Question 35

options for rate control in atrial fibrillation

Answer 35

beta blocker first line CCB digoxin (sedentary people with persistent AF)

Question 36

when to offer immediate cardioversion

Answer 36

atrial fibrillation present for >48 hours (consider long-term rhythm control, delay cardioversion until they have been on anticoag for 3 weeks) OR haemodynamically unstable

Question 37

what is done in immediate cardioversion

Answer 37

pharmacological: flecainide or amiodarone electrical

Question 38

long term rhythm control

Answer 38

1st line: beta blocker 2nd line: dronedarone 3rd line: amiodarone

Question 39

management of paroxysmal atrial fibrillation

Answer 39

flecainide taken as needed (only suitable if infrequent episodes and without structural heart disease) anticoagulation

Question 40

how does apixaban, edoxaban and rivaroxaban work

Answer 40

direct factor Xa inhibitors

Question 41

how does dabigatran work

Answer 41

direct thrombin inhibitor

Question 42

what is warfarins MOA

Answer 42

vitamin K antagonist prolongs prothrombin time

Question 43

types of SVT

Answer 43

atrioventricular nodal re-entrant tachycardia (most common) atrioventricular re-entrant tachycardia atrial tachycardia

Question 44

what is wolff-parkinson-white syndrome

Answer 44

extra electrical pathways connecting the atria and ventricles

Question 45

ECG changes in Wolff-Parkinson-White syndrome

Answer 45

short PR interval Wide QRS complex delta wave (slurred upstroke in QRS complex)

Question 46

treatment of wolff-parkinson-white syndrome

Answer 46

definitive treatment: radiofrequency ablation of accessory pathway

Question 47

acute management of SVT (patients without life-threatening features)

Answer 47

continuous ECG monitoring step 1: vagal manoeuvres step 2: adenosine step 3: verapamil or beta blocker step 4: synchronised DC cardioversion

Question 48

life threatening features of SVT

Answer 48

loss of consciousness heart muscle ischaemia (chest pain) shock severe heart failure

Question 49

management of life-threatening SVT

Answer 49

synchronised DC cardioversion under GA IV amiodarone added if initially unsuccessful

Question 50

examples of vagal manoeuvres

Answer 50

valsalva manoeuvres carotid sinus massage diving reflex

Question 51

what is adenosine and how does it work

Answer 51

slows cardiac conduction through AV node interrupts the AV node or accessory pathway during SVT

Question 52

contraindications of adenosine

Answer 52

asthma COPD heart failure heart block severe hypotension potential atrial arrhythmia

Question 53

when to use rhythm control over rate control in AF

Answer 53

coexistent heart failure first onset AF or no obvious reversible cause