Arrhythmias

Question 1

How does AF appear on an ECG?

Answer 1

No P waves
Irregularly irregular rhythm
Normal shaped QRS complex
Irregular baseline

Question 2

What causes AF?

Answer 2

Heart failure/ischaemia
Hypertension
MI
PE, pneumonia
Mitral valve disease
Hyperthyroidism
Caffeine
Alcohol
Hypokalaemia
Low magnesium

Question 3

What are the symptoms and signs of AF?

Answer 3

Asymptomatic
Chest pain
Palpitations
Dyspnoea/ syncope

Signs:

• Irregularly irregular pulse
• Variable 1st heart sound
• Signs of LVF

Question 4

How do you treat Acute AF?

Answer 4

Oxygen
U&E
Emergency cardioversion (IV amiodarone if not available)
Treat associated illness e.g. MI, PE
Control ventricular rate: 
    --> 1st line = Verapamil/bisoprolol
    --> 2nd line = Digoxin/amiodarone
Start anticoagulation

Question 5

How do you treat chronic AF?

Answer 5

Rate control

• -> Bisoprolol/Verapamil (1st line)
• -> Digoxin / Amiodarone (2nd line)

Rhythm control
–> Cardioversion

Question 6

Which anticoagulant are used in AF?

Answer 6

Acute - Use Heparin until a full risk assessment for emboli is made

Chronic - Anticoagulate with Warfarin and aim for an INR of 2-3.

Question 7

What is the CHAD2DS2-VASc score used for and how is it calculated?

Answer 7

CHAD2DS2-VASc score is used to quantify risk of stroke and may help in decision making

Score 1 point for each of the following:

• Heart failure
• Diabetes
• Hypertension
• Vascular disease
• Aged >65
• Female

Score 2 points for each of the following:

• Age> 75
• Prior TIA, stroke or thromboembolism

If the score is 1 or more, then consider oral anticoagulants

Question 8

How does Ventricular fibrillation trace present?

Answer 8

Completely disorganised activity

No association between P waves and QRS complex

Question 9

How does ventricular tachycardia present?

Answer 9

Tachycardia
Broad QRS complexes with an abnormal shape
Unable to identify T waves or P waves
Regular rhythm

Question 10

How does an NSTEMI present on an ECG?

Answer 10

ST segment is not elevated (i.e. STEMI), but is often depressed
T wave inversion
Flat T waves
Relatively normal ECG

Question 11

How does a STEMI present on an ECG?

Answer 11

Sequence of ECG changes:

1. Normal ECG
2. ST elevation
3. Appearance of Q waves
4. Normalisation of ST segments
5. Inversion of T waves

Question 12

How can you tell where the site of infarction is?

Answer 12

Anterior infarction: V2-5 (typically 3+4)

Inferior infarction: leads III, aVF

Lateral infarction: leads, aVL, V5-V6

True posterior infarction: Dominant R waves in lead V1

Question 13

What cause arrhythmia’s?

Answer 13

Cardiac: MI, coronary artery disease, LV aneurysm, mitral valve disease, cardiomyopathy, pericarditis, myocarditis

Non-cardiac: caffeine, smoking, alcohol. pneumonia, drugs (B-2 agonists, digoxin, L-dopa, tricyclics), metabolic imbalance (K+, Ca2+, Mg2+, hypoxia, metabolic acidosis, thyroid disease), phaeochromocytoma

Question 14

How is bradycardia treated?

Answer 14

If asymptomatic and rate >40bpm = none required. Look for cause (drugs, sick sinus syndrome, hypothroidism) and respond accordingly.

If rate <40bpm or symptomatic = Atropine (0.6-1.2mg). if no response give temporary pacing wire.

Question 15

How is VT treated?

Answer 15

IV amiodarone or IV lidocaine.

If no response/if compromised = SHOCK