Bradycardia

Question 1

Aetiology of bradycardia

Answer 1

Physiological
Cardiac
- Post-MI
- Sick sinus syndrome
- Aortic valve disease
- Cardiomyopathy
- Sarcoidosis
Non-cardiac
- Vasovagal
- Hyperkalaemia
- Hypothermia
- Raised ICP (Cushing’s triad)
- Hypothyroidism
Drug-induced: beta-blockers, rate limiting CCBs (verapamil, diltiazem) digoxin, amiodarone)

Question 2

Symptoms and signs of bradycardia

Answer 2

Dizziness/light-headedness
Syncope
Fatigue
Exercise intolerance
SOB

Pulse rate <40bpm
Canon-a waves in JVP/raised JVP

Question 3

Investigations for bradycardia

Answer 3

Immediate: ECG

Holter monitor/mobile cardiac telemetry
FBC
U&Es
TFTs
ABG
CK, CK-MB
Troponin
Digoxin level

Echo

Question 4

Management for unstable bradycardia

Answer 4

1. A-E
2. Look for a pulse (no pulse → arrest protocol)
3. Supportive
   - Sats <90 > oxygen
   - IV access
   - 12 lead ECG
4. Stable or unstable (shock, chest pain or ischaemia on ECG, heart failure, syncope)
5. Atropine 500mcg (0.5mg) IV
6. Repeat atropine every 3-5 minutes (maximum 3mg, 6 doses)
7. Transcutaneous pacing (IR thread a catheter into the heart )
8. Isporenaline 5mcg/min IV
   Adrenaline 2-10mcg/min IV

Question 5

Management for stable bradycardia

Answer 5

1. A-E
2. Look for a pulse (no pulse → arrest protocol)
3. Supportive
   - Sats <90 > oxygen
   - IV access
   - 12 lead ECG
4. Stable or unstable (shock, chest pain or ischaemia on ECG, heart failure, syncope)

Observe
Risk of asystole → unstable management
- Recent asystole
- Mobitz II AV block, complete heart block
- Ventricular pause >3s