ECG Weekly Collection

Question 1

50 year old gentleman decided to get his life in order on New Year. He started to be compliant to his blood pressure medication and has started intensity exercise.

One week later, he does not feel well, feeling weak and achy, a/w nausea, vomiting, light headedness on standing, generalised weakness.

O/E: HR 20, SBP 70s, RR 22, sats 98% on RA

1. Interpret the ECG. What are the differentials?
2. What is the initial treatment for bradycardia?
3. Critical lab result: K 8.5mmol/L.
   - ECG findings in hyperkalaemia
   - How would you manage?

Answer 1

1. ECG interpretation
   - Loss of P wave with bradycardia
   - Shortened QTc

Differentials: Atrial fibrillation with slow ventricular rate
- Drug induced - beta blockers
- Hypercalcaemia
- Hyperkalaemia - K sparing diuretics, rhabdomyolysis

2. Initial treatment for severe bradycardia
   - Atropine
   - Transcutaneous pacing
   - Low dose epinephrine
   - Transvenous pacing

3A. ECG findings in hyperkalaemia
- Classic ECG: peaked T waves, sine wave in very severe
- Widening of QRS, prolonged PR, flattening or loss of P wave
- Often bizarre rhythms are common: bradydysrthythmias, pseudoventricular tachycardia, advanced AV block, sinus pause
- RAD
- Fascicular and bundle branch blocks
- Pseudo Brugada syndrome

3B. Management of hyperkalaemia
- Reminder: ACLS algorithm does not work well with metabolic related ECG changes
- Give calcium gluconate and sodium bicarbonate for hyperK
- Hyperkalaemia cocktail: insulin and dextrose

Question 2

7 years old boy p/w palpitations, lightheadedness. He has short limbs and stature, looks frail and walks with crutches, has history of long bone fracture.

1. Interpret the ECG
2. What are the causes of prolonged T wave QTc vs prolonged ST segment QTc

Answer 2

1. Interpretation of ECG
   - Borderline axis
   - TWI lead I and AVL
   - Prolonged QTc due to ST segment prolongation

Differentials: prolonged QTc
- Hypoakalaemia, hypomagnesaemia, hypocalcaemia
- Sodium channel blockers (type 1a, anti-arrhythmics, TCAs)
- Elevated ICP
- Acute coronary syndromes
- Hypothermia
- Hereditary long QTc syndromes

(Most of them cause prolonged T wave, except hypothermia and hypocalcaemia that cause prolonged ST segment)

Question 3

22 year old man without PMHx presents with syncope. He is asymptomatic with normal vitals. While ECG is running, he loses consciousness and goes into polymorphic VT and was defibrillated. ECG post-defibrillation is as follows.

1. Interpret the ECG
2. How would you adjust the leads to improve sensitivity?
3. Scoring system for diagnosis
4. Management of this ECG condition
5. Mortality rate of untreated condition