ECG of the Week – 30 June 2021

A 70 year old male presents with SOB and neck pain. An ECG is done:

  1. Describe and Interpret the ECG
  2. How would you manage this patient?

Answer:

Rate:

  • Ventricular rate 48 beats/min
  • Atrial rate 96 beats/min

Rhythm : 2:1 second degree heart block

PR: 260 ms

QRS: 100 ms

QTc: 496 ms (Bazett)

Additional :

ST elevation inferior leads

ST depression I,aVL, V2

The above ECG shows fixed 2:1 second degree heart block. It is more likely to be a Mobitz Type I as there is a narrow QRS, but without further ECG/rhythm strip we cannot be certain.  There are also signs of inferior ischaemia with reciprocal changes. STE III>II suggesting right ventricular involvement. The heart block is due to ischaemia of the AV node and a vagal response

Management would include:

  1. Aspirin, Clopidogrel (Ticagrelor contraindicated as HR <50), Heparin
  2. Oxygen if sats < 94%
  3. Avoid GTN, give fentanyl for pain relief
  4. If patient hypotensive management should be aimed at fluid resuscitation as the right ventricle is preload dependant. 250ml normal saline boluses and observe response aiming for BP > 100 mmHg
  5. Heart block should resolve with reperfusion and would only require management if the patient became unstable. Atropine can be given. Care needs to be taken when giving adrenalin or isoprenaline due to demand ischaemia.
  6. Reperfusion – thrombolysis vs PCI depends on location and resources