A 60-year-old man presents to the emergency department following a collapse that proceeded a week-long history of diarrhoea and vomiting.
Describe and interpret his initial 12-lead electrocardiogram:
- Ventricular rate 79 bpm
- Sinus rhythm
- PR interval 212 ms
- Normal QRS axis 9°
- QRS duration 122 ms
- Poor R wave progression
- ST segment elevation aVR, V1-2
- Upsloping ST segment depression in leads I, II, III, aVF, V4-6
- Tall, prominent, and tented T waves, most notably in leads II, and V3-5
- QTc 493 ms
Sinus rhythm with 1st degree atrioventricular block with concerning ST segment and T wave changes. Differential diagnosis would include diffuse subendocardial ischaemia, triple vessel disease, or hyperkalaemia.
A venous blood gas revealed severe acidaemia secondary to a maximally compensated metabolic lactic acidosis and acute renal failure. The serum potassium was 7.4 mmol/L. Click here for the ECG following treatment of the hyperkalaemia.