A 56-year-old man presents to the emergency department chest pain, palpitations, and diaphoresis.
Describe and interpret his initial 12-lead electrocardiogram:
- Ventricular rate 231 bpm
- Broad complex tachycardia
- Extreme QRS axis deviation (180°); QRS is positive in aVR and negative in I and aVF
- Very broad QRS complexes; QRS duration 170 ms
- Right bundle branch block pattern