A 80-year-old man presents to the emergency department following a syncopal episode with associated chest discomfort (currently 4/10 in severity).
Describe and interpret his initial 12-lead electrocardiogram:
- Ventricular rate 49 bpm
- Sinus bradycardia
- 1st degree AV block (PR interval 286 ms)
- Normal QRS axis (4°)
- QRS duration 98 ms
- Normal R wave progression
- Downsloping ST segment depression in the lateral leads (I + aVL, V5-6)
- Slight ST elevation in the inferior leads III + aVF with associated hyperacute T waves
- Biphasic down-up T wave inversion in leads V2, I + aVL
- QTc 411 ms
These electrocardiographic features are highly suggestive of an acute occlusion of the right coronary artery.