ECG - Hyperkalemia
P wave flatten, widen, and later disappear
PR prolongation >200 msec, later absent when P waves disappear
QRS complexes begin to widen >120 msec, slurred and merge with following T waves, resulting in a "sine wave" pattern
ST segments disappear
T waves tall, peaked with narrow base. Earliest changes in II, III, V2 - V6
Sinus arrest may occur at 7.5
Asystole/VF at 10 - 12