The EKG is a poor substitute for serum potassium levels to determine the degree of abnormality. From reduction of P wave amplitude and prolongation of PR interval to absence of P waves altogether. Increase of QRS duration. Increase of QT duration. Slowing of heart rate.
T waves become tall and spiked.
Decreased R wave amplitude. Obstructive urinary disease. Oliguric, anuric renal disease. Uncontrolled diabetic ketoacidosis. Treat the underlying disease.