Hyperkalemia - ECG
Hyperkalemia (high level of serum potassium ion) can not be safely diagnosed by ECG alone, but some abnormalities can be present. However, the severity of hyperkalemia does not always correspond to the degree of abnormalities found in an ECG curve. Generally said, the high level of potassium is associated with high pointed T waves, dilated QRS complexes and bradycardia.
This is typical ECG of a patient suffering from hyperkalemia – we clearly see the high pointed T waves in the chest leads (blue). The other symptoms are not present as the heart rate is quite normal (about 75 beats per minute according to distance between QRS complexes) and the QRS complexes do not appear to be significantly wider than normal.
Conclusion: Finding a bradycardia (and possibly pointed T waves) in patients with kidney disease or elderly patients taking drugs that may increase potassium levels (drugs containing spironolactone, ACE-inhibitors, potassium supplements, etc.) should be followed by blood tests to evaluate the serum levels of major ions.