• Hyperkalemia: Tall “tented” T waves, absence of P waves, wide QRS complex
• Hypokalemia: Flat/small T waves, U waves are also seen
• Hypercalcemia: short QT interval
• Hypocalcemia: prolonged QT
• Digoxin: ST depression and T wave inversion

these are some electrolyte imbalances that are hy. you could translate the ecg reading to figure out the depolarization and repolarizations abnormalities.

I really havent come across any significant source which divulges into na+ imbalance affecting the depolarization or repolarization. They focus on swelling of the cell or not, both ways causing a CNS disturbance. Remember how goljan asked us to picture the whole brain being one cell that is either affected by hypo- or hypernatremia.. both capable of causing altered mental status. "Na+ channel" responsible for transporting na+ and k+ could be misinterpreted because defects in the channel itself or dysregulation of the ions itself could affect the depolarization. However, potassium is often involved.

here are some thoughts that ran in my head in terms of na+.. jus a thought. In ligand gated channels.. na+ doesnt play much of role since neurotransmitters are what controls the influx of na. Also, in voltage gated channels, the inward sodium is limited by threshold. maybe its jus irrevelant.

nehoo, when it comes to hypo or hyper natremia.. its def. HY to think of "cerebral edema" and "fluid shifts", thus focusing on neurologic symptoms and signs of hyrdation/dehydration.

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