Na⁺ & Cl⁻ → always think RAAS + water balance.
K⁺ → exquisitely aldosterone-sensitive, plus influenced by acid–base shifts.
HCO₃⁻ → lung-kidney duet (respiratory vs metabolic regulation).
Ca²⁺ & PO₄³⁻ → married couple, regulated by PTH + vitamin D.
Mg²⁺ → sneaky one, but loss (from diuretics, diarrhea, alcohol) causes refractory hypokalemia & hypocalcemia.

Screenshot 2025-10-02 at 7.10.46 PM.png

Cardiac Effect

Ions	Conditions	Impact on ‣ → a.k.a. AV conduction at SA/AV node	Impact on ‣ → a.k.a. time for deploarization/repolarization at Cardiac myocyte
‣	‣	Increase threshold potential (‣)
= ‣
= ‣	More rapid depolarization at ‣
= ‣
	‣		Opposite,
= ‣
‣	‣	Increase RMP = inactivate Na channel = less ‣ current
= ‣
→ loss AV conduction
= ‣
= ‣	More rapid re-polarization at ‣
= ‣

	‣		Opposite,
= ‣