Magnesium & Potassium in Lone Atrial Fibrillation (LAF), Patrick Chambers, M.D.

Role of Magnesium and Potassium, -Autonomic Nervous System, -Vitamin D, -Insulin, -Hyperthyroidism, -Dehydration, -GERD, etc. etc. etc....

“...Mg and Cell Membranes
One of the most important roles of Mg involves maintenance of the intracellular environment. It does this primarily by attaching to phospholipids in membranes (both of the cell wall and cell organelles) to reduce their permeability and enhance polarizing electrostatic effects(12). It also a required cofactor in the various membrane ATP (energy requiring) pumps. The most important of these pumps is the Na/K pump. Others include Ca/Mg, K/H and Na/H pumps. In addition there are channels (such as Ca and Na) and exchangers (such as Na-Mg, Na-Ca and Na-H). Neither channels nor exchangers require ATP and are passive (rely on diffusion). Some of these are also adversely affected by Mg deficiency. Mg is a Ca channel blocker and Mg deficiency leads to increased intracellular Ca via channel (and pump) due to a Ca gradient of 25,000:1 (outside v inside)(9). Mg deficiency also results in dysfunction of the Na-Mg exchanger(56), leading to increased intracellular Na via exchanger (and pump) due to a Na gradient of 13:1(71). If there is insufficient Mg for adequate ATP, then the primarily extracellular cations sodium (Na) and calcium (Ca) tend to leak into the cells and the primarily intracellular cations potassium (K) and Mg tend to leak out. However, membrane leakiness in magnesium deficiency depends less on ATP related activity and more on the membrane stabilizing effects of magnesium phospholipd complexes(12). This leakiness disrupts cellular function and proper gradients (difference between intracellular and extracellular concentrations). In addition Mg is an antioxidant and Mg deficiency allows accelerated free radical damage to cell membranes (lipid peroxidation), further compromising cellular cation (positive ion) homeostasis(3,24,32,60,61). Maintenance of proper cationic (Na, K, Ca, Mg) gradients is especially critical for successful muscle contraction and nerve impulse transmission. In fact the earliest symptoms of magnesium deficiency are neuromuscular symptoms, e.g., muscle twitching, difficulty sleeping, difficulty swallowing. Accordingly, the list of disorders associated with Mg deficiency is top heavy with neuromuscular diseases, e.g., asthma (bronchial smooth muscle), migraines and eclampsia (vascular smooth muscle), cramps (skeletal muscle), LAF (cardiac muscle) and even chronic constipation (GI smooth muscle)....”

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