Arrhythmogenic threshold of the myocardium under conditions of magnesium deficiency

We studied the arrhythmogenic threshold of the myocardium after injection of CaCl₂ to magnesium-deficient rats receiving Mg²⁺ L-aspartate, MgCl₂, their combination with vitamin B₆, and reference preparations Magne B₆® and MgSO₄ until complete compensation of magnesium level in the plasma and erythrocytes. Magnesium-deficient diet and deionized water were used for inducing alimentary Mg²⁺ deficiency and modeling pathological changes in rats. After reducing Mg²⁺ level to 0.7 mmol/liter in the plasma and to 1.5 mmol/liter in erythrocytes, Mg L-aspartate, MgCl₂, their combination with vitamin B₆, as well as Mg²⁺ deficiency led to a decrease in the dose of CaCl₂ provoking heart rhythm disturbances in 50% animals and shortening of animal life span. Administration of the test magnesium salts increased the arrhythmogenic threshold; Mg²⁺ salts were comparable by their efficiency with Magne B₆® and were far superior to MgSO₄.