Introduction: Magnesium is an essential element in maintaining myocardial transmembrane potential. Little is known about its contribution to atrial fibrillation (AF) appearance. Purpose: To study plasma magnesium concentrations in paroxysmal AF (PAF) with a view to their possible role in the clinical presentation of the disease. Materials and methods: 33 patients (17 men, 16 women; mean age 60.03±1.93 years) and 33 controls with no history of AF (17 men, 16 women; mean age 59.27±1.72 years) were examined. In patients, magnesium was tested three times: on entering the ward, twenty-four hours and twenty-eight days after sinus rhythm restoration. In controls the indicator was determined once. Results: Upon admission there was no significant difference in magnesium concentrations between patients and controls (1.21±0.02 vs 1.17±0.03 mmol/L, p=0.33). Twenty-four hours and twenty-eight days after the arrhythmia discontinuation, still there was no difference (1.23±0.04 vs 1.17±0.03mmol/L, p=0.29; 1.21±0.02 vs 1.17±0.02 mmol/L, p=0.23, respectively). Conclision: This is the first clinical trial for plasma magnesium levels in PAF. No changes in the microelement values were measured during and after the arrhythmia. This fact was reason to believe that magnesium has no relation to AF clinical course and its values could not be used in monitoring the disease.
