P atients with atrial fibrillation (AF) may require electric cardioversion, either because of intolerable symptoms related to AF or as part of a rhythm control strategy.
See Editorial by KotechaElectric cardioversion using a biphasic waveform has a procedural success rate of 86% to 94%, sometimes requiring multiple shocks.1-3 The success of electric cardioversion depends on the duration of AF, transthoracic impedance, delivered energy, and the type of electric shock used.1 Pharmacological cardioversion using antiarrhythmic drugs (AADs) has a lower success rate and may take a few hours to days to achieve sinus rhythm.Magnesium (Mg) is an abundant mineral in the body, present in bone, the heart, and the central nervous system. In the heart, Mg modulates potassium (slow-activating delayed rectifier K channel, I Ks ) and calcium channels (L-type) in both the atria and the ventricles. 4,5 Mg has been shown to have membrane-stabilizing properties within the atrium. 4 This membrane-stabilizing property may be particularly helpful in rhythm control of AF. Data from the Framingham offspring and Atherosclerosis Risk in Communities (ARIC) prospective cohorts have linked low serum Mg levels to AF. 6,7 Studies on pharmacological cardioversion have shown increased success of cardioversion when Mg is used along with an AAD. 8,9 A recent study on electric cardioversion showed that the infusion of a K-Mg electrolyte solution was successful in facilitating electric cardioversion of AF.3 On the basis of data suggesting an association of low Mg levels with the incidence of AF and the membrane-stabilizing property of Mg in the atrium with the modulation of I K+ and I Ca2+ currents, we postulated that administration of Mg alone would be useful in increasing the success of cardioversion. The purpose of this study was to investigate the benefit of intravenous © 2016 American Heart Association, Inc.
Circ Arrhythm Electrophysiol