Effect of intravenous magnesium sulfate on cardiac arrhythmias in critically ill patients with low serum ionized magnesium.
Magnesium affects cardiac function, although until the recent development of a new ion-selective electrode no method existed for measuring the physiologically active form of magnesium, free ions (iMg2+), in the blood. We investigated the antiarrhythmic effect of magnesium sulfate administered to critically ill patients with cardiac arrhythmias and reduced iMg2+ as determined using the ion-selective electrode. Eight patients with a low iMg2+ level (less than 0.40 mmol/L) were given intravenous magnesium sulfate (group L). Magnesium sulfate was also administered to patients with a normal iMg2+ level (more than 0.40 mmol/L) but who did not respond to conventional antiarrhythmic drugs (group N). Intravenous magnesium sulfate significantly increased the iMg2+ level in patients in group L from 0.35 +/- 0.06 mmol/L (mean +/- SD) to 0.54 +/- 0.09 mmol/L (p < 0.01), and had an antiarrhythmic effect in 7 of the 8 patients (88%). However, in group N patients, intravenous magnesium sulfate had an antiarrhythmic effect in only 1 of the 6 patients (17%) (p < 0.05 vs group L). These results suggest that intravenous magnesium sulfate may be effective in the acute management of cardiac arrhythmias in patients with a low serum iMg2+ level.
Kasaoka
S
S
Critical Care Medical Center, Yamaguchi University Hospital, Japan.
Tsuruta
R
R
Nakashima
K
K
Soejima
Y
Y
Miura
T
T
Sadamitsu
D
D
Tateishi
A
A
Maekawa
T
T
D000368:Aged; D000369:Aged, 80 and over; D000889:Anti-Arrhythmia Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D001145:Arrhythmias, Cardiac / Q000097:blood / Q000188:drug therapy* / Q000209:etiology; D016638:Critical Illness; D005260:Female; D006801:Humans; D007275:Injections, Intravenous; D008274:Magnesium / Q000097:blood; D008275:Magnesium Deficiency / Q000150:complications*; D008278:Magnesium Sulfate / Q000008:administration & dosage / Q000627:therapeutic use*; D008297:Male
D000889:Anti-Arrhythmia Agents; D008278:Magnesium Sulfate; D008274:Magnesium