Magnesium infusion and postoperative atrial fibrillation: a randomized clinical trial.
BACKGROUND
Postoperative arrhythmias are among the most common complications of cardiac surgery. Total serum magnesium concentration will change after coronary bypass surgery but compensatory prophylactic administration of magnesium has remained a controversial issue. We studied whether prophylactic administration of magnesium could prevent post-coronary artery bypass grafting (CABG) arrhythmias and evaluated the effects of diabetes mellitus on prophylactic magnesium administration.


METHODS
In a clinical trial, 345 consecutive CABG candidates were randomly assigned to study (n = 166, 48.1%) and control groups. Patients in study group received supplemental magnesium infusion as following: 2 g [corrected] after induction of anesthesia until cardio-pulmonary bypass and then 8 g upon arrival in Intensive Care Unit (ICU) until 24 hr. Total serum magnesium concentration was measured at four designated time points: onset of induction, and 0, 24 and 48 hr after ICU admission. Cardiac arrhythmias were sought with a 12-lead electrocardiogram (ECG) from the end of surgery up till discharge.


RESULTS
Atrial Fibrillation (Af) occurred in 34 patients (9.9%). Total serum magnesium concentration was significantly higher in patients who received supplemental magnesium (P < 0.001) and significantly lower in Af patients (P= 0.02). Among non-diabetics, Af incidence was significantly lower in study group compared with control group.


CONCLUSIONS
The occurrence of atrial fibrillation correlates with serum magnesium level. Diabetes mellitus probably hampers prophylactic effect of supplemental magnesium in preventing the occurrence of Af.
Najafi
Mahdi
M
Tehran Heart Center, Medical Sciences/University of Tehran, Tehran, Iran. najafik@sina.tums.ac.ir
Hamidian
Reza
R
Haghighat
Babak
B
Fallah
Nader
N
Tafti
Hossein Ahmadi
HA
Karimi
Abbasali
A
Boroumand
Mohammad Ali
MA
D000328:Adult; D000368:Aged; D001281:Atrial Fibrillation / Q000188:drug therapy*; D001026:Coronary Artery Bypass / Q000009:adverse effects*; D005260:Female; D006801:Humans; D008274:Magnesium / Q000097:blood / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000188:drug therapy*
D008274:Magnesium