Ventricular arrhythmias late after myocardial infarction are related
to hypomagnesemia and magnesium loss: preliminary trial of corrective
Ceremuzynski L; Van Hao N
Clin Cardiol 1993 Jun;16(6):493-6
It has been well established that in acute myocardial infarction (MI)
many patients display low serum magnesium (Mg). This is associated with
complex ventricular arrhythmias. The question arises whether predischarge
arrhythmias occurring late after MI might also be related to Mg imbalance.
In 118 patients subjected to heart rhythm 24 h Holter monitoring in the
second or third week after MI, we investigated (1) the relationship between
serum Mg, urinary Mg loss, and ventricular arrhythmias, and (2) the effect
of Mg supplementation on heart rhythm disturbances. In patients with undisturbed
rhythm or monomorphic ventricular ectopic beats (VEB) (Lown 0-2; n = 84),
mean serum Mg level (mg% +/- SD) was 1.83 +/- 0.21, whereas in patients
with multifocal VEB, pairs, or nonsustained ventricular tachycardia (VT)
(Lown 3-4; n = 34) serum Mg was decreased to 1.68 +/- 0.27 (p < 0.01).
Serum Mg normal range in our laboratory is 1.7-2.6 mg%. The lowest serum
Mg reaching 1.55 +/- 0.27 was found in nonsustained VT (Lown 4 b) subgroup
(n = 14). Urinary Mg loss measured in 81 patients was more pronounced
in those with Lown 3-4 arrhythmias (n = 26) than with Lown 0-2 (n = 55).
The daily values were 73 +/- 22 and 54.4 +/- 26 mg, respectively (p <
0.001). Thirteen patients with complex arrhythmias and low serum Mg received
Mg supplementation (MgSO4, 8 g in 500 ml 5% glucose intravenously during
24 h). This resulted in restoration of almost undisturbed rhythm in 10