Effect of intravenous magnesium on ventricular tachyarrhythmias associated with acute myocardial infarction.

Ventricular ectopy and left ventricular dysfunction are important predictive factors for an unfavourable outcome following an acute myocardial infarction (MI). Tachyarrhythmias are a major cause of death subsequent to MI. Magnesium was postulated to have an antiarrhythmic effect after MI. Therefore we have investigated the influence of intravenous and oral magnesium (Mg) therapy on ventricular tachyarrhythmias. 67 patients with myocardial infarction (MI) diagnosed according to the WHO criteria of anamnesis, infarct-specific electrocardiogram (ECG), and enzymatic status were included in a prospective study. 23 patients (group 1) received 2 g Mg per day (= 82 mmol Mg/24 h) intravenously for the first 3 days followed by oral magnesium adipate administration of 3 x 2 coated tablets of magnesium 50 Apogepha (= 300 mg Mg/24 h or 12.34 mmol Mg/24 h, respectively) for the full duration of the study. 26 patients (group 2) received only i.v. magnesium for the first 3 days after admission (2 g Mg/24 h). The results of this treatment were compared to those of a control group of 18 MI patients without magnesium administration. All groups were identical with regard to other forms of treatment. The magnesium levels in serum and erythrocytes of all patients were measured at the following time points: days 0 (admission time), 1, 2, the day of discharge (about day 20) and after 12 weeks. The tachyarrhythmias were monitored by 24-h-continuous-electrocardiography on days 0, 1 and on the day before discharge (about day 20). The serum magnesium levels rose significantly during i.v. Mg-administration (1 and 2 day) but decreased in group 2 subsequently until the time of discharge from hospital. In contrast group 1 patients receiving oral as well as intravenous magnesium did not show this drop. The uptake of magnesium into the erythrocytes was less obvious. The erythrocyte magnesium concentration of the control group remained significantly low in serum and red blood cells. Significantly less ventricular premature beats and runs (< 5 ventricular premature beats and > 5 ventricular premature beats) compared to admission day were observed in both treated groups. These data suggest that the frequency of ventricular tachyarrhythmias is reduced by administration of intravenous magnesium and support an early high dose administration of intravenous magnesium in the wake of myocardial infarction.

[Coronary angiography and change in antioxidative status]. / Koronarangiographie und Veränderung des antioxidativen Status.

PATIENTS AND METHODS: In a prospective study in 53 patients with stable angina pectoris symptoms the antioxidant status (glutathione peroxidase, glutathione, superoxid dismutase, malondialdehyde and selenium in serum and whole blood) was determined before and 4 to 6 hours after coronary angiography. According to the results of the coronary angiography the patients were classified in a group with "severe" (n = 16) and another with "moderate" coronary alterations. RESULTS: In both groups there was a significant reduction of selenium in serum and whole blood. The enzymes glutathione peroxidase and superoxide dismutase as well as glutathione and malondialdehyde changed only slightly. CONCLUSION: These results can be the cause of an increase of the formation of free radicals during coronary reperfusion (PTCA, implantation of stents in the group with "severe" coronary alterations) but could also be seen as a sign of formation of radicals by the method itself (in patients with "moderate" coronary alterations). Further investigations are indicated. Furthermore the amelioration of the antioxidant status of the organism by scavenger substances (vitamins A, B, C and selenium) should be discussed.

[Selenium substitution in acute myocardial infarct]. / Selensubstitution bei akutem Myokardinfarkt.

BACKGROUND: Previous examinations have demonstrated decreased selenium levels in serum and full blood in patients with myocardial infarction. PATIENTS AND METHOD: 28 patients received a selenium treatment additional to the usual treatment of myocardial infarction. 19 patients with myocardial infarction with no supplementary selenium treatment served as a control group. Selenium levels in serum, full blood and urine were measured and the complications of the myocardial infarction documanted. RESULTS: There was a significant increase of serum and full blood selenium and glutathione peroxidase levels under i.v. selenium therapy in the acute phase of myocardial infarction (first to third day). Left heart failure more rarely occurred in the selenium group (20%) than in control patients (57%). Acute tachycardial cardiac rhythm disturbances such as ventricular extrasystoles and couplets diminished in both groups; ventricular extrasystoles decreased in the selenium group. CONCLUSIONS: Selen should be substituted in patients with acute myocardial infarction and decreased selen levels. It would be useful to carry out a prospective double-blind study.

[Selenium level in patients with acute myocardial infarct and in patients with severe angina pectoris without myocardial infarct]. / Selenspiegel bei Patienten mit akutem Herzinfarkt und bei Patienten mit schwerem Angina-pectoris-Anfall ohne Herzinfarkt.

Selenium in serum and whole blood was determined in patients (n = 88) with acute cardiac infarction, in patients (n = 62) with severe clinical symptoms and signs of angina pectoris excluding cardiac infarction, and a control group (n = 62). The average selenium concentration of the 62 patients in the control group was 1.00 +/- 0.17 mumol/l in the blood. The serum selenium concentration of the patients with cardiac infarction was significantly decreased as compared with the control group both on the first and tenth day (alpha = 1%) as well as after three months (alpha = 5%). On the twentieth day as well as six and twelve months after cardiac infarction no significant difference could be established. At all times after cardiac infarction, the blood showed a clearly decreased selenium concentration as compared with the control group. The difference was highly significant (alpha = 0.1%) on the first, tenth and twentieth day as well as after three and six months, and it was significant (alpha = 1%) after twelve months. On the first day, the average selenium concentration in the serum of the 62 patients with a severe attack of angina pectoris excluding acute cardiac infarction was 0.88 +/- 0.18 mumol/l and thus highly significantly below the values for the control group (alpha = 0.1%). The decrease on the tenth day (0.93 +/- 0.19 mumol/l) turned out not to be significant. The blood selenium concentration was highly significantly decreased on the first and tenth day (alpha = 0.1%). It was measured to be 1.12 +/- 0.19 mumol/l and 1.10 +/- 0.20 mumol/l respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

[Selenium and antioxidant status in various diseases]. / Der Selen- und Antioxidanzienstatus bei verschiedenen Krankheitsbildern.

All healthy mammalian organisms are characterized by an equilibrium between the occurrence of highly reactive oxygen species and their destruction by anti-oxidants. Numerous diseases go hand in hand with a disturbance of the homoeostatis. In order to avoid or minimize the destructive effect of the oxidant stress on biological structures, therapies utilizing drugs with anti-oxidant effects are increasingly being applied. Preconditions for these therapies are a characterisation and a follow-up of the anti-oxidant status in the diseased organism. In the course of the present study selenium, glutathione peroxidase and malondialdehyde were determined in patients with various clinical pictures (terminal renal insufficiency, septic shock, high-risk gravidieties, arterioscleroisis, pulmonary carcinoma, acute myocardial infarction, test patients taking the contraceptive pill). Patients with terminal renal insufficiency and those suffering from septic shock syndromes clearly show a selenium decrease in serum and whole blood as well as a drop in the GSH-Px-activity, and increased malondialdehyde concentrations in the serum. Both are a reflection of an increased lipid peroxidation. First results of a selenium therapy are available for patients with therminal renal insufficiency and post-traumatically induced renal failure. The interpretation of the findings in the categories "high-risk gravidity" and "women on the contraceptive pill", which show a normal GSH-Px-activity and significantly increased malondialdehyde concentrations, seems problematic. The organism counteracts an increased lipid peroxidation with a normal plasma-GSH-Px-activity, clearly a sign of a still normal anti-oxidant potential.