vitamin-d-2 and Arrhythmias--Cardiac

Topics: Animals; Arrhythmias, Cardiac; Calcium; Cardiotonic Agents; Catecholamines; Cats; Culture; Death, Sudden, Cardiac; Dogs; Electrocardiography; Emotions; Ergocalciferols; Fludrocortisone; Heart Conduction System; Heart Diseases; Helplessness, Learned; Humans; Hypothalamus; Immobilization; Mice; Myocardial Reperfusion Injury; Myocardial Stunning; Myocardium; Necrosis; Parasympathetic Nervous System; Psychophysiologic Disorders; Rats; Stress, Physiological; Subarachnoid Hemorrhage; Sympathetic Nervous System; Thyroxine; Vagus Nerve

Vitamin D deficiency is a common problem worldwide. Several studies have shown an association between vitamin D deficiency and the increased risk of metabolic syndrome. No previous study has compared the efficacy and safety of ergocalciferol at 40,000 versus 20,000 IU/week in patients with metabolic syndrome.. To evaluate the efficacy of ergocalciferol supplementation on serum 25-hydroxyvitamin D [25(OH)D] concentrations and to examine safety parameters in metabolic syndrome patients.. Outpatient department of Phramongkutklao Hospital, Bangkok, Thailand.. A randomized, double-blinded, parallel study was conducted in metabolic syndrome patients with vitamin D deficiency [25(OH)D <20 ng/mL]. Ninety patients were randomly assigned into three groups of 30 patients each. Group 1 was given two capsules of placebo/week, group 2 was given ergocalciferol 20,000 IU/week, and group 3 was given ergocalciferol 40,000 IU/week for 8 weeks.. serum 25(OH)D concentrations, serum calcium, safety, and corrected QT (QTc) interval.. Of the 90 patients enrolled, 84 patients completed the study. At the end of the study, the mean serum 25(OH)D in groups 2 and 3 significantly increased from the baseline (15.1 and 14.3 to 26.8 and 30.0 ng/mL, respectively). The increase in serum 25(OH)D in groups 2 and 3 were comparable and significantly greater than that of the placebo group. The percentage number of patients achieving normal vitamin D levels in groups 1, 2 and 3 were 3.3, 33.3, and 60.0 %, respectively, which were significantly different between groups (p < 0.001). Adverse reactions in both ergocalciferol treatment groups were not different from the placebo group (p > 0.05). Serum calcium levels did not change within and between groups of treatment. No significant change in QTc was observed in any patient.. Both 20,000 and 40,000 IU/week of ergocalciferol supplementation for 8 weeks were able to increase serum 25(OH)D concentrations significantly. However, more patients in the ergocalciferol 40,000 IU/week treatment group achieved a normal serum 25(OH)D level than in the group which received 20,000 IU/week. Clinicians would have informed of choosing the dosing regimen of ergocalciferol in metabolic syndrome patients.

Topics: 25-Hydroxyvitamin D 2; Aged; Arrhythmias, Cardiac; Calcifediol; Calcium; Dietary Supplements; Double-Blind Method; Ergocalciferols; Female; Humans; Hypercalcemia; Incidence; Male; Metabolic Syndrome; Middle Aged; Thailand; Time Factors; Vitamin D Deficiency

To investigate the role of vitamin D2 on the resolution of ST-segment elevation (STE) after a primary percutaneous coronary intervention (PCI), as serum levels of vitamin D have been associated with the severity of coronary artery disease.. All patients who underwent PCI for STEMI were screened for enrolment. Vitamin D2 levels were measured on admission along with other biochemical and haematologic assays. The electrocardiography (ECG) was recorded upon arrival and 60 min after the completion of PCI. The primary endpoint of the study was a ≥ 50% resolution of ST-segment amplitude (+STR) when compared to the initial ECG. A logistic regression multivariate analysis was performed to examine the association of STR with all confounding variables, including the admission levels of vitamin D. Receiver-operator characteristics analysis was used to determine the cut-off value of vitamin D that was predictive of STR. Although there was no difference in STR based on standard classification of vitamin D sufficiency, critically low levels of vitamin D (<7.5 ng/mL) were significantly associated with the absence of STR after PCI (AUC was 0.65 ± 0.07;. We concluded that although levels below ten ng/mL were generally accepted as vitamin D deficiency, only critically low levels of this vitamin (<7.5 ng/dL) reliably predicted the resolution of ST-segment after a primary PCI for patients with STEMI.

Topics: Arrhythmias, Cardiac; Coronary Angiography; Electrocardiography; Ergocalciferols; Humans; Myocardial Infarction; Percutaneous Coronary Intervention; ST Elevation Myocardial Infarction; Treatment Outcome; Vitamin D; Vitamin D Deficiency; Vitamins

Cardiovascular disease is often associated with chronic kidney disease and vice versa; myocardial vitamin D receptors (VDRs) are among the probable links between the 2 disorders. The vitamin D receptor activator paricalcitol protects against some renal and cardiovascular complications. However, the structural and electrophysiological effects of myocardial vitamin D receptor modification and its impact on the response to ischemia-reperfusion are currently unknown. This work attempted to determine whether obstructive nephropathy induced myocardial changes (in rats) linked to vitamin D receptor deficiency and to ventricular arrhythmias in Langendorff-perfused hearts. Unilateral ureteral-obstructed and Sham-operated rats were treated with either paricalcitol (30 ng/kg/d intraperitoneal) or vehicle for 15 days. In 5 hearts from each group, we found that obstructed rats showed a reduction in VDRs and an increase in angiotensin II type 1 receptor expression (messenger RNA and protein), suffered fibrosis (determined by Masson trichrome stain) and myofibril reduction with an increase in mitochondrial size, and had dilated crests (determined by electron microscopy). These changes were reversed by paricalcitol. In 8 additional hearts per group, we found that obstructed rats showed a higher incidence of ventricular fibrillation during reperfusion (after 10 minutes of regional ischemia) than did those treated with paricalcitol. The action potential duration was prolonged throughout the experiment in paricalcitol-treated rats. We conclude that the reduction in myocardial vitamin D receptor expression in obstructed rats might be related to myocardial remodeling associated with an increase in arrhythmogenesis and that paricalcitol protects against these changes by restoring myocardial vitamin D receptor levels and prolonging action potentials.

Topics: Action Potentials; Animals; Arrhythmias, Cardiac; Coronary Circulation; Ergocalciferols; Female; Myocardial Reperfusion Injury; Myocardium; Rats; Rats, Inbred WKY; Receptor, Angiotensin, Type 1; Receptors, Calcitriol; Ureteral Obstruction

Calcification of the aorta and the coronary vessels as well as metastatic calcification of the heart muscle in the rat was produced by daily oral administration of 300,000 i.u. vitamin D2/kg for 6 consecutive days. E.C.G. tracings showed different pathological conditions. The response of the cardiovascular system to certain arrhythmogenic substances, e.g. aconitine and CaCl2 was generally reduced in comparison to non-treated rats.

Topics: Aconitine; Aconitum; Animals; Arrhythmias, Cardiac; Arteriosclerosis; Calcinosis; Calcium Chloride; Electrocardiography; Ergocalciferols; Rats

Topics: Arrhythmias, Cardiac; Calcium; Child; Electrocardiography; Ergocalciferols; Humans; Hypocalcemia; Male; Vitamin D Deficiency