Magnesium deficiency may be an important determinant of ventricular ectopy in digitalised patients with chronic atrial fibrillation.
Digitalised patients with chronic atrial fibrillation (AF) have a high prevalence of ventricular premature beats (VPB); magnesium deficiency may be a contributory factor. We have used a magnesium loading-test to examine the relationship between ventricular ectopy and magnesium status in 14 digitalised patients with chronic AF. Among seven patients with infrequent VPB (less than 250 24 h-1; mean 107 24 h-1) mean magnesium retention was 10.1% and four subjects retained no significant quantities of magnesium, indicating magnesium repletion. Among the remaining seven patients, mean magnesium retention was significantly higher (33.1%, P less than 0.02) and all patients retained 20% or more of the load given. There was an overall relationship between Mg retention and numbers of VPB (rs = 0.54; P less than 0.05). Magnesium deficiency may be determinant of ventricular ectopy in digitalised patients with chronic AF.
Lewis
R
R
Department of Clinical Pharmacology, Ninewells Hospital and Medical School, Dundee.
Durnin
C
C
McLay
J
J
McEwen
J
J
McDevitt
D G
DG
D000368:Aged; D001281:Atrial Fibrillation / Q000503:physiopathology*; D005117:Cardiac Complexes, Premature / Q000503:physiopathology*; D002908:Chronic Disease; D004077:Digoxin / Q000097:blood / Q000627:therapeutic use*; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008275:Magnesium Deficiency / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged
D004077:Digoxin