Hypocalcemia and myocardial function in uremia.
To investigate whether hypocalcemia affects cardiac performance in uremic patients, we studied the hemodynamic changes with short- and long-term correction of hypocalcemia in 4 uremic patients on dialysis using continuous wave Doppler study. At rest, 1 h of intravenous calcium infusion increased calcium level from 1.74 +/- 0.17 to 1.92 +/- 0.16 mmol/l (p less than 0.05). Cardiac output represented by minute distance increased from 10.5 +/- 2.0 to 12.1 +/- 2.5 m (p less than 0.05), but heart rate and blood pressure were unchanged. The peak velocity and acceleration of ascending aortic blood flow increased during calcium infusion. With long-term replacement, calcium level increased from 1.74 +/- 0.17 to 1.94 +/- 0.15 mmol/l (p less than 0.05), but resting hemodynamics were unchanged. On exercise testing, exercise duration increased from 10.6 +/- 1.6 min to 12.9 +/- 1.5 min (p less than 0.01), but hemodynamic parameters at peak exercise were similar. We conclude that acute calcium replacement enhanced cardiac contractility in uremic patients, but cardiac performance at rest and peak exercise was not improved with long-term therapy. This reflects different cardiac responses to acute versus chronic calcium replacement.
Wong
C K
CK
Department of Medicine, University of Hong Kong, Queen Mary Hospital.
Lau
C P
CP
Cheng
C H
CH
Mok
B K
BK
Cheng
I K
IK
D000328:Adult; D002118:Calcium / Q000008:administration & dosage; D002302:Cardiac Output / Q000187:drug effects / Q000502:physiology; D015150:Echocardiography, Doppler; D005080:Exercise Test / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D006996:Hypocalcemia / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction / Q000187:drug effects / Q000502:physiology*; D010531:Peritoneal Dialysis, Continuous Ambulatory; D006435:Renal Dialysis; D014511:Uremia / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000503:physiopathology*; D014807:Vitamin D / Q000008:administration & dosage
D014807:Vitamin D; D002118:Calcium