Delayed decline in plasma atrial natriuretic peptide levels after an abrupt reduction in atrial pressures: observation in patients with dual-chamber pacing.
The effect of an abrupt reduction in atrial pressures on atrial natriuretic peptide (ANP) secretion was studied in four patients with complete atrioventricular block with a dual-chamber pacemaker when the pacing mode was changed from the VVI to the DVI mode at an equal rate of 70/min. Simultaneous continuous hemodynamic monitoring was performed using a balloon-tipped thermodilution catheter. With DVI pacing, there was an immediate decrease of right atrial pressure from 4.5 +/- 0.9 to 1.8 +/- 1.1 mm Hg, and a reduction of pulmonary arterial wedge pressure from 7 +/- 0.8 to 4.5 +/- 0.9 mm Hg, together with a rise in cardiac output from 3.1 +/- 0.2 to 3.7 +/- 0.2 L/min. However, despite a constant hemodynamic status after dual-chamber pacing, the arterial ANP level steadily decreased from 151 +/- 26 pg/ml to a steady low level of 78 +/- 15 pg/ml after 20 minutes of dual-chamber pacing (percentage reduction- 48 +/- 8%, p less than 0.05). This persisted until the end of the study at 60 minutes. The time-dependent decay in ANP secretion after an abrupt and constant change in hemodynamic status should be considered when interpreting ANP levels.
Wong
C K
CK
Department of Medicine, University of Hong Kong, Queen Mary Hospital.
Lau
C P
CP
Cheng
C H
CH
Leung
W H
WH
Pun
K K
KK
Nicholls
M G
MG
D000368:Aged; D016275:Atrial Function / Q000502:physiology; D009320:Atrial Natriuretic Factor / Q000097:blood*; D001794:Blood Pressure / Q000502:physiology*; D002304:Cardiac Pacing, Artificial; D006327:Heart Block / Q000097:blood* / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011669:Pulmonary Wedge Pressure / Q000502:physiology
D009320:Atrial Natriuretic Factor