Changes in concentrations of neuroendocrine hormones and catecholamines in dogs with myocardial failure induced by rapid ventricular pacing.
OBJECTIVE
To describe neuroendocrine responses that develop in dogs subjected to prolonged periods of ventricular pacing.


METHODS
14 adult male hound-type dogs.


METHODS
Samples were obtained and neuroendocrine responses measured before (baseline) and after 3 periods of ventricular pacing. A pacemaker was used to induce heart rates of 180, 200, and 220 beats/min (BPM). Each heart rate was maintained for 3 weeks before increasing to the next rate. Atrial natriuretic peptide, antidiuretic hormone, aldosterone, norepinephrine, epinephrine, and dopamine concentrations and plasma renin activity were measured. Severity of left ventricular compromise was estimated.


RESULTS
Shortening fraction decreased significantly with increasing heart rates (mean +/- SE, 35.5 +/- 1.4, 25.0 +/- 1.4, 19.5 +/- 1.9, and 12.2 +/- 2.3 for baseline, 180 BPM, 200 BPM, and 220 BPM, respectively). Atrial natriuretic peptide concentrations increased significantly at 180 BPM (44.1 +/- 3.0 pg/mL) and 200 BPM (54.8 +/- 5.5 pg/mL), compared with baseline concentration (36.8 +/- 2.6 pg/mL). Dopamine concentration increased significantly at 200 BPM (70.4 +/- 10.4 pg/mL), compared with baseline concentration (44.2 73 pg/mL). Norepinephrine concentrations increased significantly from baseline concentration (451 +/- 46.2 pg/mL) to 678 +/- 69.8, 856 +/- 99.6, and 1,003 +/- 2676 pg/mL at 180, 200, and 220 BPM, respectively.


CONCLUSIONS
Dogs subjected to ventricular pacing for 9 weeks developed neuroendocrine responses similar to those that develop in humans with more chronic heart failure and, except for epinephrine concentrations, similar to those for dogs subjected to ventricular pacing for < 6 weeks.
Roche
Brian M
BM
Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus 43210, USA.
Schwartz
Denise
D
Lehnhard
Robert A
RA
McKeever
Kenneth H
KH
Nakayama
Tomohiro
T
Kirby
Timothy E
TE
Robitaille
Pierre-Marie L
PM
Hamlin
Robert L
RL
D000450:Aldosterone / Q000097:blood; D000818:Animals; D009320:Atrial Natriuretic Factor / Q000097:blood; D002304:Cardiac Pacing, Artificial / Q000009:adverse effects* / Q000662:veterinary; D002395:Catecholamines / Q000097:blood*; D004285:Dogs; D004298:Dopamine / Q000097:blood; D004452:Echocardiography; D004837:Epinephrine / Q000097:blood; D006333:Heart Failure / Q000097:blood* / Q000209:etiology / Q000503:physiopathology / Q000662:veterinary*; D006339:Heart Rate; D008297:Male; D009638:Norepinephrine / Q000097:blood; D014667:Vasopressins / Q000097:blood*
D002395:Catecholamines; D014667:Vasopressins; D000450:Aldosterone; D009320:Atrial Natriuretic Factor; D004298:Dopamine; D009638:Norepinephrine; D004837:Epinephrine