title: N-terminal atrial natriuretic peptide immunoreactivity in plasma of cats with hypertrophic cardiomyopathy.
abstract: Atrial natriuretic peptide (ANP) is an important regulator of fluid homeostasis and vascular tone. We sought to compare N-terminal ANP immunoreactivity (ANP-IR) in plasma from cats with and without hypertrophic cardiomyopathy (HCM). Secondarily, we evaluated relationships between ANP-IR and echocardiographical variables in cats with HCM and healthy cats. Venous blood samples were obtained from 17 cats with HCM and from 19 healthy cats. Plasma ANP-IR concentration was determined by an enzyme-linked immunoassay. Two cats with HCM had clinical evidence of congestive heart failure; the remainder had subclinical disease. Plasma ANP-IR concentration was higher in cats with HCM (3,808 +/- 1,406 fmol/L, mean +/- SD) than in control cats (3,079 +/- 1,233 fmol/L), but this difference was not statistically significant (P = .11; 95% confidence interval [CI] = -166 to 1,622). There was a significant, but modest correlation between plasma ANP-IR concentration and left ventricular posterior wall thickness (r = 0.42; P = .01). Additionally, plasma ANP-IR concentration was weakly correlated with left atrial size (r = 0.35; P = .03). A linear regression model was developed to further explore these relationships. Atrial size and wall thickness were included in the model; the 2 explanatory variables had an interactive effect on plasma ANP-IR concentration (R2 = 0.27; P = .02). There was no appreciable correlation between plasma ANP-IR concentration and any other echocardiographical variable. In a population that included cats with subclinical disease, those with HCM did not have significantly higher plasma ANP-IR concentration than did healthy cats. An exploratory multivariable regression analysis suggested a linear relationship between ANP-IR concentration and atrial size, wall thickness, and their interaction.
authors.affiliation: Department of Small Animal Clinical Sciences, Virginia-Maryland Regional College of Veterinary Medicine, Virginia Tech, Blacksburg 24061-0442, USA.
authors.forename: Heidi N
authors.initials: HN
authors.lastname: MacLean
authors.forename: Jonathan A
authors.initials: JA
authors.lastname: Abbott
authors.forename: Daniel L
authors.initials: DL
authors.lastname: Ward
authors.forename: William R
authors.initials: WR
authors.lastname: Huckle
authors.forename: David D
authors.initials: DD
authors.lastname: Sisson
authors.forename: R Lee
authors.initials: RL
authors.lastname: Pyle
mesh_terms: D000818:Animals; D009320:Atrial Natriuretic Factor / Q000097:blood* / Q000276:immunology*; D002312:Cardiomyopathy, Hypertrophic / Q000097:blood / Q000276:immunology / Q000662:veterinary*; D002371:Cat Diseases / Q000097:blood* / Q000276:immunology; D002415:Cats; D005260:Female; D006352:Heart Ventricles / Q000033:anatomy & histology; D008297:Male
chemical_list: D009320:Atrial Natriuretic Factor