title: Tachycardia-induced myocardial ischemia and diastolic dysfunction potentiate secretion of ANP, not BNP, in hypertrophic cardiomyopathy.
abstract: The aim of this study was to investigate what factor determines tachycardia-induced secretion of atrial and brain natriuretic peptides (ANP and BNP, respectively) in patients with hypertrophic cardiomyopathy (HCM). HCM patients with normal left ventricular (LV) systolic function and intact coronary artery (n = 22) underwent rapid atrial pacing test. The cardiac secretion of ANP and BNP and the lactate extraction ratio (LER) were evaluated by using blood samples from the coronary sinus and aorta. LV end-diastolic pressure (LVEDP) and the time constant of LV relaxation of tau were measured by a catheter-tip transducer. These parameters were compared with normal controls (n = 8). HCM patients were divided into obstructive (HOCM) and nonobstructive (HNCM) groups. The cardiac secretion of ANP was significantly increased by rapid pacing in HOCM from 384 +/- 101 to 1,268 +/- 334 pg/ml (P < 0.05); however, it was not significant in control and HNCM groups. In contrast, the cardiac secretion of BNP was fairly constant and rather significantly decreased in HCM (P < 0.01). The cardiac ANP secretion was significantly correlated with changes in LER (r = -0.57, P < 0.01) and tau (r = 0.73, P < 0.001) in HCM patients. Tachycardia potentiates the cardiac secretion of ANP, not BNP, in patients with HCM, particularly when it induces myocardial ischemia and LV diastolic dysfunction.
authors.affiliation: First Department of Internal Medicine, Asahikawa Medical College, 2-1-1-1 Midorigaoka Higashi, Asahikawa, Hokkaido 078-8510, Japan.
authors.forename: Shinsuke
authors.initials: S
authors.lastname: Kido
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Hasebe
authors.forename: Yoshinao
authors.initials: Y
authors.lastname: Ishii
authors.forename: Kenjiro
authors.initials: K
authors.lastname: Kikuchi
mesh_terms: D009320:Atrial Natriuretic Factor / Q000097:blood*; D002304:Cardiac Pacing, Artificial / Q000009:adverse effects; D002312:Cardiomyopathy, Hypertrophic / Q000097:blood* / Q000209:etiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000097:blood* / Q000209:etiology; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D013610:Tachycardia / Q000097:blood* / Q000150:complications; D018487:Ventricular Dysfunction, Left / Q000097:blood* / Q000209:etiology
chemical_list: D020097:Natriuretic Peptide, Brain; D009320:Atrial Natriuretic Factor