Baroreflex sensitivity and heart rate variability in conscious rats with myocardial infarction

• Verfasst von: Krüger, Carsten [VerfasserIn]
• Verfasst von: Kalenka, Armin [VerfasserIn]
• Verfasst von: Haunstetter, Armin [VerfasserIn]
• Verfasst von: Schweizer, Mark [VerfasserIn]
• Verfasst von: Maier, Christoph [VerfasserIn]
• Verfasst von: Rühle, Ulrike [VerfasserIn]
• Verfasst von: Ehmke, Heimo [VerfasserIn]
• Verfasst von: Kübler, Wolfgang [VerfasserIn]
• Verfasst von: Haass, Markus [VerfasserIn]
• Titel: Baroreflex sensitivity and heart rate variability in conscious rats with myocardial infarction
• Verf.angabe: Carsten Krüger, Armin Kalenka, Armin Haunstetter, Mark Schweizer, Christoph Maier, Ulrike Rühle, Heimo Ehmke, Wolfgang Kübler, Markus Haass
• E-Jahr: 1997
• Jahr: 01 Nov 1997
• Umfang: 8 S.
• Fussnoten: Gesehen am 03.12.2024
• Titel Quelle: Enthalten in: American journal of physiology. Heart and circulatory physiology
• Ort Quelle: Bethesda, Md. : American Physiological Society, 1977
• Jahr Quelle: 1997
• Band/Heft Quelle: 273(1997), 5, Seite H2240-H2247
• ISSN Quelle: 1522-1539
• DOI: doi:10.1152/ajpheart.1997.273.5.H2240
• Datenträger: Online-Ressource
• Sprache: eng
• Sach-SW: frequency domain
• Sach-SW: time domain
• K10plus-PPN: 1910729639

Abstract

The baroreflex sensitivity (BRS) and the heart rate variability (HRV) were studied in conscious rats after myocardial infarction (MI; induced by coronary artery ligation) and after sham operation (SH). BRS was determined by linear regression of R-R interval vs. arterial pressure changes induced by nitroprusside or methoxamine (intravenous bolus). HRV was calculated from 3-min electrocardiogram recordings. Left ventricular end-diastolic pressure and plasma atrial natriuretic peptide were increased after MI; plasma norepinephrine and basal heart rate (HR) remained unchanged. At 3 and 28 days after MI, BRS was reduced as indicated by decreased reflex bradycardia (RB) (MI, 0.66 ± 0.13 and 0.78 ± 0.07 ms/mmHg; SH, 1.27 ± 0.16 and 1.48 ± 0.14 ms/mmHg, respectively;P < 0.05 MI vs. SH). At 56 days after MI, BRS was normalized. RB was unaffected by atropine 3 and 28 days after MI but reduced in all other groups. The increase of basal HR by atropine 3 and 28 days after MI was less than in all other groups. HRV (SD of mean N-N interval, coefficient of variance, low- and high-frequency power; studied at 28 and 56 days) was similar in all groups. It is concluded that BRS is transiently depressed in rats with left ventricular dysfunction after MI probably due to a reduced reflex vagal activity. Even though basal HR and HRV are unchanged after MI, a temporary attenuation of tonic vagal activity is unmasked after autonomic blockade.