Abstract
Arterial baroreflex control of heart rate in young and older adults and in patients with heart failure with preserved ejection fraction
Physiology (Bethesda, Md.), Vol.38(S1)
05/2023
DOI: 10.1152/physiol.2023.38.S1.5731195
Abstract
Abstract only Background: The arterial baroreflex (ABR) plays an important role in evoking appropriate cardiovascular adjustments in response to perturbations such as exercise. The ABR control of heart rate (HR) becomes attenuated with advancing age and in a variety of patient populations, but limited information is available in patients with heart failure with preserved ejection fraction (HFpEF). The present study tested the hypothesis that the ABR control of HR is attenuated to a greater extent in patients with HFpEF compared to older and young controls. Methods: Six patients with HFpEF (71±6 years; 35.3±6.6 kg/m2), 4 older controls (68±4 years; 25.1±3.4 kg/m2), and 7 young controls (27±4 years; 26.6±3.9 kg/m2) underwent sequential bolus infusions of sodium nitroprusside (50-100 μg) and phenylephrine (150 μg) (modified Oxford technique) to provoke acute hypotension (“BP falls”) and hypertension (“BP rises”), respectively. Cardiac baroreflex gain was quantified as the weighted linear regression slope between the R-R interval and systolic blood pressure (BP). Results: Compared to young controls (10.7±3.4 ms/mmHg), overall cardiac baroreflex gain was reduced in older controls (3.4±1.6 ms/mmHg) and patients with HFpEF (2.1±1.8 ms/mmHg) (p<0.05), with no difference between the older controls and patients with HFpEF (p=0.718). During BP falls, cardiac baroreflex gain was not different between groups (p=0.06), but was qualitatively lower in patients with HFpEF (0.6±1.5 ms/mmHg) compared to young (5.3±5.5 ms/mmHg) and older controls (5.2±1.9 ms/mmHg). During BP rises, cardiac baroreflex gain was not different between older controls (2.6±0.8 ms/mmHg) and patients with HFpEF (2.3±2.0 ms/mmHg) (p>0.05); however, responses in patients with HFpEF were attenuated compared to young controls 10.7±5.8 ms/mmHg) (p<0.05). Conclusion: These findings suggest an age-related attenuation in the overall ARB control of HR that does not appear to be further exacerbated in patients with HFpEF. However, patients with HFpEF may exhibit a selective attenuation in ABR-mediated tachycardia in response to acute reductions in BP that may pose an increased risk of hypotension and frank syncope. This work was funded in part by the U.S. Department of Veterans Affairs (RX001311, to D.W.W.; IK2RX003670, to K.B.). This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.
Details
- Title: Subtitle
- Arterial baroreflex control of heart rate in young and older adults and in patients with heart failure with preserved ejection fraction
- Creators
- Kanokwan Bunsawat - University of UtahSeth Holwerda - University of Kansas Medical CenterJeremy Alpenglow - University of UtahRyan Broxterman - University of UtahMichael Francisco - University of UtahJesse Craig - University of UtahJarred Iacovelli - University of UtahJoshua Weavil - University of UtahDanilo Iannetta - University of UtahErin Inglis - University of CalgaryEric Tuday - University of UtahJonathan Harrison - University of UtahChristy Ma - University of UtahJohn Ryan - University of UtahD. Walter Wray - University of Utah
- Resource Type
- Abstract
- Publication Details
- Physiology (Bethesda, Md.), Vol.38(S1)
- DOI
- 10.1152/physiol.2023.38.S1.5731195
- ISSN
- 1548-9213
- eISSN
- 1548-9221
- Publisher
- AMER PHYSIOLOGICAL SOC; Rockville
- Grant note
- U.S. Department of Veterans Affairs: RX001311, IK2RX003670
This work was funded in part by the U.S. Department of Veterans Affairs (RX001311, to D.W.W.; IK2RX003670, to K.B.).
- Language
- English
- Date published
- 05/2023
- Academic Unit
- Health, Sport, and Human Physiology
- Record Identifier
- 9984958334102771
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