Abstract 13543: Impaired Stroke Volume Response During Exercise in Patients With Heart Failure With Preserved Ejection Fraction (HFpEF): The Role of Dynamic Starling Mechanisms
| Autor: | Seamus B Hughes, Denis J Wakeham, James P Macnamara, Bryce Balmain, Christopher Hearon, Tony Babb, Benjamin D Levine, Satyam Sarma |
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| Rok vydání: | 2021 |
| Předmět: | |
| Zdroj: | Circulation. 144 |
| ISSN: | 1524-4539 0009-7322 |
| DOI: | 10.1161/circ.144.suppl_1.13543 |
| Popis: | Introduction: Impaired stroke volume (SV) response during exercise is common in HFpEF. The regulation of SV during low intensity exercise is dependent on end-diastolic volume (EDV) reserve from a compliant left ventricle (LV). The Dynamic Starling Mechanism (DSM) quantifies beat-by-beat modulation of SV by respiratory-mediated changes in LV filling pressure and provides insight into the relationship between changes in LV compliance and SV response during exercise. We hypothesized low SV reserve during exercise would track with greater impairments in DSM gain in HFpEF patients. Methods: 11 HFpEF patients (68 ± 6 years; 7 females) were studied at rest and during 20 Watts of upright cycling and separated into higher or lower SV reserve (direct Fick) groups based on median SV response (> vs ≤ 20% increase). DSM was quantified by transfer function (input/output frequency) analyses of beat-by-beat changes in pulmonary artery diastolic pressure (PAD, right heart catheterization) and SV (modelflow from radial arterial line waveform). Due to the small group size, magnitude of differences (i.e. effect size) between conditions and groups is assessed via Hedges’ g . Results: HFpEF patients with low SV reserve had blunted increases in SV compared to higher SV group patients (Δ 2 vs 31 ml, g = -2.0; Table). Compared to higher SV reserve, the lower SV reserve group exhibited a moderately greater increase in the power spectral density (PSD) of PAD ( g = 0.4) and decrease in PSD-SV ( g = 0.5) from rest to 20W. While both groups decreased DSM gain from rest to exercise, the lower SV reserve group had a greater decline (Δ -1.37 vs -0.61 ml/mmHg, g = -1.2). Conclusion: Lower SV reserve in patients with HFpEF is associated with impaired DSM gain during exercise. The lower gain was a function of increases in PAD PSD and decreases in SV PSD suggesting lower LV compliance and lower EDV reserve during exercise. Impaired DSM may explain low SV response and contribute to exercise limitations in patients with HFpEF. |
| Databáze: | OpenAIRE |
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