Lebelo, Ntapo Marcus2025-10-152024Lebelo, Ntapo Marcus . (2024). Comparison of Aortic Haemodynamics in Community Participants and Patients with Systolic Heart Failure and the Impact of Blood Pressure Control [Master`s dissertation, University of the Witwatersrand, Johannesburg]. WIReDSpace. https://hdl.handle.net/10539/47038https://hdl.handle.net/10539/47038A research report submitted in fulfillment of the requirements for the Master of Science in Medicine (Physiology), in the Faculty of Health Sciences, School of Physiology, University of the Witwatersrand, Johannesburg, 2024In patients with systolic heart failure (HF), both decreases and increases in pulse pressure (PP) are associated with poor prognosis. If aortic PP in systolic HF is decreased due to systolic dysfunction, then improvements in stroke volume (SV) or forward wave pressure (Pf) would be beneficial. Alternatively, if hypertension is the primary cause of systolic HF, aortic PP may be increased as a consequence of high aortic characteristic impedance (Zc) and backward wave pressure (Pb), which would be detrimental. Accordingly, blood pressure (BP) lowering would be advantageous. However, the changes in central hemodynamics that accompany systolic HF are currently unclear. Hence, I aimed to assess central hemodynamics in systolic HF patients compared to community participants. I therefore compared aortic haemodynamics (central pressures [SphygmoCor], aortic tract outflow [echocardiography]), and the impact of controlled BP (SBP/DBP<140/90 mm Hg or SBP/DBP<130/80 mm Hg) between stable systolic HF patients (n=42) and age and sex-matched community participants (n=298). Systolic HF patients had lower central PP and Pb (p<0.005) and higher HR (p<0.005) than community participants. However, no other differences were noted. When assessing the impact of BP control (SBP/DBP<140/90 mm Hg), HF patients with uncontrolled BP had higher Zc (p<0.005), Pf (p<0.05), and systemic vascular resistance (SVR) (p<0.05) than both HF patients and community participants with controlled BP. Moreover, despite similar peripheral and central PP to community participants with uncontrolled BP, Zc (p<0.005) and SVR (p<0.05) were higher in HF patients with uncontrolled BP. However, when assessing more intense BP control (SBP/DBP<130/80 mm Hg), the differences in Zc, QxZc, and SVR between the systolic HF patients with uncontrolled BP and the community participants with uncontrolled BP were eliminated. In conclusion, a lower aortic PP, which was not due to decreased SV, was observed in stable systolic HF patients. However, in the presence of uncontrolled BP (SBP/DBP≥140/90 mm Hg), but not SBP/DBP≥130/80 mm Hg, Zc, QxZc and SVR were increased in patients with systolic HF. Hence, BP control and its level of control are imperative in patients with systolic HF to protect the heart from the detrimental effects of increased afterloads.en© 2024 University of the Witwatersrand, Johannesburg. All rights reserved. The copyright in this work vests in the University of the Witwatersrand, Johannesburg. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of University of the Witwatersrand, Johannesburg.UCTDAortic HaemodynamicsSystolic Heart FailureBlood Pressure ControlDissertationUniversity of the Witwatersrand, JohannesburgSDG-3: Good health and well-being