This Article Full Text Full Text (PDF) All Versions of this Article: 54/5/1092    most recent HYPERTENSIONAHA.109.135525v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Google Scholar Articles by Sharman, J. E. Articles by Marwick, T. H. PubMed PubMed Citation Articles by Sharman, J. E. Articles by Marwick, T. H. Pubmed/NCBI databases Medline Plus Health Information Exercise for Children Exercise for Seniors Exercise and Physical Fitness High Blood Pressure Related Collections Contractile function Exercise testing Other hypertension Echocardiography Other imaging

(Hypertension. 2009;54:1092.)
© 2009 American Heart Association, Inc.

Original Articles

Influence of Altered Blood Rheology on Ventricular-Vascular Response to Exercise

James E. Sharman; Joseph Brown; David J. Holland; Graeme Macdonald; Karam Kostner; Thomas H. Marwick

From the Department of Medicine (J.E.S., J.B., D.J.H., K.K., T.H.M.), University of Queensland, Queensland, Australia; School of Human Movement Studies (J.E.S., D.J.H.), Metabolism Program, Diamantina Institute of Cancer, Immunology, and Metabolic Medicine (G.M.), and the Department of Gastroenterology and Hepatology (G.M.), Princess Alexandra Hospital, Woolloongabba, Brisbane, Australia.

Correspondence to James E. Sharman, Menzies Research Institute, University of Tasmania, 199 Macquarie St, Hobart, Tasmania 7000, Australia. E-mail James.Sharman{at}menzies.utas.edu.au

Blood (or plasma) rheology is related to cardiovascular risk. Mechanisms of this association are unclear but may be partially related to impaired left ventricular (LV) function and increased central blood pressure (BP) during light activity. This study aimed to test these hypotheses. Twenty patients (14 men; aged 61±12 years) with polycythemia rubra vera (n=16) or hemochromatosis (n=4) were studied at rest and during exercise at 50% of maximal heart rate before and after venesection (500 mL; volume replaced with saline) to elicit an acute decrease in plasma viscosity at stable BP. Controls (n=20) underwent the same protocol with 25-mL venesection. Central BP and augmentation index were determined by tonometry. Resting LV systolic (peak longitudinal systolic strain rate and strain) and diastolic functions were determined by tissue-Doppler echocardiography. Venesection with blood volume replacement decreased viscosity (1.46±0.10 to 1.41±0.11 centipoise), protein, and hemoglobin (P<0.05 for all) and increased strain rate and strain (P<0.001 for both) in patients but not in controls (P>0.10 for all). There was no change in LV diastolic function (P>0.12 for all). Exercise augmentation index in patients was reduced after venesection (24±12% to 17±9%; P=0.001) despite no significant change in other BP variables. Hemodynamics (resting or exercise) were not significantly changed in controls. Exercise central systolic BP correlated with triglycerides (r=0.59; P<0.001). However, neither exercise hemodynamic changes nor LV functional changes correlated with any biochemical changes after venesection (P>0.05). We conclude that an acute change in blood rheology improves ventricular-vascular interaction by enhanced LV systolic function and reduced light-exercise central BP.

Key Words: blood pressure • hemodynamics • blood viscosity • heart ventricles • exercise