These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Evaluation by multivariate analysis of changes in systolic time intervals during exercise in the supine and upright positions.
    Author: Rengo F, Trimarco B, Vitale D, Chiariello M, Volpe M, Violini R, Ricciardelli B.
    Journal: Acta Cardiol; 1980; 35(5):357-71. PubMed ID: 6970486.
    Abstract:
    In this study multivariate analysis was adopted to establish how simultaneous changes in heart rate (HR), blood pressure (BP) and work load (W) can affect systolic time intervals (STI). Thus, 13 normal volunteers underwent two consecutive exercise stress tests in the supine and upright position on a bicycle ergometer. By multivariate analysis it was shown that, while in the supine position left ventricular ejection time (LVET) is influenced by HR and W (LVET) = 330.6 - 0.76 HR - 0.41 W, F = 224, P is less than 0.001), in the upright position LVET changes are due only to HR variations (LVET = 309 - 0.88 HR, P is less than 0.001). Pre-ejection period (PEP) in both positions is related to HR and W, but this latter has a non-linear influence (supine: PEP = 110.9 - 0.15 HR -0.34 W + 0.0012 W(2), F = 56.4, P is less than 0.001; upright: PEP = 119 - 0.16 HR - 0.5 W + 0.0025 W(2), F = 86.7, P is less than 0.001). Finally, PEP/LVET ratio is correlated both in the supine and upright position with maximal BP, HR and W; however, the influence of HR and BP is different in the two positions (supine: PEP/LVET = 0.259 + 0.00047 BP + 0.00068 HR - 0.00167 W + 0.000013 W(2), F = 5.68, P is less than 0.01; upright: PEP/LVET = 0.201 + 0.0011 HR - 0.00371 W + 0.00016 W(2), F = 4.79, P is less than 0.01).
    [Abstract] [Full Text] [Related] [New Search]