Abstract
1426 The relationship between cycle power output and HR during incremental exercise is usually (≈85% of cases) sinusodial, with a flattening (- def) of HR near peak exercise. Some individuals (10-15%) display a disproportionate increase in HR (+def). To determine whether there might be an overriding physiologic reason for this difference in pattern, we evaluated LV function in individuals with + (n=10) & - (n=10) def. LV function was measured during upright cycle exercise at ventilatory threshold (VT) and maximal effort (Max) using first pass radionuclide angiography TableTableAlthough there were trends for more negative responses in LVEF and a smaller normalized increase in SV in the +def group, there were no statistically significant differences between the groups. These data suggest that the different pattern of HR response between + and - def groups does not represent a compensatory mechanism to defend cardiac output in the presence of other abnormalities of LV function.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
