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Mechanisms of Exercise Intolerance in Heart Failure With Preserved Ejection Fraction
| Content Provider | Scilit |
|---|---|
| Author | Dhakal, Bishnu P. Malhotra, Rajeev Murphy, Ryan M. Pappagianopoulos, Paul P. Baggish, Aaron L. Weiner, Rory B. Houstis, Nicholas E. Eisman, Aaron S. Hough, Stacyann S. Lewis, Gregory D. |
| Copyright Year | 2015 |
| Description | Journal: Circulation: Heart Failure Background—: Exercise capacity as measured by peak oxygen uptake (V o$ _{2}$ ) is similarly impaired in patients with heart failure with preserved ejection fraction (HFpEF) and heart failure with reduced ejection fraction (HFrEF). However, characterization of how each component of V o$ _{2}$ changes in response to incremental exercise in HFpEF versus HFrEF has not been previously defined. We hypothesized that abnormally low peripheral o$ _{2}$ extraction (arterio-mixed venous o$ _{2}$ content difference, [C(a-v)o$ _{2}$ ]) during exercise significantly contributes to impaired exercise capacity in HFpEF. Methods and Results—: We performed maximum incremental cardiopulmonary exercise testing with invasive hemodynamic monitoring on 104 patients with symptomatic NYHA II to IV heart failure (HFpEF, n=48, peak V o$ _{2}$ =13.9±0.5 mL kg$ ^{−1}$ min$ ^{−1}$ , mean±SEM, and HFrEF, n=56, peak V o$ _{2}$ =12.1±0.5 mL kg$ ^{−1}$ min$ ^{−1}$ ) and 24 control subjects (peak V o$ _{2}$ 27.0±1.7 mL kg$ ^{−1}$ min$ ^{−1}$ ). Peak exercise C(a-v)o$ _{2}$ was lower in HFpEF compared with HFrEF (11.5±0.27 versus 13.5±0.34 mL/dL, respectively, P <0.0001), despite no differences in age, hemoglobin level, peak respiratory exchange ratio, Ca o$ _{2}$ , or cardiac filling pressures. Peak C(a-v)o$ _{2}$ and peak heart rate emerged as the leading predictors of peak V o$ _{2}$ in HFpEF. Impaired peripheral o$ _{2}$ extraction was the predominant limiting factor to exercise capacity in 40% of patients with HFpEF and was closely related to elevated systemic blood pressure during exercise ( r =0.49, P =0.0005). Conclusions—: In the first study to directly measure C(a-v)o$ _{2}$ throughout exercise in HFpEF, HFrEF, and normals, we found that peak C(a-v)o$ _{2}$ was a major determinant of exercise capacity in HFpEF. The important functional limitation imposed by impaired o$ _{2}$ extraction may reflect intrinsic abnormalities in skeletal muscle or peripheral microvascular function, and represents a potential target for therapeutic intervention. |
| Related Links | http://europepmc.org/articles/pmc5771713?pdf=render https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5771713/pdf https://www.ahajournals.org/doi/reader/10.1161/CIRCHEARTFAILURE.114.001825 |
| Ending Page | 294 |
| Page Count | 9 |
| Starting Page | 286 |
| ISSN | 19413289 |
| e-ISSN | 19413297 |
| DOI | 10.1161/circheartfailure.114.001825 |
| Journal | Circulation: Heart Failure |
| Issue Number | 2 |
| Volume Number | 8 |
| Language | English |
| Publisher | Ovid Technologies (Wolters Kluwer Health) |
| Publisher Date | 2015-03-01 |
| Access Restriction | Open |
| Subject Keyword | Journal: Circulation: Heart Failure Peripheral Vascular Disease Heart Failure |
| Content Type | Text |
| Resource Type | Article |
| Subject | Cardiology and Cardiovascular Medicine |
