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Regulation of the pressor reflex response during progressive handgrip exercise in heart failure
Author(s) -
OˈKeefe Zachary Barrett,
Witman Melissa A. H.,
Richardson Russell S.,
Wray D. Walter
Publication year - 2012
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.26.1_supplement.1138.13
Subject(s) - medicine , heart rate , cardiology , heart failure , blood pressure , reflex , stroke volume , cold pressor test , population , mean arterial pressure , peripheral , cardiac output , anesthesia , environmental health
Exercise intolerance is a hallmark symptom of heart failure (HF), which may be due, in part, to an exaggerated exercise pressor reflex. Thus, the objective of this study was to better define the magnitude and mechanisms of the exercise pressor response in HF. Six HF patients (NYHA Class II‐III) and six young, healthy controls performed dynamic handgrip exercise for 2‐min at 15, 30, 45, and 60% of maximal voluntary contraction. Arterial blood pressure was determined non‐invasively (Finapres), stroke volume (SV) was estimated (Modelflow method), and cardiac output (CO) was calculated as the product of heart rate (HR) and SV. At all exercise intensities, HF patients exhibited an exaggerated increase in mean arterial blood pressure (3±1, 10±1, 15±4, and 24±4 mmHg) compared to controls (1±1, 5±1, 6±1, and 9±2 mmHg). CO increased substantially in the control group (0.2±0.1, 0.3±0.1, 0.6±0.2, and 0.9±0.1 L/min), but was unchanged in HF patients. These findings document an intensity‐dependent augmentation in the exercise pressor response in HF patients. The exaggerated rise in MAP in the absence of increased CO suggests that the exaggerated exercise pressor reflex is expressed exclusively through changes in peripheral resistance, which may contribute to exercise intolerance in this patient population. Research support from NIH PO1 HL‐091830, VA RR&D E6910R, and AHA 0835209N.