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Effect of a cold pressor test (CPT) on the cardiovascular (CV) responses to static handgrip exercise and peak force production
Author(s) -
Kimmerly Derek,
Chisholm-Drane Rory
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.1138.38
Subject(s) - isometric exercise , cold pressor test , cardiology , medicine , heart rate , blood pressure , mean arterial pressure , anesthesia , physical therapy
The transition from an inverted to upright position results in greater maximal voluntary contraction (MVC) force and greater CV response to exercise. It is unclear whether these results are due to the postural change per se or the heightened sympathetic state associated with the upright posture. We tested the hypothesis that elevated baseline sympathetic activity, elicited using a CPT, produces greater MVC handgrip force and a larger CV response to isometric handgrip exercise (IHG). 13 (8F/5M) normotensive subjects (22 ± 2 years) were randomized between cold (~10ºC) and thermoneutral (~24ºC) conditions. During each condition, their foot was submerged for 6 minutes. Non‐dominant MVC handgrip force (kg) was recorded then followed by a 150s rest period, 90s of IHG (40% MVC), and 120s of post‐exercise ischemia (no exercise). Heart rate (HR), mean arterial pressure (MAP) and calf blood flow (CBF) were measured throughout. Calf vascular resistance (CVR) was calculated. At rest, MAP (+4 ± 1 mmHg) and CVR (+5 ± 3 PRU) were increased in the cold condition. Handgrip MVC was greater (24 ± 10 vs. 22 ± 8 kg) in the thermoneutral condition. MAP during IHG was higher in the cold condition (93 ± 12 vs. 86 ± 7 mmHg). Application of a cold stimulus augmented resting MAP and CVR. This heightened sympathetic state resulted in a lower handgrip MVC force but an exaggerated MAP response to IHG