Mitigating Initial Orthostatic Hypotension: Mechanistic Roles of Muscle Contraction Versus Sympathetic Activation.

ABSTRACT:

Background

Initial orthostatic hypotension (IOH) is defined by a large drop in blood pressure (BP) within 15 s of standing. IOH often presents during an active stand, but not with a passive tilt, suggesting that a muscle activation reflex involving lower body muscles plays an important role. To our knowledge, there is no literature exploring how sympathetic activation affects IOH. We hypothesized involuntary muscle contractions before standing would significantly reduce the drop in BP seen in IOH while increasing sympathetic activity would not.

Methods

Study participants performed 4 sit-to-stand maneuvers including a mental stress test (serial 7 mental arithmetic stress test), cold pressor test, electrical stimulation, and no intervention. Continuous heart rate and beat-to-b

SUBMITTER: Sheikh NA 

PROVIDER: S-EPMC8828707 | biostudies-literature | 2022 Mar

REPOSITORIES: biostudies-literature