Preload failure

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In cardiac physiology, preload is the end diastolic volume that stretches the right or left ventricle of the heart to its greatest dimensions under variable physiologic demand.[citation needed] It is defined as the length of the heart muscle just before it starts to pump and is measured clinically by the volume of blood in the left ventricle, the main pumping chamber, when it is most relaxed.[citation needed] Preload failure occurs when the maximal exercise-induced cardiac output (CO) is decreased without a concomitant increase in right heart or pulmonary vascular pressures.[citation needed]

Preload can be influenced by blood volume, heart rhythm, left ventricular relaxation, and alterations in afterload.[citation needed]

Preload failure is associated with exercise intolerance in myalgic encephalomyelitis, chronic fatigue syndrome, orthostatic hypotension, and postural orthostatic tachycardia.[1] David Systrom at Brigham Women's Hospital in Boston is currently trialing the use of Mestinon in patients with preload failure.[2]

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The information provided at this site is not intended to diagnose or treat any illness.
From MEpedia, a crowd-sourced encyclopedia of ME and CFS science and history.