Muscle ischaemia in patients with orthostatic hypotension assessed by velocity recovery cycles

Abstract

Muscle membranes in patients with orthostatic hypotension become progressively depolarised during standing. Membrane depolarisation is most likely the result of muscle ischaemia, related to the drop in perfusion pressure caused by orthostatic hypotension. Coat-hanger ache is most likely a consequence of this muscle ischaemia.

Early changes of muscle membrane properties in porcine faecal peritonitis

“…Similar changes of muscle membrane properties have already been shown in critically ill patients diagnosed with probable CIM [20], during ischaemia [15,17] and in patients with chronic renal failure [16]. In probable CIM, we found a significant relationship between membrane dysfunction (that is fall in ESN and rise in MRRP) and potassium.…”

Membrane dysfunction in Andersen‐Tawil syndrome assessed by velocity recovery cycles

“…7). MVRCs show promise as a practical new clinical neurophysiology tool for detecting muscle membrane dysfunction,35, 39–41 and these results suggest that that they have the potential to help in the diagnosis of muscle channelopathies such as ATS.…”

Temperature dependency of human muscle velocity recovery cycles

“…In contrast to the high sensitivity of MRRP to temperature, ESN and also the ISI for peak supernormality did not change significantly in the temperature range of 30°–34°C. In several earlier studies, ESN has been shown to be a highly valuable parameter to detect changes in muscle membrane potential 2–7. If adequate temperature control is not possible, ESN should be considered the most suitable parameter to detect changes of muscle membrane properties.…”

“…The depolarizing afterpotential is associated with a period of increased conduction velocity, that is, supernormality. Recent studies have demonstrated that this method is very sensitive to changes in membrane potential 2–7. However, the effects of changes in muscle temperature have not been investigated previously.…”