Defining ischaemiaBMJ 1995; 311 doi: https://doi.org/10.1136/bmj.311.7010.890 (Published 07 October 1995) Cite this as: BMJ 1995;311:890
- Nicholas Sperelakis, Professor
- Department of Molecular and Cellular Physiology, University of Cincinnati, PO Box 670576, Cincinnati OH 45267 0576, USA
When cells start screaming for help
Ischaemia is a Greek-Latin word that means a stopping or restraint of the blood.1 Last December's issue of Cardiovascular Research published 33 responses by “eminent cardiologists” to the question “Myocardial ischaemia: can we agree on a definition for the 21st century?”1 The short definitions included: “supply-demand imbalance,” “blood supply inadequate to meet the energy needs of the heart,” “coronary flow is insufficient to cope with the oxygen demand,” and “coronary flow is incapable of delivering enough oxygen to support mitochondrial oxidation.”
Concluding the section, the then editor of Cardiovascular Research, David Hearse, proposed that “biochemical ischaemia” exists when coronary blood flow is inadequate to permit the maintenance of a steady state metabolism, while “physiological ischaemia” exists when coronary flow is inadequate to permit the organ to perform at a level sufficient to support the body over its full physiological range of activity. While not wanting to add to the traditional definitions given by these experts, I want to present a functional view of ischaemia and specifically what happens to the ion channels of myocardial cells.
In my contribution I jokingly defined ischaemia as when the myocardial …