Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0022116 (ischemia)
 91,303 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Persistent unrecognized subendocardial ischemia with development of subendocardial necrosis is a major cause of patient death following cardiopulmonary bypass. The lesion is caused by a discrepancy between the oxygen needs of subendocardial muscle and the available blood supply. If sole reliance is placed upon monitoring conventional vital signs, the more subtle factors contributing to decreased blood flow may go unrecognized. Reported studies have confirmed that the adequacy of subendocardial perfusion can be predicted by calculating the supply/demand ratio, defined as the ratio of the diastolic pressure-time index (DPTI) divided by the systolic pressure-time index (TTI). An analog computer was designed and built that measures the area under the systolic and diastolic component, calculates the DPTI/TTI ratio, and digitally displays the result as the endocardial viability ratio (evr). The EVR was used to determine the adequacy of left ventricular subendocardial blood flow in 64 consecutive patients undergoing cardiac operations. Unidirectional intraaortic balloon counterpulsation (IABC) was utilized in 14 patients with 9 long-term survivors. The difference in mean EVR between survivors and nonsurvivors at the initiation of balloon support was statistically significant. Early application of unidirectional IABC when subendocardial ischemia persists following open cardiac procedures may prevent deterioration to subendocardial necrosis with subsequent morbidity or mortality.
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PMID:Intraoperative application of intraaortic balloon counterpulsation determined by clinical monitoring of the endocardial viability ratio. 83 44

Due to its purely diastolic perfusion pattern, the subendocardium is particularly sensitive to ischemia. The subendocardial perfusion can be hemodynamically assessed by the subendocardial viability ratio (EVR), ratio of the diastolic pressure-time index to the systolic pressure-time index. EVR may be either calculated in the catheterization laboratory or contimously monitorized in intensive care unit. Contimous EVR monitoring may prove useful in some critical hemodynamic states (cardiogenic shock, cardiac surgery) to asess the effects on subendocardial perfusion of the various proposed therapeutics either pharmacological (catecholamines, vasodilatators) or mechanical (intra-aortic baloon conterpulsation).
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PMID:[Hemodynamic assessement of the subendocardial perfusion (author's transl)]. 91 89