A short summary
George Khechinashvili and Kjell Asplund, Department of Medicine, University Hospital, Umea, Sweden
Acute myocardial infarction is not uncommon in acute stroke. However, diagnostication of myocardial infarction is complicated by the fact that clinical symptoms or patient complaints like chest pain do not usually accompany myocardial damage in acute stroke. Also, the stress of acute stroke may cause unspecific elevations of biochemical markers of myocardial damage. This systemic literature review summarizes the present knowledge about ECG repolarization and ischemic-like changes in patients with acute stroke.
Repolarization, ischemic-like ECG changes and/or QT prolongation are found in 76% (95% CI 73-79%) of patients with subarachnoid hemorrhage, irrespective of whether they have pre-existing heart disease or not. Such ECG changes are present in more than 90% of unselected patients with ischemic stroke and intracerebral hemorrhage, but the prevalence is much lower after exclusion of patients with pre-existing heart disease. When compared with findings by other diagnostic methods (cardiac wall motion abnormality detected by echocardiography, elevated levels of biochemical markers of myocardial injury, autopsy findings, thallium scintigraphy), these ECG changes are characterized by a high sensitivity but a very low specificity.
Thus, in patients with SAH patients, absence of repolarization and ischemic-like changes essentially rules out cardiac abnormalities on other investigations. In these patients, ECG changes usually indicate unspecific, stress-induced myocardial damage rather than acute myocardial infarction.
In patients with ischemic stroke or intracerebral hemorrhage, ECG changes most often represent pre-existing ischemic heart disease. The very low specificity of ECG changes in such patients implies that they alone are not reliable to diagnose acute myocardial infarction in the acute phase of stroke. Due to this uncertainty, other diagnostic methods must be applied.
