Myocardial injury associated with CNS disease
What is the nature of the myocardial injury associated with CNS disease?
CNS lesions, particularly intracerebral and subarachnoid hemorrhage, may cause a number of electrocardiogram (ECG) abnormalities suggestive of myocardial ischemia.
These changes may closely resemble myocardial infarction and include prolongation of the QT interval, ST segment depression, flattening or inversion of T waves, and the appearance of U waves.
With the exception of QT interval prolongation and the U waves, these changes usually revert to normal within 2 weeks after the CNS event.
Other less frequently observed ECG changes are increased amplitude of the P wave, development of Q waves, ST segment elevation, and T wave elevation, notching, or peaking.
Differentiation between a centrally induced ECG abnormality and a true myocardial infarction may be difficult, but the patient must be cared for in a monitored setting until a “true” myocardial infarction is excluded.
The ECG changes are thought to be due to a neurogenically mediated excessive release of catecholamines upon cardiac myocytes, resulting in myonecrotic changes.
In fact, a higher level of serum catecholamines correlates with a poor outcome in patients with subarachnoid hemorrhage