Final answer:
EKG changes in subarachnoid hemorrhage are caused by a surge of catecholamines and potential damage to the brain's autonomic control areas, not by electrolyte abnormalities. These changes can resemble those seen in myocardial infarction and are often temporary and reversible.
Step-by-step explanation:
The changes in an ECG or EKG seen in cases of subarachnoid hemorrhage (SAH) are not primarily due to electrolyte abnormalities; rather, they result from the stress response and injury to the brain, triggering cardiac effects. When a subarachnoid hemorrhage occurs, it can cause a surge of catecholamines (stress hormones) which affect the heart, leading to abnormalities in heart rhythm that are reflected on an EKG. These changes might mimic the signs of a myocardial infarction (heart attack) or other forms of cardiac distress. Additionally, it has been hypothesized that the insular cortex, an area of the brain involved with autonomic control, may also play a role when damaged during a hemorrhage. EKG changes can include peaked T waves, ST segment changes, and abnormal QRS complexes. These EKG abnormalities are usually temporary and can be reversible with appropriate treatment of the underlying SAH.