Particular attention should be accorded to a history of atherosclerotic heart
disease (e.g., angina, myocardial infarction, bypass surgery); cardiac valvular
disease (e.g., aortic stenosis); cerebrovascular disease (e.g., stroke); seizure
disorder, especially if not well-controlled by medication; and any medical
condition in which rapid loss of 500 mL of blood, or a prolonged vasovagal
reaction, might pose a risk.