What could be the cause of a female 69 yr old fall without blacking out female has a stent in her heart for a blockage. Has had 1 heart attack. Has had breast cancer within the last 5 yrs. An had a breast removed an has been tested for heart problems now

Needs more work up . This could be related to her heart and less likely her breast cancer but there are many other causes of a fall without blacking out. Breast cancer is probably the least likely but metastases to the brain can happen and may cause stroke-like symptoms that could cause a fall without passing out. However, this really is unlikely. She needs further work up.
We . We just need more information here. If there was loss of consciousness, passing out, seizure disorder is one cause. Low blood pressure is another. A heart irregularity is a third. Too often we do not find the cause for an episode of so called syncope. Ask the doctors to find out what they discover.