What Causes Pain In Chest Along With Fatigue And Tiredness?

My mom had one strong chest pain at 4am that hit front front and shot out back. Somewhere between 5-7 am she made pancakes, ate, washed dishes, cleaned table, and put away the dishes but she has no recollection of it. Between 7:40-8:10 she felt tired and then blacked out. At 9 she was sitting on her bed and felt like stretching so she laid back and blacked out again until 9:50am. Then at noon she was sitting and started to feel tired again but I called and she didn't get to lay down.. What could be happening??