My dog had a some what heart attack and we put her to sleep. but what does the other stuff she was doing mean?

about a year ago my sister said she witnessed a spasm like episode(she also peed) my dog had. we thought she might have kicked the dog because she peed on the floor and caused a episode. then a week later i was playing a video game when i heard her trip over a shoe(shes blind and deaf and also 15 years old) and she started yelping. i woke my mom up and she picked the dog up and her head just went limp. after a few minutes she woke and peed. we thought to put her to sleep but she was alright the next day. but this morning i woke up to my mom yelling "she tried to get up but she couldn't!" then my dad saying "ill get dressed and well take her" i came down stairs and my mom explained that she peed on the floor so she took her out side to go to finnish and she was walking in circles then fell over on her side and had another episode but instead of yelping she was barking in pain loudly that was when she noticed there was blood in her stool. she carried her in and tried to calm her and give her water when she came to. she fell over again, went stiff, and salivated, and seemed dead but after a minute she woke up. they took her and put her to sleep. when they came back the doctor said that her heart was stopping and restarting but can someone explain to me the rest of what she was doing? or is it all related?