Wa'aleykum Salaam dear sis-
SubhanAllah! Having a heart condition is verry serious! May Allah protect us all from it. Insha'allah, Of course Our dear sister's In my du'aa- May Allah give her a speedy recovery, make this easy on her, Grant her the best health and make it A purification for her Insha'allah!
When you visit our sister again, give her my best wishes insha'allah...and don't forget to read this du'aa for her:
....say it seven times:
‘'I ask Allaah The Supreme, Lord of the magnificent throne to cure you’'.
…he (the sick person) will be cured Insha'allah.