Hello thanks for asking from HCM for your health related queries I can understand your concern. She has underwent heart surgery recently and prior to that she had blockages in brain and had minor stroke. Both these conditions are known to aggravate cognitive decline and may result in delirium. He symptoms like frightening hallucinations, delusions are most probably occurring due to some delirium or ICU induced psychosis. So first thing you should do is to talk with her doctor and ask about her orientation. If she is conscious oriented to time place person then there is no immediate danger. But if there is cloudiness of consciousness, lack of orientation then she should be attended immediately. Medicines like HALOPERIDOL along with PHENARGAN are commonly used in ICU psychosis or delirium. Consult her doctor for re-evaluation. Thanks, Hope this helps you. Take care Dr. Seikhoo Bishnoi, Psychiatrist.