hi.. i have understood your concerns... your father is suffering from the coronary artery disease and for that he has undergone triple bypass before 12 years and now stenting in the artery... he must be on antihypertensive medications..i dont know u are going for regular follow-up to your cardiologist or not.. if not then u shud consult him and go for proper evaluation.. in a patient of ischemic heart disease, the cardiologist usually prescribe some anxiolytics to calm down their anxiety level, otherwise increased anxiety can increase the work load on the heart and create so many problems.. so.,, i ll suggest to consult your treating doctor and explain the symptoms and the stress patient is undergoing...he will understand the symptoms and will himself suggest to concern a psychiatrist.. the long lasting anxiety can be control with anxiolytics [benzos] and antidepressant medications.. i am just suggesting the drugs to calm him down and reduce the level of anxiety on the long run... drugs are: tablet. escialopram [lexapro 10 mg] at night tablet. clonazepam [klonopin 0.25 mg] twice daily.. this meds will surely benefit him and there are no significant side effects on heart... i hope u ll find this advice helpful... best luck...