i'm so sorry for your loss i know you loved your dad very much and am just distraught over his death. Beating oneself up after a loved one's passing is common but i know knowing that doesn't ease the guilt or pain. i felt the same way when my mother died. all the should haves and could haves. i have found out that, for me, the only way i could get rid of the guilt was to see the facts. for example, your dad's arterial blockage, even his doctor did not know about it, so how were you supposed to know? we go by what doctors tell us. as for his coughing and smoking, you said the doctor said his lungs were fine, and had nothing to do with his passing. your dad sounds like the kind of person who did not like to bother others, so regarding not going to the doctor with him, i am sure he did not want to bother you. men are very independent about those things anyways. my mother was the same way, she did not like to bother others or complain but that can work against the situation in some cases. i know if you had known something was wrong you would have taken your dad to the er right away. you did your best with what you knew at the time. so please be gentle with yourself. i hope that when your grief subsides, you will be able to see that you were not at fault at all. many hugs to you.