Hello Judy,   If you father recently (within the past month) had a cardiac catherization and it was OK per his cardiologist, then the possibility that he has a blockage causing his tiredness is likely low.  A cardiac catherization (I assume this what you mean when you say he had an angiogram) is a procedure performed by a cardiologist where a catheter (or small, hollow tube) is inserted into a large blood vessel in your groin. This catheter is advanced up through your aorta and then into the coronary vessels that supply your heart with blood.  The cardiologist then injects dye and uses a xray-like machine to see whether these vessels are patent (open) or stenosed (blocked).   Depending on his heart rate and his EKG findings, you father's tiredness could be associated with his bradyarrhythmia (slow heart rate).  And always, if you father's symptoms do not improve, he should see his physician to determine the cause of his tiredness.   To your (and your father's) health, Neil MD