Hello and thank you for using HCM.I carefully read your question and I understand your concern.You shoud not worry .I ll try to explain you something and give you my opinion. As you explain your father has a stent on a coronary artery. This means that the artery whith a stenosis now should have normal blod flow. You should know that for the fist 6 months tjere is a risk for stent stnosis, so it is mandatory to take the medication and do regular control after 1,3 and 6 months. Normaly after stent intervention your father should be back to a normal live becouse this is why we intervene to have a normal life whithout chest pains or dispnea. Feeling weak or tired might be related to several thinks like hypotension becouse of medication or his cardiac function, might be related to low heart rate or different patologyes like anemia or thyroid gland problems. About his medication ecospir does not cause such symtoms.Lasix might give electrolyte imbalance that might cause weakness. So, to find the real reason my opinion is that you should monitor his blood pressure and his heart rate during the day. Than it is necesary a full blood analyze to exclude anemia, thiroid problems or electrolyte imbalance. I will also suggest a cardiac echo to see cardiac function even though I suppose he jas already done it. Hope I was helpful.Wish your father good health. Best regards.