In 2015 I had a massive heart attack, 9 week's later I had surgery for 5 bypass. I was granted 60 percent, and am currently at 80 percent. This month I had a defibrillator put in my chest to control my heart rate. Should I try to get 100 percent for the defibrillator?
You're a Vietnam veteran with an agent orange IHD rating. It sounds as if your rating has been lowballed from the start. Sixty then eighty percent for what your heart is going through really isn't near enough.
VA is notorious for fudging the seriousness of a heart attack and subsequent damage to the muscle of the heart. They use obscure and obtuse methodology to determine the functional strength of the muscle and that usually is a gross understatement of the overall condition of the heart and the patient. I have yet to see an accurate rating for IHD.
In any case, if you had a pacemaker, an AICD or any other cardiac rhythm or pump assist device implanted, your rating should be adjusted to 100% from the date of implant and maybe then some. If you have other ratings that total up to 60% along with the 100% for the AICD, you should get the SMC housebound benefit.
You will have to keep applying for increases until VA gets it right. Good luck.