My n law has CHF and was admitted to hospital recently. He was told only 15% of heart is working and will not get better and when he gets u his oxygen drops low. They are putting a life vest on him. My question is how long can person live with heart in that shape and oxygen also has fluid on right lung? He is 87 yrs of age and not sure he wants the vest. He use to be in good shape walked daily etc until Monday when he went into a cold sweat chest hurting and respirations was 9 and O2 was 87. Could you give me more info on life vest an what causes O2 to drop quick. I m a CNA and know a little but not about the vest? He also has AFIB. Thank you very much. We was told he probably wouldn t make it long due to this sudden health problems. He had same symptoms 4 yrs ago but returned back to normal and then this episode.