question: My Dad is 87 years old with right sided heart failure COPD stage three and kidney disease. When he walks ( which is very slow) with a walker he labors to breath. They did an oxygen test read on him and came to a conclusion it is the heart that is the problem. How does the heart cause you to breath hard. He tires out quickly and they told me not to have him you his oxygen concentrator unless his oxygen drops down under 89. My Dad takes breathing treatments during the day and night also an inhaler once a day. I tried to explain to my Dad that they say it isn t his copd that is the major issue for trouble getting air but he and I are still confused. Thanks for your time and inform.