When you have heart failure, the heart can't pump as well as it should. Blood and fluid may back up into the lungs. Some parts of the body don't get enough oxygen-rich blood to work normally. As the condition gets worse, you may start to have symptoms. These include fatigue, rapid weight gain, shortness of breath, and swelling of the legs and ankles.
Another sign that heart failure is getting worse is a rise in pressure in the PA. This main artery connects your heart to your lungs. It carries blood to your lungs for oxygen. A rise in PA pressure occurs before you notice changes in your symptoms. So by monitoring it, your doctor can tell early on if your heart failure is getting worse. They can then make changes to your treatment to prevent a hospital stay.