Hello, As when there is atrial enlargement there is a cardiac assessment for the same and an Echocardiogram and electromyogram is advised. Post which the medicines are given is to help reduce the enlargement of the atriums. The difficulty in breathing is common for people having cardiac pathology. Cardio-Respiratory is always related to each other. The swelling is due to lack of venous return as the atrium is enlarged. I will advise you to get the echocardiogram, electromyogram, blood pressure measurement, Oxygen saturation measurements, thyroid function test. Also, consume the medicine as guided. Modify the water intake and measure the output. Also, modify the diet which can help you feel lighter. Also do simple exercises like deep breathing exercises, coughing exercises, huffing exercises as this will help avoid the respiratory trouble which you are facing. Doing lower limb and core exercises in low intensity will help reduce the swelling and help the atrium to come to a normal shape. Exercises like - core stability, static hamstring, static Quadriceps, straight leg raise, ankle toe movements, etc in low intensity will help. Hope I have answered your query. Let me know if I can assist you further. Take care Regards, Jay Indravadan Patel, Physical Therapist or Physiotherapist