<s>[INST] Hello, my name is Tim My 23.8 yr old son has DMD and is showing signs of tricuspid and bicuspid regurg. He has VERY little muscle left in his body. If the dystrophy is attacking his heart at this point will it become more aggressive against organs or will it continue as slowly as when he had muscle tissue? [/INST] Hello! Thank you for asking on Chat Doctor! I am sorry to hear your unpleasant and desperate situation. Duchess muscular dystrophy affects almost all body muscles, including heart and respiratory muscles, giving rise to heart and respiratory failure. It is a progressive disease, leading to muscle replacement with adipose tissue. It is the cardiac (heart failure and arrhythmia), and respiratory complications that determine their life expectancy. Lab tests may be performed to clarify the rate of disease progression. You need to talk with his attending physician about the available tests, in the attending medical center. Its median life expectancy is improved from around 25 to possibly 30 years. Rare cases may survive to their forties or fifties (with specialized medical support). Hope to have been helpful to you. Greetings!  </s>