beta blockers and lung function in heart failure

This study compares three different beta-blocker medications — a class of drugs commonly used to treat heart failure — to see how they affect lung function and blood pressure. While all three are used for heart failure, there are reasons to think they may work differently, especially for patients who also have breathing problems such as asthma or chronic lung disease. The study will compare the effects of these medications head-to-head in stable heart failure patients. You may be eligible if: - You have stable heart failure (classified as NYHA Class I, II, or III) - You are already taking a beta-blocker medication - You may have breathing/airway problems (this is specifically included in half the study group) You may NOT be eligible if: - There are no specific exclusion criteria listed for this study Talk to your doctor about whether this trial might be right for you.