Swan-Ganz catheters are balloon-tipped catheters inserted into the heart to measure pressures and collect blood samples from the right atrium, right ventricle, and pulmonary artery. This allows clinicians to assess conditions like shock, respiratory distress, and complications of myocardial infarction. Measurements of pressures, oxygen saturations, and cardiac output can guide therapy for critical illnesses and help evaluate the effects of treatments. While useful for management, the procedure does carry risks of complications if not performed carefully.