A 68-year-old woman develops sudden severe breathlessness at night. She is wheezing and coughing pink frothy sputum. Her blood pressure is 210/110 mmHg, oxygen saturation is 82%, and examination reveals bilateral crackles and an elevated JVP. Which diagnosis best explains the overall presentation?

A 54-year-old man develops central chest discomfort while climbing stairs. He describes it as “indigestion” and feels sweaty and nauseated. His blood pressure and oxygen saturation are normal. What is the most important reason not to simply assume this is gastrointestinal?

A 32-year-old woman develops pleuritic chest pain and mild shortness of breath after starting a medication to delay her menstrual period. Her ECG is normal. What is the most appropriate clinical approach?