Valvular insufficiency (regurgitation) Quiz: Ace Your Exams

A 61-year-old woman presents to the emergency department with two days of worsening shortness of breath. At baseline, she can only walk up half a flight of stairs before stopping to catch her breath, but today she could only walk up two steps before having to stop. There is no associated chest pressure, lightheadedness, or dizziness. Past medical history is significant for recurrent rheumatic fever as an adolescent, as well as hypertension controlled well with amlodipine. Temperature is 37.0ºC (98.6ºF), pulse is 102/min, respiratory rate is 20/min, blood pressure is 109/68 mmHg, and SpO₂ is 96% on room air. On physical examination, the patient appears fatigued. A holosystolic blowing, high-pitched murmur is heard best at the left 5^th intercostal space in the midclavicular line. There are faint bibasilar crackles on lung auscultation. There is moderate bilateral lower extremity edema. Chest radiograph shows mild pulmonary edema and trace bilateral pleural effusions. Which of the following is the most likely diagnosis?