A 29-year-old woman with a 3-year history of systemic lupus erythematosus presents to the emergency department with acute-onset dyspnea, orthopnea, and hemoptysis. She reports chest discomfort with exertion over the past week. Vital signs: BP 98/62 mmHg, HR 118/min, RR 24/min, SpO2 86% on room air. On cardiac auscultation, a holosystolic murmur is heard at the apex. Chest X-ray shows pulmonary edema with cardiomegaly. Transthoracic echocardiography demonstrates severe mitral regurgitation secondary to papillary muscle rupture, with a dilated left atrium, ejection fraction of 35%, and elevated pulmonary artery systolic pressure of 58 mmHg. Which of the following cardiac chambers experiences the most severe hemodynamic consequence from this valve pathology?
- A)Left atriumGABARITO
- B)Left ventricle
- C)Right ventricle
- D)Right atrium
- E)Aorta
Explicação
In mitral regurgitation, blood regurgitates backward from the left ventricle during systole, directly into the left atrium. This causes volume overload and dilation of the left atrium, leading to elevated left atrial pressure. The elevated pressure backs up in... Ver explicação completa e trilha adaptativa →