A 28-year-old woman with a lifelong cardiac murmur presents with progressive cyanosis and digital clubbing. She has never undergone corrective surgery for her congenital atrial septal defect. Vital signs show BP 118/76 mmHg, HR 102/min, RR 22/min, SpO2 88% on room air. Echocardiography reveals severe pulmonary hypertension (RVSP 65 mmHg) and right-to-left shunting. She denies dyspnea on exertion initially. Which mechanism best explains the change in her shunt direction?
- A)Increased systemic vascular resistance causing more left to right flow
- B)Progressive pulmonary vascular remodeling causing right sided pressures to exceed left sided pressuresGABARITO
- C)Closure of the ductus arteriosus after birth
- D)Acute papillary muscle rupture decreasing left ventricular afterload
- E)Fibrosis of the AV node leading to bradycardia
Explicação
Eisenmenger syndrome develops when a long standing left to right shunt causes irreversible pulmonary vascular remodeling and pulmonary hypertension. Eventually right sided pressures exceed left sided pressures, reversing the shunt to right to left and causing ... Ver explicação completa e trilha adaptativa →