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Eisenmenger syndrome is a late complication of an uncorrected congenital left-to-right cardiac shunt (e.g., VSD, ASD, PDA), leading to pulmonary hypertension, shunt reversal (right-to-left), and cyanosis.
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It represents the final stage of pulmonary vascular remodeling due to chronic high flow and pressure.
| Phase | Event |
|---|---|
| Initial phase | Left-to-right shunt increases pulmonary blood flow |
| Progressive damage | Shear stress → intimal proliferation → medial hypertrophy of pulmonary arteries |
| Pulmonary hypertension | Pulmonary vascular resistance ↑ |
| Shunt reversal | Becomes right-to-left as PVR > SVR |
| Result | Hypoxemia, polycythemia, cyanosis, clubbing |
Developmental pathophysiology of Eisenmenger Syndrome. Long-standing unrepaired left-to-right shunt (represented by ventricular septal defect in this figure) increases pulmonary blood flow and causes shear stress on the pulmonary vascular endothelium. Over time, this leads to an irreversible elevation in pulmonary vascular resistance resulting in a right-to-left or bidirectional shunt and systemic hypoxemia. PVR - pulmonary vascular resistance. SVR - systemic vascular resistance. Created with BioRender.com
Banerjee R, Opotowsky AR. Update on Eisenmenger syndrome – Review of pathophysiology and recent progress in risk assessment and management. International Journal of Cardiology Congenital Heart Disease. 2024;17:100520-100520. doi:https://doi.org/10.1016/j.ijcchd.2024.100520
Common underlying cardiac lesions:
| Defect | Type |
|---|---|
| ‣ | Most common |
| ‣ | Secundum or primum |
| ‣ | Classic for differential cyanosis |
| ‣ | Especially in Down syndrome |
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Differential cyanosis (cyanosis in lower limbs only) is classically seen in PDA with Eisenmenger physiology.
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| General Findings | Advanced Disease |
|---|---|
| Cyanosis (central) | Clubbing (fingers/toes) |
| Dyspnea on exertion | Syncope, fatigue |
| Polycythemia | Stroke, brain abscess (paradoxical embolism) |
| Palpitations | Arrhythmias |
| Hemoptysis | Pulmonary hemorrhage |
| Right heart failure | Hepatomegaly, ascites, edema |
Multisystem complications of Eisenmenger syndrome. While the primary pathophysiology relates to pulmonary vascular remodeling consequent to chronic left-to-right shunting, most clinical sequelae relate to chronic hypoxemia, which is caused largely by right-to-left shunting. Created with BioRender.com.
Banerjee R, Opotowsky AR. Update on Eisenmenger syndrome – Review of pathophysiology and recent progress in risk assessment and management. International Journal of Cardiology Congenital Heart Disease. 2024;17:100520-100520. doi:https://doi.org/10.1016/j.ijcchd.2024.100520
| Modality | Imaging features |
|---|---|
| CXR | • Enlarged pulmonary arteries |
| • Peripheral pruning | |
| • Right atrial and RV enlargement | |
| • Straightening of left heart border | |
| MR/CT | • Accurate anatomical delineation |
| • RV mass and volume quantification | |
| • Assess PA dilatation and thrombus | |
| Cardiac catheterization | Confirms: |
| • mPAP ≥20 mmHg | |
| • PVR ≥3 Wood units | |
| • Right-to-left shunting |
Eisenmenger syndrome in a 37-year-old woman with a patent ductus arteriosus (PDA): A) AP chest X-ray showing bulging of the left hilum with vessels leading to the "abnormal" bulge (yellow arrow). B) CTA in axial and coronal planes confirming vascular origin (yellow arrows).
Ludeña T, Lozano-Samaniego A, Maldonado S, Salas F. The hilum of the lung: Two classical radiological signs to decipher it. Radiología (English Edition). 2022;64(1):60-68. doi:10.1016/j.rxeng.2020.09.005
Echocardiography: Detects original shunt anatomy