What is Eisenmengerization, also known as Eisenmenger's syndrome?

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Last updated: April 11, 2025 • View editorial policy

From the Guidelines

Eisenmengerization is a severe complication of untreated congenital heart defects where blood flow abnormally shunts from the right side of the heart to the left side, eventually reversing to a right-to-left shunt, and is diagnosed as Eisenmenger syndrome when associated with subpulmonary ventricular hypertension and right-to-left shunting through septal defects or connections between the great arteries 1. This occurs when a long-standing left-to-right cardiac shunt (such as from ventricular septal defects, atrial septal defects, or patent ductus arteriosus) causes progressive pulmonary hypertension. As pulmonary vascular resistance increases over time, the pressure in the right heart eventually exceeds that in the left heart, causing the shunt direction to reverse.

Key Points

  • This reversal leads to deoxygenated blood bypassing the lungs and entering the systemic circulation, resulting in chronic hypoxemia and cyanosis.
  • Patients with Eisenmengerization typically develop symptoms including shortness of breath, fatigue, chest pain, syncope, and signs of right heart failure.
  • Management focuses on treating symptoms rather than correcting the underlying defect, as surgical repair at this stage is usually contraindicated.
  • Treatments may include oxygen therapy, pulmonary vasodilators (such as endothelin receptor antagonists, phosphodiesterase-5 inhibitors, or prostacyclins), careful fluid management, and avoidance of situations that could worsen hypoxemia.
  • Heart-lung transplantation may be considered in select cases, and bosentan is beneficial in symptomatic adults with Eisenmenger syndrome with ASD or VSD 2.

Diagnosis and Treatment

  • Accurate diagnosis of Eisenmenger syndrome and exclusion of other potential contributors to right-to-left shunting or pulmonary hypertension by means of advanced imaging and cardiac catheterization are crucial prerequisites to optimize therapy for adults with Eisenmenger syndrome 1.
  • In symptomatic adults with Eisenmenger syndrome, bosentan and PDE-5 inhibitors are reasonable in combination if symptomatic improvement does not occur with either medication alone 2.

From the Research

Definition of Eisenmengerization

  • Eisenmengerization refers to the process by which a left-to-right shunt in the heart, often due to congenital heart disease, leads to pulmonary vascular disease and eventually reverses the shunt to a right-to-left direction 3, 4.
  • This process results in the development of Eisenmenger syndrome, a multisystem disorder characterized by pulmonary arterial hypertension, chronic hypoxemia, and involvement of multiple organ systems 3, 4.

Pathophysiology of Eisenmengerization

  • The initial left-to-right shunt triggers the development of pulmonary vascular disease, which progresses to pulmonary arterial hypertension and increasing pulmonary vascular resistance 3, 4.
  • As the pulmonary vascular resistance increases, the shunt eventually reverses, leading to a right-to-left shunt and the characteristic findings of Eisenmenger syndrome 3, 4.

Clinical Implications of Eisenmengerization

  • Eisenmengerization is a preventable condition, and early detection and management of intracardiac and extracardiac shunts are crucial to preventing its development 3.
  • The syndrome is associated with significant morbidity and mortality, with heart failure being the most common cause of death 4.
  • Advanced pulmonary arterial hypertension therapies, such as bosentan and sildenafil, have been shown to improve functional capacity, quality of life, and survival in patients with Eisenmenger syndrome 5, 6, 7.

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.