Pericardial agenesis

Pericardial agenesis is a rare condition where there is absence of the pericardium to varying degrees. If it is only a small portions of the paricardium that is absent it is known as a pericardial defect.

Epidemiology

According to a surgical surgical and pathological series, the prevalence (inclusive of cases with other cardiopulmonary anomalies) is approximately 0.002-0.004% ¹³.

Clinical presentation 

Most patients are asymptomatic although some may present with symptoms such as fatigue, pain (especially non non-exertional paroxysmal stabbing chest pain ⁶) or cardiac conduction abnormalities ⁹. 

Pathology

Pericardial agenesis occurs from a premature atrophy of the common cardinal vein. Agenesis can be complete or partial. In partial cases absence of the left hemipericardium is more common.

Associations

With pericardial defect there can be several associations anomalies:

• congenital cardiac abnormalities ¹¹
  • atrial septal defect (ASD)
  • patent ductus arteriosus (PDA)
  • bicuspid aortic valve

Radiographic features

Plain film - chest radiographyradiograph

No specific but may show levoposition of the heart with resultant loss of the right heart border.

CT - Cardiac/Cardiac CT

• allows loss of direct visualised the thin pericardial lining around the heart
• may also be useful to assess for certain complication
• may also show excessive levoposition of the heart.
• the lateral and posterior portions of the pericardium may be difficult to visualise on CT

Cardiac MRI

Probably the best method for assessment.

Described features include:

• loss of direct visualisation of the pericardium - low signal on T2
• levoposition of heart
• increased cardiac mobility (e.g. excessive apical motion ¹¹) - on cine sequences
• interposition of lung tissue
  • between the heart and other intrathoracic structures ⁵
  • a "tongue" of lung tissue interposing between the main pulmonary artery and aorta - this is considered a very specific sign^{4, 13}
  • between the diaphragm and the base of the heart 

MRI is also useful to assess for associated complications.

Complications

Recognised but uncommon complications include:

• cardiac valvular insufficiency
• herniation(in cases with partial agenesis⁷) with incarceration of cardiac tissue, which includesatrial appendage entrapment
• compression of the left coronary artery secondary to herniation ¹

Treatment and prognosis

Asymptomatic isolated agenesis usually requires no treatment ¹⁰. Symptomatic patients who have the complete form may benefit from a pericardioplasty ⁴.