Introduction
The absence of pericardium is also called pericardial agenesis. It is the non-occurrence of the outer covering of the heart. It is a congenital disorder. This has a prevalence of 0.0002 % and has been found more in males as compared to females. The defect can be a complete, incomplete, or partial absence of the pericardium. People with such defects are asymptomatic, and the maximum cases are incidental findings. However, there are options to correct pericardial agenesis.
Why Does the Absence of Pericardium Happen?
The heart develops in the third week of intrauterine life. The two heart tubes fuse into a single heart tube by lateral foldings. This line of fusion is called the transverse septum, and lateral foldings are called pleuropericardial folds. Failure of fusion of the pericardial sac at the transverse septum or the pleuropericardial folds. These folds are supplied by ducts of Cuvier. In cases of premature atrophy of the ducts of Cuvier can cause pericardial agenesis.
What Are the Symptoms in the Absence of Pericardium?
Patients are asymptomatic and live normal lives. Even after doing regular physical activity, sports, stress-related work, traveling, etc., patients never have breathing problems, pain, or headaches. These findings are often incidental and need treatment if symptoms arise.
Symptoms like chest pain, dyspnea, restlessness, syncope, heart compression, or acute infarction could be seen.
How to Diagnose the Absence of Pericardium?
Common cardiac function tests include electrocardiogram (ECG), chest X-ray, and MRI (magnetic resonance imaging).
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Electrocardiogram - An ECG (electrocardiogram) may reveal changes when the patient is placed on the same side of the defect. In order to explain better, for a patient with pericardial agenesis defect on the left side of the heart, ECG changes are noted when the patient is examined in the left lateral position. However, the ECG comes normal when the position is changed to supine or right lateral. The ECG reports will be increased sinus rhythm with a deviation of the axis to the affected side, absence of R-wave growth, and presence of swinging phenomenon on the affected side.
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X-Rays - They are taken on a regular basis to view hard tissue changes (bone). It also shows dense, soft tissues, such as the heart. Yet the impression of the heart on the X-ray remains inaccurate. However, change in the shape of the heart and change in size and position of the heart can be noted. In the absence of pericardium, the shift of position of the heart towards the affected side is seen, thus losing the integrity of the cardiac groove.
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Magnetic Resonance Imaging (MRI) - The accurate test to view soft organs in the body is MRI. On MRI, a shift of the heart to the defect site can be seen; heart apex placed posteriorly, no pericardial effusion, absence of complete pericardial lining around the heart, interposition of lung tissue between the heart aorta and pulmonary artery, and affected side lung interposition between the diaphragm and inferior side of the heart on the affected side.
What Other Factors Can Be Seen With Pericardial Agenesis?
The congenital defect of pericardial agenesis is often associated with other disorders, collectively called syndromes.
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Marfan Syndrome- It is a genetic disorder affecting connective tissues in the body. The syndrome affects the connective tissue fibers and ligaments, thus affecting bone, muscles, and organs. People with such syndrome present with tall and thin body types, long and thin fingers, and overly flexible joints. Cardiac Marfan syndrome, which is a syndrome affecting the heart, has a higher risk of mitral valve prolapse and aortic aneurysm, which are life-threatening. Treatment of this disease is based on addressing the symptoms. It can be treated with medications like beta channel blockers and calcium channel blockers or surgically repair the valve and aorta as symptoms arise.
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Vater Syndrome- A congenital defect of unknown cause. The effects are vertebral anomalies, anal atresia, cardiovascular anomalies, tracheoesophageal fistula, esophageal atresia, renal anomalies, and limb defects. Physicians prefer to treat such conditions symptomatically.
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Pallister-Killian Syndrome- A genetically inherited rare disorder that affects the muscles. This syndrome extremely weakens the muscles in infants and causes intellectual disability, shortened limbs, facial hypoplasia, flat nasal bridge, frontal bossing of the forehead, high arched palate, and cardiac defects. This condition can be diagnosed prenatally through USG- ultrasonography. However, symptomatic treatment is the choice.
What Are the Types of Pericardial Defects?
The pericardium is a two-layer structure enclosing the most important organ of the body, the heart-serous layer (outer layer) and visceral layer (inner layer).
Defects involving pericardium can be acquired or congenital.
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Acquired Pericardial Defects - They occur from infection or injury to the heart that is attained after birth. The most common is pericarditis. It can be constrictive or restrictive pericarditis, acute or recurrent pericarditis, pericardial effusion, or cardiac tamponade. Treating these conditions vary according to the disease.
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Congenital Pericardial Defects - They are present from birth. The most anticipated common cause is developmental disturbance during the formation of the heart. Pericardial defects can be of different grades and affect different locations in the heart. It can affect the left or right side - that is, the absence of pericardium on the left side of the heart or right side of the heart. It can be graded as complete absence, incomplete, partial, or diaphragmatic. As per defect size, it can be mild, moderate, or severe. Treatment requires surgical intervention.
How to Treat Pericardial Agenesis?
Some organs of the human body have the ability to regenerate and repair physiologically. Sadly, pericardium cannot repair or regenerate itself. Hence, to correct pericardial agenesis, surgical intervention is required. Mild to moderate grades of pericardial agenesis need pericardiectomy, widening of the discontinuity to reduce risks of heart incarceration, and pericardial plasty by conservative surgery or surgical repair.
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Pericardiectomy - This procedure involves complete removal of the pericardium.
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Pericardial Plastic - Includes repair of the defect with alloplastic graft or patchwork from the adjacent pericardium or Gore-Tex graft.
However, treating pericardial agenesis has been a topic of continuous research and controversies with research in medical science.
Conclusion
Pericardium absence is a rare birth defect that is clinically asymptomatic. It is often found to be associated with syndromes. Syndromic cardiac defects need immediate treatment and must consult pediatricians and neonatologists. With early detection of the underlying causes and suitable, timely intervention helps avoid fatalities to a great extent.
