What is Pericarditis?
Pericarditis is a human heart disorder in which the lining of the heart becomes inflamed. This lining is called the pericardium.
What is the Pericardium?
The pericardium is a tissue membrane which encloses the human heart & root of the great vessels (pulmonary vein, pulmonary artery, vena cava & aorta). It consists of two main layers: the outer tough layer called the fibrous pericardium & the internal thin layer called the serous pericardium.
What are the Major Functions of the Pericardium?
The fibrous pericardium is made of deep connective tissue that holds the human heart in its appropriate position in the chest & separates it from the adjacent internal organs. Therefore, it serves to protect the human heart from infection or tumors that might spread directly from other organs near the heart, such as the lung or esophagus. As this layer is less flexible & does not stretch much, it also prevents the heart from increasing in size too quickly. Therefore, it is helpful to prevent overfilling of the heart with blood.
The serous pericardium consists of 2 layers which are outer parietal layer & inner visceral layer. Between these two layers is the pericardial cavity that contains a small quantity of fluid called the pericardial fluid. This helps to lubricate the human heart & prevents the friction caused by the contraction & relaxation of the human heart muscles as they move within the thoracic cavity.
What are the Causes of Pericarditis?
The most common cause is a viral infection, followed by heart attack and then certain diseases like HIV, renal failure or tuberculosis. However, in most cases, the cause is unknown.
How Does Pericarditis Affect The Heart?
As described above, the pericardium has many important physiological functions that aid in the smooth running of the heart. Pericarditis leads to malfunction in performing these functions.
The swelling of the pericardium causes the tissues in the heart to rub against each other and increases the internal friction. This affects the speed with which the heart contracts and relaxes. Prolonged irritation to the tissues causes excess fluid to collect in the pericardial cavity. This increases the pressure on the heart walls and in turn affects the capacity of the blood the human heart can pump.
Pericarditis can be either acute or chronic. In the acute type, the condition develops suddenly and typically does not last long (less than three weeks). The most common clinical symptom experienced by patients is sudden chest pain that resembles a heart attack. However, this pain is slightly different from a heart attack pain. The key differentiating feature of this pain is that it increases when the patient inhales and the pain is improved when the patient changes posture to lean forward while sitting. When the symptoms of pericarditis develops gradually over time and take longer to treat (more than three months), the conditions is chronic in nature. Both can disrupt the normal rhythm or function of the heart.
What are the Complications Arising From Pericarditis?
If left untreated, chronic pericarditis may lead to other serious heart disorders.
Cardiac tamponade is a condition that may develop if there is excessive fluid accumulated in the pericardium. This fluid creates a lot of pressure on the heart and so does not allow the heart to fill properly with blood. This means the heart is now pumping out less quantity of blood and this causes the blood pressure to decrease. Excessive low blood pressure over a prolonged period could be life threatening.
Chronic constrictive pericarditis is another condition that may develop if pericarditis is untreated over a prolonged period. In this condition, the scar tissue starts forming across the pericardium. Gradually this causes the pericardium to become stiff and so it hampers the movement of the heart. The patients generally experience severe swelling in the regions of their arms and legs along with shortness of breath.
Early diagnosis and treatment will reduce the risk of developing long-term complications.