**6. Pathophysiology**

In constrictive pericarditis, the pericardium leaves are stuck together and the thickness may be 5–6 mm, sometimes more than 1 cm. Focal or diffuse calcification is seen in 50% of cases. Calcification can sometimes envelop the entire pericardium. The heart in this state is called the "armored heart". In constrictive pericarditis, the basis of the pathophysiological event is the obstruction of the diastolic filling of the right heart and venous return. As a result, cardiac output decreases, venous pressure rises and systemic arterial pressure decreases. The pathological process often extended to the myocardium. In this case, myocardial contractility is impaired (systolic dysfunction). In constrictive pericarditis, in contrast to the symptoms in cardiac tamponade, blood and plasma administration does not increase cardiac output. With decreased cardiac output,

*Chronic Constrictive Pericarditis DOI: http://dx.doi.org/10.5772/intechopen.110136*

liver and kidney perfusion decrease. Salt and water retention increases. Increased blood volume and increased venous pressure do not increase cardiac output. Venous pressure elevation causes congestive symptoms and signs. In constrictive pericarditis, although the left ventricular ejection fraction is normal, stroke volume and cardiac output are decreased. As a result, exercise dyspnea occurred. Because cardiac volume is limited due to constriction, cardiac filling and output vary depending on respiration. The right ventricle will not dilate even though venous return is increased in the inspiration. Rarely, right ventricular volume may be increased by a shift (shift) of the ventricular septum towards the left ventricle. This will reduce left ventricular filling and output.

### **7. Clinical presentation**

The hemodynamic changes and symptoms of constrictive pericarditis are shown in **Table 1**. In chronic constrictive pericarditis, patients may have retrosternal pain and palpitations. In constrictive pericarditis, fatigue and exertional dyspnea develop due to low cardiac output. However, signs of pulmonary congestion (orthopnea, paroxysmal nocturnal dyspnea) are not seen. There may be syncope attacks caused by exertion as a result of the cardiac output not meeting the adequate perfusion. Although exertional dyspnea and peripheral edema are common symptoms in most patients, peripheral edema is scarce [31, 32, 37]. Initially, abdominal discomfort, tenderness, pain, and then ascites occur due to passive hepatic congestion (Pick's disease-Pseudocirrhosis) (**Table 2**).
