In cases of constrictive pericarditis, the thickened, fibrotic pericardium hinders the filling of the heart's ventricles due to spatial constraint. The heart's contraction force continues to decrease while the disease progresses. Constrictive pericarditis usually arises as a consequence of other forms of pericarditis, but may also develop after a heart attack or heart surgery.
Patients present symptoms associated with a decreased cardiac output, restricted ventricular filling and consecutive systemic venous congestion. Clinical signs are typical for both left and right sided heart failure and include dyspnea and even orthopnea, poor resistance to exercise and rapid fatigue. Hepatomegaly and ascites may also be present.
Diagnosis of constrictive pericarditis is not an easy task. The disease shares several clinical features with restrictive cardiomyopathy and it may not always be possible to distinguish the two conditions.
Patients present with signs of heart failure and venous congestion, such as hepatomegaly, ascites, peripheral edema and low tolerance to exercise. Their jugular venous pressure is elevated, particularly during inspiration (Kussmaul's sign), but rapidly decreases during diastole. A pericardial knock is detectable in approximately half of the cases.
Diagnostic imaging is a valuable tool and may reveal a thickened pericardium, pericardial effusion and characteristic hemodynamic signs comprising an increased filling during early diastole and a decreased filling during late diastole. Because the myocardium is affected in cases of restrictive cardiomyopathy, this condition is associated with a reduced filling even during early diastole. Patients suffering from restrictive cardiomyopathy also show a significant thickening of the wall of the left ventricle.
The constrained movements of the heart in cases of constrictive pericarditis entail further signs recognizable in echocardiography. Due to the restricted distensibility of the ventricular walls, the increase in ventricular pressure upon atrial contraction provokes a considerable displacement of the septum.
A blood test for Brain Natriuretic Peptide (BNP) may help to distinguish constrictive pericarditis from restrictive cardiomyopathy, as it is only present in cases of patients affected by the latter.
Pulmonary catheterization may be conducted to prove equal diastolic pressures in both atria and ventricles.
Treatment of constrictive pericarditis comprises causal and symptomatic therapy. The former requires the identification of the causative agent of the underlying infection and inflammation. An adequate treatment plan may then include tuberculostatics or other antibiotics.
Any symptomatic therapy aims at improving heart function and limiting its constraints. Pericardial effusion may be treated with diuretics. Chest pain may require the administration of analgesics. Severe cases of constrictive pericarditis may require surgery: the necessary pericardiectomy involves the removal of a part of the pericardium.
Patients need to be advised to adjust their lifestyle. They may need to reduce physical activity and should maintain a low-sodium diet.
Constrictive pericarditis is potentially curable, but prognosis depends on the underlying disease, the severity of the case and available therapeutic options. Due to the low incidence of the disease, reliable prognostic data are rare. An early diagnosis is essential in order to avoid a fatal outcome.
The patient's prognosis in cases of idiopathic constrictive pericarditis and constrictive pericarditis following heart surgery is significantly better than in cases of postradiation constrictive pericarditis (88% and 66% vs. 27% survival after 7 years, respectively). The presence of another disease requiring radiation therapy may serve as an explanation for this considerable difference.
With regards to the severity of the disease, an acute onset of symptoms is generally associated with a poorer prognosis. If the myocardial function is impaired because the inflammatory process did infiltrate the tissue, the patient's prognosis rapidly worsens. In this advanced stage of the disease the cardiac output is significantly reduced and systemic venous congestion can be observed. These conditions may lead to tissue hypoxia, multisystem failure and death. The presence of pericardial calcifications cannot be associated to prognosis.
Untreated patients, particularly children, have a poor prognosis. Conservative treatment is also associated with a poor prognosis, while survival rates after pericardiectomy have been reported to be 71% and 52% after 5 and 10 years, respectively. The survival rate after surgical intervention does depend on the overall condition of the cardiovascular system and the kidneys and decreases with heart failure, abnormal left ventricular systolic function, high pulmonary artery systolic pressure, low serum sodium level, restricted renal function and age    .
Constrictive pericarditis is an inflammatory disease that may develop if an inflammation is triggered in close proximity to the heart. This may occur upon:
Although these are the most frequent causes of constrictive pericarditis, with complications of heart surgery and radiation therapy being responsible for about 37% and 9% of evaluated cases respectively, the vast majority of cases of constrictive pericarditis (about 46%) cannot be clearly associated to any cause and are thus considered of idiopathic origin .
Constrictive pericarditis may occur as an aftereffect of any type of pericarditis. It is usually observed in adults and rarely affects children.
Due to heart surgery being one of the main causes of pericarditis and constrictive pericarditis being a complication of the former, it is to be expected that the incidence of constrictive pericarditis is augmented in patients that underwent cardiac surgery. While cases of constrictive pericarditis have been reported in patients aged 8 to 70 years, it is more often observed in adults. Nevertheless, it is still considered a rare condition even in this age group. Studies regarding the demographics of patients suffering from this disease have reported a median age between 45 and 61 years, with a trend towards older ages in recent times. This trend may be due to overall demographic changes. Men are apparently affected three times more than women. No racial predisposition has been observed so far.
Acute pericarditis is the most common condition leading to constrictive pericarditis. Approximately 9% of such cases entail the constrictive complication . Given that about 0.1% of hospital admissions are due to acute pericarditis and less than a tenth of those results in constrictive pericarditis, the overall frequency of diagnosis is presumably about 1 in 10,000 admissions. Of note, this estimation does not consider primary diseases other than acute pericarditis.
Since constrictive pericarditis occurs as a complication of different inflammatory conditions of the pericardium, the etiology of the latter has to be taken into account when considering the etiology of the former. For a long time, infectious causes had been responsible for the majority of cases of constrictive pericarditis and this fact still holds true today in developing countries. Here, the highest incidence of constrictive pericarditis has been reported in association with tuberculosis. Today, nearly half of all cases remain without an identification of a clear cause and are therefore termed idiopathic constrictive pericarditis.
The pericardium envelopes the heart and is composed of a fibrous, parietal layer and a smooth, visceral layer. The intrapericardial space contains approximately 50 mL of serous fluid produced by the epicardium and allows for cardiac motion with minimum friction .
In cases of acute or subacute pericarditis, the amount of pericardial fluid may be increased, a condition known as pericardial effusion. Also, during the process of inflammation, fibrin is deposited on the pericardium. In the long term, a chronic pericarditis may lead to tissue remodelling, chronic fibrotic scarring and calcification . These processes generally involve both pericardial layers and are accompanied by a significant thickening of these layers. Moreover, adjacent tissues tend to fuse together, and in this way further aggravating the limitation of movements of the heart.
This primarily results in a reduced distensibility of the heart's ventricles that do not fill with the adequate volume of venous blood. The heart's hemodynamics are characterized by a functional myocardium and the spatial limitations imposed by the constrictive pericarditis: ventricle filling during early diastole is not affected and is accompanied by an initial, rapid decrease in atrial and ventricular pressure. However, later diastole is accompanied by an aprupt increase in ventricular pressure that is maintained until the beginning of the systole and equals the pressure encountered in the atria. Pressure waveform tracings thus represent a characteristical “dip-and-plateau waveform”, also known as a “square root sign” . The necessary preload cannot be maintained, since small increases in ventricular filling result in pathologic rises of ventricular diastolic pressure. Consequently, the blood volume available for the systole decreases.
Only in late stages of the disease do hemodynamic changes also affect the systole. At that point, this may be due to the inflammation affecting the myocardium that had been able to fulfill its physiological function so far. While fibrosis and scarring may then be found in the myocardium, this is not the case in earlier stages of constrictive pericarditis. Indeed, the fact that the myocardium stays essentially functional can be used to distinguish a constrictive pericarditis from a restricitive cardiomyopathy. Both diseases show similar hemodynamic profiles, but only in case of constrictive pericarditis does early diastole remain unaffected.
As constrictive pericarditis progresses, so does the decrease in the heart stroke volume. This leads to symptoms of congestive heart failure, particularly of right-sided heart failure and chronic systemic venous congestion, that first become visible under physical stress and later appear at rest .
There are no preventive measures known except avoidance of conditions leading to constrictive pericarditis and their proper treatment.
Constrictive pericarditis is an inflammatory disease affecting the pericardium. The pericardium thickens and presents fibrin deposits, but may eventually even show calcifications, fibrotic scarring and tissue fusion in chronic cases. A pericardial effusion may also be present. These conditions severely restrict the heart's movements and impair an adequate filling of its chambers . The disease primarily affects the parietal pericardium, although the visceral pericardium and, in later stages, even the myocardium may be compromised.
Since patients present with clinical signs also detectable in cases of myocardial infarction, aortic dissection, connective tissue disorders, pneumonia or influenza, diagnosis of constrictive pericarditis is a major challenge. However, an early diagnosis is essential in order to increase the probability of a favorable outcome for the patient.
The term pericarditis refers to an inflamed pericardium, which is a sac-like tissue surrounding the heart. Its function is to minimize friction and to allow smooth movements of the heart. In cases of prolonged, i.e. chronic inflammation, the pericardium thickens and acquires scars. These conditions significantly limit the heart's movements; this affects its capability to pump sufficient amount of blood through the body. Although the disease is rare, its possibly severe consequences require an early diagnosis and adequate treatment. Otherwise, the volume of blood pumped by the heart may decrease to life-threatening levels. Constrictive pericarditis is, however, a potentially curable disease.
Constrictive pericarditis is a long-term consequence of inflammation of the pericardium. These inflammatory processes reduce its elasticity and turn it into a rigid sac around the heart that restricts its normal movements and function.
Since constrictive pericarditis results from an inflamed pericardium, the next question should address possible causes of pericardial inflammation. The most common triggers for pericarditis, as such an inflammation is called, are heart surgery, radiation therapy and tuberculosis. Besides tuberculosis, other bacterial and viral infectious diseases may also provoke pericarditis. An uncommon cause for pericarditis is the presence of a certain type of cancer, a mesothelioma, resulting from exposure to asbestos. It is, however, not always possible to identify the exact cause of pericarditis, but treatment is still possible.
Patients suffering from constrictive pericarditis may note the following symptoms:
The symptoms described above correspond to different degrees of heart failure. Such symptoms occur in a variety of diseases, such as restrictive cardiomyopathy and cardiac tamponade. While restrictive cardiomyopathy mainly affects the heart muscle that turns stiff and impairs filling of the heart's chambers, cardiac tamponade occurs when the room between the pericardium and the heart fills up with an excess of fluid.
The physician's task is to identify the exact cause of the symptoms and to distinguish between possible diseases. In order to do so, the physician will proceed to an exam and will check for weak or distant heart sounds, changes in blood pressure of the neck veins, liver swelling and an accumulation of fluid in the abdomen.
Additional tests may be necessary to reach the correct diagnosis and may include imaging (echocardiography, MRI and CT scans), an electrocardiogram and a cardiac catheterization.
If constrictive pericarditis is not adequately treated, it is potentially life-threatening. Prognosis improves considerably with adequate treatment and recovery is possible.