INTRODUCTION — The normal pericardium consists of a visceral monolayer adherent to the epicardial surface of the heart, and the parietal pericardium, a fibroelastic layer that is continuous with the visceral pericardium and forms a sac surrounding the heart that contains a thin layer of fluid. When larger amounts of fluid accumulate (pericardial effusion) or when the pericardium becomes scarred and inelastic, one of three pericardial compressive syndromes may occur:

●Cardiac tamponade – Cardiac tamponade, which may be acute or subacute, is characterized by the accumulation of pericardial fluid under pressure. Variants include low pressure (occult) and regional tamponade.

●Constrictive pericarditis – Constrictive pericarditis is the result of scarring and consequent loss of the normal elasticity of the pericardial sac. Pericardial constriction is typically chronic, but variants include transient (or reversible) and occult constriction.

●Effusive-constrictive pericarditis – Effusive-constrictive pericarditis is characterized by underlying constrictive physiology with a coexisting pericardial effusion, often with cardiac tamponade. This usually results in a mixed hemodynamic picture with features of both constriction and tamponade. The course is generally subacute. Such patients may be mistakenly thought to have only cardiac tamponade; however, elevation of the right atrial and pulmonary wedge pressures after drainage of the pericardial fluid points to the underlying constrictive process. (See 'Effusive-constrictive pericarditis' below.)

In each of these compressive syndromes, cardiac filling is impeded by an external force. The normal pericardium can stretch to accommodate physiologic changes in cardiac volume. However, after its limited reserve volume is exceeded, the pericardium markedly stiffens. In both typical constrictive pericarditis and effusive-constrictive pericarditis, cardiac filling is impeded by an external force (ie, the virtually inelastic parietal and/or visceral pericardial tissue, which is thickened, fibrotic, and sometimes calcified). This results in a markedly impaired ability to adapt to volume changes. As a result, an important pathophysiologic feature of constrictive pericarditis is greatly enhanced ventricular interdependence, in which the hemodynamics of the left and right heart chambers are directly influenced by each other to a much greater degree than normal. (See "Constrictive pericarditis", section on 'Hemodynamic evaluation'.)

The clinically important variants of constrictive pericarditis (ie, occult disease, transient or reversible disease, and effusive-constrictive pericarditis) will be reviewed here. The typical presentation of constrictive pericarditis, along with issues related to cardiac tamponade, and the evaluation and management of pericardial diseases that do not compromise hemodynamics, are discussed separately. (See "Constrictive pericarditis" and "Cardiac tamponade" and "Diagnosis and treatment of pericardial effusion" and "Acute pericarditis: Clinical presentation, diagnostic evaluation, and diagnosis".)

TRANSIENT CONSTRICTIVE PERICARDITIS — A subset of patients with constrictive pericarditis undergoes spontaneous resolution of constrictive pericarditis or responds to medical therapy [1-3]. In a review of 212 patients with echocardiographic findings of constrictive pericarditis, 17 percent had follow-up studies showing resolution at an interval ranging from two months to two years [2]. Some degree of effusion is common in these cases. The most common cause of transient constrictive pericarditis was pericardial inflammation after pericardiotomy (25 percent of cases); infection (viral, bacterial, or tuberculous), idiopathic, collagen vascular disease, trauma, and malignancy accounted for the remaining cases. Treatment included nonsteroidal anti-inflammatory drugs, corticosteroids, antibiotics, chemotherapy, and angiotensin converting enzyme inhibitors plus diuretics. Five patients had resolution of constriction without any specific therapy.

This syndrome may overlap with effusive-constrictive pericarditis, the chief distinctions being its transient or reversible nature and the more advanced constrictive findings in effusive-constrictive pericarditis. As a practical matter, the diagnosis of transient constrictive pericarditis can only be made in retrospect, after evidence suggesting constrictive pericarditis reverses, suggesting that early (subacute) constrictive pericarditis may actually be a more accurate description. Cases that do not reverse either spontaneously or after a trial of anti-inflammatory therapy (algorithm 1) are best classified as either conventional constrictive pericarditis or effusive-constrictive pericarditis, depending on presence or absence of effusion and degree of chronicity. (See "Constrictive pericarditis", section on 'Treatment'.)

Cardiac magnetic resonance (CMR) imaging, specifically the degree of late gadolinium enhancement (LGE) of the pericardium, appears promising as a way to identify patients with early (subacute) constrictive pericarditis who may have reversal or resolution of the process [4]. In a retrospective cohort study of 29 patients with constrictive pericarditis who underwent CMR prior to receiving anti-inflammatory medications, 14 of the 29 patients ultimately had resolution of constrictive pericarditis [5]. There was significantly greater baseline LGE pericardial thickness (4 mm versus 2 mm) and greater LGE qualitative intensity in those with transient constrictive pericarditis than in the group of patients who ultimately had persistent constrictive pericarditis. LGE pericardial thickness ≥3 mm predicted reversibility of constriction with 86 percent sensitivity and 80 percent specificity.

In a cohort of 16 patients with constrictive pericarditis (50 percent tuberculous), F-18 fluorodeoxyglucose PET/CT predicted with high accuracy the resolution of symptoms and signs and constrictive physiology after 12 weeks of corticosteroid therapy [6].

The clinical course in these patients implies the presence of acute inflammatory pericarditis with constrictive symptoms due to inflammation that resolved after standard treatment with anti-inflammatory agents for acute pericarditis. However, a caveat is that an unknown number might have resolved spontaneously without anti-inflammatory agents. For patients with newly diagnosed constrictive pericarditis who are hemodynamically stable and without evidence of chronic constriction, we suggest a trial of conservative management rather than pericardiectomy (algorithm 1). Detection of LGE by CMR provides support for this approach. The limited literature available [5,6] does not strongly support a specific anti-inflammatory regimen. More information on the approach to treatment is presented elsewhere. (See "Constrictive pericarditis", section on 'Treatment of early (subacute) disease'.)

EFFUSIVE-CONSTRICTIVE PERICARDITIS — The pericardial cavity is typically obliterated in patients with chronic constrictive pericarditis. However, pericardial effusion may be present in some cases. In this setting, the scarred pericardium not only constricts the cardiac volume but can also put pericardial fluid under increased pressure, leading to signs suggestive of cardiac tamponade. Pericardial pathology consistent with constrictive pericarditis with a concomitant effusion is called effusive-constrictive pericarditis [7-11]. In many cases there is not a clear distinction between effusive-constrictive pericarditis and transient constrictive pericarditis. (See "Cardiac tamponade".)

Incidence and etiology — Effusive-constrictive pericarditis appears to be relatively uncommon, although there are only limited published data. In one series of 95 patients undergoing surgery for constrictive pericarditis, 24 percent were diagnosed with effusive-constrictive pericarditis [8]. In another series of 190 patients with cardiac tamponade who underwent pericardiocentesis and cardiac catheterization, effusive-constrictive pericarditis was diagnosed in 15 patients (8 percent) [10].

Most cases of effusive-constrictive pericarditis are idiopathic, reflecting the frequency of idiopathic pericardial disease in general [8,10]. Other reported causes include radiation, malignancy, chemotherapy, infection, and postsurgical pericardial disease. Tuberculosis is a frequent cause of effusive-constrictive pericarditis in regions where tuberculosis is common [12]. In a series of 68 patients with tuberculous pericardial effusion, effusive-constrictive disease was present in just over half; compared with patients with pericardial effusion without constrictive physiology, pre-pericardiocentesis right atrial pressure and pericardial and serum IL-10 levels were higher among patients with effusive-constrictive pericarditis [13]. Reflecting overlap with transient constrictive pericarditis, some of these patients have evidence of active pericardial inflammation based on late gadolinium enhancement on cardiac magnetic resonance (CMR). (See "Tuberculous pericarditis".)

The incidence, associated findings, and natural history of effusive-constrictive pericarditis (defined by post-procedure echocardiogram) were described in 205 consecutive patients following pericardiocentesis [14].

●Effusive-constrictive pericarditis was diagnosed in 33 patients (16 percent).

●Etiologies in this series were cardiac surgery (29 percent), idiopathic (25 percent), procedure-related (16 percent), and malignancy (12 percent).

●Clinical evidence of cardiac tamponade was noted in only 38 percent of the entire cohort and was similarly present in those with and without effusive-constrictive pericarditis.

●During a median follow-up of 3.8 years, six patients were re-hospitalized for heart failure, 24 resolved their CP features either spontaneously or with medical therapy, and only two patients required pericardiectomy for persistent constrictive symptoms and features, suggesting a favorable long-term prognosis.

Clinical features — Patients with effusive-constrictive pericarditis usually present with clinical features of pericardial effusion or constrictive pericarditis or both. The following clinical observations were made in one series of 15 patients [10]:

●Symptoms were usually present for less than three months (range four days to 26 months)

●All patients had jugular venous distention and hepatomegaly

●Eight patients had pericardial chest pain, fever, and a pericardial rub

●Pulsus paradoxus was seen in 10 patients

●All patients were in normal sinus rhythm

●No patients had pericardial calcification

A number of clinical clues suggest that a patient with suspected constrictive pericarditis may actually have effusive-constrictive pericarditis:

●Pulsus paradoxus is often present; this finding is uncommon in classical constrictive pericarditis because the inspiratory decline in intrathoracic pressure is not transmitted to the right heart chambers. (See "Constrictive pericarditis", section on 'Echocardiography'.)

●A pericardial knock is absent.

●The Y descent is less marked than expected. (See "Constrictive pericarditis", section on 'Hemodynamic evaluation'.)

●Kussmaul's sign is frequently absent.

Diagnosis — The diagnosis of effusive-constrictive pericarditis often becomes apparent during pericardiocentesis in patients initially considered to have uncomplicated cardiac tamponade. In such cases, the right atrial pressure remains abnormal after removal of the pericardial effusion due to constriction by the visceral pericardium. Right heart pressures and systemic arterial blood pressure should be monitored simultaneously during elective pericardiocentesis in order to allow for the detection of effusive-constrictive pericarditis [15]. (See "Diagnosis and treatment of pericardial effusion", section on 'Treatment'.)

Prior to pericardiocentesis, effusive-constrictive pericarditis is suggested by the unexpected persistence of a v wave in the right atrial pressure recording. The diagnosis is further supported by the following on the right atrial pressure tracing findings after pericardiocentesis [10,11]:

●Persistence of elevated right atrial pressure despite lowering of the pericardial pressure to near 0 with pericardiocentesis

●The development of a marked, rapid y descent

●The lack of an inspiratory decline in right atrial pressure

By definition, in patients with effusive-constrictive pericarditis, pericardiocentesis fails to decrease the right atrial pressure by 50 percent or to a level below 10 mmHg [10]. A persistently elevated right atrial pressure after pericardiocentesis may also be due to right heart failure or tricuspid regurgitation. Thus, appropriate studies should be performed to exclude these disorders before making the diagnosis of effusive-constrictive pericarditis.

In the series from the Mayo Clinic, the following echocardiographic findings were noted in effusive-constrictive pericarditis (defined by respiratory variation of early diastolic mitral inflow velocity (E) >25 percent plus either a respirophasic septal shift; hepatic vein expiratory diastolic flow reversals; or increased early diastolic mitral septal annular velocity (e') to a level higher than the lateral mitral e' on a post-pericardiocentesis echocardiogram) [14]:

●Prior to pericardiocentesis, the prevalence of respirophasic septal shift (21 versus 1 percent), mitral inflow variation (89 versus 62 percent), medial e' (8.9 versus 6.9 cm/s), and hepatic vein flow reversal (48 versus 23 percent) were greater in effusive-constrictive than effusive pericarditis, respectively.

●The post-pericardiocentesis prevalence of mitral inflow variation (100 versus 1.2 percent), respirophasic septal shift (94 versus 22 percent), hepatic vein flow reversal (82 versus 2 percent), and dilation of the IVC (100 versus 41 percent) were greater in effusive-constrictive than effusive pericarditis, respectively.

Noninvasive imaging may not be useful to confirm the diagnosis of effusive-constrictive pericarditis [11]. In a number of cases, the visceral layer of pericardium may be responsible for the constrictive component of this process and it is not typically thickened to a degree that is detectable on imaging studies. Nonetheless, CMR and/or CT scanning remain helpful in many cases to document pericardial thickening and inflammation.

Treatment and course — Medical therapy should be directed at the underlying cause of effusive-constrictive pericarditis whenever possible. In cases with clear evidence of pericardial inflammation as discussed for transient constrictive pericarditis, a trial of an anti-inflammatory regimen is warranted. NSAIDS, colchicine, and corticosteroids have all been used with variable success, but randomized data are lacking. (See 'Transient constrictive pericarditis' above.)

Pericardiocentesis alone may produce at least temporary relief of symptoms in patients with effusive-constrictive pericarditis, although it does not fully reverse the underlying condition. In a series of 15 patients, marked improvement after pericardiocentesis was noted in five, mild improvement in eight, and no benefit in two [10].

Pericardiectomy should be reserved for patients with refractory symptoms or clinical evidence of chronic constrictive pericarditis (anasarca, cachexia, atrial fibrillation, hepatic dysfunction) and when undertaken, should remove the pericardium completely. In effusive-constrictive pericarditis, it is often the visceral rather than the parietal layer of pericardium that is responsible for the constrictive symptoms and physiology. Thus, if surgery is performed, a visceral pericardiectomy may be required [11]. Removal of the visceral pericardium is often difficult, requiring sharp dissection of many small fragments until an improvement in ventricular motion is observed [10]. Thus, pericardiectomy for effusive-constrictive pericarditis should be performed only at centers with experience in pericardiectomy for constrictive pericarditis.

OCCULT CONSTRICTIVE PERICARDITIS — A report in 1977 described 19 patients with a syndrome called occult constrictive pericardial disease [16]. The symptom complex of this proposed syndrome was comprised of chest pain, dyspnea, and fatigue. Risk factors and examination findings consistent with constrictive pericarditis in this patient population included a history of acute pericarditis in 12 patients (which was recurrent in five), pericardial calcification in two patients, and nonspecific repolarization changes in 16 patients. A plausible cause for pericardial disease was present in 10. The authors proposed that very mild constrictive pericarditis can cause these symptoms in the absence of abnormal physical or hemodynamic findings when the patient is evaluated in the basal state.

To test this hypothesis, they measured hemodynamics invasively before and after infusing a liter of warm saline over a period of six to eight minutes to determine if occult constriction would then become overt. Six patients known not to have heart disease and 12 patients with myocardial disease served as controls.

The results can be summarized as follows:

●Saline infusion caused an elevation and equalization of ventricular filling pressures, and development of pressure waveforms in diastole characteristic of constrictive pericarditis (waveform 1) in the patients presumed to have occult constrictive pericarditis.

●Ventricular filling pressures and diastolic waveforms were unaltered in the subjects free from heart disease.

●The patients with myocardial disease developed elevated ventricular filling pressures, but unequally on the two sides.

Eleven of the symptomatic patients underwent pericardiectomy with dramatic improvement. All 11 cases had mild gross or histologic evidence of pericardial disease. The fluid challenge was repeated postoperatively in five of the patients, with normal hemodynamic findings.

Despite these promising findings, little has subsequently been published on occult constrictive pericardial disease, and no additional case series or randomized studies have replicated these results. Even though the above study was conducted using high fidelity pressure tracings in a laboratory well known for high-quality hemodynamic studies, it is unclear why or how such mild constriction could cause disabling symptoms, or why chest pain was a feature. Furthermore, the dramatic relief by pericardiectomy is unexplained in these patients with normal venous pressures that were modestly elevated by a rapid fluid challenge, and in whom the cardiac output was normal at rest and was not changed by the infusion.

A saline infusion test looking for occult constrictive pericarditis is seldom indicated and, if performed, the results should not be the sole evidence leading to pericardiectomy. Patients suspected of having occult pericardial constrictive disease should undergo cardiac catheterization, including measurement of oxygen consumption during progressive bicycle exercise. A study of this nature would document exertional dyspnea and fatigue, and may help clarify the responsible mechanism. Rather than infusing fluid, diuretic therapy (if administered) can be suspended for several days prior to cardiac catheterization.

SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Pericardial disease".)

INFORMATION FOR PATIENTS — UpToDate offers two types of patient education materials, "The Basics" and "Beyond the Basics." The Basics patient education pieces are written in plain language, at the 5^th to 6^th grade reading level, and they answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials. Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are written at the 10^th to 12^th grade reading level and are best for patients who want in-depth information and are comfortable with some medical jargon.

Here are the patient education articles that are relevant to this topic. We encourage you to print or e-mail these topics to your patients. (You can also locate patient education articles on a variety of subjects by searching on "patient info" and the keyword(s) of interest.)

●Beyond the Basics topic (see "Patient education: Pericarditis (Beyond the Basics)")

SUMMARY AND RECOMMENDATIONS

●A subset of patients with constrictive pericarditis undergo spontaneous resolution of constrictive pericarditis or respond to medical therapy, resulting in what is termed transient constrictive pericarditis or early (subacute) constrictive pericarditis. Cardiac magnetic resonance imaging, specifically the degree of late gadolinium enhancement of the pericardium, appears promising as a way to predict which patients with constrictive pericarditis will have reversal or resolution of the process. The clinical course in these patients implies the presence of acute inflammatory pericarditis with constrictive symptoms due to inflammation that resolve after standard treatment with anti-inflammatory agents for acute pericarditis. (See 'Transient constrictive pericarditis' above and "Constrictive pericarditis", section on 'Treatment of early (subacute) disease'.)

●Pericardial pathology consistent with constrictive pericarditis with a concomitant effusion is called effusive-constrictive pericarditis. Most cases of effusive-constrictive pericarditis are idiopathic, although other causes reflect the spectrum of etiologies of pericardial disease in general. The distinction from isolated cardiac tamponade becomes apparent by the unexpected persistence of an elevated right atrial pressure following pericardiocentesis and drainage of any pericardial effusion. Pericardiocentesis alone may produce at least temporary relief of symptoms in patients with effusive-constrictive pericarditis, although it does not fully reverse the underlying condition. If surgery is required, a visceral pericardiectomy must be performed. (See 'Effusive-constrictive pericarditis' above.)

●Little is known about occult constrictive pericardial disease, a syndrome described in the 1970s that was comprised of chest pain, dyspnea, and fatigue. Patients suspected of having occult pericardial constrictive disease should undergo cardiac catheterization, including measurement of oxygen consumption during progressive bicycle exercise. A study of this nature would document exertional dyspnea and fatigue, and may help clarify the responsible mechanism. (See 'Occult constrictive pericarditis' above.)