Constrictive pericarditis: Diagnostic evaluation

INTRODUCTION — The diagnostic evaluation of constrictive pericarditis and effusive-constrictive pericarditis are reviewed here. Related issues are discussed separately:

●(See "Constrictive pericarditis: Clinical features and causes".)

●(See "Constrictive pericarditis: Management and prognosis".)

●(See "Pericardial effusion: Approach to diagnosis" and "Cardiac tamponade".)

●(See "Acute pericarditis: Clinical presentation and diagnosis" and "Acute pericarditis: Treatment and prognosis" and "Recurrent pericarditis".)

DEFINITIONS

●Constrictive pericarditis – Constrictive pericarditis is a clinical syndrome in which an inelastic thickened pericardium restricts cardiac filling [1-3]. The condition may be chronic or transient:

•Chronic constrictive pericarditis – Most patients with constrictive pericarditis have a chronic course, with constriction persisting for greater than three to six months. Pericardial effusion is rarely a prominent feature of chronic constrictive pericarditis. (See "Constrictive pericarditis: Clinical features and causes", section on 'Constrictive pericarditis'.)

•Transient constrictive pericarditis – In a minority of cases of constrictive pericarditis, the constriction resolves within three to six months spontaneously or with medical therapy. Cases of transient constrictive pericarditis commonly present as effusive-constrictive pericarditis. (See "Constrictive pericarditis: Clinical features and causes", section on 'Transient constrictive pericarditis'.)

●Effusive-constrictive pericarditis – Effusive-constrictive pericarditis is a clinical syndrome caused by constrictive pericarditis and coexisting hemodynamically significant pericardial effusion [4-9]. This syndrome overlaps with transient constrictive pericarditis. (See "Constrictive pericarditis: Clinical features and causes", section on 'Effusive-constrictive pericarditis'.)

DIAGNOSTIC APPROACH

When to suspect constrictive pericarditis — Constrictive pericarditis should be suspected in any patient with symptoms and signs consistent with the diagnosis (such as dyspnea on exertion, peripheral edema, and unexplained elevation of jugular venous pressure with prominent y descent (figure 1)), particularly if there is a history of a predisposing condition such as malignancy, prior cardiac surgery, or prior radiation therapy. (See "Constrictive pericarditis: Clinical features and causes", section on 'Constrictive pericarditis' and "Constrictive pericarditis: Clinical features and causes", section on 'Incidence and causes'.)

Effusive-constrictive pericarditis should be considered in patients with symptoms and signs of constrictive pericarditis and/or cardiac tamponade, particularly when the clinical presentation includes a mixture of signs of these two conditions (eg, jugular venous pressure waveform like that of constrictive pericarditis (figure 1) but with a less prominent y descent and/or presence of pulsus paradoxus). The unexplained persistence of elevated jugular venous pressure after treatment of cardiac tamponade with pericardiocentesis is a key sign of effusive-constrictive pericarditis [9]. (See "Constrictive pericarditis: Clinical features and causes", section on 'Effusive-constrictive pericarditis'.)

General approach — All patients with suspected constrictive pericarditis (or effusive-constrictive pericarditis) should undergo the following evaluation [1,2]:

●History and physical examination. (See "Constrictive pericarditis: Clinical features and causes".)

●Initial tests including an electrocardiogram (ECG) and chest radiograph. In patients with suspected subacute or transient constrictive pericarditis, also inflammatory markers (C-reactive protein [CRP] and erythrocyte sedimentation rate [ESR]). (See 'Initial tests' below.)

●A transthoracic echocardiogram (TTE), which is often diagnostic. (See 'Echocardiography' below.)

●Additional testing in selected patients as needed to establish the diagnosis or guide management. (See 'Additional testing' below.)

Identification of subtypes

Transient versus chronic — As a practical matter, the diagnosis of transient constrictive pericarditis (a manifestation of early or subacute disease) can only be made in retrospect, when clinical manifestations of constrictive pericarditis reverse within three to six months either spontaneously or with medical therapy. Cardiovascular magnetic resonance (CMR) imaging findings that suggest an early (subacute) process are discussed below. (See 'Additional testing' below.)

Cases that do not reverse spontaneously or after a trial of antiinflammatory therapy (algorithm 1) are classified as either conventional chronic constrictive pericarditis or effusive-constrictive pericarditis, depending on presence or absence of effusion and degree of chronicity.

Effusive-constrictive pericarditis — The diagnosis of effusive-constrictive pericarditis often becomes apparent after pericardiocentesis in patients initially considered to have uncomplicated cardiac tamponade. (See 'Effusive-constrictive pericarditis' below.)

Occult constrictive pericarditis — Patients suspected of having occult pericardial constrictive disease should undergo cardiac catheterization, including measurement of oxygen consumption during progressive bicycle exercise. (See 'Occult constrictive pericarditis' below.)

Initial tests

Electrocardiogram — A 12-lead ECG is routinely performed, although there are no pathognomonic ECG findings for constrictive pericarditis or effusive-constrictive pericarditis [9]. Nonspecific ST- and T-wave changes and tachycardia are common, and low voltage may sometimes be present. In advanced cases, atrial fibrillation is common due to increased atrial pressures. In a series of 143 patients with surgically confirmed constrictive pericarditis, 22 percent had atrial fibrillation and 27 percent had low voltage [10].

Chest radiograph — The presence of pericardial calcification by chest radiograph, especially in conjunction with the appropriate clinical presentation, is highly consistent with constrictive pericarditis. Chest radiographs that demonstrate a ring of calcification around the heart, best seen on lateral or anterior oblique projections (image 1), strongly suggest constrictive pericarditis in patients with symptoms of right-sided heart failure [1].

However, the majority of patients with constrictive pericarditis do not have pericardial calcification detected on chest radiograph [11], so its absence does not exclude constrictive pericarditis. A retrospective review from the Mayo Clinic of 135 patients with constrictive pericarditis confirmed surgically or at autopsy reported that 36 patients (27 percent) had pericardial calcification [11]. Compared with those without calcification, patients with calcification had the following:

●A greater likelihood of having idiopathic pericardial disease (67 versus 21 percent)

●A longer duration of symptoms

●A greater likelihood of having a pericardial knock, larger atria, and/or atrial arrhythmias

●A higher perioperative mortality, though rates of long-term survival were similar

While pericardial calcification is more common with chronic tuberculous constrictive pericarditis than with most other causes of chronic constrictive pericarditis, calcification is usually absent with subacute tuberculous constrictive pericarditis [12,13].

Of note, pericardial calcification can occur in the absence of constrictive pericarditis, but in such cases the calcification is usually patchy and less dense than with pericardial constriction.

Inflammatory markers — Although elevated inflammatory markers (such as CRP and ESR) are not required for diagnosis of constrictive pericarditis, these markers are commonly elevated in this setting. A study in 25 patients with suspected constrictive pericarditis or restrictive cardiomyopathy suggested that CRP level may be an ancillary test in distinguishing these disorders [14]. A CRP level >0.57 mg⁄dL yielded a sensitivity of 85 percent and a specificity of 75 percent for constrictive pericarditis.

While CRP is commonly elevated in patients with constrictive pericarditis, a role in guiding treatment has not been established. In a small study of patients with constrictive pericarditis, baseline levels of high-sensitivity CRP and ESR were similar in patients who did and did not respond to three months of glucocorticoid therapy [15]. (See 'Transient versus chronic' above.)

The role of imaging to identify pericardial inflammation is discussed below. (See 'Additional testing' below.)

Natriuretic peptide — While we do not recommend obtaining a plasma natriuretic peptide level (B-type natriuretic peptide [BNP] or N-terminal pro-BNP [NT-proBNP]) to diagnose constrictive pericarditis, many patients will have had this test performed as part of an evaluation of dyspnea. There is no threshold for BNP which confirms or excludes the diagnosis of constrictive pericarditis. (See "Natriuretic peptide measurement in heart failure".)

Among patients with heart failure, BNP is released by the myocardium, particularly the ventricles, in response to wall stretch and wall stress. However, wall stretch is limited in constrictive pericarditis by the thickened, stiff pericardium. Thus the elevation in natriuretic peptides in constrictive pericarditis is expected to be lower than with cardiomyopathy (eg, restrictive cardiomyopathy). This was confirmed by a meta-analysis of small studies which found that BNP and NT-proBNP values were lower in patients with constrictive pericarditis than in those with restrictive cardiomyopathy [16]. (See "Differentiating constrictive pericarditis and restrictive cardiomyopathy", section on 'Plasma BNP'.)

ECHOCARDIOGRAPHY — TTE is an essential diagnostic test in patients being evaluated for constrictive pericarditis and can confirm the diagnosis in many patients [1,17]. Two-dimensional (2D) and M-mode echocardiography allow structural visualization, while Doppler echocardiography provides hemodynamic information.

Echocardiography is also helpful in identifying alternative causes for the patient's symptoms and signs, such as cardiomyopathy (including restrictive cardiomyopathy) and cardiac tamponade. (See 'Differential diagnosis' below.)

Diagnostic findings — While there is no single diagnostic echocardiographic finding for constrictive pericarditis, the presence of one or more characteristic 2D, M-mode, or Doppler finding described below suggests the presence of constrictive physiology (algorithm 2) [1,10,17,18]. (See "Echocardiographic evaluation of the pericardium".)

In a study of 130 patients with surgically confirmed constrictive pericarditis who were compared with 36 patients with restrictive myocardial disease or severe tricuspid regurgitation, respirophasic ventricular septal shift, preserved or increased medial annular early diastolic tissue Doppler velocity at the mitral annulus (E'), and hepatic vein expiratory diastolic flow reversal (which collectively are sometimes referred to as the Mayo criteria) were independently associated with constrictive pericarditis [19]. The finding of ventricular septal shift in combination with either a medial E' ≥9 cm/s or an expiratory diastolic reversal ratio ≥0.79 was 87 percent sensitive and 91 percent specific for constrictive pericarditis. When all three factors were present, the specificity increased to 97 percent, but the sensitivity decreased to 64 percent.

Two-dimensional and/or M-mode findings

●IVC dilation – Dilation of the inferior vena cava (IVC) and hepatic veins (plethora) with absent or diminished inspiratory collapse. (See "Echocardiographic evaluation of the atria and appendages", section on 'Vena cava'.)

●Atrial dilation – Moderate biatrial dilation is commonly present with constrictive pericarditis. In contrast, severe enlargement is more compatible with restrictive cardiomyopathy. (See "Differentiating constrictive pericarditis and restrictive cardiomyopathy", section on 'Noninvasive testing'.)

●Respirophasic interventricular septal shift – Transient posterior (leftward) movement of the interventricular septum with inspiration and anterior (rightward) movement of the interventricular septum with expiration. This septal motion is caused by ventricular interdependence and is a specific finding of constrictive pericarditis.

●Septal bounce or shudder – An abrupt anterior or posterior movement of the interventricular septum in early diastole (septal bounce or shudder or diastolic checking) is commonly seen with constrictive pericarditis, but may also be seen with restrictive cardiomyopathy [18]. This finding corresponds to the dip and plateau sign identified in invasive ventricular pressure recordings. (See "Differentiating constrictive pericarditis and restrictive cardiomyopathy", section on 'Cardiac catheterization'.)

●LV inferolateral wall motion – Rapid posterior motion of the left ventricular (LV; inferolateral) posterior wall is followed by flattening of the wall in mid-diastole (which is also a feature of restrictive cardiomyopathy).

●Premature opening of the pulmonic valve – The pulmonic valve opens prematurely when right ventricular (RV) diastolic pressure rises above pulmonary arterial pressure.

●Pericardial thickness – TTE (2D or M-mode) is unreliable for measuring pericardial thickness [17,20]. Mildly increased pericardial thickening is often missed by TTE, and high-intensity signal falsely suggesting calcification may be identified if the gain setting is too high.

Cardiac computed tomography (CT) and CMR imaging are generally the primary modalities for measuring pericardial thickness. Transesophageal echocardiography (TEE) is an additional validated modality for measuring pericardial thickness, as TEE measurements of pericardial thickness correlate well with those obtained by cardiac CT [21]. (See 'Cardiac CT or CMR' below.)

Doppler findings — Doppler echocardiography is critical for the diagnosis of constrictive pericarditis. The following findings on Doppler echocardiography are suggestive of constrictive pericarditis:

●Restrictive LV and RV diastolic filling patterns – An increased early diastolic (E) velocity of LV and RV inflow with a shortened deceleration time and a reduced atrial (A) wave are seen, reflecting abnormally rapid early diastolic filling associated with a small ventricular volume and rapid recoil.

●Pronounced respiratory variation in blood flow

•Mitral and tricuspid inflow – The percentage respiratory variation for mitral and tricuspid inflow are calculated as [17]:

Mitral inflow velocity falls as much as 25 to 40 percent and tricuspid velocity greatly increases (>40 to 60 percent) in the first cardiac cycle following inspiration [17]. Changes of 25 and 40 percent (mitral and tricuspid inflows, respectively) or greater are considered significant [17]. The respiratory variation in pulmonary venous flow is even more pronounced [22]. These phenomena, which are manifestations of ventricular interdependence, are not present in either normal subjects or patients with restrictive cardiomyopathy [23].

Although increased respiratory variation of mitral inflow may not be detected in patients with markedly elevated left atrial pressure, it can sometimes be elicited in such patients by preload reduction with semirecumbent (rather than supine) positioning or diuretic administration [24].

•Hepatic venous flow reversal – Hepatic venous flow reversal is accentuated with expiration, reflecting ventricular interdependence and the dissociation of intracardiac and intrathoracic pressures [25].

●Tissue Doppler

•E' is generally prominent (unless slowed by mitral annular calcification) in patients with constrictive pericarditis, unlike restrictive cardiomyopathy in which E’ is reduced (generally <7 cm/s) [1]. The usually positive linear relation between E/E' and left atrial pressure, which is useful for assessing left atrial pressure in cardiomyopathy, is reversed (annular paradox) in constrictive pericarditis [26]. This is a sign of pericardial tethering [18]. (See "Differentiating constrictive pericarditis and restrictive cardiomyopathy".)

E' velocities are generally lower in constrictive pericarditis secondary to surgery or radiation than in other etiologies.

•The mitral lateral/medial E' ratio is reversed in the majority of patients with constrictive pericarditis (ie, lateral E’ is less than medial E’ in most patients). After pericardiectomy, annular velocities are reduced, and the lateral/medial E' ratio normalizes [27].

●Propagation velocity – On color M-mode, the propagation velocity of early diastolic transmitral flow is normal or increased (commonly >100 cm/s) [28,29].

Myocardial strain imaging — For patients with clinical findings suggestive of constrictive pericarditis or restrictive cardiomyopathy, 2D speckle tracking echocardiography is helpful in distinguishing these disorders. In constrictive pericarditis, global longitudinal strain is generally preserved (although tethering of the pericardium may result in reduced lateral wall but preserved septal longitudinal strain), whereas circumferential strain and torsion are reduced [30]. A normalization of the lateral to septal longitudinal strain ratio following antiinflammatory treatment may identify patients with transient constrictive pericarditis [31]. (See "Differentiating constrictive pericarditis and restrictive cardiomyopathy", section on 'Speckle tracking echocardiography (STE)'.)

ADDITIONAL TESTING

Indications for further evaluation — A diagnosis of constrictive pericarditis is commonly established by the initial evaluation, including echocardiography (algorithm 2). The need for additional diagnostic evaluation with cardiac CT, CMR imaging, and/or invasive cardiac catheterization is based upon factors including the findings and diagnostic quality of the echocardiogram, the index of suspicion (eg, high in patients with typical clinical findings and relevant history, such as prior radiation therapy), and the potential need for surgical intervention.

Patients with a suspected but unconfirmed diagnosis of constrictive pericarditis after echocardiography should generally undergo cross-sectional imaging of the chest with either cardiac CT or CMR imaging (algorithm 2) [1,32,33]. The choice between cardiac CT or CMR is based upon individual patient characteristics (eg, choice of CMR in patients with suspected transient constrictive pericarditis or choice of CT in patients with suspected pericardial calcification or need for coronary artery assessment) as well as institutional availability and expertise with a particular imaging technique.

Cardiac CT or CMR — Cardiac CT or CMR findings seen with constrictive pericarditis include:

●Globally or regionally thickened pericardium – Pericardial thickness can be accurately quantified by cardiac CT or CMR. Increased pericardial thickness suggests constrictive pericarditis; presence or absence of pericardial thickening is not sufficient to establish or exclude the diagnosis.

Of note, although the presence of increased pericardial thickness suggests the presence of constrictive pericarditis, this finding is not sufficient to establish a diagnosis of constrictive pericarditis, and absence of pericardial thickening does not exclude the presence of constrictive pericarditis [10,17,20].

In a series of 143 patients with surgically confirmed constrictive pericarditis, the pericardium was thickened (>2 mm) on pathologic examination in 117 (82 percent) but was of normal thickness (≤2 mm) in 26 (18 percent) [10]. Pericardiectomy was effective in relieving symptoms regardless of the presence or absence of increased pericardial thickness. Thus, a normal pericardial thickness or nonvisualization of the pericardium does not rule out constrictive pericarditis.

●Lack of adjacent pulsation – In the presence of thickened pericardium, the failure of pulmonary structures immediately adjacent to the heart to pulsate during the cardiac cycle is virtually diagnostic of constrictive pericarditis, but is not commonly seen.

●Pericardial inflammation – CMR or ¹⁸F-fluorodeoxyglucose positron emission tomography/cardiac CT (FDG-PET/CT) provide means of identifying evidence of pericardial inflammation. (See 'Cardiac CT' below and 'CMR' below.)

●Additional findings that may be identified by either cardiac CT or CMR:

•Dilation of the inferior vena cava (IVC)

•Deformed ventricular contours with or without angulation of the ventricular septum

CMR — CMR imaging can provide detailed anatomic information including the extent of pericardial inflammation, thickening, and scarring that might alter the decision to proceed with surgery based on the likelihood of resolution with medical therapy alone. (See 'Transient versus chronic' above.)

Findings identified by CMR include [18]:

●Pericardial thickness – CMR better differentiates small pericardial effusions from pericardial thickening than cardiac CT.

●Late gadolinium enhancement (LGE) of the pericardium is common but not universal in patients with constrictive pericarditis [34,35]. A small study found that individuals with constrictive pericarditis and pericardial LGE had greater fibroblast proliferation, chronic inflammation, and pericardial thickening compared with those without LGE [35].

Pericardial LGE [32] and prominent transverse relaxation time-weighted short-tau inversion recovery (T2 STIR) may be predictors of reversibility of constrictive pericarditis following treatment with antiinflammatory agents [32,34,36]. Increased T2 STIR pericardial signal suggests pericardial edema and provides evidence of acute pericardial inflammation [37]. In a retrospective cohort study of 29 patients with constrictive pericarditis who underwent CMR prior to receiving antiinflammatory medications, 14 of the 29 patients ultimately had resolution of constrictive pericarditis [34]. 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.

Some patients with effusive-constrictive pericarditis have evidence of pericardial LGE, reflecting overlap with transient constrictive pericarditis. (See "Tuberculous pericarditis".)

●Evidence of pericardial tethering to the epicardium on tagged CMR images.

●Respirophasic changes (like those identified by echocardiography) are identified on real-time free-breathing phase contrast CMR.

•Interventricular septal bounce with abrupt transient leftward movement of the interventricular septum with inspiration and rightward movement of the interventricular septum with expiration (resulting from ventricular interdependence).

•Respiratory variation in mitral and tricuspid inflow is enhanced with constrictive pericarditis. In a study of 16 patients, the sensitivity and specificity of respiratory variation of transmitral flow >25 percent and transtricuspid flow >45 percent were 100 and 100 percent and 90 and 88 percent, respectively [38].

Cardiac CT — Cardiac CT scanning is useful in the diagnosis of constrictive pericarditis and can provide additional data to guide perioperative management decisions, including:

●The location and extent of pericardial calcification. Pericardial calcification is suggestive of constriction, but limited focal calcification is not always associated with constriction. Cardiac CT is superior to CMR in detecting calcification.

●An assessment of coronary artery disease. CT coronary angiography may enable some patients to avoid the need for invasive coronary angiography.

●The extent of lung injury in patients with previous radiation exposure.

●Identification of critical vascular structures to assist in the preoperative planning of pericardiectomy.

PET/CT — PET/CT imaging using FDG can identify pericardial inflammation or malignancy [18,39]. A small study suggested that FDG-PET/CT may predict the response to antiinflammatory therapy in selected patients with constrictive pericarditis [15]. The study excluded patients with pericardial calcification, malignancy, or radiation therapy. Among 16 patients with constrictive pericarditis (50 percent tuberculous), pericardial standardized uptake value >3.0 on FDG-PET/CT predicted the resolution of symptoms and signs and constrictive physiology after three months of glucocorticoid therapy with a sensitivity of 100 percent and specificity of 71 percent. (See 'Transient versus chronic' above.)

Cardiac catheterization — Invasive hemodynamic evaluation (right heart catheterization) is occasionally needed to confirm the diagnosis of constrictive pericarditis, particularly in patients with suboptimal or nondiagnostic echocardiographic findings in whom cross-sectional imaging with cardiac CT or CMR is either unavailable or nondiagnostic [25]. Moreover, patients with diagnostic-quality echocardiographic findings may require coronary angiography for evaluation of coronary anatomy prior to pericardiectomy. In this setting, an invasive hemodynamic evaluation may also be performed. (See "Differentiating constrictive pericarditis and restrictive cardiomyopathy".)

Features of constrictive pericarditis — While there is no single diagnostic hemodynamic parameter, one or more of the following findings are commonly seen on cardiac catheterization:

●Increased mean right atrial and pulmonary capillary wedge pressure with equalization.

●Prominent x and y descents of venous and atrial pressure tracings (figure 1). In contrast, the y descent of diastolic ventricular filling is absent in tamponade. (See "Cardiac tamponade", section on 'Diagnosis'.)

●Kussmaul sign (the lack of an inspiratory decline or an inspiratory increase in central venous pressure).

●Increased RV end-diastolic pressure, usually to a level one-third or more of RV systolic pressure.

●"Square root" signs in the RV and LV diastolic pressure tracings (an early diastolic dip followed by a plateau of diastasis; the last stage of diastole just before contraction), often with an absent a wave [1]. This finding, also called dip and plateau, reflects rapid early diastolic filling of the ventricles, followed by lack of additional filling due to compression in mid and late diastole (figure 2). The plateau configuration (of the dip and plateau pattern) may be diminished or absent in patients who are tachycardic due to the shortening of diastole.

●A greater inspiratory fall in pulmonary capillary wedge pressure compared with LV diastolic pressure.

●Equalization of LV and RV diastolic plateau pressure tracings, with little separation with exercise, since filling, and therefore diastolic pressure, in both ventricles is constrained by the inelastic pericardium [1]. In some patients, this finding is seen only during inspiration (figure 3).

●Mirror-image discordance between RV and peak LV systolic pressures during inspiration, another sign of increased ventricular interdependence. During peak inspiration, an increase in RV pressure occurs when LV pressure is lowest [40].

In a series of 143 patients with surgically confirmed constrictive pericarditis, 78 underwent cardiac catheterization [10]. The mean right atrial pressure was 21 mmHg. A dip and plateau pattern was seen in 77 percent, diastolic equalization of pressures in 81 percent, and respiratory variation in the RV-LV pressure relationship in 44 percent.

Effusive-constrictive pericarditis — Prior to pericardiocentesis, effusive-constrictive pericarditis is suggested by the unexpected persistence of a y descent in the right atrial pressure recording in a patient with cardiac tamponade. Effusive-constrictive pericarditis often becomes apparent after pericardiocentesis in patients initially considered to have uncomplicated cardiac tamponade. In such cases, the right atrial pressure remains elevated after removal of the pericardial effusion.

The diagnosis of effusive-constrictive pericarditis is further supported by the following on right atrial pressure tracing findings after pericardiocentesis [7,8]. 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 [41]. (See "Pericardial effusion: Approach to management".)

●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

In patients with effusive-constrictive pericarditis, pericardiocentesis fails to reduce the right atrial pressure by 50 percent or to a level below 10 mmHg [7]. A persistently elevated right atrial pressure after pericardiocentesis may also be due to right heart failure or tricuspid regurgitation. Thus, these conditions should be excluded before making a 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 postpericardiocentesis echocardiogram) [42]:

●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 postpericardiocentesis 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.

CMR and/or cardiac CT is helpful in many cases to document pericardial thickening and inflammation. However, increased pericardial thickness on noninvasive imaging lacks specificity and sensitivity in diagnosing effusive-constrictive pericarditis [8]. The visceral layer of pericardium may be responsible for the constrictive component of effusive-constrictive pericarditis and it is typically not thickened to a degree that is detectable on imaging studies (or evident on visual inspection at surgery).

In a study of patients with pericarditis in South Africa, 36 of 68 patients with tuberculous pericarditis had effusive-constrictive pericarditis [43]. Prepericardiocentesis right atrial pressure and pericardial and serum interleukin 10 (IL-10) levels were higher among patients with effusive-constrictive pericarditis compared with patients with pericardial effusion without constrictive physiology.

Occult constrictive pericarditis — As noted above, 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. 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. Rather than infusing fluid, diuretic therapy (if administered) can be suspended for several days prior to cardiac catheterization.

DIFFERENTIAL DIAGNOSIS — The symptoms and physical findings in patients with constrictive pericarditis or effusive-constrictive pericarditis are similar to those of several other disorders. Most importantly, the clinician must distinguish between constrictive pericarditis, which is treated by pericardiectomy; cardiac tamponade, which is treated by drainage of the pericardial effusion; and disorders such as restrictive cardiomyopathy and cirrhosis, which require markedly different treatment [25]. Other edematous states (eg, nephrotic syndrome) can occasionally cause confusion as well.

Comparison with restrictive cardiomyopathy — Patients with constrictive pericarditis and restrictive cardiomyopathy have elevated left- and right-sided filling pressures, often of similar magnitude, and usually have normal systolic ventricular function. While the history, physical examination, and imaging findings may suggest a particular diagnosis, constrictive pericarditis and restrictive cardiomyopathy are usually distinguished by hemodynamic findings from Doppler echocardiography and/or cardiac catheterization (algorithm 3 and table 1) [1]. Cardiac amyloidosis, a common cause of restrictive cardiomyopathy, is strongly suggested by striking increases in RV and LV wall thickness. This is discussed in more detail separately. (See 'Doppler findings' above and "Differentiating constrictive pericarditis and restrictive cardiomyopathy".)

Comparison with cardiac tamponade — Several similarities exist in the clinical presentation of constrictive pericarditis and cardiac tamponade. However, these entities differ in their effects on diastolic ventricular filling, which can lead to different findings on physical examination, echocardiography, and invasive hemodynamic assessment.

Comparison with chronic liver disease — Patients with constrictive pericarditis presenting with ascites as the main manifestation are often thought to have cirrhosis as their primary diagnosis, sometimes considered cryptogenic because the history does not reveal an obvious cause. Common physical examination findings in both constrictive pericarditis and chronic liver disease include peripheral edema, ascites, hepatomegaly (part of the syndrome of congestive hepatopathy), and pleural effusion. These findings may lead to the misdiagnosis of chronic liver disease.

The evaluation of jugular venous pressure (JVP) can help distinguish constrictive pericarditis from chronic liver disease. In constrictive pericarditis, there is marked elevation in JVP with characteristic changes in the morphology of the jugular venous pulsations (figure 1). In patients with cirrhosis from chronic liver disease, unless there is tense ascites, JVP is normal or only slightly elevated. JVP in patients with tense ascites should rapidly normalize following removal of ascitic fluid [44]. (See "Congestive hepatopathy" and "Clinical manifestations and evaluation of edema in adults".)

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

●Initial evaluation – All patients with suspected constrictive pericarditis should undergo initial evaluation including history and physical examination, ECG, chest radiography, and transthoracic echocardiography (TTE). (See 'General approach' above.)

●Echocardiography – The diagnosis of constrictive pericarditis is usually made by echocardiography (algorithm 2). (See 'Diagnostic approach' above and 'General approach' above.)

While there is no single diagnostic echocardiographic parameter, the presence of annulus reversus or strain reversus or the combination of three other findings (respirophasic ventricular septal shift, hepatic vein diastolic flow reversal ratio ≥79 percent, and medial e' velocity >8 cm/s) is generally sufficient to confirm a diagnosis of constrictive pericarditis (algorithm 2). A thickened pericardium is suggestive of constrictive pericarditis but is not sufficient to confirm the diagnosis. (See 'Echocardiography' above.)

●Additional evaluation – The need for additional diagnostic evaluation with cardiac computed tomography (CT), cardiovascular magnetic resonance (CMR) imaging, and/or invasive cardiac catheterization is based upon factors including the findings and diagnostic quality of the echocardiogram, the index of suspicion (eg, high in patients with typical clinical findings and relevant history, such as prior radiation therapy), and the potential need for surgical intervention (algorithm 2). For most patients requiring additional evaluation after echocardiography, the choice between CMR and cardiac CT is based upon individual patient characteristics as well as institutional availability and expertise. Some patients benefit from undergoing both CMR and cardiac CT. (See 'Additional testing' above.)

•CMR – Key CMR findings of constrictive pericarditis include increased pericardial thickness (which is well differentiated from pericardial effusion), late gadolinium enhancement (LGE; suggesting inflammation), pericardial tethering, respirophasic interventricular septal motion, and enhanced respiratory variation in mitral and tricuspid inflows.

•Cardiac CT – Key cardiac CT findings include increased pericardial thickness (although this can be difficult to distinguish from small pericardial effusion) and pericardial calcification. Positron emission tomography (PET)/CT can identify pericardial inflammation.

•Cardiac catheterization – Key findings of constrictive pericarditis include increased right atrial pressure; prominent x and y descents of venous and atrial pressure tracings (figure 1); Kussmaul sign (the lack of an inspiratory decline or an inspiratory increase in central venous pressure); increased right ventricular (RV) end-diastolic pressure, usually to a level one-third or more of RV systolic pressure; "square root" signs in the RV and left ventricular (LV) diastolic pressure tracings (an early diastolic dip followed by a plateau of diastasis) (figure 2); a greater inspiratory fall in pulmonary capillary wedge pressure compared with LV diastolic pressure; equalization of LV and RV diastolic plateau pressures (figure 3); and mirror-image discordance between RV and peak LV systolic pressures during inspiration.

●Identification of subtypes

•Transient versus chronic – As a practical matter, the diagnosis of transient constrictive pericarditis (a manifestations of early or subacute disease) can only be made in retrospect, after clinical manifestations of constrictive pericarditis reverse within three to six months either spontaneously or with medical therapy.

•Effusive-constrictive pericarditis – This condition often becomes apparent after pericardiocentesis in patients initially considered to have uncomplicated cardiac tamponade. (See 'Effusive-constrictive pericarditis' above.)

●Differential diagnosis – The symptoms and physical findings in patients with constrictive pericarditis are similar to those of several other disorders. Most importantly, the clinician must distinguish between constrictive pericarditis, which is treated by pericardiectomy; cardiac tamponade, which is treated by drainage of the pericardial effusion; and disorders such as restrictive cardiomyopathy and cirrhosis, which require markedly different treatment. (See 'Differential diagnosis' above and "Differentiating constrictive pericarditis and restrictive cardiomyopathy".)