Constrictive pericarditis

Constrictive pericarditis is the result of scarring and consequent loss of the normal elasticity of the pericardial sac, leading to restriction in ventricular filling.

Pericardial constriction is typically chronic, but variants include subacute, transient, and occult constrictive pericarditis.

Normal pericardial thickness is 2 mm or less.

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Etiology

Chronic constrictive pericarditis is a disease that has multiple possible causes and is associated with variable clinical findings, depending on its severity. In many cases, no etiology is ever determined. 

All forms of pericarditis may eventually lead to pericardial constriction.

Reasons may be broadly classified into common, less common, and rare forms. 

Common 

     -Idiopathic

     -Infection  (bacterial or viral)

         - Worldwide, the leading cause of constrictive pericarditis is tuberculosis

         - In developed nations, the leading cause of this condition is idiopathic or post-viral infection with incidence being 40% to 60% of total cases.

     -Cardiac surgery

     -Radiation

 Less common

     -Connective tissue disorders (e.g. SLE, rheumatoid arthritis, sclerodermia)

     -Post MI

     -Drugs

     -Trauma

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Pathophysiology 

In constrictive pericarditis, the easily distensible, thin parietal and visceral pericardial linings become inflamed, thickened, and fused.

‍Because of these changes, the potential space between the linings is obliterated, and the ventricle loses distensibility.

Venous return to the heart becomes limited, and ventricular filling is reduced, with associated inability to maintain adequate preload.

Filling pressures of the heart tend to become equal in both the ventricles and the atria.

Ventricular filling in early diastole is not affected and is only impeded when the elastic limit of the pericardium is reached.

      - in contrast to cardiac tamponade where the ventricular filling is impeded throughout the diastole.

This results in decreased end diastolic volume and decreased stroke volume and cardiac output.

The thickened and scarred pericardium prevents the normal inspiratory decrease in intrathoracic pressure from being transferred to the heart chambers.

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Clinical presentation 

Early on in the course of the disease, patients may present with symptoms secondary to a reduction in cardiac output rather than those due to elevated filling pressures. 

These include fatigue and exertional dyspnoea, commonly referred to as “out of puff”.

Once the filling pressures become significantly elevated, and systemic venous pressure rises, signs of overt RHF develop. Abdominal complaints are secondary to either ascites or congestive hepatomegaly.

Direct questioning, particularly for a prior history of pericarditis, is relevant in any patient presenting with HFpEF.

On physical examination, the jugular venous pressure (JVP) is usually elevated, however, may be normal in early constrictive pericarditis. The level of the JVP may only become visible with the patient in an upright position, and it is therefore imperative to evaluate it with the patient standing when the diagnosis is suspected.

Kussmaul’s sign, observed as either a failure of the JVP to drop, or more commonly a paradoxical inspiratory rise in the JVP, occurs in only 21% of CP cases and is therefore not a sensitive sign.

Pulsus paradoxus may be seen in approximately 20% of patients.

There are no specific signs of constrictive pericarditis on ECG which may reveal nonspecific ST changes and low voltage. Advanced and long-standing cases may show atrial fibrillation secondary to elevated atrial pressures.

ECHO

The classic diagnostic conundrum associated with constrictive pericarditis is the difficulty distinguishing this condition from restrictive cardiomyopathy.

The accurate differentiation of CP from RCM can be a diagnostic challenge even to the experienced clinician, but is of paramount importance, since CP is a potentially curable disease, while in RCM prognosis is poor due to limited therapeutic options. 

It is reliant on demonstrating the two hallmark physiological features of CP - dissociation of intrathoracic and intracardiac pressures and enhanced ventricular interdependence. 

What is independently associated with the diagnosis of constrictive pericarditis ?

1) respiration-related ventricular septal shift towards the right side (septal bounce)

2) preserved or increased medial mitral annular e' velocity

3) pulsed wave doppler - with inspiration results in a decrease in the initial driving pressure for left ventricular filling

4) prominent hepatic vein expiratory diastolic flow reversals 

‍Image 1 Constrictive pericarditis vs. restrictive cardiomyopathy

Adapted from: Adler Y, Charron P, Imazio M, et al.; ESC Scientific Document Group. 2015 ESC Guidelines for the diagnosis and management of pericardial diseases: The Task Force for the Diagnosis and Management of Pericardial Diseases of the European Society of Cardiology (ESC)Endorsed by: The European Association for Cardio-Thoracic Surgery (EACTS). Eur Heart J. 2015 Nov 7;36(42):2921-2964.

1) Septal bounce

Septal bounce is a sign of ventricular interdependence, manifested by paradoxical interventricular septal movement during early diastole (i.e. initial septal movement towards and then away from the left ventricle) seen mainly in constrictive pericarditis.

When motion of the ventricular walls is decreased (tethered by the pericardium in constrictive pericarditis), changes in ventricular volumes and pressures in early diastole are then reflected through deviations of the septum.

Septal bounce is a specific and relatively sensitive sign of ventricular interdependence due to constrictive pericarditis and is considered a reliable sign to distinguish constrictive pericarditis from restrictive cardiomyopathy.

‍‍Video 1  Constrictive pericarditis, A4C window taken during inspiration - ventricular septal shift towards the right side, septal bounce is present. Abnormally hyperechogenic pericardium alongside the right side. 

Video 2 Constrictive pericarditis, PSAX window at the papillary muscles level - septal bounce and hyperechogenic pericardium around the left ventricle.

Video 3 Constrictive pericarditis, A3C view - hyperechogenic pericardium, septal bounce

Video 4  Constrictive pericarditis, PLAX window

Video 5 A4C window - septal bounce with slight deviation of the IVS to the right sided chamber

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2) Preserved or increased medial mitral annular e' velocity

In general, a mitral annular e’ velocity 8 cm/s represents a discrete amplitude cut point to distinguish CP from RCM, possibly due to a greater contribution by the longitudinal movement of the left ventricle for diastolic filling and normal LV relaxation. 

Annulus reversus

Due to the tethering of the adjacent fibrotic and scarred pericardium, which influences the lateral mitral annular translocation in patients with CP, the lateral e’ velocity is lower than the medial e’ velocity, a phenomenon termed annulus reversus, which is present in up to 75% of surgically proven CP.

‍Image 2 Tissue Doppler in a patient with constrictive pericarditis - Medial (left) and lateral (right) mitral annular tissue Doppler recording (apical window) in a patient with constrictive pericarditis. Note normal to increased early relaxation velocity (e'), with medial velocity greater than lateral (annulus reversus).

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3) Pulsed wave Doppler

With inspiration, the dissociation of intrathoracic and intracardiac pressures results in a decrease in the initial driving pressure for left ventricular filling !!! Consequently, there is a decrease in peak mitral E-wave velocity by >25% during the first beat of inspiration, as well as prolongation of the isovolumic relaxation time (usually >20%).

Ventricular interdependence is responsible for reciprocal changes in the trans-tricuspid inflow pattern with an inspiratory increase in peak E-wave velocity by >40%. Reverse changes do occur with expiration in both ventricles. 

In simplified terms, diastolic flow to the left heart decreases with inspiration, while opposite changes are observed for the right heart.

However, subsequent larger studies discovered the absence of mitral inflow respiratory variation in one third of patients with CP.

Image 3  Pulsed-wave Doppler recording, A4C window at the level of the tricuspid valve opening in a patient with constrictive pericarditis. Note inspiratory increase and expiratory decrease in early (E) right-sided inflow velocity .

4) Expiratory hepatic vein flow reversal

Expiratory hepatic vein reversals and decreased diastolic forward flow occur due to rightward ventricular septal motion from an expiratory increase in LV preload, with a resultant decrease in effective operating right ventricular compliance.

‍Image 4 Hepatic vein flow reversal in CP, PW Doppler - Pulsed-wave Doppler recording (subcostal window) within the hepatic vein in a patient with constrictive pericarditis. Note prominent diastolic flow reversals in expiration, with the diastolic reversal ratio defined as reversal velocity divided by forward velocity (≈0.35 m/s reversal velocity divided by ≈0.30 cm/s forward flow velocity yields a diastolic reversal ratio of 1.2).

Welch TD, Ling LH, Espinosa RE, Anavekar NS, Wiste HJ, Lahr BD, Schaff HV, Oh JK. Echocardiographic diagnosis of constrictive pericarditis: Mayo Clinic criteria. Circ Cardiovasc Imaging. 2014 May;7(3):526-34. doi: 10.1161/CIRCIMAGING.113.001613. Epub 2014 Mar 14. PMID: 24633783.

‍The M mode may also be very important to rule out constrictive pericarditis.

‍The following features are frequently seen in constrictive pericarditis and an absence of these features on M mode makes the diagnosis of constrictive pericarditis unlikely.

• Posterior motion of ventricular septum on early diastole in inspiration 
• Absence of increase in systemic venous return with inspiration 
• Premature opening of the pulmonic valve due to higher right ventricular diastolic pressure compared to pulmonary arterial pressure

Image 5  Midventricular septal M-mode recording (parasternal long axis) in a patient with constrictive pericarditis. Note leftward ventricular septal shift in inspiration. Also evident is a beat-to-beat septal diastolic shudder.

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Other echocardiographic findings also expected, although not unique to CP are:

1) Systemic venous congestion (inferior vena cava plethora)

2) A ratio of mitral early (E) to late (A) transmitral filling velocities that is pseudonormal or restrictive (E/A>0.8), given elevated left atrial pressure.

3) Biatrial enlargement

Image 6 A brief overview of difference between CP and RCM

Adapted from: Adler Y, Charron P, Imazio M, et al.; ESC Scientific Document Group. 2015 ESC Guidelines for the diagnosis and management of pericardial diseases: The Task Force for the Diagnosis and Management of Pericardial Diseases of the European Society of Cardiology (ESC)Endorsed by: The European Association for Cardio-Thoracic Surgery (EACTS). Eur Heart J. 2015 Nov 7;36(42):2921-2964.

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‍Management

Pericardiectomy is the only definitive management of chronic constrictive pericarditis and effort should be made to remove as much of the pericardium as possible. Operative mortality is high.

Diuretics can be used to reduce edema or elevated venous pressures before the surgery or for palliative control of symptoms in patients who are not surgical candidates.

Patients with newly diagnosed constrictive pericarditis who are hemodynamically stable and do not have stigmas of chronic constriction may be treated with anti-inflammatory agents for up to three months with close monitoring. If these patients develop signs of chronic constriction and hemodynamic instability they should undergo prompt surgical treatment.

References

1. Yadav NK, Siddique MS. Constrictive Pericarditis. 2021 Jul 19. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan–. PMID: 29083701.
2. Constrictive pericarditis – prevalence, causes and clinical presentation. European Society of Cardiology [online]. Copyright © 2021 European Society of Cardiology. All rights reserved. [cit. 20.08.2021]. Available from: https://www.escardio.org/Journals/E-Journal-of-Cardiology-Practice/Volume-15/Constrictive-pericarditis-prevalence-causes-and-clinical-presentation
3. Constrictive pericarditis: role of echocardiography and magnetic resonance imaging. European Society of Cardiology [online]. Copyright © 2021 European Society of Cardiology. All rights reserved. [cit. 20.08.2021]. Available from: https://www.escardio.org/Journals/E-Journal-of-Cardiology-Practice/Volume-15/Constrictive-pericarditis-role-of-echocardiography-and-magnetic-resonance-imaging
4. Constrictive Pericarditis: Background, Pathophysiology, Etiology. Diseases & Conditions - Medscape Reference [online]. Copyright © 1994 [cit. 20.08.2021]. Available from: https://emedicine.medscape.com/article/157096-overview