Pericardial constriction

Template:Pericardial constriction Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor-In-Chief: Atif Mohammad, M.D.

See also: pericarditis, pericardial effusion, cardiac tamponade

Diagnosis

History

Patients often complain of shortness of breath and edema. Patients also commonly present with nonspecific complaints of weakness and fatigue. Patients may also complain of weight gain, chest pain, abdominal fullness, and atrial arrhythmias (1/3-1/2 will have atrial fibrillation).

Physical Examination

Physical examination reveals elevation of the JVP (jugular venous pulse). The waveform is characteristic with a prominent x and y descent. Kussmaul’s sign may be found (13% in the Stanford series). It occurs because the fall in intrathoracic pressure during inspiration is not transmitted to the cardiac chambers and pericardial space.

Vital Signs

Pulsus paradoxus, though more typical in cardiac tamponade, can be seen in 20% of patients.

Neck

Jugular venous distention

Heart

Widely split S2 can be heard and a pericardial knock can be heard in approximately 50% of patients.

Abdomen

Evidence of right heart failure is also common and may mimic findings in chronic liver disease, e.g. pulsatile liver, ascites, scrotal edema.

Extremities

Pedal edema can be observed

Laboratory Findings

Protein losing enteropathy, nephrotic syndrome, LFT abnormalities c/w hepatic congestion and chylous ascites has also been reported.

Cardiac Catheterization

Typically, there is equalization of diastolic pressures in all four chambers. These filling pressures are typically elevated. RVSP is usually moderately elevated but rarely exceeds 60 mmHg.

If RVSP is >60 mmHg, restriction is suggested. The RVEDP is usually at least 1/3 of the RVSP. Again, if it is lower, restriction is suggested. Some say that the LVEDP may be slightly higher than the RVEDP in restriction, especially after volume load or exercise.

The RV and LV waveforms exhibit a “dip and Plateau or square root” sign, which is another manifestation of the early rapid diastolic filling, followed by abrupt cessation of flow. Discordance between the RVS and LVS pressures can also be seen during inspiration.

Diuresis can obscure the hemodynamic findings in the catheterization laboratory, and diuretics should be held and careful IVF rehydration given if the diagnosis is entertained.

Perciardial constriction should be differentiated from restriction (which involves the left ventricle more selectively). The clinical features and hemodynamic findings of the two syndromes have significant overlap. One useful test in the cardiac catheterization laboratory to distinguish the two is a volume challenge. On simultaneous LV and RV diastolic pressure tracings, constriction compromises both ventricles equally (the LV and RV diastolic pressures will rise equally). Restriction on the other hand, will affect the LV more than the RV, and the LV diastolic pressure will rise out of proportion to the RV diastolic pressure. If restriction is suspected, one should screen for hemochromatosis, sarcoid, the hypereosinophillic syndrome, amyloid and radiation induced-myopathy.

Constrictive Pericarditis can also be differentiated from Restrictive Cardiomyopathy during cardiac catheterization using "Systolic Area Index" as a reliable hemodynamic criterion .Systolic Area Index is the ratio of right ventricular to left ventricular systolic area pressure -time (mm Hg X s) area during inspiration and expiration .It is increased (>1.1) in Constrictive Pericarditis as compared to Restrictive Cardiomyopathy which confirms the "ventricular interdependence" phenomenon present in Constrictive Pericarditis. |url=http://linkinghub.elsevier.com/retrieve/pii/S0735-1097(07)03432-8}}

MRI and CT

MRI or CT may demonstrate thickening or calcification of the pericardium.

Below is a video demonstrating MR findings of constrictive pericarditis where, in mid-diastole, the thickened pericardium begins to restrict right ventricular filling, causing a rapid increase in ventricular pressure. Early changes of septal flattening and bowing of the interventricular septum toward the left ventricle (normally concave in shape toward the left ventricle during diastolic filling) are seen. This pressure change results in diastolic septal dysfunction, the septal bounce described in echocardiography. <youtube v=5srXVJdWIAM/>

Echo

Echocardiography can demonstrate thickening of the pericardium and specific flow patterns across the mitral and tricuspid valves that are evidence of the abnormal diastolic filling in constriction. Collapse of the IVC and hepatic veins can be seen.

Complete Differential Diganosis

In many cases, constrictive pericarditis is a late sequela of an inflammatory condition of the pericardium. The inflammatory condition is usually an infection that involves the pericardium, but it may be after a heart attack or after heart surgery.

Almost half the cases of constrictive pericarditis in the developing world are idiopathic in origin. In regions where tuberculosis is common, it is the cause in a large portion of cases.

Causes of constrictive pericarditis include:

• Post Viral Pericarditis
• Tuberculosis
• Postsurgical
• Prior mediastinal radiation therapy
• Chronic Renal Failure
• Connective Tissue Disorders
• Neoplastic pericardial infiltration
• Incomplete drainage of purulent pericarditis
• Fungal and Parasitic Infections
• Following pericarditis associated with ST elevation myocardial infarction (Dressler's syndrome)
• In Association with pulmonary asbestosis

Treatment

Constriction is a progressive disease without spontaneous reversal of thickening or hemodynamic changes. Some patients can be medically managed for several years. Edema can be controlled with diuretics and slowing heart rate can maximize diastolic filling.

Most patients develop significant debility from impaired cardiac output and elevated right and left sided filling pressures. Treatment is complete excision of the pericardium. This operation is associated with 12% mortality. Some patients do not have complete relief of symptoms and up to 60% will have at least echocardiographic evidence of a restrictive filling pattern at approximately 2 years. Radiation induced disease seems to have a worse prognosis for improvement in functional class. The 5 and 10-year survival after pericardiectomy is 78 and 57% respectively, but obviously is most correlated with underlying illness.

The definitive treatment for constrictive pericarditis is pericardial stripping, which is a surgical procedure where the entire pericardium is peeled away from the heart. This procedure has significant risk involved, with mortality rates of 6% or higher in major referral centers. The high risk of the procedure is attributed to adherence of the thickened pericardium to the myocardium and coronary arteries. In patients who have undergone coronary artery bypass surgery with pericardial sparing, there is danger of tearing a bypass graft while removing the pericardium. Given the thin wall of the right ventricle, this can be a dangerous procedure and should only be undertaken if the patient's symptoms are incapacitating.

If any pericardium is not removed, it is possible for bands of pericardium to cause localized constriction which may cause symptoms and signs consistent with constriction.

Due to the significant risks involved with pericardial stripping, many patients are treated medically, with judicious use of diuretics.

References

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