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Constrictive Pericarditis

posted Mar 5, 2015, 5:34 PM by Kevin Hauck   [ updated Mar 5, 2015, 5:46 PM ]

A Fantastic Monte Minute brought to you by Jian Shan from Firm 2!  It was based on a November CRS. 

56M with PMH of hypothyroidism, CKD, ‘cryptogenic cirrhosis’ with chief complain of dyspnea for 2 weeks with worsening LE swelling and abdominal distension.

CONSTRICTIVE PERICARDITIS

Etiology

Constrictive pericarditis is the end stage of an inflammatory process involving the pericardium. In the developed world, the etiology is most commonly idiopathic, postsurgical, or radiation injury (Table 1). Tuberculosis is the most common cause in the developing world. It usually takes months to years to develop constriction after initial injury. The end result is dense fibrosis, often calcification, and adhe­sions of the parietal and visceral pericardium. Scarring is usually more or less symmetric and impedes filling of all heart chambers.

 

TABLE 1 Causes of Constrictive Pericarditis

Idiopathic

Irradiation

Postsurgical

Infectious

Neoplastic

Autoimmune (connective tissue) disorders

Uremia

Post-trauma

Sarcoid

Methysergide therapy

Implantable defibrillator patches

Pathophysiology

 

Pericardial scarring is markedly restricted filling of the heart which results in elevation and equilibra­tion of filling pressures in all chambers and the systemic and pulmo­nary veins. In early diastole, the ventricles fill abnormally rapidly because of markedly elevated atrial pressures and accentuated early diastolic ventricular suction, the latter related to small end-systolic volumes. During early to mid diastole, ventricular filling abruptly ceases when intracardiac volume reaches the limit set by the stiff pericardium. As a result, almost all ventricular filling occurs early in diastole.

 

Systemic venous congestion results in hepatic congestion, peripheral edema, ascites and sometimes anasarca, and cardiac cir­rhosis. Reduced cardiac output is a consequence of impaired ventricu­lar filling and causes fatigue, muscle wasting, and weight loss. In “pure” constriction, contractile function is preserved, although ejection frac­tion can be reduced because of reduced preload. The myocardium is occasionally involved in the chronic inflammation and fibrosis, leading to true contractile dysfunction that can at times be quite severe and predicts a poor response to pericardiectomy.

 

High systemic venous pressure and reduced cardiac output result in compensatory retention of sodium and water by the kidneys. Inhibition of natriuretic peptides also may contribute to renal sodium retention, further exacerbating increased filling pressures.

Clinical Presentation

·          Signs and symptoms of right-sided heart failure: LE edema, vague abdominal complaints, and passive hepatic congestion happen at a relative early stage.

·          As the disease progresses, hepatic congestion worsens and can prog­ress to ascites, anasarca, and jaundice due to cardiac cirrhosis.

·          Signs and symptoms ascribable to elevated pulmonary venous pressures: exertional dyspnea, cough, and orthopnea, Atrial fibrillation and tricuspid regurgitation.

·          In end-stage constrictive pericarditis, the effects of a chron­ically low cardiac output are prominent: severe fatigue, muscle wasting, and cachexia.

·          Other findings: recurrent pleural effusions and syncope.

·          Constrictive pericarditis can be mistaken for any cause of right-sided heart failure as well as end-stage primary hepatic disease.

Physical Examination

·          markedly elevated jugular venous pressure with a prominent, rapidly collapsing y descent, combined with a normal x descent, results in an M- or W-shaped venous pressure contour

·          Kussmaul sign, an inspiratory increase in systemic venous pressure, is usually present,or the venous pressure may simply fail to decrease on inspi­ration. These characteristic abnormalities of the venous waveform contrast with tamponade.

·          A paradoxical pulse occurs in perhaps one third of patients with constriction, especially when there is an effusive-constrictive picture.  Table 75-3 is a comparison of hemodynamic findings in tamponade and constrictive pericarditis.

·          pericardial knock, an early diastolic sound best heard at the left sternal border or the cardiac apex. It occurs slightly earlier and has a higher frequency content than a typical third heart sound. Widen­ing of second heart sound splitting may also be present.

·          Abdominal examination reveals hepatomegaly, often with palpable venous pulsations, with or without ascites.

·          Jaundice, spider angiomas, and palmar erythema may exist.

·          Lower extremity edema is the rule.

·          With end-stage constriction, muscle wasting, cachexia, and massive ascites and anasarca may appear.

Table 2: Hemodynamics in Cardiac Tamponade and Constrictive Pericarditis

 

 

TAMPONADE

CONSTRICTION

Paradoxical pulse

Usually present

Present in 1/3

Equal left- and right-sided filling pressures

Present

Present

Systemic venous wave morphology

Absent y descent

Prominent y descent (M or W shape)

Inspiratory change in systemic venous pressure

Decrease (normal)

Increase or no change (Kussmaul sign)

“Square root” sign in ventricular pressure

Absent

Present

 

 

 

 

Laboratory Testing

ECG. There are no specific electrocardio­graphic findings. Nonspecific T wave abnormalities, reduced voltage, and left atrial abnormality may be present. Atrial fibrillation is also common.

CHEST RADIOGRAPHY. The cardiac silhouette can be enlarged secondary to a coexisting pericardial effusion. Pericardial calcification is seen in a minority of patients and suggests tuberculosis.  but calcification per se is not diagnostic of constrictive physiology. Pleural effusions are occasionally noted and can be a presenting sign of constrictive pericarditis.

 

ECHOCARDIOGRAPHY.  Pericardial thickening, abrupt displacement of the interventricular septum during early diastole (septal “bounce”), and signs of systemic venous congestion such as dilation of hepatic veins and distention of the inferior vena cava with blunted respiratory fluctuation. Premature pulmonic valve opening as a result of elevated right ventricular early diastolic pressure may also be observed. Exaggerated septal shifting during respiration is often present.

Tissue Doppler examination reveals increased E′ velocity of the mitral annulus as well as septal abnormalities corresponding to the bounce. Tissue Doppler appears to be at least as sensitive as mitral-tricuspid inflow Doppler for diagnosis of constriction. Superior vena caval flow velocities are helpful in distinguishing constrictive pericarditis from chronic obstructive pulmonary disease. Patients with pulmonary disease display a marked increase in inspiratory superior vena caval systolic forward flow velocity, which is not seen in constriction. TEE is superior to TTE for measuring pericardial thickness and has an excellent correlation with CT. When mitral inflow velocities by TTE are technically inadequate or equivocal, measurement of TEE pulmonary venous Doppler velocity demonstrates pronounced respiratory variation, larger than that observed across the mitral valve.

CARDIAC CATHETERIZATION AND ANGIOGRAPHY. Cardiac catheterization provides documentation of the hemodynamics of constrictive physiology and assists in discriminating between constrictive pericarditis and restrictive cardiomyopathy. Whereas there is limited need for contrast ventriculography, coronary angiography should ordinarily be performed in patients being considered for pericardiectomy. On rare occasions, external pinching or compression of the coronary arteries by the constricting pericardium is detected.

Both right and left ventricular pressures reveal an early, marked diastolic dip followed by a plateau (“dip and plateau” or “square root” sign; Fig. 3). Stroke volume is almost always reduced, but resting cardiac output can be preserved because of tachycardia. Depression of stroke volume is primarily caused by reduced diastolic filling.

 COMPUTED TOMOGRAPHY AND CARDIAC MAGNETIC RESONANCE. CT provides detailed pericardial images and is helpful in detecting even minute amounts of pericardial calcification. Its major disadvantage is the frequent need for iodinated contrast medium to best display pericardial disease. The thickness of the normal pericardium measured by CT is <2 mm. CMR provides a detailed and comprehensive examination of the pericardium without the need for contrast material or ionizing radiation. It is somewhat less sensitive than CT for detection of calcification. The “normal’’ pericardium visualized by CMR is up to 3 to 4 mm in thickness. This measurement most likely reflects the entire pericardial “complex,” with physiologic fluid representing a component of the measured thickness.

Additional findings include distorted ventricular contours, hepatic venous congestion, ascites, pleural effusions, and occasionally pericardial effusion. Cine acquisition (CMR or CT) shows abnormal motion of the interventricular septum (septal bounce) in early diastole.  Enhanced uptake of gadolinium appears useful for detection of pericardial inflammation. There is a cohort of patients with well-documented constriction who have no pericardial thickening on the basis of measurements in pathologic specimens despite histologic evidence of inflammation and calcification. These patients constituted 18% of those with constrictive pericarditis in a Mayo Clinic series. Almost all had normal pericardial thickness by CT. Calcification and distorted ventricular contours occurred in a majority, providing clues to the diagnosis despite normal thickness.

Differentiation of Constrictive Pericarditis from Restrictive Cardiomyopathy

Because their treatment is radically different, distinguishing constrictive pericarditis from restrictive cardiomyopathy is extremely important (Table 3).
 

ECHO: TEE measurements of pericardial thickness correlate well with CT. With use of two-dimensional speckle tracking, differences in contraction mechanics that are useful in distinguishing constriction from restriction have been described. In constriction, deformation of the left ventricle and early diastolic recoil velocity were attenuated in the circumferential direction, whereas in restriction, they were attenuated in the longitudinal direction. Doppler measurements are also useful in differentiating constrictive from restrictive physiology. Enhanced respiratory variation in mitral inflow velocity (>25%) is seen in constriction; in restriction, velocity varies by <10%. In restriction, pulmonary venous systolic flow is markedly blunted and diastolic flow is increased. This is not observed in constriction. Hepatic veins demonstrate enhanced expiratory flow reversal with constriction, in contrast to increased inspiratory flow reversal in restriction. Tissue Doppler echocardiography and color M-mode flow propagation are complementary to mitral Doppler respiratory variation in distinguishing constriction from restrictive cardiomyopathy. Higher tissue Doppler mitral annulus E′ values in constriction versus restrictive cardiomyopathy are reported to have a higher sensitivity than mitral inflow parameters for making the distinction.

Cath: In both conditions, right and left ventricular diastolic pressures are markedly elevated. In restrictive cardiomyopathy, diastolic pressure in the left ventricle is usually higher than in the right ventricle by at least 3 to 5 mm Hg; in constrictive pericarditis, left- and right-sided diastolic pressures typically track closely and rarely differ by more than 3 to 5 mm Hg. Pulmonary hypertension is common with restrictive cardiomyopathy but rare in constriction. The absolute level of atrial or ventricular diastolic pressure elevation is also sometimes useful in distinguishing the two conditions, with extremely high pressures (>25 mm Hg) much more common in restrictive cardiomyopathy. Finally, the ratio of right ventricular to left ventricular systolic pressure-time area during inspiration versus expiration is greater in constriction versus restriction (reflecting exaggerated ventricular interaction) and is reported to have a high sensitivity and specificity for distinguishing between them.

CT and CMR:  Pericardial calcification or distorted ventricular contour is helpful in making the correct diagnosis in these patients.

Endomyocardial or abdominal fat pad biopsy: This establishes the diagnosis of restrictive cardiomyopathy due to amyloidosis.

Brain natriuretic peptide (BNP) levels: May be useful in distinguishing constriction from restriction. BNP is reported to be elevated in restrictive cardiomyopathy and normal in constriction. More recent data indicate that this difference is more useful in secondary constriction (e.g., postoperative, irradiation) than in idiopathic cases.

 

Table 3. Hemodynamic and Echocardiographic Features of Constrictive Pericarditis Compared with Restrictive Cardiomyopathy

 

CONSTRICTION

RESTRICTION

Prominent y descent in venous pressure

Present

Variable

Paradoxical pulse

1/3 of cases

Absent

Pericardial knock

Present

Absent

Equal right- and left-sided filling pressures

Present

Left at least 3-5 mm Hg > right

Filling pressures >25 mm Hg

Rare

Common

Pulmonary artery systolic pressure >60 mm Hg

No

Common

“Square root” sign

Present

Variable

Respiratory variation in left- and right-sided pressures or flows

Exaggerated

Normal

Ventricular wall thickness

Normal

Usually increased

Atrial size

Possible left atrial enlargement

Biatrial enlargement

Septal bounce

Present

Absent

Tissue Doppler E′ velocity

Increased

Reduced

Pericardial thickness

Increased

Normal

BNP

Normal

Elevated

Management

Surgical pericardiectomy is the definitive treatment. surgery should not be delayed once the diagnosis is made.

exceptions:

·         Transient constriction should be suspected in patients presenting relatively earlier after cardiac surgery or with relatively rapid development of symptoms. Such patients can be monitored for several months to look for spontaneous improvement. They may respond to a course of corticosteroids.

·         High risk patients: Patients with major comorbidities or severe debilitation are often at too high risk to undergo pericardiectomy. Radiation-induced disease is also considered a relative contraindication to pericardiectomy. Healthy older patients with very mild constriction may also be managed nonsurgically, with pericardiectomy held in reserve until there is disease progression. 

 

Medical management with diuretics and salt restriction is useful for relief of fluid overload and edema, but patients ultimately become refractory.

treatment of sinus tachycardia:  it is a compensatory mechanism, beta-adrenergic blockers and calcium antagonists should be avoided. In patients with atrial fibrillation and a rapid ventricular response, digoxin is recommended first. In general, the rate should not be allowed to drop below 80 to 90 beats/min.

 

Prognosis of pericardiectomy:

Hemodynamic and symptomatic improvement is achieved in some patients immediately after operation. In others, improvement may be delayed for weeks to month. After pericardiectomy, 70% to 80% of patients remain free from adverse cardiovascular outcomes at 5 years and 40% to 50% at 10 years. Long-term results are worse in patients with radiation-induced disease, impaired renal function, relatively high pulmonary artery systolic pressure, reduced left ventricular ejection fraction, moderate or severe tricuspid regurgitation, low serum sodium, and advanced age.

Pericardiectomy has a 5% to 15% perioperative mortality in patients with constriction. The highest mortality occurs in patients with Class III or IV symptoms, supporting the recommendation of early pericardiectomy.

 

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