The pericardium is a slim fibroelastic sac composed of two layers that separate the love from the bordering mediastinal structures. The outer layer of the pericardium is described as the fibrous pericardium and usually measures less than 2 mm in thickness. The inner portion of the pericardium is a two-layered sac called the serous pericardium. The visceral pericardium or epicardium is closely adherent come the basic myocardium and also is reflect upon itself to form the external parietal pericardium i beg your pardon lines the fibrous sac. Between the 2 layers of the serous pericardium lies the pericardial cavity i beg your pardon normally contains up to 50 mL that pericardial liquid (Figure 1). While the pericardium is not an important for life that serves important functions consisting of maintenance the cardiac place within the chest and as a obstacle to infection and inflammation.1

Acute Pericarditis

Definition

Acute pericarditis is one inflammatory process involving the pericardium that results in a clinical syndrome characterized by chest pain, pericardial friction rub, changes in the electrocardiogram (ECG) and also occasionally, a pericardial effusion.2 Generally, the diagnosis calls for 2 of this 3 features.

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Prevalence

Acute pericarditis is the admitting diagnosis in 0.1% the hospital admissions and also 5% the admissions with chest pain. That occurs an ext commonly in guys than in women.

Etiology

The most common kind of acute pericarditis is idiopathic, which accounts for about 90% of cases (Box 1). Various other common reasons include infection, renal failure, myocardial infarction (MI), post-cardiac injury syndrome, malignancy, radiation, and also trauma.1 this are debated in much more detail later.


Box 1: Common causes of Pericarditis and also Pericardial Effusion
Idiopathic
InfectiousViral (including HIV)BacterialMycobacterialFungal and also protozoal
Post-Myocardial infarction (early and late)
Postoperatively after open up heart surgery
Chest traumaBluntSharp
Radiation
MalignancyPrimary: mesothelioma, angiosarcomaMetastatic: lung, breast, bone, lymphoma, melanoma
Collagen vascular diseasesRheumatoid arthritisSystemic lupus erythematosus
Inflammatory/infiltrative diseasesSarcoidosisAmyloidosis
MetabolicHypothyroidismUremia
PharmacologicCromolyn sodiumDoxorubicinHydralazineMethysergideMinoxidilPenicillinPhenytoinProcainamide

Signs and Symptoms

Acute pericarditis generally presents v acute beginning severe, sharp retrosternal chest pain, frequently radiating come the neck, shoulders, or back. Positional changes are characteristic v worsening of the ache in the supine position and with inspiration; and development with sitting upright and leaning forward.


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Figure 2: Click come Enlarge

Classically, a scratchy, grating, high-pitched friction obstacle (which has been likened to the squeak of animal leather of a new saddle) is heard. This is felt to be led to by fibrinous deposits in the inflamed pericardial room (Figure 2) the timing of which have the right to be mono-, bi-, or triphasic (corresponding to atrial systole, ventricular systole, and also early ventricular diastole, respectively). It is best heard during inspiration in ~ the left reduced sternal border, through the patience leaning forward. The rub may disappear v the development of an effusion and also impending cardiac tamponade.2

Specific TypesIdiopathic Pericarditis

The cause of acute pericarditis is often daunting to establish, and also idiopathic pericarditis stays the most common diagnosis. Most instances are presumed to have actually a viral etiology.

Viral Pericarditis

Coxsackievirus B and echovirus are the most typical viruses, and also a fourfold rise in antiviral titers is compelled for the diagnosis. Patients regularly experience a prodrome the an upper respiratory street infection. The prognosis of famous pericarditis is normally good, v a self-limited course, and if uncomplicated, patients may be treated on one outpatient basis.

Purulent Pericarditis

Before the antibiotic era, pneumonia was the prime cause of purulent pericarditis. Currently, causes include thoracic surgery, chemotherapy, immunosuppression, and also hemodialysis, as well as extension from pneumonia and also empyema. Presentation is typically acute with high fevers, chills, night sweats, and dyspnea, yet the classic findings of chest ache or friction rub space rare. Cardiac tamponade is common (42% come 77% of patients in selected series), and also mortality is high.

If purulent pericarditis is suspected, hospital admission, treatment through intravenous, broad-spectrum antibiotics and also urgent drainage is recommended. Result on pericardial fluid analysis include a high protein level (>6 g/dL), a short glucose level (3).3

Tuberculous Pericarditis
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Figure 3: Click come Enlarge
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R and V1 leads and PR depression elsewhere.">
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Tuberculous pericarditis occurs in 1% to 2% of situations of pulmonary tuberculosis. It continues to be the leading reason of pericarditis in some developing countries. Immunocompromised or person immunodeficiency virus (HIV)‑positive patients are at raised risk.4 Nonspecific symptom such together dyspnea, fever, chills, and night sweats build slowly, and also a friction obstacle or chest ache is often absent. A patient v suspected or diagnosed pericardial tuberculosis should be hospitalized and also antituberculous therapy started promptly.

Analysis of the pericardial liquid shows high details gravity, very high protein level (often >6 g/dL), and also predominantly lymphocytic cells. A pericardial biopsy v acid-fast bacilli polymerase chain reaction trial and error is encourage for all patients through suspected tuberculous pericarditis. However, a regular pericardial biopsy does no exclude the diagnosis.

Uremic and Dialysis-Associated Pericarditis

Uremic pericarditis occurs in 6% to 10% of patients with progressed renal failure prior to hemodialysis is initiated; blood urea nitrogen levels commonly exceed 60 mg/dL. The common ST-segment elevation on the ECG generally is absent. A big hemorrhagic effusion assisted in by impaired platelet role may occur, back tamponade is rare. Alternatively, a serous pericardial effusion connected to liquid overload might occur. With both forms, initiation or intensification the hemodialysis is indicated, typically leading to development in 1 to 2 weeks.5,6

Pericarditis complying with Myocardial Infarction

Post-MI pericarditis is a usual complication (25%–40% the patients v MI) and also occurs early, in ~ 3 come 10 days after the MI. Its breakthrough correlates through the level of necrosis, is more common with anterior 보다 inferior infarcts, and also is linked with a higher 1-year mortality rate as well as a higher incidence the congestive love failure.7

The diagnosis the post-MI pericarditis needs symptoms or a new pericardial friction rub; a pericardial effusion alone is nonspecific. In addition to the usual ST key seen through acute pericarditis that may be daunting to identify from the yes, really MI in this setting, result on the ECG space persistently hopeful T waves much more than 2 work after MI or normalization of previously inverted T waves.8

Post-Cardiac Injury Syndrome

Dressler"s syndrome typically occurs 2 come 3 weeks after ~ MI or open up heart surgery. One autoimmune component including sensitization come myocardial self-antigens at the moment of infarction is thought to be responsible. The completely expressed syndrome is composed of pleuritic chest pain, fever, leukocytosis, and also a pericardial friction rub. Pleural effusions or pulmonary infiltrates might be seen.9

Malignancy

Pericarditis linked with malignancy is caused greatly by metastatic disease. Pericarditis is common in metastasized bronchogenic or breast carcinoma, Hodgkin"s disease, and also lymphoma (Figure 3); that is rarely in major mesothelioma and angiosarcoma. Diagnosis is based on analysis of pericardial fluid cytology, which has actually a sensitivity ranging from 70% come 90% and a specificity that 95% to 100%.2

Radiation Pericarditis

Recent or far mediastinal radiation can reason pericarditis at any time from weeks to month after the exposure.

Traumatic Pericarditis

Sharp or blunt trauma (Figures 4 and also 5) and invasive cardiac procedures such as electrophysiological ablation procedures, cardiac diagnostic, or interventional catheterization have actually been linked with pericardial irritation and inflammation.

Diagnosis

The diagnosis of acute pericarditis continues to be a clinical one based upon history, physical examination, ECG and the echocardiogram. Various other imaging studies, consisting of computed tomography (CT) and magnetic resonance imaging (MRI) might be provided in selected instances to investigate the pericardium.10

Electrocardiography

The ECG in acute pericarditis has 4 consecutive stages (Table 1). Stage 1, characterized by diffuse concave-upwards ST elevation and PR segment deviation in the direction opposite indigenous the p polarity, is the most advantageous stage for the diagnosis the acute pericarditis (Figure 6). The distinction between pericarditis and also acute MI is daunting at times, but there exist several useful electrocardiographic ideas (Table 2).11 Troponin levels may be elevated in up to 50% the patients v pericarditis but in the lack of myocarditis, the prognosis remains unchanged.12


Table 1: stages of Acute Pericarditis through ElectrocardiographyStageTimeST SegmentT WavePR Segment
1HoursDiffuse elevationUprightLeads aVR, V1: elevationAll others: depression
2DaysResolutionFlatteningResolution
3Days-weeksInversion
4Days-weeksUpright

Table 2: Electrocardiographic Differentiation the Acute Pericarditis and Myocardial InfarctionParameterAcute PericarditisAcute Myocardial Infarction
ST elevationDiffuse in I, II, and also IIIOriginating native S waveConcave upwardsLead V6: ST-T amplitude >0.24 mmFocal—vascular territoryOriginating native R waveConvex upwards
ST depressionLead aVR onlyPresent; reciprocal transforms to ST key according come territory
PR segmentLeads aVR, V1: key frequentRare changes if atrial infarction is present

Blood Tests

Testing should incorporate a complete blood count, markers of inflammation consisting of erythrocyte sedimentation price and/or C-reactive protein, markers of myocardial ischemia (troponins/CK-MB) come assess for myopericarditis, and assessment of renal function. Relying on presentation and clinical evaluation, added blood trial and error may be crucial such as viral titers, blood cultures, thyroid-stimulating hormone, antinuclear antibodies, HIV serology, or QuantiFERON-TB assay.

Chest Radiography
Figure 7A: Click to Enlarge

The chest radiograph might be completely normal unless there is a pericardial effusion resulting in cardiomegaly (Figure 7A-B) or there are alters caused by an underlying disease.

Echocardiography

Trans-thoracic echocardiography (TTE) is supplied to detect and evaluate because that pericardial effusion and also any concomitant cardiac disease. Evaluate of local wall movement abnormalities can aid differentiate acute pericarditis native myocardial ischemia. Echocardiography is crucial in the presence of hemodynamic abnormalities, history of current cardiac surgery, or if over there is a clinical uncertainty of a huge or raising pericardial effusion.

Cardiac Computed Tomography and Cardiac Magnetic Resonance Imaging

Advanced imaging modalities are increasingly used in the diagnotic assessment of patients with acute pericarditis, and also to assist guide your management. Cardiac computed tomography (CCT) is useful to assess because that loculated effusions and to advice for boosted thickness of the pericardium, return these features are no diagnostic the acute pericarditis. If over there is clinical suspicion, CCT is valuable in diagnosing the basic etiology the acute pericarditis such as in the evaluate of doubt malignancy-induced pericarditis. Inflammation the the pericardium produces characteristic alters that can be detected on cardiac magnetic resonance (CMR) imaging with really high sensitivity. Special, T2 load short-tau inversion restore (STIR) imaging is helpful for visualizing edema, when detection the a glowing pericardium on late gadolinium improvement (LGE) imaging is very sensitive for pericardial inflammation (Figure 8A-B).1,10,13

Treatment

Most situations of acute pericarditis room uncomplicated and self-limited, and also may be cure on one outpatient basis. Indications for an progressed imaging modality, hospital admission, or both include clinical skepticism of a large effusion, hemodynamic instability, major pain or various other symptoms, hesitation of a severe underlying condition, or any kind of other indications or symptoms of clinical instability or imminent deterioration. Other functions which indicate a more facility course incorporate fever >38°C, subacute onset, absence of response to at the very least one week of anti-inflammatory therapy, myopericarditis, immunosuppression, trauma, or concurrent treatment with oral anticoagulant therapy.11

Medical Management

In acute idiopathic and also viral pericarditis, the target of treatment is the resolution that pain and also inflammation. For various other etiologies that acute pericarditis treatment of the underlying an illness is the mainstay of therapy.12,14 combination therapy through colchicine and also nonsteroidal anti-inflammatory drugs (NSAIDs) is recommended. Ibufrofen 600 mg or indomethacin 50 mg every 8 hrs for one to two weeks adhered to by a steady taper till resolution that symptoms and also inflammatory markers, in mix with colchicine 0.6 mg twice everyday (0.6 mg once daily if p = 0.003).15 In the an ext recent randomized, double-blinded, placebo-controlled ICAP (Investigation on Colchicine for Acute Pericarditis) trial, a comparable reduction in recurrent pericarditis to be observed when colchicine was added to aspirin monotherapy (from 37.5% to 16.7%, p 16 usage of steroids in acute pericarditis has actually been associated with recurrence.17 The correct dosing for steroid therapy remains controversial; however, our exercise it to gift with roughly 0.5 mg/kg/day v a an extensive and sluggish taper. Just like non-aspirin NSAIDs, steroids should be avoided in post-MI pericarditis as result of their disability of scar formation and also a consequently increased incidence the myocardial wall surface rupture.

Pericardiectomy

Pericardiectomy is not suggested in the monitoring of acute pericarditis.

Outcomes

Patients through uncomplicated acute pericarditis need to have consistent follow-up after the early stage visit to ensure resolution the symptoms and also rule the end the advancement of constrictive symptoms.


Pericardial Effusion

Definition

Pericardial effusion is defined as an increased amount the pericardial fluid.

Etiology

The etiology that a pericardial effusion can frequently be deduced indigenous the clinical presentation (Box 1); because that example, in patient who existing with significant hypothyroidism, end-stage kidney failure, acute myocardial infarction, or that underwent a current invasive cardiac procedure. The relative frequency of various etiologies the pericardial effusions counts on the geography and also the patient population.18,19

Pathophysiology

The pericardial sac normally consists of up come 50 mL of fluid; it can hold 80 to 200 mL of liquid acutely, and also even approximately 2 l if the liquid accumulates slowly.

Signs and also Symptoms

Pericardial effusions may be asymptomatic unless linked with inflammation or tamponade physiology. Other symptoms arise indigenous the compression of surrounding structures (lung, stomach, phrenic nerve) or diastolic heart failure and also include chest press or pain, dyspnea, nausea, ab fullness, and dysphagia. Phrenic nerve irritation can reason hiccups.

With a tiny effusion, the physics examination is unremarkable. Bigger effusions cause muffled love sounds and, rarely, Ewart"s authorize (dullness come percussion, bronchial breath sounds, and also egophony listed below the edge of the left scapula).

DiagnosisElectrocardiography
Figure 9: Click to Enlarge

Low voltage and also electrical alternans (Figure 9) may be checked out if the effusion is big — the former as result of increased distance from the chest leads, the latter caused by swinging of the heart within the effusion. These features in mix with sinus tachycardia have to raise concern regarding the potential hemodynamic influence of the effusion and urgent assessment for tamponade physiology must be performed. Absence of hypotension need to not dissuade the clinician from a feasible diagnosis that pericardial effusion and tamponade, because hemodynamic instability normally does not take place until the patient nears circulatory collapse.

Chest Radiography

Cardiomegaly wake up if there is much more than 250 mL of liquid in the pericardial sac (Figure 7A). Displacement of the pericardial lining much more than 2 mm away from the lower heart border is finest seen top top lateral film.20

Echocardiography

Echocardiography is the key diagnostic tool used in the evaluation of pericardial effusion. A pericardial effusion causes an echo-free space between visceral and also parietal pericardium; the level of the room defines the size of the effusion (Table 3). Huge effusions can develop the picture of a swinging heart. Return echocardiography is the imaging modality of an option for diagnosing a pericardial effusion, small loculated effusions attitude a higher diagnostic challenge.


Table 3: Sizing the Pericardial Effusion by EchocardiographyParameterSmallMediumLarge
Volume (mL)500
LocalizationLocalizedCircumferentialCircumferential
Width (cm)2

Magnetic Resonance Imaging and also Computed Tomography

If there is a high level that clinical apprehension of a pericardial effusion and the TTE is nondiagnostic, different tomographic imaging need to be considered. This is specifically true for patients who have actually recently undergone open heart surgery, who commonly have echocardiographic studies with suboptimal imaging quality, and also effusions which might be loculated and also complex. Cardiac CT and MRI will also help in separating an effusion from pericardial fat, pericardial cysts and pleural effusions, all of which have the right to mimic a pericardial effusion.

Laboratory Tests

Laboratory evaluation in a patient v a pericardial effusion should incorporate a complete blood count, chemistry panel, and also erythrocyte sedimentation rate. Further experimentation should be excellent according come clinical suspicion.

Analysis of Pericardial Fluid

The early stage inspection need to assess even if it is the fluid is hemorrhagic, purulent, or chylous. A red blood cabinet count higher than 100,000/mm3 is suggestive the trauma, malignancy, or pulmonary embolism (rare). Chylous fluid implies injury come the thoracic duct by trauma or infiltration. The fluid should be sent for a cabinet count; Gram stain; culture; cytology; acid-fast bacilli; decision of glucose, protein, and also lactate dehydrogenase (LDH) levels; and details gravity. The parameters listed in Table 4 have actually a high sensitivity for distinguishing exudates versus transudates. An elevated protein level greater than 6.0 g/dL regularly indicates tuberculous, purulent, or parapneumonic effusion. An secluded increased liquid LDH level (>300 U/dL) v a normal serum LDH level is most likely caused by malignancy. A low pericardial fluid glucose level (3


Table 4: Pericardial Effusion: Exudate versus TransudateParameterExudateTransudate
CauseMalignancyRadiation
Infectious, parainfectiousUremia
Postpericardiotomy syndromeHypothyroidism
Collagen vascular diseaseTrauma
Specific heaviness (g/mL)>1.0153.00.50.61.0

LDH = lactate dehydrogenase.


Treatment

The medical monitoring of pericardial effusion is based on treating the basic cause. Effusions resulting in pretamponade or tamponade require instant drainage. Volume expansion and inotropic support might be used for hemodynamic stabilization pending drainage. In the instant postoperative setting, operation management and also open drainage space preferred due to the fact that of the high incidence of loculated effusions. Anti-coagulation must be avoided if possible.

Pericardiocentesis

Pericardiocentesis need to be performed because that diagnostic objectives if the cause of the effusion is unclear, or if malignancy or a purulent effusion is suspected. Therapeutic pericardiocentesis must be performed because that effusions amenable to percutaneous drainage the are leading to pretamponade or tamponade physiology.

Surgical Treatment

Subxiphoid pericardiostomy, also known as a pericardial window, might be done under regional anesthesia. It has a high success rate, with few complications, and recurrence the fluid buildup is rare.

Percutaneous balloon pericardiotomy is the least invasive that the surgical procedures. That is used mostly as palliative therapy for neoplastic effusions through a poor prognosis. The success rate for relieving reaccumulation that pericardial liquid is 85% come 92% in ~ 30 days. It might be carry out in the catheterization laboratory under fluoroscopy making use of a balloon-dilating catheter.

Outcomes

After drainage, follow-up echocardiography need to be carry out in every patients to dominance out reaccumulation and/or constrictive physiology.

Cardiac Tamponade

Definition

Cardiac tamponade occurs as soon as fluid buildup in the limited serous pericardial an are causes an increase in pressure, with subsequent cardiac compression and also hemodynamic compromise.

Prevalence

Of patient with huge pericardial effusions, 25% to 30% develop tamponade.21

Pathophysiology

Elevated intrapericardial press leads to steady limitation the diastolic ventricular filling, leading to lowered cardiac output.18,19

Signs and also SymptomsSymptoms

Symptoms resulting from lessened cardiac output and also congestion include dyspnea, chest discomfort, weakness, restlessness, agitation, drowsiness, oliguria, and anorexia. If the tamponade creates acutely as a complication of an acute MI (free wall rupture) or trauma, the presentation is usually catastrophic, v shock or sudden death.

Physical examination Findings

The combination of the classic findings recognized as Beck"s triad (hypotension, jugular venous distention, and muffled love sounds) wake up in just 10% to 40% that patients. Tachycardia and tachypnea space common. Pulsus paradoxus is defined as one inspiratory decline in systolic blood press of an ext than 10 mmHg resulting from compression and poor filling of the left ventricle. Pulsus paradoxus is nonspecific and insensitive and also can happen with extracardiac disease, such as significant chronic obstructive pulmonary disease or asthma.22

Diagnosis

The diagnosis that cardiac tamponade is a clinical diagnosis through echocardiagraphic comfirmation.

Electrocardiography

The ECG might be unremarkable. Abnormal findings on ECG encompass tachycardia, electrical alternans (Figure 9), short voltage, and also may encompass changes linked with acute pericarditis (Figure 6).

Transthoracic Echocardiography

Usually, a moderate-size or large pericardial effusion is present and also leads to enhancing compression and subsequent diastolic compression of the cardiac chambers, normally in the sequence appropriate atrium, appropriate ventricle, left atrium (with the lowest pressure chamber being influenced first). The many sensitive finding because that tamponade physiology on the echocardiogram is worse vena cava plethora, with lacking inspiratory collapse; yet this is not an extremely specific. Right atrial inversion for >1/3 the cardiac cycle length is the most sensitive and particular sign. Ideal ventricular diastolic reverse may additionally been seen. Other, less-specific findings incorporate excessive respiratory variations throughout the mitral valve inflow (>30%), i beg your pardon is analogous to pulsus paradoxus and the tricuspid inflow (>60%). Lacking diastolic circulation from the hepatic views suggests tamponade physiology.1,19

Right love Catheterization

The most common finding on best heart catheterization is equalization of average right atrial, ideal ventricular and also pulmonary artery diastolic, and also mean pulmonary capillary wedge pressures.

Differential Diagnosis

The symptoms of pericardial tamponade can mimic those that right-sided love failure, right ventricular infarction, constrictive pericarditis, and pulmonary embolism. However, with the usage of echocardiography and occasionally appropriate heart catheterization, these might be distinguished.

Treatment

Patients v pretamponade and also tamponade require instant hospital admission and also prompt pericardial drainage by pericardiocentesis. The drain catheter may be left in place for approximately 48 hours if drainage is slow-moving or reaccumulation likely. If follow-up echocardiography documents fluid reaccumulation, a pericardial window should be considered, because the infection risk associated with a pericardial drain increases after ~ 48 hours.19 Pending drainage, intravenous fluid expansion and inotropic support may be provided for hemodynamically unstable patients.

Pericardial Constriction

Definition

Constrictive pericarditis refers to an abnormal scarring and also loss the elasticity of the pericardium, causing impaired ventricular filling and also decreased cardiac output.

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Etiology

The frequency the different reasons of constrictive pericarditis depends on the populace and geography in question. In developed countries, cardiac surgery and idiopathic constriction room the top cause, if in certain developing countries tuberculous continues to be the number one etiology.