2Pericardium - AnatomyNormal pericardium is a fibro-serous sac which surrounds the heart and adjoining portions of the great vessels.The inner visceral layer, also known as the epicardium, consists of a thin layer of mesothelial cells closely adherent to the surface of the heart. The epicardium is reflected onto the surface of the outer fibrous layer with which it forms the parietal pericardium.The parietal pericardium consists of collagenous fibrous tissue and elastic fibrils.Between the two layers lies the pericardial space, which contains approximately 10-50ml of fluid, which is an ultrafiltrate of plasma.Drainage of pericardial fluid is via right lymphatic duct and thoracic duct.
4Function of the Pericardium 1. Stabilization of the heart within the thoracic cavity by virtue of its ligamentous attachments -- limiting the heart’s motion.2. Protection of the heart from mechanical trauma and infection from adjoining structures.3. The pericardial fluid functions as a lubricant and decreases friction of cardiac surface during systole and diastole.4. Prevention of excessive dilation of heart especially during sudden rise in intra-cardiac volume (e.g. acute aortic or mitral regurgitation).
6Pathogenesis Pathology 1) Vasodilation: transudation of fluid 2) Increased vascular permeability leakage of protein3) Leukocyte exudationneutrophils and mononuclear cellsPathologydepends on underlying cause and severity of inflammationserous pericarditisserofibrinous pericarditissuppurative (purulent) pericarditishemorrhagic pericarditis
7Clinical Features of Acute Pericarditis Idiopathic/viral* Pleuritic Chest pain* Fever* Pericardial Friction Rub3 component:a) atrial or pre-systolic componentb) ventricular systolic component (loudest)c) ventricular diastolic component* EKG: diffuse ST elevationPR segment depression
9Diagnostic Tests Echocardiogram: Pericardial effusion N.B.: absence does not rule out pericarditisN.B.: Pericarditis is a clinical diagnosis, not an Echo diagnosis!Blood tests: PPD, RF, ANAViral titersSearch for malignancyPericardiocentesis:low diagnostic yielddone therapeutically
10Treatment Pain relief analgesics and anti-inflammatory ASA/NSAID’s Steroids for recurring pericarditisAntibiotics/drainage for purulent pericarditisDialysis for uremic pericarditisNeoplastic: XRT, chemotherapy
11Pericardial Effusion Normal 15-50 ml of fluid ETIOLOGY 1. Inflammation from infection, immunologic process.2. Trauma causing bleeding in pericardial space.3. Noninfectious conditions such as:a. increase in pulmonary hydrostatic pressure e.g. congestive heart failure.b. increase in capillary permeability e.g. hypothyroidismc. decrease in plasma oncotic pressure e.g. cirrhosis.4. Decreased drainage of pericardial fluid due to obstruction of thoracic duct as a result of malignancy or damage during surgery.Effusion may be serous, serofibrinous, suppurative, chylous, or hemorrhagic depending on the etiology.Viral effusions are usually serous or serofibrinousMalignant effusions are usually hemorrhagic.
12Pathophysiology Pericardium relatively stiff Symptoms of cardiac compression dependant on:1. Volume of fluid2. Rate of fluid accumulation3. Compliance characteristics of the pericardiumA. Sudden increase of small amount of fluid (e.g. trauma)B. Slow accumulation of large amount of fluid (e.g. CHF)
13Clinical featuresSmall effusions do not produce hemodynamic abnormalities.Large effusions, in addition to causing hemodynamic compromise, may lead to compression of adjoining structures and produce symptoms of:dysphagia (compression of esophagus)hoarseness (recurrent laryngeal nerve compression)hiccups (diaphragmatic stimulation)dyspnea (pleural inflammation/effusion)
14Physical Findings Physical Findings: Muffled heart sounds Paradoxically reduced intensity of rubEwart's sign:Compression of lung leading to an area of consolidation in the left infrascapular region (atalectasis, detected as dullness to percussion and bronchial breathing)
16Cardiac TamponadeFluid under high pressure compresses the cardiac chambers:acute: trauma, LV rupture – may not be very largegradual: large effusion, due to any etiology of acute pericarditis
17CardiacTamponade -- Pathophysiology Accumulation of fluid under high pressure:compresses cardiac chambers & impairsdiastolic filling of both ventricles SV venous pressures CO systemic pulmonary congestionHypotension/shock JVD ralesReflex tachycardia hepatomegalyascitesperipheral edema
18Tamponade-- Clinical Features Symptoms:Acute: (trauma, LV rupture)profound hypotensionconfusion/agitationSlow/Progressive large effusion (weeks)Fatigue (CO)DyspneaJVDSigns:TachycardiaHypotensionrales/edema/ascitesmuffled heart soundspulsus paradoxus
19Pulsus ParadoxusIntrapericardial pressure (IPP) tracks intrathoracic pressure.Inspiration:negative intrathoracic pressure is transmitted to the pericardial space IPP blood return to the right ventricle jugular venous and right atrial pressures right ventricular volume interventricular septum shifts towards the left ventricle left ventricular volume LV stroke volume blood pressure (<10mmHg is normal) during inspiration
20Pulsus Paradoxus Exaggeration of normal physiology > 10 mm Hg drop in BPwith inspiration
21Tamponade -- Diagnosis EKG: low voltage, sinus tachycardia,electrical alternansEchocardiographypericardial effusion(r/o other etiologies in dif dx)RA and RV diastolic collapse
22Right Heart Catheterization Catheterization Findings:Elevated RA and RV diastolic pressuresEqualized diastolic pressuresBlunted “y” descent in RA tracingy descent: early diastolic filling (atrial emptying) BP and Pulsus paradoxusPericardial pressure = RA pressure
23Jugular venous pressure waves Normal JVP contours (1) A-wave 1) results from ATRIAL contraction 2) Timing - PRESYSTOLIC 3) Peak of the a-wave near S1(2) V-wave 1) results from PASSIVE filling of the right atrium while the tricuspid valve is closed during ventricular systole (Remember the V-wave is a "V"ILLING WAVE) 2) Large V-waves on the left side of the heart may be seen with mitral regurgitation, atrial septal defect, ventricular septal defect. The v-wave in the jugular venous pulse reflects right atrial events. To see the v-wave on the left side of the heart Swan-Ganz monitoring is needed 3) timing - peaks just after S2(3) X-descent 1) results from ATRIAL RELAXATION 2) timing - occurs during ventricular systole, at the same time as the carotid pulse occurs(4) Y-descent 1) results from a FALL in right atrial pressure associated with opening of the tricuspid valve 2) timing - occurs during ventricular diastole(5) Generalizations 1) the A-wave in a normal individual is always larger than the V-wave 2) the X-descent is MORE PROMINENT than the Y-descent
24RA Pressure Tracing a wave: atrial contraction v wave: passive filling of atria duringventricular systole with mv/tv closedy descent: early atrial emptying with mv/tvopen (early passive filling of ventricle)Tamponade:blunted y descent (impaired rapid ventricular filling due to compression by high pericardial pressure)
27Constrictive Pericarditis Late complication of pericardial diseaseFibrous scar formationFusion of pericardial layersCalcification further stiffens pericardiumEtiologies:any cause of pericarditisidiopathicpost-surgerytuberculosisradiationneoplasm
28Pathophysiology Rigid, scarred pericardium encircles heart: Systolic contraction normalInhibits diastolic filling of both ventricles SV venous pressures CO systemic pulmonary congestionHypotension/shock JVD ralesReflex tachycardia hepatomegalyascitesperipheral edema
30Kussmaul’s Signinspiration: intrathoracic pressure, venous return to thoraxintrathoracic pressure not transmitted though to RV no pulsus paradoxus!no inspiratory augmentation of RV filling (rigid pericardium)intrathoracic systemic veins become distendedJVP rises with inspiration (normally falls)
32Cardiac Catheterization Elevated and equalized diastolic pressures (RA=RVEDP=PAD=PCW)Prominent y descent: “dip and plateau”:rapid atrial emptying rapid ventricular fillingthen abrupt cessation of blood flow due to rigid pericardium
33Constriction vs. Restriction Similar presentation and physiology, important to differentiate asconstriction is treatable by pericardiectomyMajority of diseases causing restriction are not treatable