11 21 2014 Pericardium Flashcards
Layers of the peridcardium
- visceral pericardium– adheres to the outer wall of the heart and is reflected back on itself to make:
- Parietal pericardium at the level of the great vessels – tough fibrous outer layer
what are the functions of the pericardium
- fixes heart within mediastinum and limits its motion
- prevents extreme dilation of the heart during sudden rise in intracardiac volume
- function as a barrier to limit spread of infection from adjacent lungs
What is pericarditis?
inflammation of the layers of the pericardium.
What are some of the infections causes of pericarditis?
Idiopathy/viral: echovirus/ coxsackie virus B
Tuberculosis : immunosupressed (burn patients, diabetics..etc)
Pyogenic bacteria: pneumococcus, staph, strep, mycoplasm, lyme HIV (common manifestation of CVD in patient)
What are some non-infections causes of pericarditis?
- postmyocardial infacrtion
1. 1-3 days (acute) = inflammation – friction rub may be heard
2. 2weeks– moths : Dressler syndrome: antibodies against pericardium ( transmural infarct) - Uremia (complications of renal failure)
- neoplastic : tumor involvment. Usually metastasis from lungs, breast, lymph.
- Radiation-induced: local inflammation = pericardial effusions
- CT disease: systemic lupus erythematosus (SLE), rheumatoid arthritis -Drug induced : procainamide, hydrazine
Clinical features (symptoms) of acute pericarditis
Pleuritic chest pain ( alleviated by sitting and leaning forward)
- sharp, pleuritic and positional
- retrosternal area and left precordium and may also radiate to back and ridge of the left trapezius muscle
Dyspnea –relucance of patient to break properly.
Fever
Pericardial friction rub: movement of inflamed pericardial layers. Can hear it better when patient leans forward.
- scratchy
- ventricular systole, early diastolic filling, atrial constriction
What are some ECG abnormalities associated with Acute pericarditis?
diffuse ST segment elevation in almost all of the ECG leads (except V1 and AVR)
PR depression in several leads
Treatment of acute pericarditis?
1 Viral
- Bacterial/fungal
- Neoplastic
VIRAL: - analgesic and anti-inflammatory drugs (aspirin, ibuprofen, and other NSAIDs) - Colchicine : drug with anti-inflammatory properties usually used to treat gout.
Suspected bacterial -ID etiology and catheter drainage and antibiotics
Neo-palstic = palliative because it usually means heavy metastasis.
Management of acute pericarditis if it is relapsing pericarditis:
Relapsing: - NSAIDs, colchinine Prednisone
How much fluid can the pericardium usually hold?
15-50mL of pericardial fluid – made from mesothelial cells that line the serosal layer
What 3 factors determine whether a pericardial effusion remains clinically silent or whether symptoms of cardiac compression ensue:
- volume of fluid 2. rate of fluid accumulation 3. compliance characteristics
What are some causes of acute pericardital effusion?
SUDDEN INCREASE IN PERICARDIAL Volume
- Aortic Dissection rupture
- chest trauma : stab wound or a gunshot wound
Clinical features of a large pericardial effusion
- dull constant ache in the left side of the chest
- dull soft heart sounds
- reduced intensity of a friction rub
- Ewart sign = dullness over posterior left lung
- Compression on nearby structures:
- dysphagia : pain swallowing (compression of esphagus)
- dyspnea : lung compression
- hoarseness of breath : compression on recurrent laryngeal
- Hiccups: compression on phrenci nerve stimulation
What are some ECG abnormalities seen with a pericardial effusion?
Alternating QRS amplitude = electrical alternans
-due to a constantly changing electrical axis as the heart swings from side to side within percardial volume.
What would you see if you had a pericardial effusion on an CXR and an echocardiography?
CXR: see effusion if more than 250mL accumulated; cardiac silhouette enlargement
Echocardiography: identify pericardial collections as small as 20mL
-quantify the volume of pericardial fluid
Treatment of pericardial effusion:
- undelrying disorder (ex. dialysis for uremic effusion)
- pericardiocentesis : needle to remove fluid from pericardium
Etiology of Cardiac Tamponade:
- Acute Pericarditis that progresses to cardiac tamponade
- neoplastic, post-viral, and uremic - Acute hemorrhage
- rupture of LV wall after an MI
- blunt trauma to chest or penetrating wound to chest
- complication of dissected aortic aneurysm
Pathophysiology of Cardiac Tamponade?
acute accumulation of pericardial fluid causes high pressure –> constricts the cardiac chambers
- severely limits filling.
- Decrease in stroke volume due to limited LV filling
- decrease in CO
- lead to activation of the nervous system
- inadequat perfusion to orangs = shock, death
*Diastolic pressure within each chamber becomes elevated and equal to pericardial pressure.
What are some Clincal features (symptoms) of Cardiac Tamponade?
- hypotension due to decreased SV and CO.
- Reflex tachycardia due to above
Another symptom of cardiac tamponade is high venous pressures (pulmonary and systemic):
- JVP
- Hepatomegaly asciteis
- peripheral edema
- Pulmonary rales
- dyspnea
What are some things one may find during physical examination in a patient with cardiac tamponade?
- JVP
- systemic hypotension
- sinus tachycardia
- “small, quiet heart”
- pulsus paradoxus: decrease in systolic pressure (greater than 10mmH) during inspiration
- Blunted y descent
What are some tests/technology that would help you determine whether a cardiac effusion –> cardiac tamponade?
- Echocardiography : indicator of high-pressure pericardial fluid is compression of th RV and RA during diastole.
- * differentiate between cardiac tamponade and other causes of low cardiac output (ventricular dysfunction) - Cardica catherization: measurement of intracardiac and intrapericardia pressures
treatment of cardiac tamponade?
- Removal of high-pressure fluid is the only intervention
- needle below xiphoid space (to avoid hitting coronary arteries) to drain fluid= pericardiocentesis
IF Tamponade reoccurs after pericardiocentesis then removal of part or all of pericardium is required to prevent reacumulation of the effusion
Constrictive pericardium pathogenesis?
Pericardial effusion or pericarditis (idiopathic) that gradually accumulates fluid slowly.
- Pericardium can accomodate a larger volume without marked elevation of intrapericardial pressure.
- fluid undergoes organization: fusion of the pericardial layers**
= fibrous scar formation and calcification of adherent layers = further stiffening of pericardium.
Rigid scarred pericardium encircles th heart and inhibitss normal filling of the cardiac chambers
what happens to the capability of the RV to fill and what are the consequences to the systemic venous pressures?
RV expands and quickly reaches the limit imposed by constrictive pericarditis
-further fillinging of RV is arrested and VR in right heart ceases
= increase in systemic venous pressure
= signs of right-side heart failure
Clinical features of Constrictive Pericarditis:
- reduction in CO = fatigue, hypotension, reflex tachycardia
- elevated systemic venous pressures: JVP, hepatomegaly with ascities, peripheral edema.
- Dyspnea ( due to pulmonary rales)
Physical exam findings on patient with constrictive pericarditis?
Kussmaul sign: jugular veins become more distended during inspriation ( opposite of normal physiology)
- increased venous return during inspiration cannot be accomadated by heart so it gets backed up.
early diastolic knowck may follow the second heart in patients with severe calcified pericardium
-sudden cessation of ventricular diastolic filling imposed by rigid pericardial sac.
What would you see on a chest radiograph in someone with constrictive pericarditis?
How about on ECG?
- normal or enlarged silhouette
- calcificatin of pericardium in some patients
ECG:
- nonspeciic ST and T-wave abnormalities; atrial arrhythmias are common
What can be seen on echocardiographic as evidence for constrictive pericarditis?
pericardium is visually thickened
Ventricular cavities are small and contract vigorously, but ventricular filling terminates abruptly in early diastole.
Doppler also reflect abnormal pattern of diastolic filling.
Constrictive pericarditis can be confrmed with what procedure and it demonstrates what 4 key features?
cardiac catherization
- elevation and equalization of diastolic pressures in each of the cardiac chambers
- early diastolic “dip and plateau” of RV and LV pressure tracings
- sudden cessation of filling - prominant y -decent in RA pressure tracing (after tricuspid valve opens, the RA quickly empties into the RV)
- lower LV systolic pressure
- reduced LV volume allows interventriucular septum to shift woard left ~ enlarges RV (Ventricular interdependence)
- increase in RV filling augements systolic pressure during inspiration
