8/21- Pericardial Diseases Flashcards
What are the layers of the pericardium?
- Fibrous (mostly acellular)
- Serous: parietal layer
- Serous: visceral layer (epicardium)
Pericardial cavity is between the parietal and visceral portions of the serous pericardium; normally ~50cc of fluid
What are the 4 basic functions of the pericardium?
- Restraining effect on cardiac volume
- Maintain optimal P-V relationships in the cardiac chambers
- Favor ejection of similar stroke volumes for both ventricles
- Shield heart against infections from contagious structures
What is a pericardial effusion?
The buildup of fluid within the pericardial space
What are some causes of pericardial effusions?
- Idiopathic (most common)
- Infectious; viral, bacterial, mycobacteria, fungal, protozoal
- Immune/inflammatory: CT disease, arteritis, inflammatory bowel disease, early/late post-MI, drug induced
- Neoplastic disease
- Radiation
- Thyroid disease
- ESRD (end stage renal disease)
- Early post cardiac surgery
- Trauma
- Congenital (e.g. born without pericardium)
- Hemopericardium: trauma, post MI free wall rupture, device or procedure related, dissecting aortic aneurysm
What is cardiac tamponade?
What determines the hemodynamic consequences?
- Reduces the volume of the cardiac chambers such that cardiac output begins to decline
- Continuation from an effusion causing minimally detectable effects to full-blown circulatory collapse
Hemodynamic consequences determined by:
- Intrapericardial pressure
- Ability of the heart to compensate for elevated pressure
What is the body’s compensatory response to cardiac tampanode/rapidly accumulating pericardial fluid?
- Increased adrenergic stimulation and PS withdrawal (tachycardia and increased contractility); done to maintain CO
- In terminal stages: depressive reflex = paradoxical bradycardia (about to code)
Hemodynamics of cardiac tamponade?
- Abrupt rise of pericardial pressure
- Rise of atrial and ventricular diastolic pressures (intracardiac pressures)
- Equalization of intracardiac pressures (not normal)
- Loss of y-descent
- Pulsus paradoxus
Describe the negative components of the atrial pressure waveform?
What can indicate pathology?
x-descent: seen when atria are actively relaxing; ventricular contraction
y-descent: occurs during ventricular systole
- blunted in cardiac tamponade because of constriction by pericardial fluid
What is shown here?
Pulsus paradoxus
- “exaggerated inspiratory drop in SBP > 10 mmHg”
- Hallmark of cardiac tamponade!
(Variation in systemic blood pressure and pulse due to constriction by pericardial fluid of the heart)
- Filling of the L and R sides of the heart become dependent on each other (not normal)- “intra-ventricular dependence”
- During inspiration, negative pressure typically helps right side of the heart fill; in tamponade, filling of the R causes septum to bulge into L side of the heart and decreases SV and CO of L side
(IV shift into LV -> reduced LV EDV -> SV decreases (Frank-Starling law) -> SBP decreases)
- See decrease in BP and pulse during inspiration in cardiac tamponade
Symptoms and PE of cardiac tamponade?
- Pericardial chest pain
- Dyspnea/tachypnea**
- Shock
- Non-specific sense of discomfort (generalized malaise)
- Tachycardia
- Pulsus paradoxus
- Beck’s triad: hypotension, muffled heart sounds (due to fluid), elevated JVP (normal decrease on inspiration)
Is pulsus paradoxus always present in cardiac tamponade?
No
- Severe hypotension of hypovolemia prevents the rise in RV filling in inspiration
- Volume replacement often facilitates its detection
What is seen here?
Typical of cardiac tamponade/pericardial effusion
- “Electrical alternans”
- QRS varying with every other beat of the heart (due to swinging of heart with large pericardial fluid)
What is seen here?
CXR of pericardial effusion
- Very large, globular heart
- Typically, heart borders should be less than half the thoracic cavity distance
What is seen here?
Pericardial effusion by echo (diagnostic)
- Dark area on left (blood/fluid) is in the pericardial space
What is constrictive pericarditis?
- Impairment of diastolic filling due to chronic thickening and/or calcification of the pericardium
- Typically a chronic process (where cardiac tamponade was more acute)
What is seen here?
CXR and CT of constrictive pericarditis with extensive pericardial calcification
- Will see rim (light segment), which is the pericardium filled with calcium
- “Thick bright rim of calcified pericardium”
What is seen here?
Chest CT form pt with pericardial constriction showing thickened pericardium (arrows) and a left pleural effusion(*)
What is Kussmaul sign?
- More prominent neck veins during inspiration
- Distended neck veins that do NOT collapse with inspiration
How is constrictive pericarditis diagnosed?
Right heart catheterization with dip-and-plateau RV pressure
Compare and contrast cardiac tamponade and constrictive pericarditis
- Filling
- Heart sounds
- Observed in JVP/cath
