Pericardial Disease Flashcards
(32 cards)
The pericardium is composed to two layers what are they?
visceral and parietal pericardium
What is the visceral pericardium?
- Membrane composed of single layer mesothelial cells
- Similar to pleural and peritoneal cavity
- Adherent to the epicardial surface of the heart
What is the parietal pericardium?
– Fibrous layer 2mm in thickness
– Contains collagen and elastic fibers
– Collagen: Low levels of stretch –>Wavy bundles & High levels of stretch–> Straight bundles
– Reflects the mechanical characteristics of the pericardial tissue
What happens to the pericardium near the origin of the great vessels?
visceral pericardium reflects back near the origin of the great vessels and becomes the parietal pericardium
What is the pericardial space?
- space between the visceral and parietal pericardium
– Contains ≈ 50ml serous fluid
– Part of posterior wall of the left atrium is extrapericardial
The pericardium is stabilized by ligamentous attachments?
– Diaphragm
– Sternum
– Spine
Where do the phrenic nerves run?
enveloped by parietal pericardium
What does phrenic nerve irritation cause?
hiccups
What are the major functions of the pericardium?
- Maintains heart position
- Lubrication of visceral and parietal layers
- Barrier to infection
- Prostaglandin secretion
- Restraining effect on cardiac volume
How does the pericardium restrain cardiac volume?
– Mechanical properties of pericardial tissue
– Small reserve volume
– Tensile strength similar to rubber
– Normal cardiac volume: More elastic –> stretches easily
– Increase cardiac volumes: Pericardial tissue becomes stiff –> resistant to further stretch
Acute vs chronic cardiac dilatation effects on pericardium?
- Chronic cardiac dilatation results in adaptations to accomodate increased cardiac volumes.
- Pericardial growth occurs in response to chronic stretch
- Pressure volume curve shifts to the right with decreased slope
- Slowly accumulating pericardial effusions can become very large before becoming symptomatic (Hypothyroidism)
What is the major cause of acute pericarditis?
Majority (80-90%) of cases “Idiopathic” most of which are assumed to be viral but that rarely alters management
What are some of the infectious causes of acute pericarditis?
- viral: echo, coxsackie, adenovirus, CMV, HIV
- bacterial: pneumococcus, strep, staph, myclplasma, haemophilus
- mycobacteria
General categories of possible causes of pericarditis?
idopathic infectious radiation blunt & penetrating trauma connective tissue disorders Post MI
Symptoms of acute pericarditis include:
– Chest pain
– Almost always present
– Usually moderate to severe in intensity
– Better sitting forward, worse when lying down
– Sharp, pleuritic like
– Substernal, epigastric, left chest, trapezius muscle area
– Can be associated with dyspnea, cough, hiccups, fever
Differential diagnoses for chest pain in pericarditis:
– Pneumonia with pleurisy (Pleuro-pericarditis) – PE with infarction – Costochondritis – GERD – Intraabdominal processes – Aortic dissection – Pneumothorax – Herpes Zoster (Before skin lesions) – Myocardial ischemia/infarction
Physical exam findings for acute pericarditis?
- Uncomplicated acute pericarditis
- Fever, tachycardia, anxiety (Not always present)
- Pericardial friction rub
What is pericardial friction rub?
– Contact between parietal and visceral
– Best heard at left LSB, with patient leaning forward
– Dynamic (Similar to ECG findings)
– Disappearing/returning over short periods of time
What are the ECG findings for acute pericarditis?
- ECG changes are dynamic
- ST segment elevation: Diffuse (Not in leads AVR,V1), Occasionally focal (Trauma and post-op), ST segment concave & No reciprocal changes
- Upright T waves
- PR depression (Elevation in AVR)
- PR depression may be only ECG finding
What do you see on chest radiograph for acute pericarditis?
– Usually normal in uncomplicated pericarditis
– Abnormal CXR findings consided secondary to disorders: Pleural effusions, Infilrates, Mass lesions, CHF
What do you see on an echo of acute pericarditis?
- Small otherwise clinically silent effusion not uncommon
- Large effusion consider secondary disorder
- LV function assessment in pt with myocarditis
- Check for WMA if ischemia/MI suspected
Treatment course for acute pericarditis?
– Uneventfull recovery in 70% - 90% of patients
– Treatment with NSAIDS (Post MI use aspirin)
– Colchicine With NSAIDS or Alternative to NSAIDS, Decreased incidence of recurrent pericarditis
– Steroids: Rapid response to treatment but may encourage relapses (Avoid if possible)
How does colchicine work?
- Exact mechanism of colchicine action not fully understood.
- Related to its capacity to disrupt microtubules.
- Inhibits the process of microtubule self-assembly
- This takes place either in the mitotic spindle or in the interphase stage
What cells does colchicine specifically work against?
Colchicine has preferential concentration in leukocytes where it Inhibits movement of intercellular granules and the secretion of various substances causing significant anti-inflammatory effect
