Pericarditis, Effusion and Tamponade Flashcards
What is the anatomy and function of the pericardium?
2x layers:
- Outer = fibrous
- Inner = serous
Contained between is serous fluid
- c. 50mls
both layers are innervated by the phrenic nerve
- C4 (C3 + C5)
The pericardium:
- Limits dilatation, aids atrial filling
- Protects the heart by reducing external friction and a barrier to external malignancy
- Fixes the heart anatomically with ligaments
What is the aetiology of pericarditis?
Viral infection:
- Most common
- e.g. Coxsackieviruses, echoviruses, influenza viruses, adenoviruses, mups, HIV, hepatitis
Other infections:
- TB - most common cause of constrictive pericarditis in developing world
- Other bacterial, fungal and parasitic causes
Inflammatory conditions:
- RA
- SLE, scleroderma, sarcoidosis, granulomatosis with polyangiitis etc.
Metabolic:
- Uraemia (so patients with CKD pre-dialysis)
- Hypothyroidism
Cardiovascular:
- MI - either during (transmural infarcts or persistent ST elevation = common) or post (Dressler’s syndrome)
- Aortic dissection
Neoplastic:
- Relatively common
- Metastatic disease (lung, breast and haematological)
Drugs:
- Doxorubicin, cyclophosphamide
- Methyldopa, isoniazid, hydralazine (all can cause drug induced SLE)
- Small pox vaccine
- Dantrolene
- Phenytoin
- Minoxidil
- Irradiation
Idiopathic = Most common overall; a portion of these will likely be due to undiagnosed viral causes
What is the pathophysiology of pericarditis?
Inflammation of the pericardium:
- Can be fibrinous (dry) OR
- Effusive - serous, haemorrhagic or purulent
Acute:
- <4-6wks
Chronic:
- Chronic effusive pericarditis - due to long term accumulation of fluid in pericardium
- Chronic constrictive pericarditis - a thickening of the pericardium and symptomatic even after drainage of fluid
Pathogenesis suggests a clinical continuum initiated by acute pericarditis and progressing through pericardial effusion, chronic effusive pericarditis, effusive-constrictive pericarditis to chronic constrictive pericarditis
What is Dressler’s syndrome?
An autoimmune response to myocardial tissue
- Antimyocardial antibodies (though not known if these are the cause or consequence of the syndrome)
1-6 wks following an MI; can be as late as 3/12
c.1% of patients post MI
Can follow a relapsing course
How does acute pericarditis present?
Chest pain
- Usually central
- Sudden onset
- Sharp/stabbing (but may be more dull and steady like an MI)
- May radiate to L neck or trapezius ridge
- Exacerbated by coughing, breathing, lying down
- Alleviated with sitting up or leaning forward
Breathlessness
- Also exacerbated by the same things as above
Palpitations
Other symptoms depending on cause
- E.g. fever, cough - from a viral infection
What are the examination findings in acute pericarditis?
Pericardial friction rub:
- Classical/most important
- Specific but not that sensitive
- Heard best with the diaphragm of stethoscope at the L sternal border, when supine and at the end of an exhalation (not held as noise made by movement)
- Squeaky or scratching sound resembling leather surfaces rubbing against each other or boots walking over fresh snow
Triad of pericardial tamponade:
- Tamponade = compression of heart due to fluid in sac
- Hypotension
- Muffled heart sounds
- Jugular venous distension
Tachycardia
How do you investigate acute pericarditis?
ECG:
- Characteristic changes
Bloods:
- Troponin - to rule out MI (but may be raised if myocardial concurrent myocarditis)
- FBC - leukocytosis if infection
- ESR/CRP - raised
- U+E - uraemia?
- TFT - hypothyroidism?
- Rheumatoid factor + other autoimmune biomarkers
- HIV etc. serology
Echo:
- Important to detect pericardial effusion
CXR:
- Usually normal, sometimes cardiomegaly, signs of pleural effusions, malignancy, TB etc.
Chest CT/cardiac MRI:
- More detail of pericardial involvement, thickness, fluid volume etc
Pericardialcentesis/biopsy:
- Fluid sent for MC+S
What are the characteristic ECG changes in acute pericarditis?
4 Stages:
- (though <50% progress through all 4 stages and evolution may not follow classical pattern)
- *1) Occurs over <14 days
- Widespread saddle-shaped/concave ST elevation AND PR depression in most of limb leads (I, II, III, aVL, aVF) and precordial leads (V2-6)
- Reciprocal ST depression and PR elevation in lead aVR (+/- V1)
- Sinus tachy = common due to pain/pericardial effusion
2) Occurs over 1-3 wks
- Normalisation of ST changes
- Generalised T wave flattening
3) Occurs over 3-several wks
- Inversion of T waves
4) Several weeks +
- Normalisation of ECG
What are they key steps to differentiate acute pericarditis from STEMI?
- Is there ST depression in a lead other than AVR or V1? This is a STEMI
- Is there convex up or horizontal ST elevation? This is a STEMI
- Is there ST elevation greater in III than II? This is a STEMI
- Now look for PR depression in multiple leads… this suggests pericarditis (especially if there is a friction rub!)
Serial ECG is very useful if there is diagnostic uncertainty as things may become clear with time (though should not substitute good clinical judgement)
What are the key diagnostic factors for acute pericarditis?
At least 2x of the following:
- Chest pain
- Pericardial rub
- ECG changes consistent with pericarditis
- (at least a) small pericardial effusion on echo
+/- presence of risk factors
How do you manage acute pericarditis?
NSAIDs:
- Ibuprofen = first choice
(+ PPI if needed)
+ Colchicine:
- If unresponsive or persistent
+ Corticosteroids if still unresponsive
Treat underlying cause if known
- e.g. TB treatment
For massive effusion +/- tamponade:
- Therapeutic pericardiocentesis
How does chronic pericarditis present?
Effusive:
- Dyspnoea, esp on exertion
- Chest pain
- Syncope, light-headedness
- Palpitations
- Possible cough, hoarseness, hiccough
- Hypotension + raised JVP + diminished heart sounds (= Beck’s triad/ acute compression triad)
Constrictive:
- Gradual onset (usually months)
- Signs of right heart failure e.g. dyspnoea, peripheral oedema, JVP elevated +/- doesn’t fall with inspiration, pulsatile hepatomegaly
How do you investigate chronic pericarditis?
CXR:
- Calcification of pericardium strongly suggests constrictive pericarditis in patients with heart failure
Echo:
- Can help differentiate from restrictive cardiomyopathy
MRI:
- Can estimate thickness of pericardium
Pericardial biopsy:
- esp. if infective, malignant or granulomatous causes suspected
How do you mange chronic pericarditis?
Effusive:
- Catheter pericardiocenteis or surgical drainage
- Pericardectomy
Constrictive:
- Some causes are reversible through anti-inflammatory meds so if stable enough can trial
- If ineffective, gold standard is complete pericardectomy
What are pericardial effusions?
Collections of fluid in the pericardial space:
- Transudate (hydropericardium), exudate (pyopericardium) or haemopericardium
Can be of varying sizes and presentation will depend on how quickly effusion accumulates
