Pericarditis Flashcards
Describe the pericardium
Acts as a protective covering for the heart
Consists of an outer fibrous pericardial sac and inner serous pericardium.
What layers make up the inner serous pericardium
Inner visceral epicardium
50 ml Serous fluid
Outer parietal pericardium
Describe the inner visceral epicardium
Single cell layer adherent to myocytes of the epicardium, that lines the heart and great vessels
What is purpose of the serous fluid of inner serous pericardium?
Acts as a lubricant to allow two surfaces to move over each other easily
What makes up the outer parietal pericardium
mainly collagen and elastin fibres (with no cells)
Pros of pericardium
It promotes cardiac efficiency by limiting dilation, maintaining ventricular compliance and distributing hydrostatic forces
Aids atrial filling by creating a closed chamber, reduces external friction and acts as a barrier against infection and extension of malignancy
Anatomically fixes the heart to the sternum, diaphragm and costal cartilages
Initially stretchy but becomes stiff at higher tension
If the proximal segment (ascending) of the aorta is ruptured, where will it bleed into?
The pericardial space
Result in a cardiac tamponade if even a small volume of fluid is added to this space.
Which heart chamber mainly lies outside the pericardium
Left atrium
Define acute pericarditis
Acute inflammation of the pericardium, with or without effusion
Acute pericarditis epidemiology
Majority are idiopathic and most commonly seen in the young, previously healthy patient
Occurs in men more than women
Occurs in adults more than children
Acute pericarditis aetiology - infectious causes
Viral (common) - Enteroviruses (e.g. coxsackieviruses & echoviruses) or Adenoviruses
Bacterial - Mycobacterium tuberculosis
Fungal (rare) - Histoplasma spp. (generally in immuno-compromised patient)
Acute pericarditis aetiology - non-infectious causes
Autoimmune (common):
• Sjorgrens syndrome
• Rheumatoid arthritis
• SLE
Neoplastic; secondary metastatic tumours (generally lung or breast cancer)
Dressler’s syndrome - post cardiac injury syndromes
Traumatic and iatrogenic
Acute pericarditis aetiology - non-infectious causes - examples of early onset traumatic causes
Direct injury - penetrating thoracic injury or oesophageal perforation
Indirect injury - non-penetrating thoracic injury or radiation
Acute pericarditis aetiology - non-infectious causes - examples of delayed onset traumatic causes (common)
Pericardial injury syndromes (common)
Iatrogenic trauma e.g. coronary percutaneous intervention or pacemaker lead insertion
Acute pericarditis pathophysiology
Pericardium becomes acutely inflamed, with pericardial vascularisation and
infiltration with polymorphonuclear leukocytes
A fibrinous reaction frequently results in exudate and adhesions within the
pericardial sac, and a serous or haemorrhagic effusion may develop
Clinical presentation of Acute pericarditis
Chest pain
Dyspnoea
Cough
Hiccups (due to phrenic involvement)
Pericardial friction rub present on auscultation
Fever and lymphocytosis (increase in lymphocytes) if due to virus or bacteria
Tachycardia
Describe chest pain from acute pericarditis
- Severe
- Sharp & pleuritic (without constricting crushing character of ischaemic pain)
- Rapid onset
- Worse on inspiration or lying flat - relieved by sitting forward
- Left anterior chest or epigastrium
- Radiates to arm, more specifically the trapezius ridge (has co- innervation with the phrenic nerve) - whereas a STEMI would be arms, jaw & teeth
Differential diagnosis of acute pericarditis
- Angina
- MI (most important to rule out)
- Pleuritic pain
- Pulmonary infarction
- Pneumonia, GI reflux, peritonitis & aortic dissection