Acute pericarditis + cardiac tamponade Flashcards
Pericarditis is inflamation of the pericardium. What is the function of the pericardium?
Composed of two layers (fibrous pericardium and serous pericardium; possessing a space that contains 15-35mL of fluid), the pericardium is responsible for protecting and restraining the heart.
What is the innervation of the pericardium?
It is innervated by the phrenic nerve, and hence when inflamed, can result in severe pain.
Causes of pericarditis
- Idiopathic
-
Viral
- Coxsackie B virus
- Mumps
- Epstein-Barr virus (EBV)
- Cytomegalovirus (CMV)
- Varicella Zoster virus (VZV)
- HIV
- Dressler syndrome
- Post myocardial infarction
- Uraemic pericarditis
- (high levels of urea, due to renal disease, irritates the serous pericardium)
- Autoimmune disease
- Rheumatoid arthritis
- SLE
- Scleroderma
Epidemiology and risk factors for pericarditis
Accounts for up to 5% of presentations to the emergency appartment.
- Male
- 20-50 years of age
- Previous myocardial infarction
- Viral or bacterial infection
- Systemic autoimmune disorders
Symptoms of pericarditis
-
Chest pain
- Sudden onset, sharp, central and pleuritic
- Releif upon sitting up or leaning forward
- Exacerbated by lying flat
- May last from hours to days
- Prodromal viral illness eg upper respiratory tract infection
- Fever and myalgia
- Shortness of breath
- Peripheral oedema: suggests right sided heart failure secondary to constrictive pericarditis
Signs of pericarditis
-
Pericardial rub
- Heard at left sternal edge as the patient leans forward
- Extra heart sound of a to and fro character
- High pitched or squeaky
- Tachycardia
- Tachypnoea
Investigations for pericarditis
- ECG: widespread saddle-shaped ST-elevation (highly sensitive) and PR depression (highly specific)
- Chest X-ray: may demonstrate an associated pericardial effusion; “water-bottle heart”
- Transthoracic echocardiogram: to exclude pericardial effusion or tamponade
- ESR and CRP: elevated secondary to inflammation
- Troponin: positive in 35-50%
- Urea: elevated levels indicate a uraemia cause
ECG changes in pericarditis
1) First days to weeks
2) Following weeks and months
1) Widespread ST elevation and PR depression
2) T waves flatten, then become inverted, then returns to normal
ECG changes in pericardial effusion
Low QRS complex voltage or electrical alternans (as a result of the heart swinging back and forth in a pool of pericardial fluid)
Managment of acute idiopathic or viral pericarditis
- 1st line: NSAIDs and colchicine
- 2nd line: NSAIDs, colchicine and low dose prednisolone
Managment of bacterial pericarditis
IV antibiotics and pericardiocentesis with washout, culture and sensitivities
Managment of pericarditis that is refractory to medical therapy
Pericardectomy
Complicatios of pericarditis
-
Pericardial effusion
- accucumlation of fluid in the pericardial sac secondary to pericardial inflammation
- can result in cardiac tamponade
-
Myocarditis
- inflammation of the myocardium
- may require steroids initially, whilst chronic cases of myocarditis can result in heart failure
-
Constrictive pericarditis
- a thickened, fibrotic pericardium limits the heart’s ability to function normally, potentially resulting in congestive heart failure
- most commonly associated with tuberculosis
Pericarditis prognosis
The majority of cases of idiopathic and viral pericarditis are self-limiting, whereas bacterial pericarditis can be fatal if untreated.
Pathphysiology of cardiac tamponade
Cardiac tamponade describes a reduction in cardiac output due to a raised intrapericardial pressure secondary to a pericardial effusion.
As the intrapericardial pressure exceeds intrachamber pressures, the chambers of the heart are compressed, reducing stroke volume and cardiac output.
