Cardiac Tamponade (2*)

Question 1

What is this?
→ What type of substance can collect here?

What is the physiology of the pericardium and its fluid?

What occurs in a Pericardial Effusion?
→ What effect does this have?

When does a pericardial effusion lead to Cardiac Tamponade?
→ What effect does this have?
→ What is required at this point?

Answer 1

➊ Excess fluid collects in pericardial sac
→ Transudates (low protein), Exudates (associated w/inflammation), Blood, Pus, Gas (associated w/bacterial infections)

➋ 2 layers, which contains a small (< 50 mls) of fluid between them for lubrication. This lubrication allows the heart to beat w/o generating much friction

➌ The potential space between the layers, which usually isn’t filled, but becomes filled
→ This fluid puts pressure on the heart and makes it more difficult for it to expand during diastolic filling

➍ Effusion becomes large enough to increase the intra-pericardial pressure
→ This pressure squeezes the heart and reduces it’s effectiveness during diastole AND systole → Reduced CO
→ Rapid drainage

Question 2

Causes:
What is associated with a Transudative Effusion?
→ What can cause this?

What is associated with an Exudative Effusion?
→ What can cause this?

What occurs to make blood fill the pericardium?
→ What can cause this?

Answer 2

➊ Increased venous pressure, which reduces drainage from the pericardial cavity
→ • CHF
• Pulmonary HTN

➋ Inflammation of the pericardium (pericarditis)
→ • Infection
• Autoimmune e.g. SLE, RA
• Injury to pericardium e.g. post-MI, surgery, trauma
• Uraemia secondary to renal impairment
• Cancer
• Medications e.g. methotrexate

➌ Rupture of heart/aortic root
→ • MI
• Trauma
• Type A Aortic Dissection

Question 3

Presentation:
How does its presentation vary with onset of the effusion?

What are the symptoms of Pericardial Effusion?
→ The effusion may compress surrounding structures, causing other symptoms. Which structures may this be, and what symptom would be present?

What is the Triad of signs with Cardiac Tamponade?

What may be found O/E?

Answer 3

➊ • A rapid collection of fluid can quickly cause haemodynamic instability and collapse (Cardiac Tamponade)
• A slower collection of fluid may initially be asymptomatic, and as pressure rises, the symptoms develop

➋ • Chest pain
• SOB
• Orthopnoea
• Feeling of fullness in chest
→ • Phrenic nerve → Hiccups
• Oesophagus → Dysphagia
• Recurrent laryngeal nerve → Hoarse voice

➌ Beck’s Triad – Hypotension, Muffled heart sounds, Raised JVP

➍ • Muffled heart sounds
• Pulsus Paradoxus (large fall in BP on inspiration)
• Hypotension
• Raised JVP
• Fever and pericardial rub with pericarditis

Question 4

Which investigations should be done?

Answer 4

• Echo
• Pericardiocentesis - Fluid analysis on the pericardial fluid to determine the underlying cause:
- Protein (distinguishes between transudative and exudative)
• ECG – Small QRS complexes
• CXR – Large globular heart

Question 5

Management:
What is the 1st thing to do if the pt is haemodynamically unstable?
→ Which complication can occur here? What should therefore be done post-procedure?

What is the 1st thing to do if a haemopericardium, associated malignancy, or traumatic/purulent effusion?

Answer 5

➊ Pericardiocentesis
→ Pneumothorax, myocardial damage etc. – CXR should be done post-procedure to exclude this

➋ Surgical drainage