Chapter 107 : Pericardial surgery

Question 1

What are the 2 layers of the pericardium?

Answer 1

• Outer fibrous layer
• Inner serous layer (closed mesothelial lined sac with parietal and visceral layers)

Question 2

List the functions of the pericardium

Answer 2

• Keeps the heart in position
• Restrains cardiac filling
• Enhances diastolic ventricular coupling
• Protects against atrial rupture
• Prevent spread of infection or neoplasia to heart from pleural cavity
• Provides a gliding surface for heart motion

Question 3

What does pericardial fluid contain?
What is it’s oncotic pressure relative to serum?

Answer 3

Pericardial fluid is an ultrafiltrate of the serum
- phospholipids for lubrication
- Protein 1.7-3.6g/dL

• Colloid osmotic pressure is 25% of serum

Question 4

What are the physiologic effects of cardiac tamponade?

Answer 4

• Decreased cardiac output
• Increased central venous pressure
• Activation of compensatory RAAS and catecholamine release
• As atrial wall stretching is limited, atrial natriuretic peptide is not released to stop RAAS effects
• Increase in systemic venous and portal pressures causing jugular vein distention, liver congestion, ascites and peripheral edema
• Compression of coronary arteries causes poor myocardial perfusion
• Cardiogenic shock and death

Question 5

What is pulsus paradoxus?

Answer 5

A variation in systolic arterial pressures up to 10mmHg from increasing venous return during inspiration in a relatively nonexpandable heart (due to pericardial effusion)

NOT pathognomonic - Can also be seen with obstructive lung disease, restrictive cardiomyopathy or hypovolemic shock

Question 6

Parietal pericardium is not very compliant, after how much fluid accumulation do pressures increase?

Answer 6

5-60mL

Question 7

Chapter 107:What is a normal volume of pericardial fluid?

Answer 7

1-15mL