The parietal layer is on the outside and the visceral/serosal/epicardium layer is on in inside. Between these layers is the pericardial space where it is normal to have 20-50mL of pericardial fluid.
Function of the Pericardium
1. Stabilization of the heart within the thoracic cavity
2. Protection of the heart from mechanical trauma and infection from adjoining structures
3. The pericardial fluid functions as a lubricant and dicreases friction of cardiac surface during systole and diastole
4. Prevention of excessive dilation of the heart, especially durinng a sudden rise in intra-cardiac volume
Inflammation of the pericardial layers
Often characterized by sharp, pleuritic chest pain. Pain is classically improved by sitting up (increases space between the pericardial layers), and worse with laying down.
On physical exam you may be able to hear a friction rub (sounds like velcro).
Etiology of Pericarditis
3. Post-MI (Dressler's)
4. Autoimmune disease
Diffuse ST-elevation with PR-depression.
Complications of Pericarditis
1. Pericardial tamponade
2. Pericardial constriction
Treatment of Pericarditis
Treat the underlying cause, if present.
Anti-inflammatory medicine such as high-dose ASA, NSAIDS, and colchicine.
An abnormal accumulation of pericardial fluid (over 50mL) in the pericardial space.
This may occur from a variety of reasons that is very similar to the etioliogy of pericarditis, however the top 4 are... Malignancy is higher on the list
Consequences of Too Much Pericardial Fluid
With an increase in pericardial compliance and pressure, the heart has a tougher time beating and must work harder to pump blood.
Symptoms of Pericardial Effusion
Chest pain (+/-)
Pericardial Effusion - Physical Exam
Quiet (muffled) heart sounds
* Those three are known as Beck's triad
Seen in pericardial effusion.
Refers to seeing low blood pressure, increased JVP, and quiet (muffled) heart sounds on physical exam.
Diagnosis of Pericardial Effusion
CT / MRI
A pericardial effusion that has accumulated under pressure and is limiting cardiac chamber filling by compressing the underlying chambers.
Results in low-output, hypotension, tachycardia, and JVP.
This is a medical emergency.
Symptoms of Pericardial Tamponade
Patient looks unwell
Quiet heart sounds
The drop in blood pressure on inspiration of >10 mmHg.
Everybody's blood pressure will drop on inspiration, but in a healthy individual this will be less than 10 mmHg.
Mechanism: on inspiration, there is a decrease in intra-thoracic pressure, so more blood flows into the right side of the heart. This decrease in pressure also expands the pulmonary vasculature, leading to a drop in blood pressure.
ECG Pericardial Tamponade
Low-voltage, sinus tachycardia, with electrical alternans.
Electrical alternans is where the QRS complexes vary in size. One large one, then one small one, then one large one, etc. Look at Leads below.
Treatment of Pericardial Tamponade
Drainage by needle (pericardiocentesis) or by surgery.
Fluid is sent for investigation which yields a diagnosis 30% of the time.
Compression of the cardiac chambers by a stiff, thickened, fibrotic, contracted pericardium. This limits the heart's ability to function normally.
Results in elevated and equal pressures in the cardiac chambers. This results in low stroke volume, and therefore low cardiac output.
Pericardial Constriction - Physical Exam
Elevated JVP (Kussmaul's sign, rapid x and y descent)
Quiet heart sounds
Ascites (elevated right-sided pressure)
Peripheral edema (elevated right-sided pressure)