Pericardial diseases Flashcards
What is acute pericarditis?
Acute inflammation of the pericardium. Classically, fibrinous material is deposited into the pericardial space and pericardial effusion often occurs.
What are the causes of acute pericarditis?
CARDIAC RIND
- Collagen vascular disease
- Autoimmune / Aortic aneurysm
- Radiation
- Drugs
- Infection - Viral, bacterial
- AKI/Uraemia
- Cardiac infarction
- Rheumatic fever
- Injury / Idiopathic
- Neoplasm (malgnancy)
- Dressler’s syndrome
What are viral causes of acute pericarditis?
- Coxsackie
- Flu
- EBV
- Mumps
- Varicella zoster
- HIV
What are bacterial causes of acute pericarditis?
- Pneumonia
- Rheumatic fever
- TB
- Staphlococcus
- Streptococcus
What drugs can cause acute pericarditis?
- Hydralazine
- Penicillin
- Isoniazid
What are the most common causes of viral pericarditis?
Coxsackie B and echovirus
What is dressler’s syndrome?
An autoimmune response to cardiac damage occurring 2–10 weeks’ post-infarct. It is a type of pericarditis.
It is believed to result from an autoimmune inflammatory reaction to myocardial neo-antigens formed as a result of the MI. A similar pericarditis can be associated with any pericardiotomy or trauma to the pericardium or heart surgery.
How does pericarditis occur in uraemic patients?
Uraemia causes irritation of the pericardium due to accumulation of toxin. It can occur in 6–10% of patients with advanced kidney disease if dialysis is delayed.
What conditions is bacterial pericarditis associated with?
- Pneumonia
- Septicaemia
- Thoracic surgery
- Endocarditis
How does TB pericarditis present?
- Low-grade fever - particularly in the evening
- Features of acute pericarditis
- Dyspnoea
- Malaise
- Weight loss
- Night Sweats
What are the most common causes of malignant pericarditis?
- Carcinoma of the bronchus
- Carcinoma of the breast
- Hodgkin’s lymphoma
What are the symptoms of acute pericarditis?
Sharp Central chest pain
What are specific features of pericarditic chest pain?
- Exacerbated by movement, inspiration and lying down
- Relieved by sitting forward
What are the signs seen in pericarditis?
- Pericardial friction rub - LLSE
- Fever
- Features of pericardial effusion
What causes a pericardial friction rub?
https://www.youtube.com/watch?v=J1R8Oxgqhfk
Inflammation causes the pericardial and visceral surfaces of the pericardium (which are normally separated by a small amount of fluid) to rub together. It occurrs in three phases corresponding to atrial systole, ventricular systole and ventricular diastole. It may also be heard as a biphasic ‘to and fro’ rub.
The rub is heard best with the diaphragm of the stethoscope at the lower left sternal edge at the end of expiration with the patient leaning forward.
What symptoms can occur with a pericardial effusion?
Dyspnoea
What are signs of pericardial effusion?
- Raised JVP with prominenet x descent
- Soft heart sounds
- Pericardial friction rub
- Ewart’s sign
- If severe - signs of tamponade
What is Ewart’s sign?
A combination of the following signs:
- Dullness to percussion over the left scapula
- Aegophony (increased vocal resonance)
- Bronchial breath sounds over the left lung
What causes Ewart’s sign?
A large pericardial effusion can compress the left lung, causing consolidation and/or atelectasis, which alters percussive resonance. If the effusion enlarges sufficiently to collapse and/or consolidate the lung, increased vocal resonance and bronchial breath sounds will be heard.
Why can pericardial rub be present initially with a pericardial effusion, but the disappear as the effusion gets bigger?
Becomes quieter as fluid accumulates and pushes the layers of the pericardium apart
What is prominent x descent?
The x-descent occurs in the jugular venous waveform after atrial contraction, during ventricular systole, and is timed with the carotid pulse.
The x-descent represents the decrease in JVP, which occurs due to:
- Atrial relaxation
- Tricuspid valve being pulled downwards during ventricular systole
- Ejection of blood volume from the ventricles.
All of these aspects enlarge or relax the atrium, decreasing the atrial pressure. A prominent x-descent is faster and larger than normal. It is a sign that shows that forward venous flow only occurs during systole.
What is the mechanism behind a prominent x-descent in cardiac tamponade/pericardial effusion?
A prominent x-descent is an exaggeration of the normal waveform descent. In cardiac tamponade, compression of the chambers of the heart leads to elevated RA pressure. This raised pressure eventually blocks the forward flow of venous blood (i.e. filling) from the jugular vein into the atrium during diastole.
When the atrium relaxes and the ventricles contract in systole, the tricuspid valve is pulled down towards the apex of the heart, and there is a momentary increase in atrial volume and decrease in atrial pressure, allowing a rapid descent in atrial pressure and the JVP.
What are signs of cardiac tamponade?
- Tachycardia
- Hypotension
- Pulsus paradoxus
- Increased JVP
- Kussmaul’s sign
- Muffled heart sounds
What is pulsus paradoxus?
An inspiratory fall in systolic blood pressure exceeding 10 mmHg. It is elicited by inflating the blood pressure cuff to above systolic pressure and noting the peak systolic pressure during expiration. The cuff is then deflated until the clinician can hear the Korotkoff sounds during inspiration and expiration and this pressure value is noted. When a difference between these two pressures of greater than 20 mmHg occurs, pulsus paradoxus is present.
What is the mechanism behind pulsus paradoxus?
Fluid within the pericardial sac places pressure on all chambers of the heart and impairs LV filling but does not impair right ventricular filling to the same extent. Inspiration increases right ventricular filling compared to left ventricular filling, and the IV septum is pushed into the left ventricle, which further impairs left ventricular filling. When impaired LV filling is combined with pooling of blood in the lungs on inspiration, it exaggerates the normal decrease of LA and ventricular filling on inspiration. In addition to this, pulmonary venous pressure tends to be lower than the pressure in the left atrium, resulting in a decrease in left ventricular filling as more blood is pulled back towards the pulmonary veins.
What is the mechanism behind Kussmaul’s sign in cardiac tamponade/constrictive pericarditis?
Kussmaul’s sign is thought to be caused by a combination of increased venous return to the heart in conjunction with a constricted or non-compliant right ventricle, which cannot accommodate the venous return, and right atrial pressure exceeds the fall in pleural pressure. The blood then backs up into distended neck veins.
What might you see on ECG in someone with acute pericarditis?
- Widespread concave-upwards (saddle-shaped) ST elevation
- Reciprocal ST depression in leads aVR and V1
- PR segment depression
What is constrictive pericarditis?
Condition where the pericardial sac becomes heavily fibrosed and calcified. This results in a rigid, non-compliant casing for the heart. This disrupts the later filling stage of diastole, as the heart comes up against the rigid, unyielding pericardium
What is friedrich’s sign?
A faster and more prominent descent of the JVP during diastole, coinciding with the drop in right atrial pressure that occurs after opening of the tricuspid valve.
Seen on physical examination as an abrupt collapse of the neck veins during diastole.
What is the mechanism behind the diastolic pericardial knock heard in constrictive pericarditis?
The sudden slowing of blood flow into the ventricle in early diastole that occurs when the ventricle meets the rigid pericardial sac
What might you see on CXR in someone with constrictive pericarditis?
- Relatively small heart
- Pericardial calcification
