Myocarditis & Pericarditis Flashcards
Name infective organisms that can cause myocarditis from the following classifications [2]
Viral [5]
Bacterial [4]
Spirochaete [1]
viral:
- HIV
- Coxsackie B
- Influenza A
- Herpes virus 6
- Parvovirus B-19
Bacterial:
- Diptheria
- Streptoccous A (rheumatic fever)
- Clostridia
- TB
Spirochaete:
- Lyme disease
Which protozoa can cause myocarditis? [2]
Chagas’ disease
toxoplasmosis
Which chemotherapeutic drugs may cause myocarditis? [2]
- Doxorubicin
- Trastuzumab (also known as Herceptin)
Describe the pathophysiology for:
- Viral myocarditis [2]
In the case of viral myocarditis, the mechanisms proposed are:
* Direct cellular injury resulting from viral infection
* Immune response arising from the viral proteins intracellularly
Describe the process of radiation causing myocarditis and potential further complications [3]
Radiotherapy:
- Causes inflammation that progresses to myocardial or pericardial fibrosis; fibrosis related CAD and/or valve abnormalities
Which is the most common cause of myocarditis
Viral
Bacterial
Spirochaete
Protozoa
Which is the most common cause of myocarditis
Viral
Bacterial
Spirochaete
Protozoa
Describe the clinical presentation of a patient with myocarditis
- Chest pain
- Systemic features (fatigue, fevers)
- SOB
- Reduced exercise tolerance
- Palpitations (could be triggered by arrythmias)
- Collapse (arrhythmias leading to low output cardiac state)
- Sudden death
The is often a history of a recent preceding viral infection, which may be upper respiratory or gastrointestinal.
What sign might indicate myocarditis on ascultation of heart? (if they have concurrent pericarditis) [1]
On auscultation of the heart, a pericardial friction rub may be heard in patients with concurrent pericarditis and a pansystolic murmur may be present in patients with functional mitral regurgitation
A pericardial friction rub is a grating, to-and-fro sound produced by friction of the heart against the pericardium. This sounds similar to sandpaper rubbed on wood.
What blood results would indicate myocarditis? [3]
↑ inflammatory markers in 99%
↑ cardiac enzymes
↑ BNP
Which autoimmune diseases (and tests used) would you conduct to rule out autoimmune disesaes when investigating myocarditis? [4]
Anti-nuclear antibodies (if positive, may suggest an underlying autoimmune aetiology)
Rheumatoid factor (if positive, may suggest rheumatoid arthritis)
Serum ACE (if positive, may suggest sarcoidosis)
Ds-DNA (if positive, may suggest systemic lupus erythematosus )
What would an ECHO help determine in a patient with myocarditis? [1]
Confirm whether there is any evidence of pericardial effusion and if present, whether this is causing any degree of cardiac tamponade, which may suggest the effusion should be drained.
What ECG changes would indicate myocarditis [3]
- tachycardia
- Prolonged QRS
- QT prolongation
- Diffuse T wave inversion
Can trigger arrhythmias
What are the potential complications of myocarditis? [2]
Complications
* heart failure
* arrhythmia; frequent premature ventricular complexes, irregular and polymorphic VT, or ventricular fibrillation possibly leading to sudden death
* dilated cardiomyopathy: usually a late complication
What are differential diagnoses for myocarditis? [5]
Myocardial ischaemia secondary to vasospasm or infarction
Aortic dissection
Sudden cardiac death of another cause e.g. long QT syndrome
Pericarditis
Takotsubo cardiomyopathy
Cardiomyopathy
How would you differentiate between myocarditis to the following:
Aortic dissection
Pericarditis
Aortic dissection:
- tearing chest pain radiating to the back (as opposed to the more generalised pain typically described in myopericarditis)
Pericarditis
- usually presents with chest pain, typically described as dull, central and relieved by sitting forwards
- Pericarditis patients should NOT exhibit the raised cardiac enzymes found in myocarditis patients
- Echocardiogram should demonstrate clear differentiation between pericarditis and myocarditis with associated pericarditis.
How would you treat myocarditis? [6]
Maintsay is supportive managment:
- Oxygen where required.
- Monitoring for and control of any underlying arrhythmias.
- Fluid balance management.
- Treat underlying cause if any identified.
- Early escalation to specialist intensive care physicians
- Organ support as required.
What treatment is given to patients with suspected giant cell myocarditis? [1]
In patients with suspected giant cell myocarditis, steroids are recommended and have been shown to improve survival
E.g. methylprednisolone
Define pericardial effusion [1]
Define pericardial tamponade [3]
Pericardial effusion is when the potential space of the pericardial cavity fills with fluid. This creates an inward pressure on the heart, making it more difficult to expand during diastole (filling of the heart).
Pericardial tamponade
* Pericardial effusion is large enough to raise the intra-pericardial pressure.
* This increased pressure squeezes the heart and affects its ability to function: it reduces heart filling during diastole, decreasing cardiac output during systole.
* This is an emergency and requires prompt drainage of the pericardial effusion to relieve the pressure.
Explain the effect of cardiac tamponade on chamber pressures [2]
- Because the pericardial sac isn’t very compliant, when it becomes full of liquid it doesn’t expand much
- Therefore the pressures inside the heart chambers equalise as the ventricles have less room to fill during diastole
- Therefore EDV, SV & BP decrease
Define pulsus paradoxus [1]
Explain what is meant by pulsus paradoxus in cardiac tamponade [4]
Pulsus paradoxus:
* Auscultation of heart sounds in the inspiration associated with a drop in systolic blood pressure of > 10 mmHg
Pathophysiology:
* During inspiration, get decrease in intrathoracic pressure
* However, in cardiac tamponade you have an increased return to RA (due to equalised chamber pressures)
* This means that increase in RV filling
* Causes expansion into septal side & into the LV
* Thereby reducing stroke volume and blood pressure.
What are the triad (Beck’s) assocaited with cardiac tamponade? [3]
Classical features - Beck’s triad:
* Hypotension
* Raised JVP
* Muffled heart sounds
Other features:
* Dyspnoea
* Tachycardia
* An absent Y descent on the JVP - this is due to the limited right ventricular filling
* Pulsus paradoxus - an abnormally large drop in BP during inspiration
* Kussmaul’s sign - much debate about this
* ECG: electrical alternans
What are key differences between constrictive pericarditis and cardiac tamponade with regards to: [4]
- JVP
- Pulsus paradoxus
- Kussmauls sign
- Features on CXR
Define acute pericarditis [1]
Acute pericarditis is a condition referring to inflammation of the pericardial sac, lasting for less than 4-6 weeks.
Describe the major clinical feature of acute pericarditis
Retrosternal chest pain (85-90%)
* Usually sharp and pleuritic in nature
* Improved by sitting up and leaning forward
* Radiation to the trapezius ridge
Pericardial friction rub (≤33%)
* Superficial, scratchy or squeaky quality on auscultation, best heard using the diaphragm of the stethoscope
* Usually best heard at the left lower sternal border
