Acute pericarditis + adenosine Flashcards
1
Q
What are the features of acute pericarditis?
A
- chest pain: may be pleuritic
- often relieved by sitting forwards
- non-productive cough, dyspnoea and flu-like symptoms
- pericardial rub (extra heartsound, one systolic and two dialostic)
- tachypnoea
- tachycardia
2
Q
What are causes of acute peridcarditis?
A
- viral infections (Coxsackie)
- tuberculosis
- uraemia (causes ‘fibrinous’ pericarditis)
- trauma
- post-myocardial infarction, Dressler’s syndrome (immune system response after damage to heart tissue or to the pericardium)
- connective tissue disease
- hypothyroidism
- malignancy
3
Q
What investigations are needed in pericarditis?
A
-
ECG changes
- the changes in pericarditis are often global/widespread, as opposed to the ‘territories’ seen in ischaemic events
- ‘saddle-shaped’ ST elevation
- PR depression: most specific ECG marker for pericarditis
- all patients with suspected acute pericarditis should have transthoracic echocardiography
4
Q
What is the management of pericarditis?
A
- treat the underlying cause
- combination of NSAIDs and colchicine is generally first-line for patients with acute idiopathic or viral pericarditis
5
Q
When is adenosine used?
A
- Most commonly used to terminate supraventricular tachycardias
- Effects of adenosine:
- enhanced by dipyridamole (antiplatelet agent)
- blocked by theophyllines
- Avoid in asthmatics due to possible bronchospasm
6
Q
What is the mechanism of action of adenosine?
A
- causes transient heart block in the AV node
- agonist of the A1 receptor in the AVN
:. inhibits adenylyl cyclase
:. reducing cAMP
:. hyperpolarization by increasing outward potassium flux
- adenosine half-life: 8-10 seconds
7
Q
How do you administer adenosine?
A
large-calibre cannula due to it’s short half-life
8
Q
What are the adverse effects of adenosine?
A
- chest pain
- bronchospasm
- transient flushing
- can enhance conduction down accessory pathways, resulting in increased ventricular rate (e.g. WPW syndrome)
