Cardiology Flashcards
Non-Ischaemic causes of ST Elevation
- pericarditis
- benign early repolarisation
- left ventricular hypertrophy
- left ventricular aneurysm
- left bundle branch block with or without AMI
Left Ventricular Aneurysm
Left ventricular aneurysm
- concave initial portion of the ST segment
- ST elevation rarely > 3mm
- Q waves present in the same leads as the ST elevation
- loss of R waves
- V1-4 T amplitude sum/QRS amplitude sum
- < 0.22 in 90% of LV aneurysms
- < 0.26 in 95%
•V1-4 T amplitude sum/QRS amplitude sum > 0.22
- 95% sensitive
- 90% specific for STEMI if ECG within 6 hours of symptom onset
- reduced accuracy with later presentations (due to the development of Q waves)
•in any of V1-4, highest T amplitude/QRS amplitude > 0.36
- 95% sensitive
- 80% specific for STEMI
•echocardiography will help to differentiate aneurysm from STEMI
Benign Early Repolarisation
ECG appearance
•ST segment elevation
- most common in V2-4
- maximum in V2 or V3
- usually < 2 mm
- commences from an elevated J point
- concave in shape
- notching of the down stroke of the QRS complex common
- large concordant T waves
- does not change with time
- more prominent at slow heart rates
Causes of Pericarditis
Causes of pericarditis/pericardial effusion
Viral
- approximately 80% of cases seen in the ED
- Enteroviruses
- Coxsackie A&B
- Echovirus
- Adenovirus
- EBV
- Parvovirus B19
- Mumps
- Varicella zoster
- Hepatitis B
- Influenza
- HIV
- Lyme disease
Bacterial
•usually Staph aureus
-higher incidence amongst indigenous Australians
- Pneumococci
- Streptococci
- Legionella pneumophilia
- Salmonella
- Psittacosis
Myocarditis
- rheumatic fever
- viral
- granulomatous
- other
Post cardiac surgery
- very common
- up to 20% of cases
Normal pregnancy
•asymptomatic pericardial effusion present in healthy pregnancy in
- 15% during the first trimester
- 20% during the second trimester
- 45% during the third trimester
- effusions are usually small but can be moderate or large
- effusions resolve by 6 weeks post partum
- pericardial effusion also seen in 20% of women following stimulation for IVF or embryo transfer
Malignancy
- occurs in approximately 10% in cancer patients
- most common primary sites in adults
- lung
- breast
- lymphoma
- leukaemia
- melanoma
•most common primary sites in children
- Hodgkin’s disease
- lymphosarcoma
- leukaemia
•effusions progress to tamponade in 50 - 85% of cases
Auto immune
•rheumatoid arthritis
- most common
- frequently asymptomatic
- SLE
- hydralazine
- procainamide
Irradiation
Serum sickness
Myocardial infarction
- usual onset within 1-5 days of STEMI
- occurs in only approximately 1% of cases of STEMI
Severe uraemia
- pericardial effusions often blood stained
- relatively high risk of tamponade
Dressler’s syndrome
- autoimmune
- occurs up to 6 weeks following MI or cardiac surgery
Tuberculous
- the most common cause in developing countries or where HIV prevalence is high
- can occur in miliary stage or due to direct pulmonary spread
- commonly constrictive in nature
