Cardiology - Acute coronary syndrome Flashcards
What is acute coronary syndrome?
refers to 3 states of myocardial ischemia:
- unstable angina
- non-ST elevation MI and
- ST-elevation MI
What is the biggest contributing factor to ACS?
Atherosclerosis - arteries become clogged with fatty substances called plaques
What are the clinical features, ECG findings, and cardiac enzymes found with patients with ST-elevation myocardial infarction?
ST-segment elevation
new-onset left bundle branch block
raised troponins
What are the clinical features, ECG findings, and cardiac enzymes found with patients with non-ST elevation myocardial infarction?
Non-specific signs of ischemia
normal ECG
raised troponins
What are the clinical features, ECG findings, and cardiac enzymes found with patients with unstable angina?
Characteristic clinical features
non-specific signs of ischemia
normal ECG
normal troponins
What is required for a diagnosis of myocardial infarction?
A cardiac biomarker - a rise/fall in troponin levels
New ECG changes
pathological Q waves
Symptoms of myocardial ischaemia
What are symptoms of myocardial ischemia?
- Pain or discomfort in the upper body
- Trouble breathing
- Feeling full, indigestion, or a choking feeling (may feel like heartburn)
- Nausea or vomiting
How is myocardial infarction different to myocardial injury?
Myocardial injury is seen as a rise in troponin, without evidence of acute myocardial ischemia, whilst myocardial infarction has evidence of acute myocardial ischemia
What are 3 symptoms of ACS?
- Chest pain for over 15 minutes, which can radiate to the neck or arm
- palpitations
- sweating and SOB
What are 3 signs of ACS?
- Tachycardia
- clammy
- pale
What should be checked on an ECG, when looking for ACS?
ST elevation or left bundle branch block (LBBB). If absent, look for other features of ischaemia (e.g. ST depression, T wave inversion)
What can cause ST elevation on an ECG?
acute myocardial ischaemia pericarditis coronary vasospasm benign early repolarisation bundle branch block ventricular aneurysm
What can cause ST depression on an ECG?
acute myocardial ischaemia
electrolyte disturbances
digoxin effect
bundle branch blocks.
When approaching a patient with chest pain, what should be checked and what would should be done next based on the result?
Check for ST elevation/left bundle branch block and treat for STEMI if found
if not, check troponin levels
When checking troponin levels, what should be done based on the results?
- if pain has lasted over 6 hours, then low risk
- if normal or high, then check again in 3 hours
- if highly abnormal, start invasive management
