Causes of cardiac arrest Flashcards
How are the distinct categories of ACS initially recognised?
Presence or absence of ST elevation on an ECG
If no elevation then presence of a raised troponin
What does the rupture or erosion of an atherosclerotic plaque within a coronary artery cause?
- acute thrombosis within the vessel lumen with often haemorrhagic extension into the plaque
- contraction of smooth muscle cells within the artery wall resulting in vasoconstriction that reduces the lumen of the artery
- associated partial or complete obstruction of the lumen, often with embolism of thrombus into the distal part of the vessel
What does an ECG show in a STEMI
ST elevation or new LBBB
What indicates a high risk NSTEMI
ST segment depression
Dynamic ECG changes
Unstable rhythm
Unstable haemodynamics
Diabetes
High GRACE score
What suggests myocardial damage in the section of the occluded artery?
Development of Q waves on ECG
Impairment of left ventricular function on ECHO
What is there an acute risk of in the initial phase of STEMI?
VF and VT
In a patient with suspected ACS how quickly should an ECG be performed?
10 minutes
What does the diagnosis of STEMI mandate?
PPCI within 120 minutes
If this cannot be achieved then fibrinolytic therapy should be considered
Reperfusion therapy should not be delayed while awaiting the results of a troponin
Anterior or anteroseptal infarction is seen in which leads? Which vessel does this correspond to?
V1-V4
LAD
Anterolateral infarct is seen in which leads?
V5-V6, I and aVL
Inferior infarction is seen in which leads?
II, III aVF. Lesion is in right coronary artery or the circumflex
Lateral infarction is seen in leads?
V5-V6 and/or aVL Caused by a lesion in the circumflex or diagonal branch of the LAD
How can posterior myocardial infarction appear on ECG?
reciprocal ST depression in anterior chest leads
usually due to right coronary artery occlusion but can be caused by dominant circumflex circulations
How can a posterior MI be confirmed?
By using posterior ECG leads- V8, V9, V10 should be placed in a horizontal line around the chest continuously
What can be used to detect right ventricular infarction?
Two dimensional echocardiography
Right sided precordial leads
The ST segment depression and T wave inversion that may occur in NSTEMI are ____related to the site of myocardial damage than the changes in STEMI
The ST segment depression and T wave inversion that may occur in NSTEMI are less-clearly related to the site of myocardial damage than the changes in STEMI
What conditions other than ACS may show ST segment depression/elevation
SAH or TBI
What might an ECG of someone with acute PE have?
TWI in leads V1-V4
What condition might cause ST elevation in lead V1 and V2?
Brugada syndrome
What other conditions may cause a raised troponin?
- PE
- aortic dissection
- myocarditis
- acute/chronic heart failure
- arrhythmias
- chronic renal failure
-sepsis
What is directly linked to prognosis in someone with acute chest pain?
LV systolic function
What are some complications of AMI?
VSD
Severe mitral regurg
What are the variables used in GRACE score?
- age
- signs of heart failure
- heart rate at presentation
- bP at presentation
- serum creatinine concentration
- ECG changes
- troponin concentration
- cardiac arrest at presentation