Chapter 4 - cardiac causes of cardiac arrest Flashcards
what are the 3 types of ACS?
STEMI
NSTEMI
Unstable angina
what is the definition of ACS?
group of clinical syndromes that cause chest pain/discomfort, resulting from myocardial ischaemia
what causes ACS? (pathophysiology)
Originally from coronary artery disease, initiated by rupture of an atherosclerotic plaque within a coronary artery. This causes acute thrombosis within the vessel lumen often with haemorrhagic extension into the atherosclerotic plaque. This eventually causes partial or complete obstruction of the lumen, causing sudden loss of blood flow to the coronary artery.
Typical symptoms of angina?
chest tightness
pain in jaw/neck
radiates left arm
worse on exertion, relieved by rest
Atypical symptoms of angina/MI?
pain radiating to the neck, both arms, abdomen
breathlessness
what is the criteria for unstable angina?
1) angina on exertion, which is occuring in increasing frequency over several days due to less and less exertion (i.e. crescendo)
2) angina pain occuring randomly not due to exercise - relieved by GTN
3) prolonged period of pain, but without ECG/trop changes
what is the most reliable way of differentiating between angina and MI?
trop
typical symptoms of MI?
chest pain and tightness radiating to left jaw and left arm, or both arms and abdomen sweating nausea/vomiting beltching lasting 20mins
however - MI can be silent or atypical symptoms such as breathlessness
Criteria for diagnosis of STEMI?
History of sustained chest pain
ECG changes of STEMI or new LBBB
troponin rise - however not needed to initiate treatment
What are the lateral leads?
I, aVL, v6
what vessel causes an infarct in the lateral leads?
circumflex artery
what are the anterior leads?
V2, V3, V4
what vessel causes infarct in the anterior leads?
LAD
what are the inferior leads?
II, III, aVF
what vessel causes infarct in the inferior leads?
right coronary artery
less commonly circumflex
What ECG changes indicate a posterior infarct?
reciprocal ST segment depression in anterior chest leads
how can you confirm a posterior infarct?
repeat the ECG using posterior leads -V8, V9, V10 placed in horizontal line across the chest
what conditions may also cause ECG abnormalities that replicate STEMI?
subarachnoid haemorrhage, TBI, PE, brugada syndrome, takutsobu
what score indicates risk of further MI/complications?
GRACE score
what does GRACE score stand for?
Global Registry of Acute Coronary Events
what does the GRACE score take into consideration?
age signs of HF HR at presentation BP at presentation serum creatinine concentration ECG changes troponin concentration cardiac arrest at presentation
what is the initial management of ACS generally?
aspirin 300mg clopidogrel 300mg GTN O2 if hypoxic Morphine IV pain relief
what is the management of STEMI specifically?
CORONARY REPERFUSION!!
PPCI
Fibrinolytic therapy
how quickly should PPCI be done?
Generally within 12 hrs of symptoms
Hospitals should aim for <120 mins of call to balloon time
what medications are given alongside PPCI for maximum effect?
clopidogrel 600mg OR ticagrelor 180mg OR prasugrel 60mg (if not <75yrs, <60kg, history of bleeding or stroke)
unfractionated or LWMH
What is the benefit of fibrinolytic therapy?
does not need to be delivered in cardiac catheter laboratory or skilled angioplasty team
contraindications for fibrinolytic therapy?
previous haemorrhagic stroke ischaemic stroke in last 6 months CNS damage recent surgery active bleeding known or suspected aortic dissection known bleeding disorder
what is given alongside fibrinolytic therapy?
aspirin 300mg
ticagrelor 180mg
LMWH
what should be done for patients who have undergone unsuccesful fibrinolytic therapy?
transfer for urgent rescue PCI
management of NSTEMI?
fondaparinux 2.5mg OD aspirin 75mg OD clopidogrel 75mg OD OR ticagrelor 90mg OD start BB consider ACE-I statin GTN stop smoking diuretics if HF manage HTN plan for angio
management of arrest in cath lab?
if VF/VT- 3 stacked shocks should be attempted. If ROSC not achieved - follow ALS guidelines.
management of acute cardiogenic shock?
inotropes
insertion of intra-aortic balloon pump
I+V
what are some causes of sudden cardiac death?
long QT syndrome brugada syndrome short QT syndrome hypertrophic cardiomyopathy WPW syndrome severe AS dilated cardiomyopathy
what is the process following sudden cardiac death?
autopsy -> molecular autopsy -> if no cause found then termed “sudden arrhythmic death syndrome”
indicator or risk of sudden cardiac death?
regular syncope, particularly during exertion
