Acute Coronary Syndrome Flashcards
what is an acute coronary syndrome?
constellation of symptoms and clinical findings which results from impaired cardiac perfusion at rest
what are the sub-types of ACS?
- unstable angina
- non-ST elevation myocardial infarction
- ST-elevation myocardial infarction
what is the difference betwen MI and angina?
MIS is the underperfusion of the myocardium leading to death of myocardial tissue
what are the non-modifiable risk factors for ACS?
- age
- male sex
- family history
- ethnicity (particularly South Asians)
what are the modifiable risk factors?
- smoking
- hypertension
- hyperlipidaemia
- hypercholesterolaemia
- obesity
- diabetes
- stress
- high fat diets
- physical inactivity
what is a STEMI?
complete occulsion of a coronary artery
what is an NSTEMI?
severe by incomplete stenosis/occlusion of a coronary artery
some patients can have NSTEMIs due to lack of cardiac oxygenation for other reasons (e.g. severe sepsis, hypotension, hypovolaemia, coronary artery spasm)
describe the chest pain typically experienced in ACS
in terms of SOCRATES
- site - central/left sided
- onset - sudden
- character - crushing (‘like somene is sitting on your chest’)
- radiation - left arm, neck and jaw
- associated symptoms - nausea, sweating, clamminess, shortness of breath, sometimes vomiting or syncope
- timing - constant
- exacerbating/relieving factors - worsened by exercise/exertion and may be improved by GTN
- severity - extremely severe
name some atypical presentations of ACS
- epigastric pain
- acute breathlessness
- palpitations
- acute confusion
- diabetic hyperglycaemic crises
- syncope
what patients are more likely to experience ACS without pain?
elderly and patients with diabetes
what are the diagnostic features of unstable angina?
- cardiac chest pain
- abnormal/normal ECG
- normal troponin
what are the diagnostic features of NSTEMI?
- cardiac chest pain
- abnormal/normal ECG (not ST-elevation)
- raised troponin
what are the diagnostic features of STEMI?
- cardiac chest pain
- persistent ST-elevation/new LBBB
no need for a tropnin in this case
what are the ECG requirements for a diagnosis of STEMI?
- ST segment elevation 2mm in adjacent chest leads
- ST segment elevation 1mm in adjacent limb leads
- new LBBB with chest pain or suspicion of MI
what investigations should be undertaken in ACS?
- ECG
- troponin - at least 3 hours after pain starts and then repeated at 6-12 hours
- renal function
- blood glucose
- lipid profile
- FBC and CRP
- chest x-ray
what region and coronary artery is affected when there is ST elevation in II, III and aVF?
- inferior
- right coronary artery (RCA)
what region and coronary artery is affected when there is ST elevation in V1-2?
- septal
- proximal left anterior descending
what region and coronary artery is affected when there is ST elevation in V3-4?
- anterior
- left anterior descending
what region and coronary artery is affected when there is ST elevation in V5-6?
- apex
- distal left anterior descending/right coronary artery
what region and coronary artery is affected when there is ST elevation in I and aVL?
- lateral
- left circumflex
what region and coronary artery is affected when there is ST elevation in V7-V9 (ST depression V1-3)?
- posterolateral
- right coronary artery/left circumflex
what are some non-ACS causes of a raised troponin?
- MI
- pericarditis
- myocarditis
- arrythmias
- defibrillation
- acute heart failure
- pulmonary embolus
- type A aortic dissection
- chronic kidney disease
- prolonged strenuous exercise
- sepsis
what is the acute managemnet of a STEMI?
- targeted oxygen therapy (aiming for stats >90%)
- loading dose of PO aspirin 300mg
- sublingual GTN spray
- IV morphine/diamorphine
- PCI
what are the criteria for PCI?
- present within 12 hours of onset of pain AND
- are **<2 hours **since first medical contact
what is the acute management of an NSTEMI?
- targeted oxygen therapy (aiming for stats >90%)
- loading dose of PO aspirin 300mg and fondaparinux
- sublingual GTN spray
- IV morphine/diamorphine
- antithrombin therapy - LMWH
- high 6 month risk of mortality = angiogram within 96 hours of symptom onset
what is the post-MI management?
- aspirin 75mg OM + second antiplatelet (clopidogrel 75mg OD or ticagrelor 90mg OD)
- beta blocker (bisoprolol)
- ACE inhibitor high dose statin (ramipril)
- high dose statin (atorvastatin)
ECHO + cardiac rehabilitation
what are the complications of an MI?
- ventricular arrhythmia
- recurrent ischaemia/infarction/angina
- acute mitral regurgitation
- congestive heart failure
- 2nd, 3rd degree heart block
- cardiogenic shock
- cardiac tamponade
- ventricular septal defects
- left ventricular thrombus/aneurysm
- left/right ventricular free wall rupture
- dressler’s syndrome
- acute pericarditis
what are ventricular arrhythmias?
in the context of post-MI
- can occur as a consequenc eof MI, during cardiac catheterisation or after reperfusion
- short-lived and self-resolve
- if sustained VT or VF -> ALS
what is recurrent ischaemia/infarction/angina?
in the context of post-MI
- occasionally inserted stents can thrombose requring reintervention
- new infarcts can occur in different vascular territories
- angina and chest pain can continue for some time after an MI
what is congestive heart failure?
in the context of post-MI
- heart failure can occur as a consequence of impairment heart muscle function secondary to ischaemia
- treated as any other acute heart failure
- ventricular function may improve over months as the heart muscle recovers
what is heart block?
in the context of post-MI
common following inferior infarcts
management =
* simple observation
* transcutaneous/venous pacing
* permanent pacing
what is left ventricular thrombus/aneurysm?
in the context of post-MI
- occur following an anterior MI
- definitely diagnosed on ECHO
what is acute mitral regurgitation?
in the context of post-MI
- occur because of papillary muscle rupture
- pansystolic murmur best heard at the apex
- severe and sudden heart failure
what is ventricular septal defect?
in the context of post-MI?
- short-term complication
- rupture caused by anterior = apical and simple
- rupture caused by inferior = basal and complex
- occurs within the 1st week afer the infarction
what are the features of ventricular septal rupture?
- shortness of breath
- chest pain
- heart failure
- hypotension
- harsh, loud pan-systolic murmur
- palpable parasternal thrill
what is dressler’s syndrome?
- post-infarction pericarditis that typically presents with persistent fever and pleuritis chest pain 2-3 weeks post-MI
- symptoms resolve after several days
pericarditis immediately following MI is NOT considered dresslers syndrome
what is the management of dresslers syndrome?
high dose aspirin
