Extra ACS notes Flashcards
What does the term ACS encompass?
Unstable angina
STEMI
NSTEMI
How do you manage an MI?
- Bedside tests -
- ECG (stress test)
- urine dipstick
- sputum sample
- ABG
- Bloods
- FBC
- cardiac enzymes
- U&E
- CRP
- Scans
- CX (rule out aortic dissection)
- CT angiogram
- 24 hour tape (ECG)
- Echocardiogram
Old infarct is shown by Q waves on ECG
How do you treat an MI acutely?
- Pain relief
- Nitrates (GNT spray)
- Oxygen
- Aspirin - stops clotting
- Anticoagulants
How do you treat an MI chronically?
Clopidogrel (blood thinner)
(and manage symptomatic heart failure)
What is the advantage and disadvantage of warfarin over other DOACS? What does INR stand for?
Warfarin is reverible but requires more monitoring in INR clinics.
NB: International Standardised Ratio
- 1.0-1.5 is normal
- low= blood not thin enough
- high = thin blood
Which patients should you not give beta blockers to?
Asthmatics - they can precipitate bronchospasm
What groups of patients are more likely to develop a silent myocardial infarction?
Older women
Diabetics
Elderly
Describe the management of ACS.
Acronym: MONAC FP
- Morphine - to relieve pain and its related sympathetic activity
- Oxygen - only if saturation is less than 90%
- Nitrates - GTN sublingual - reduces myocardial oxygen demand
- Aspirin+ P2Y12 inhibitor - limit secondary thrombosis by inhibiting platelet activation and subsequent platelet aggregation
- Clopidogrel (P2Y12 inhibitor) - antiplatelet
- Fondaparinux - like a LMW heparin - anticoagulant
- PCI - percutaenous coronary intervention or CABG
What is the aetiology of cardiac chest pain? Why does angina change?
Fatty deposits called plaque build up in the coronary arteries over time(atherosclerosis). These plaques obstruct flow and may cause myocardial ischaemia, which is felt as chest pain.
Diagram: if coronary flow doesn’t keep up with increased myocardial oxygen consumption then MI occurs. Vicious cycle - MI leads to increased O2 demand and blood flow.
Arteries are able to constrict and relax in the presence of atheromateous lesions. This gives rise to changing patterns of angina e.g. cold days.
How do these drugs affect the triad of factors which contribute to MI? (beta blockers, Ca channel blockers, nitrates)
Beta blockers - reduce exercise induced heart rate and reduce myocardiac oxygen demand
Ca channel blockers (e.g.amlodipine) - decrease the peripheral resistance against which heart has to pump
Nitrates - increase coronary dilatation so increases blood flow
Is angina essential for a heart attack to occur?
You can get a coronary thrombus leading to MI before previous angina pectoris.
Describe the atheroma process.
- There has to be damage to the vascular endothelium to begin with.
- Plaques probably rupture and heal a few times. It is only when there is a major rupture and clot formation at the site that leads to MI.
What percentage of people who suffer MI die outside the hospital?
Can atherosclerosis only occur in the arteries?
True or false: vessels can dilate and constrict in the presence of a thrombus.
True or flase: patients that have a coronary thrombosis causing MI usually have angina pectoris beforehand.
40%
Yes - sometimes called arteriosclerosis.
True
False - only 20% have angina before MI
Put these into order (pathogenesis of atherosclerosis)
- Leukocyte recruitment
- Endothelial damage
- Lipoprotein oxidation
- Foam cell formation
Endothelial damage occurs (by whatever means e.g. metabolic stress), this allows lipoprotein to collect in the intima. As the lipoproteins are free from plasma antioxidants they will then become oxidatively modified. Next leukocytes are recruited and finally mononuclear phagocytes differentiate into macrophages and transform into lipid laden foam cells.
Define angina pectoris. What are some other causes?
Chest discomfort due to MI typically associated with coronary artery disease i.e. it is not synonymous with MI but is usually due to MI.
(NB: other causes include aortic stenosis, hypertrophic obstructive cardiomyopathy)
Cardinal symptoms of aortic stenosis: chest pain, SOB, dizziness, collapse (also low BP)
What are the types of angina?
Stable angina - occurs over several weeks without major deterioration although symptoms may vary considerably over time e.g. with exertion, stress.
Unstable angina - abruptly worsening angina or new angina at low work load
Variant (Prinzmetal) angina - spontaneous (i.e. no precipitating cause) angina with ST elevation on ECG. Intense coronary spasm at the site of an atheromatous lesion, usually occurs at night.
Syndrome X - angina with objective evidence of MI (e.g. ST depression) in the absence of evident coronary atherosclerosis or epicardial (large vessel) disease.
Who gets syndrome X? What is the triad?
Usually post menopausal females.
Triad of this syndrome: anginal chest pain, positive exercise test, angiographically normal coronary arteries.
What are the ECG changes in Prinzmetal’s angina? What information is key in diagosis?
Profound ST elevation in lead II when symptomatic which goes away as the symptoms disappear.
Usually at night (so monitor for 24hr)
History is key: patients get an intense chest pain when they go to bed which wakes them up at night
What is decubitus angina? Describe the aetiology.
Chest pain when patients lie flat in bed. This is caused by a severe obstruction in the coronary artery.
Lie down –> decreased venous pooling –> increase in myocardial work
What is meant by acute coronary insufficiency?
What is meant by crescendo?
ACI- another term for unstable angina
Crescendo - increasing frequency and severity of the chest pain.