Angina + ACS Flashcards
What are the branches of the left main coronary artery and what part of the heart do they supply?
Circumflex= left atrium and ventricle
Left anterior descending= anterior and inferolateral part of LV and septum
What parts of the heart does the right coronary artery supply?
RA RV Inferior LV Branch to SAN Septum
I.e. dominant vessel in 85% of people
What is the primary cause of angina? Why does exertion or emotional stress precipitate angina?
Narrowing or occlusion of 1 (+) major coronary arteries by atheroma
They cause an imbalance between myocardial O2 demand and supply which results in ischaemia that causes the pain associated with angina
Why is angina associated with ST-depression?
Dysfunction between O2 demand and supply leads to cellular acidosis and lactate production due to changes to anaerobic respiration which leads to ST depression
ST depression is associate with ischaemia rather than infarction
What pathologies can cause angina and why?
Aortic stenosis
-unable to maintain adequate coronary perfusion
Hypertrophic cardiomyopathy
-increased O2 demand due to increased thickness of myocardium
Severe anaemia
-decreased O2 capacity
What is the pathology behind angina developing into MI?
Atherosclerotic plaque ruptures to induce an acute thrombosis and cause complete occlusion of a coronary artery
Ischaemic heart disease can be associated with different clinical outcomes/conditions. What are examples of manifestations?
Angina
Myocardial infarction
Sudden death
Cardiac failure due to damage experienced from previous MI
Arrhythmias (atrial fibrillation or ventricular arrhythmias)
What are the differentials for chest pain outside of ACS?
Musculoskeletal pain
Thoracic/cervical root pain (can radiate into arms)
Peptic ulcer disease
GORD
PE
Aortic coarctation
Aortic dissection
A patient presents with squeezing feeling in chest and their chest feels heavy. They also say they have pain behind their breastbone. Is this cardiac or non-cardiac?
Cardiac
Pain behind breast bone= retrosternal discomfort
A patient comes with sharp stabbing chest pain which is aggravated by respiration or movement. Is this cardiac or non-cardiac?
Non-cardiac
A patient presents with pain across the mid-thorax and they say it is moving to their arms, neck and jaw. Is this cardiac or non-cardiac?
Cardiac
A patient presents with pain in left sub-mammary area or hemithorax. Is this cardiac or non-cardiac pain?
Non- cardiac
If someone was experiencing cardiac pain, when would you expect it to be exacerbated and relieved? Why?
During exercise
Excitement or stress
Associate with increased HR or BP
Relief:
- rest
- Nitrates (GTN)
If someone was experiencing non-cardiac chest pain, when would you expect it to be exacerbated and relieved? Why?
After exercise With specific movements i.e. Moving arms Possible localised tenderness Pain at rest Cold weather After meals
Relief:
- analgesics
- antacids
What clinical signs or co-morbidities would you expect to find in someone suspected of angina/IHD?
Hyerlipidaemia= look for arcus, xanthomas or tendons
Hypertension
Peripheral vascular disease= reduced or absent pulses
Diabetes (neuropathy or retinopathy or peripheral vascular disease)
Anaemia
Murmurs
What are the features of unstable angina?
New onset= w/i 4 weeks
Progressively worse i.e. increased freuquency/severity =crescendo angina
Prolonged cardiac pain w/o evidence of mi= >15-20 mins despite rest and GTN
How can patients with refractory unstable angina be managed? What needs to be done in-order to select patients for this form of management?
Early coronary angiography to revascularise
Patients been to have been stabilised by initial therapy
Troponin needs to be measure to determine if myocardium damaged
Stress-testing done
How can you differentiate between ischaemia and infarction on an ECG?
Ischaemia= ST depression Infarction= ST elevation, T inversion and Q wave formation (T + Q waves changes occur later)
Changes in leads II/III/aVF indicate indicate ischaemia or infarction in which part of the heart? Which arteries are likely to be affected?
Inferior= part of heart supplied by R coronary or distal circumflex artery
Changes in leads V4-6 and aVL indicate ischaemia or infarction in which part of the heart? Which arteries are likely to be implicated?
NOTE: tend to be leads which ST segment change can be seen
Anterolateral part of heart
Arteries= LAD
What blood tests are important to do with IHD?
FBC= look for presence of anaemia
Lipids= hyperlipidaemia
HbA1c= need to exclude diabetes
Thyroid function