Ses 9 Cvs Coronary Artery Disease Flashcards
identify and differentiate between the common causes of chest pain
Somatic pain from stimulation of sensory nerves:
Skin
Musculoskeletal (bone, muscle & cartilage) - chostocondritis, rib fracture
Trachea
Lungs - pneumonia (inflammation of pleura causes lateral pain, cough, fever)
Heart - pericarditis
Gastrointestinal tract- oesophagus - acid reflux
Blood vessels- aortic dissection
describe the risk factors for coronary atheroma
pathophysiology of stable angina, unstable angina
clinical features
Finish
Stable Angina is ischaemic pain - experienced during exertion and resolves with rest.
blood flow through LCA is compromised as diastole is shorter and oxygen demand of heart has inc.
can happen when coronary stenosis of more than 60% due to artherosclerosis.
Stable = Chronic occlusion
Unstable = plaque rupture then thrombus formation then sudden inc occlusion - could cause UA, NSTEMI, STEMI
In UA pain occurs at rest, is of limited duration and the duration of the ischaemia is not sufficient to cause cell death.
describe the signs and symptoms of angina and distinguish the
characteristics of unstable angina from stable angina
Finish
Cardiac ischaemia stimulates visceral afferent nerve endings in sympathetic fibres which enter spinal cord at T1-5.
Also have somatic sensory afferents from T1-5 dermatomes entering here.
Brain ‘interprets’ pain signals as arising from skin
So:
Central, poorly localised pain
Dull
Pain can be referred - jaw, neck, arm.
Dyspnoea, discomfort, fatigue when carrying out physical activity - stable
All of these experienced at rest - unstable
describe the signs and symptoms of myocardial infarction
Finish
Dull central crushing pain that radiates to left neck, jaw, arm
Nausea and sweating and pallor
Cause - atherosclerotic plaque rupture with thrombus formation.
Causing acute increased occlusion in coronary artery (in already partially occluded lumen).
blockage caused by the thrombus is sufficient to cause cell death in a region of myocardium.
describe the investigations for myocardial infarction
analysis of a blood sample for the cardiac isoforms of troponin-I (cTnI) or troponin -T (cTnT).
Typically raised within 3 hrs of cardiac damage, peaks at 24 to 48 hrs, remains elevated 2+weeks.
STEMI shows elevation of the ST segment in leads viewing the affected area in ECG and troponin present in blood.
NSTEMI shows depression of ST segment + T wave inversion in leads viewing affected area and troponin present in blood.
Unstable angina would have ST depression but no troponin in blood.
understand the concept of ‘Acute Coronary Syndrome’ and
explain the difference between unstable angina, NSTEMI and
STEMI
Acute coronary syndrome refers to a spectrum of acute ischaemic events - sudden increased occlusion due to plaque rupture, ulceration etc and thrombus formation.
UA - sudden inc occlusion but no cell death
NSTEMI - cell death limited to the sub- endocardial tissue
STEMI - full thickness of the myocardial wall is affected
describe the use of the ECG in the diagnosis of MI, distinguishing
STEMI from a NSTEMI
Finish + notion
NSTEMI is likely to show ST segment depression and / or T wave inversion in leads viewing that affected area.
STEMI shows elevation of the ST segment in leads viewing the affected area.
The ECG changes during a STEMI evolve with time - finish
identify region of the heart affected from the particular groups of
leads which show changes in myocardial infarction
Septal: V1 and V2
Anterior: V1- V6
Lateral: V5 and V6
Anteroseptal: V1-V4
Anterolateral: V3-V6
Inferior: II, III, aVF
High Lateral: I, aVL
describe the use of cardiac biomarkers as a marker for MI and to
distinguish between NSTEMI & unstable angina in a patients with
Acute Coronary Syndrome
Myocardial cell death can be detected from analysis of a blood sample for the cardiac isoforms of troponin-I (cTnI) or troponin -T (cTnT). useful diagnostic evidence of injury to cardiac myocytes.
Only raised in NSTEMI and STEMI, not unstable angina.
describe the principles of the management of angina, unstable
angina and acute myocardial infarction
All conditions - lifestyle changes - low fat, exercise, low salt, smoking cessation.
Statin so cholesterol less than 4
ACE inhibitor so BP less than 140/80.
STEMI:
Aspirin 300mg
Morphine 5-10mg IV
Oxygen if Sats <92% through oxygen mask.
Direct transfer to cardiac catheter labs for PCI (percutaneous coronary intervention).
Nitrates
Bisoprolol - beta blockers
NSTEMI:
Antiplatelets and antithrombotic - Aspirin
Anti-ischaemics - beta-blockers
Secondary Prevention - Statin, ACE inhibitors
ECG changes or arrhythmias = Urgent PCI
Invasive coronary angiogram
understand the use surgical treatments in coronary artery disease
PCI - stent - keep vessel patent - reduce ischaemia
Invasive coronary angiogram - see type of leison and location
radial/femoral artery access
Dilate with balloons
Stent to keep vessel patent
describe the signs and symptoms of acute pericarditis
Finish
Cause - viral
Sharp, pleuritic pain (localised) worsened by being supine; eased with sitting up or forward
Tachycardia
Pericardial rub (on auscultation of heart)
ECG
Blood tests
