Chest Pain Flashcards
Where do you feel pain for lungs and pleura?
Lateral chest which increases on inspiration
What is affected if the chest pain is in the centre?
Heart and great vessels
What can cause pain in the lung and pleura?
Pneumonia
Pneumothorax
Pulmonary embolism
What can cause GI pain?
Gastro-oesophageal reflux
GB disease
Peptic ulcer
What can cause pain in heart and great vessels?
Ischaemic heart disease
Pericarditis
Aortic dissection
When does myocardial ischaemia occur?
When the supply of blood cannot reach the demand of the muscles
What does myocardial oxygen supply depend on?
Coronary blood flow
-perfusion diastolic pressure and coronary artery resistance
Oxygen carrying capacity of the blood
What does myocardial oxygen demand depend on?
Heart rate Contractility Wall tension -preload -afterload
When does coronary flow occur?
During diastole
In which direction is coronary flow? What does this mean?
From the epicardium to endocardium. Sub endocardial muscles is the most vulnerable to ischaemia.
What can decrease myocardial oxygen supply?
Severe anaemia
Severe hypotension
What can increase myocardial oxygen demand?
Tachycardias
Thyrotoxicosis
Aortic stenosis
Non-modifiable risk factors for coronary artery disease?
Increased age
Male gender - females catch up after menopause
Family history
Important modifiable risk factors for coronary artery disease?
Hyperlipidaemia
Smoking
Hypertension
Diabetes mellitus
Lack of exercise
Obesity
Stress
Structure of a stable plaque?
Small necrotic core
Thick fibrous cap which is less likely to fissure or rupture
Structure of vulnerable plaque?
Large necrotic core
Thin fibrous cap which is more likely to fissure or rupture
How can an unstable plaque lead to thrombus formation?
Fibrous cal can erode or fissure
Exposes blood to thrombogenic material in the necrotic core
Platelet clot followed by fibrin thrombus
What effects does stable plaque have?
Moderate reduction in blood flow
Transient ischaemia during periods of increased oxygen demand
May progress gradually over time to severe fixed narrowing causing ischaemia with less demand
Describe the pain in stable angina
Mild to moderate central crushing pain with typical radiation to left/right/both arms or shoulders, neck, jaw, back, epigastrium
What can cheat pain in stable angina be brought on by?
Exertion
Emotional stress
What can stable angina pain be relieved by?
Rest or nitrates
What signs and symptoms can people who have stable angina present with?
Signs related to risk factors such as raised BP, corneal arcus, absent pulses, LV dysfunction
How is the diagnosis of stable angina confirmed?
Exercise stress rest.
Graded exercise in a treadmill until target heart rate is reached or chest pain occurs or ECG changes or there are other problems such as arrhythmias or drop in BP
What does stable angina show up as on an ECG during exertion?
ST segment depression
With rest ST segment goes back to baseline
What is the aim of treatment in stable angina?
To reduce myocardial oxygen demand by
- reducing preload and afterload
- reducing heart rate
- reducing myocardial contractility
Increase bloodflow
Prevent progression of atheroma, stabilise plaques and prevent thrombosis
What do calcium blockers do?
Reduce afterload because they cause peripheral vasodilatation
What do nitrates do?
Reduce preload because the cause venodilatation
Effects of beta blockers?
Reduce heart rate and contractility
Effects of aspirin?
Reduced platelet aggregation therefore reduced thrombus formation if plaques are disrupted.
What do statins do?
Lower LDL cholesterol ➡️ reduces progression of atherosclerosis ➡️ increases plaque stability
Which vessels can be used for a coronary bypass?
Internal mammary artery
Radial artery
Saphenous vein
Features of a STEMI?
Normally total occlusion of an artery
Injury extends to sub-epicardial area which is manifested as an ST elevation in leads facing the injured area
Infarct is full thickness of myocardium
What is an MI?
Complete occlusion of a coronary vessel leading to an infarct of the myocardium it supplies
Features of an NSTEMI?
No ST elevation
Infarct is not full thick was of myocardium
How are acute episodes of angina treated?
Sub-lingual nitrate spray
What drugs are used to prevent episodes of angina?
β-blockers
Calcium channel blockers
Oral nitrates
What drugs are used to prevent cardiac events?
Aspirin
Statins
ACE inhibitors
What is unstable angina classified as?
Ischaemic chest pain that occurs at rest or with minimal exertion, described as severe pain and occurring with a crescendo pattern.
What is acute coronary syndrome?
A group of symptoms that attribute to the obstruction of the coronary arteries.
What is coronary artery syndrome a result of?
Unstable angina
NSTEMI
STEMI
Do you get occlusion by a thrombus in unstable angina, NSTEMI or STEMI?
Unstable angina - partial
NSTEMI - partial
STEMI - total
Do you get myocardial necrosis in unstable angina, NSTEMI or STEMI?
Unstable angina - none
NSTEMI - some
STEMI - large myocardial infarct
ECG in unstable angina?
ST segment depression
T wave inversion (sometimes)
Biomarkers in blood for unstable angina, NSTEMI or STEMI?
No biochemical markers in unstable angina
Troponin in NSTEMI and STEMI
How can previous MIs be identified?
Persistence of the pathological, deepened Q wave on an ECG
Which two proteins are released in myocyte death?
Troponin I
Troponin T
When does troponin begin to rise and peak?
3-4 hours
18-36 hours
After the first onset of pain
When do creatine kinase levels rise and peak?
3-8 hours
24 hours
How long after pain in an MI does it take for troponin and CK to return to normal levels?
Troponin - 10-14 days
CK - 48-72 hours
Goal of treatment in unstable angina?
Prevent it from progressing to MI and limiting muscle loss in MI
Goals of treating an MI?
Prevent progression of the thrombosis
Restore perfusion of partially occluded vessels
Pain control
What drugs are used in anti-thrombotic therapy?
Aspirin (antiplatelet)
Heparin (anticoagulant)
How is perfusion restored in a partially occluded vessel?
Angioplasty (PCI)
Coronary bypass graft
What do you find on examination of someone who has had an MI?
Patient is Angus and distressed Sweaty, sold, clammy skin Pale Tachycardia/arrhythmias Low blood pressure Signs of heart failure -S3/S4 -crackling in lungs
How to treat a STEMI?
Try to do an emergency PCI within 90-120 mins
Fibrinolytic therapy
How to treat an NSTEMI?
Anti thrombotic therapy
Angiography and PCI/CABG
How else do you treat an NSTEMI/STEMI?
Analgesics Oxygen Antiplatelets - Clopidogrel and aspirin Anti-ischaemic therapy - nitrates and beta blockers ACE inhibitors Statins
Complications of an MI?
Sudden cardiac death
- ventricular fibrillarion
- asystole
First, second or third degree heart block
Ventricular tachycardia
Heart failrue
Cardiogenic shock
Why is ST depression only evident during exercise in angina?
As the heat rate increases with exercise, diastole is disproportionately shortened and therefore coronary artery filling is compromised while the oxygen demand is increased.