Session 9 ILOS - Chest Pain and Acute Coronary Syndromes Flashcards
What are the 2 types of chest pain?
Cardiac (ischaemic)
Pleuritic
Describe the anatomy of the thoracic cavity from superficial to deep that can result in chest pain (7)
- Skin
- Musculoskeletal (bone/muscle/cartilage)
- Trachea
- Lungs
- Heart
- GI Tract
- Blood vessels - aorta
Identify the different systems that can cause chest pain (5)
Different systems can because chest pain:
- Cardiac (heart muscle and pericardial sac)
- Respiratory (lungs and pleura)
- Musculoskeletal
- GI
- Vascular
Name 2 Musculoskeletal causes of chest pain
- Costochodritis
- Rib fracture
Name a vascular cause of chest pain
Aortic dissection
Name a skin cause of chest pain
Shingles
Name 2 GI causes of chest pain
- Gastro-oesophageal reflux disease(GORD)
- Peptic ulcer disease
Name a respiratory cause of chest pain
Pneumonia
What determines the features of the chest pain?
The type of nerve ie visceral or somatic the signals are being sent through to reach the spinal cord and the brain
Give 3 cardiac causes of chest pain and state the type of pain that it causes and the innervation
- Pericarditis - pleuritic pain because pain signals pass from the pericardium through somatic afferent nerves to the brain and spinal cord
- Stable angina - visceral pain because the pain signals pass from the cardiac muscle through visceral afferent nerves to reach the brain and spinal cord
- Acute coronary syndromes - visceral pain because the pain signals pass from the cardiac muscle through visceral afferent nerves to reach the brain and spinal cord
What kind of pain do you get from the heart muscle due to ischaemic or infarct reason? Why do you get this pain?
- Visceral pain
- Because pain signals from the heart are transferred through visceral afferent nerve to the brain and spinal cord
What kind of pain do you get from lungs, pleura, pericardial sac or MSK features of the chest wall?
- Somatic pain
- Because pain signals from these places are transferred through somatic afferent nerves to the brain and spinal chord
Describe the features of cardiac (ischaemic) chest pain (4)
- Dull, felt centrally (centre of chest)
- Poorly localised
- Pain can be referred (perceived to come from another location e.g. shoulder)
- Worsened with exercise/exertion
Describe the features of pleuritic chest pain (5)
- Sharp
- Well localised
- No radiation
- Worsened with position ie pericarditis
- Worsened with inspiration and coughing (ie Respiratory or MSK cause)
Why can cardiac chest pain be referred to other parts of the body? (4)
- Visceral afferents send signals towards spinal cord and enter at segments T1-T4/T5
- Sensory/somatic afferents from T1-T4/5 dermatomes enter at same level
- Brain interprets signals as arising from skin instead of from the heart, confusingly
- So patient describes feeling the pain in T1-T4/5 dermatomes, which correspond to the front of your chest and a little bit down your arm
Pericardium innervation vs cardiac muscle innervation
- Pericardium - innervated by somatic afferents that run in peripheral nerves
- Cardiac muscle - innervated by visceral afferents that run in sympathetic nerves
What is pericarditis?
Inflammation of the pericardial sac
What is the typical presentation history for pericarditis? (3)
- Usually more common in males than females
- Usually due to Infection - typically viral cause
- May have a prior history of viral infection leading up to development of symptoms
Which nerve innervates the pericardium?
Phrenic nerve
Describe the pain presentation of acute pericarditis (6)
- Pleuritic/somatic pain
- Sharp
- Well localised
- Sitting forward or up relieves pain
- Lying down flat makes it worse
- Coughing makes it worse
Describe the signs and symptoms of acute pericarditis (8)
- May be normal
- Tachycardia
- Pounding or racing heartbeat (heart palpitations)
- Pericardial rub on auscultation (scratchy noise)
- Fatigue or general feeling of weakness or being sick
- Low-grade fever
- Cough
- Shortness of breath when lying down
Name some further investigations that you might do with a patient with suspected pericarditis and describe what you may find in someone with pericarditis (4)
- ECG - widespread saddle-shaped ST elevation in all leads.
- Series of blood tests - inflammatory markers may be elevated ie CRP
Other investigations to rule out other causes of chest pain :
- chest x-ray
- echocardiogram
Compare Pericarditis ST elevation to MI ST elevation
Pericarditis:
- Widespread
- Saddle-shaped
MI:
- Only in the leads looking at the bit of the heart that is affected
- Non-saddle-shaped
Name 4 acute coronary syndromes
Name something that is not
- Unstable angina
- Myocardial infarction:
- Non-ST-elevation myocardial infarction (NSTEMI)
- ST-elevation myocardial infarction (STEMI)
NOT STABLE ANGINA
Describe the risk factors for coronary atheroma (10)
Risk factors:
- Hypertension
- Hyperlipidaemia
- Smoking
- Diabetes
- Obesity
- Sedentary lifestyle
- Gender (male)
- Advancing age
- Family history
- Ethnicity
What are acute coronary syndromes? (5)
- A spectrum of acute myocardial ischaemic events,
- caused by atheromatous plaque rupture with thrombus formation
- causing acute increased occlusion in an already partially occluded coronary artery lumen
- Leading to ischaemia and potentially infarction (mocardial tissue necrosis)
- Causes chest pain
What causes acute coronary syndromes?
- Atheromatous plaque rupture with thrombus formation
What do acute coronary syndromes cause? (2)
- Acute/sudden increased occlusion in an already partially occluded coronary artery lumen
- Chest pain
What can acute coronary syndromes lead to?
- Leading to ischaemia and potentially infarction (mocardial tissue necrosis)
What is ischaemic heart disease?
Give 4 examples
Insufficient blood supply to heart muscle due to atherosclerotic disease of coronary arteries
eg stable/unstable angina, NSTEMI, STEMI
Describe the pathophysiology of stable angina
Stable angina:
- Partial, chronic (stable) occlusion of a coronary artery with atherosclerotic plaque
- Only pain on exercise, due to increased metabolic demands and insufficient blood flow
Why does stable angina only present with pain during exercise?
- Due to increased metabolic demands and insufficient blood flow
What determines whether you get Unstable Angina, NSTEMI or STEMI?
Severity of occlusion
Describe the pathophysiology of unstable angina (5)
- Partial, chronic (stable) occlusion of a coronary artery with atherosclerotic plaque
- Plaque ruptures (acute/sudden)
- Leads to thrombus formation
- Sudden increased occlusion of coronary vessel by plaque disruption and platelet aggregation
- Chest pain at rest as well as during exercise
Describe the pathophysiology of an NSTEMI (5)
- Partial, chronic (stable) occlusion of a coronary artery with atherosclerotic plaque
- Plaque ruptures (acute)
- Leads to thrombus formation
- Greater sudden increased occlusion of coronary vessel by thrombus formed on plaque - not fully occluding
- Chest pain at rest as well as during exercise
Describe the pathophysiology of a STEMI (5)
- Partial, chronic (stable) occlusion of a coronary artery with atherosclerotic plaque
- Plaque ruptures (acute)
- Leads to thrombus formation
- Complete sudden occlusion of coronary vessel - thrombus fully occludes vessel
- Chest pain at rest as well as during exercise
What differentiates stable angina from an acute coronary syndrome?
ACS has atheromatous plaque actually rupturing and thrombus formation, leading to sudden occlusion of the coronary vessel SA doesn’t
Describe the difference in management of someone with stable angina, vs someone with ACS
- SA patients do not need hospitalisation and can be treated with drug and lifestyle advice
- ACS patients need to be in hospital
What will all ACS present with?
Cardiac ischaemic sounding chest pain
Describe the signs and symptoms of angina (5)
- Chest pain
- Heaviness or tightness in your chest, can radiate to shoulders, arms, neck, jaw, back
- Shortness of breath
- No associated anatomical features ie sweating, nausea
- Ischeamic heart disease risk factors
Distinguish the characteristics of unstable angina from stable angina (6)
Characteristics between stable and unstable angina: (6)
- Stable relieves upon rest, unstable doesn’t and chest pain is present at rest
- No changes on ECG for stable generally
- Changes on ECG for unstable due to ischaemia, ST depression or T wave inversion
- Pain may be more intense in Unstable
- Pain may last longer in unstable
- Risk of deteriorating further (NSTEMI/STEMI) in unstable
Describe the signs and symptoms of myocardial infarction (7)
2 types of myocardial infarction = NSTEMI or STEMI
Signs/symptoms:
- Central Crushing chest pain at rest
- Pain can radiate from the chest to the jaw, neck, arms and back
- Cold sweat
- Nausea
- Looks unwell (sweaty/pallor)
- Shortness of breath
- Feeling weak or lightheaded
Explain the difference between unstable angina, NSTEMI and STEMI
Unstable angina - partial sudden occlusion of a coronary artery, due to plaque disruption and platelet aggregation, without necrosis of cardiac muscle tissue
NSTEMI - greater sudden occlusion of coronary vessel by thrombus , leading to necrosis of cardiac muscle tissue
STEMI - complete sudden occlusion of coronary vessel by thrombus, leading to necrosis of cardiac muscle tissue
Describe the use of the ECG in the diagnosis of MI, distinguishing STEMI from a NSTEMI and unstable angina
- NSTEMI and unstable angina would show ST depression and maybe T wave inversion (or ECG could be normal)
- STEMI would show ST elevation
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
- NSTEMI and STEMI would have elevated troponin due to cardiac myocyte death
- Unstable angina would have no elevated troponin
Describe the investigations for ACS
2 main investigations
- ECG
- NSTEMI and unstable angina would show ST depression and maybe T wave changes (t wave inversion - or the ECG could be normal)
- STEMI would show ST elevation
2 . Troponin blood test
- Unstable angina would not have elevated troponin
- NSTEMI and STEMI would have elevated troponin
- Chest x-ray
Allows DR to check size of heart and blood vessels and look for fluid in lungs - pulmonary oedema
If widened mediastinum = aortic dissection maybe
Blood tests NSTEMI (5)
- Haemoglobin (rule out anaemia as considering antiplatelets)
- Renal function (angiogram iodine-based contrasts can induce nephropathy in patients with renal impairments)
- Cholesterol
- HBA1C (diabetes)
- Troponin
1) When is troponin raised?
2) When does it peak?
3) How long does it remain elevated for?
Raised within 3 hours of damage
Peaks at 24-48 hours
Remains elevated 2+ weeks
If there is ST elevation but no troponin present in the blood, what is the diagnosis?
Aborted STEMI
Main cause of acute coronary syndrome
Atheromatous plaque rupture, leading to thrombus formation, leading to decreased blood flow through coronary arteries
Other pathologies myocardial infarction apart from atheromatous plaque rupture
- Coronary dissection (tear in tunica media)
- Coronary spasm
Give 5 things that can confirm the diagnosis of an MI
- Symptoms of ischaemia ie retrosternal chest pain that can radiate to jaw/arm
- With rise and/or fall in cardiac biomarker preferably cardiac troponin
- Pathological Q waves (patient had their infarct a few days ago and myocardium is dead)
- Imaging evidence of wall abnormality (echocardiogram)
- Coronary angiography detects thrombus
What is type 1 MI?
Atheromatous plaque rupture, leading to thrombus formation, leading to decreased blood flow through coronary arteries and subsequent myocardial necrosis
Coronary artery anatomy
What are the anterior leads of the heart and what do they look at?
V1-V6
Look at the front of the heart
What are the:
- Lateral leads of the heart
- What do they look at?
- Which artery supplies them?
- I, aVL, (high lateral)
V5, V6 - They are supplied by the left circumflex artery
L for Lateral for LEFT
What are the:
- Inferior leads of the heart
- What do they look at?
- Which artery supplies them?
- II, III and aVF
- They look at the bottom part of the heart
- They are supplied by the right coronary artery
Anteroseptal ECG leads
What artery supplies them?
V1
V2
=. Septal
V3
V4
= Anterior
(left anterior descending)
Describe the management of STEMI (7)
1) Aspirin (300mg)
2) P2Y12 inhibitor (thin blood even more) such as Ticagrelor 180mg
3) Morphine 5-10mg (ease pain) + antisickness drug (metoclopramide 10mg IV) as morphine can cause nausea
4) Nitrate 2 puffs under tongue if SBP>110mmHg (vasodilator)
5) Oxygen if low sats
6) Direct transfer catheter lab for PCI
- Time is muscle!
Describe the principles of management of NSTEMI (4)
1) Antiplatlets and antithrombotics (Aspirin and Ticagrelor/Clopidogrel - P2Y12 inhibitors)
2) Anti-ishcaemics (Bisoprolol and GTN infusion - slow the heart rate down)
3) Secondary prevention (e.g. statins, ACE inhibitors - help with positive remodelling)
4) Consider referral to the catheter lab
When should a patient with NSTEMI when to go to catheter lab for urgent percutaneous coronary intervention? (2)
- If chest pain persists with dynamic ECG changes (ECG is evolving)
- If patient develops arrhythmias
Describe the principles of the management of stable angina (5)
- GTN spray (Sublingual glyceryl trinitrate) -
to reduce symptoms of angina and for use before performing activities known to cause symptoms of angina. - Beta blockers long term (e.g. Bisoprolol) or a calcium-channel blocker to reduce the symptoms of stable angina.
- Stop smoking
- Low fat and low salt diet
- Exercise
Describe the principles of management of unstable angina (3)
- Antiplatlets and antithrombotics (e.g. Aspirin and Ticagrelor/Clopidogrel) to thin blood
- Consider referral to catheter lab for percutanous coronary intervention (stent)
- Lifestyle changes ie stop smoking, exercise, low fat and salt diet
What does GTN do?
What condition can it be given in?
What condition can’t it be given in?
- GTN causes vasodilation of veins to decrease the workload of the heart by reducing cardiac return.
- Relives stable angina
- Does not work in unstable angina
What does invasive coronary angiogram do?
- Establishes the type of leison and its location so we can treat it with stents
Describe invasive coronary angiogram (9)
- 30 min procedure
- Local anaesthetic (to access radial or femoral artery)
- Catheter guided through artery in arm or leg into coronary arteries
- Then a liquid dye is injected through catheter
- Allows doctors to identify blockages by tracing flow of dye
- Wire occluded vessel with catheter with small inflatable balloon and stent at tip
- Inflate balloon so anything causing the blockage is pushed towards the edges and to put stent in place
- Stent acts as metal scaffold to keep vessel open
- Catheter withdrawn
Describe some non-surgical managements of ACS and SA (8)
1) Life style changes (low fat/salt, regular exercise, stop smoking)
2) Dual antiplatelets for 12 months min - Ticagrelor/Clopidogrel, Prasugrel
3) Aspirin for life
4) Statins to reduce cholesterol to less than 4mmol/L, LDL cholesterol below 2mmol/L
5) Bisoprolol (beta-blocker) aiming for HR around 70bpm
6) ACE inhibitor aiming for BP <140/80
7) If echocardiogram shows the ejection fraction is below 40%, then eplerenone
8) If ejection fraction is consistently low for 3 months, implantable cardiac defibrillator
Describe an alternative surgical treatment to stent placement (LEARN IF TIME)
Coronary artery bypass graft surgery
- Diverts blood around narrowed or clogged parts of major arteries, and provides an alternative route for blood to flow to improve blood flow and oxygen supply
