S8) Ischaemic Heart Disease Flashcards
Outline, in detail, the principles of history-taking
- Site: location of the pain and if it radiates
- Quality: how the pain feels (sharp, dull, etc)
- Intensity: severity score
- Timing: when it started (sudden/gradual onset)
- Aggravating factors: what makes pain worse?
- Relieving factors: what makes the pain better?
- Secondary symptoms: other symptoms
What are the two types of chest pain?
Describe the features of visceral pain
Cardiac ischaemic pain:
- Dull, poorly localised
- Worsened with exertion
Describe the features of somatic pain
Pleural/pericardial pain:
- Sharp pain, often well localised
- Worse with inspiration, coughing or positional movement
What are the different causes of chest pain?
- Cardiac causes – ischaemia, infarction, inflammation (pericarditis)
- Non-cardiac causes – upper GI, respiratory, MSK
What are the respiratory causes of chest pain?
- Pneumonia
- Pulmonary embolism
- Pleurisy
What are the upper gastro-intestinal causes of chest pain?
- Reflux
- Peptic ulcer disease
What are the musculoskeletal causes of chest pain?
- Rib fracture
- Costochondritis (inflammation of the costal cartilages)
What is pericarditis?
- Pericarditis is the inflammation of the pericardium often secondary to a viral illness
- It commonly occurs in men and adults
How does the pain in pericarditis present?
- Retrosternal, sharp
- Localised to front of chest
- Aggravated with inspiration, coughing, lying flat
- Relieved with sitting up and leaning forward
What can be heard on the examination of pericarditis?
Pericardial rub may be heard on auscultation
Briefly, explain what cardiac ischaemic chest pain is and how it is managed
- Pain secondary to pathology involving the heart (ischaemic heart disease)
- Primary concern is to rule out urgent, potentially life-threatening causes of chest pain
When does heart tissue ischaemia occur?
Heart tissue ischaemia occurs only when metabolic demands of cardiac muscle are greater than what can be delivered via coronary arteries
Describe the pathophysiology of ischaemic heart disease
- Ischaemic heart disease is a disease of the coronary arteries
- Fatty deposits build up over time → lipid-laden core with a fibrous external cap (atherosclerosis)
Risk factors for atherosclerosis are the same as risk factors for ischaemic heart disease.
Identify 6 modifiable risk factors
- Smoking
- Hypertension
- Hypercholesterolaemia
- Diabetes
- Obesity
- Sedentary lifestyle
Risk factors for atherosclerosis are the same as risk factors for ischaemic heart disease.
Identify 3 non-modifiable risk factors
- Age – advanced
- Genetics – family history
- Gender – males
In stable angina, the atherosclerotic plaque is ‘stable’.
Describe the clinical features
- Dull, retrosternal chest pain
- Triggered by exertion
- Relieved completely by rest
What are some causes of stable angina?
- Coronary artery stenosis
- Spasm
- Anaemia
- Severe aortic valve stenosis
What are the investigations for stable angina?
- Bloods: FBC, cholesterol, renal and thyroid function
- ECG: rhythm disturbance, atrial fibrillation, pathological Q waves
- Chest X Ray
What can be used to treat stable angina?
GTN spray – relieve pains
How does unstable angina differ from stable angina?
- Pain occurs at rest
- Pain may be more intense
- Pain may last longer
- Risk of deteriorating further (NSTEMI/STEMI)
What is the cause of unstable angina?
Coronary plaque rupture
Describe the signs and symptoms of a myocardial infarction
- Dull, retrosternal chest pain
- Radiates to neck & shoulders
- Severe chest pain at rest
- Look unwell (sweaty, pallor)
- Nausea
- Dyspnoea
How do you account for the pallor, nausea and vomiting that is accompanied with MI?
- Increased autonomic output – SNS reduces functions of all non-essential parts of the body (immunity, GI)
- Pain creates substance P which acts on vomiting centres in the brain
What causes myocardial infarction?
Coronary Heart Disease is the leading cause of heart attacks
What is Coronary Heart Disease?
CHD is a condition in which atherosclerotic plaques accumulate in the coronary arteries
In 3 steps, explain how CHD leads to an MI
⇒ Atherosclerotic plaque ruptures
⇒ Blood clot develops at the site of the rupture
⇒ Clot block blood supply to heart, triggering a heart attack
What is an acute coronary syndrome?
- An acute coronary syndrome is a condition wherein acute myocardial ischaemia occurs due to atherosclerotic coronary artery disease
- Atheromatous plaques rupture with thrombus formation causing an acute increased occlusion leading to ischaemia
Identify some conditions which are considered as acute coronary syndromes
- Unstable angina
- Myocardial infarction
- NSTEMI
- STEMI
In 3 steps, explain how acute coronary syndromes involve a spectrum of increased occlusion following a plaque rupture
⇒ Atherosclerotic plaque rupture
⇒ Platelet aggregation and formation of thrombus
⇒ Partially occlusive thrombus → completely occlusive thrombus
Differentiate between ischaemia and infarction
- Heart tissue ischaemia: reduced O2 supply without enzyme leak
- Heart tissue infarction: cardiac enzymes leak from necrosed cardiac muscle cells
Differentiate between the clinical examination findings of stable angina and acute coronary syndromes
- Stable angina: normal clinical examination (chest pain free at rest)
- Acute coronary syndromes: normal clinical examination but may appear sweaty, anxious, pale ± clinical signs secondary to complications of cardiac tissue death
Identify and describe the investigations used in the diagnosis of MI
- ECG – ST segments, T waves, ± pathological Q wave
- Blood tests – Troponin
- Other investigations – to exclude potential diagnoses & identify potential complications
Describe the ECG changes in STEMI
Patterns of infarct:
- ST segment elevation
- Hyperacute T waves
Describe the ECG changes in Unstable angina and NSTEMI
Patterns of ischaemia:
- ST segment depression
- T wave flattening or inversion
How does one differentiate between NSTEMI and Unstable angina?
Blood tests – there is troponin release in NSTEMI due to cardiac myocyte death
Describe the clinical use of Troponin
- Troponin is a biomarker of myocardial damage
- However, it released in almost any condition (specificity poor)
Which cardiac conditions result in the release of Troponin?
- Acute coronary occlusion / severe stenosis
- Acute heart failure
- Prolonged tachycardia
- Cardiac trauma
Which non-cardiac conditions call for the release of troponin?
- Acute PE
- Pulmonary hypertension
- Severe anaemia
- Rhabdomyolysis
- Kidney failure
Describe the pharmacological management of stable & unstable angina
- Aspirin – prevent heart attack, prevent blood clots
- Beta blocker – reduces blood pressure and slows heart rate
- Statin – reduce LDL cholesterol
- ACE inhibitor – lower BP
- Oral nitrate – ease angina pains, includes GTN (stable angina only)
Identify two surgical interventions in the management of stable & unstable angina
Repercussion:
- Percutaneous coronary intervention
- Coronary artery bypass graft
Describe the general management of myocardial Infarction
- Oxygen
- Pain relief
- GTN spray (sublingual)
- Aspirin
- Repercussion (PCI & CABG)
