SIHD and Angina Flashcards
What is the definition of angina?
Cardiac chest pain
What is the pathophysiology of myocardial ischaemia and angina?
- Mismatch between supply of O2 and metabolites to myocardium and the myocardial demand for them
- Most commonly due to reduction of coronary blood flow
What ways are the coronary arteries blocked?
- Obstructive coronary atheroma
- Coronary artery spasm (dynamic obstruction)
- Coronary inflammation/arteritis
What other ways can O2 be reduced to the myocardium?
- Anaemia
- LVH (from persistent hypertension, aortic stenosis or hypertonic cardiomyopathy)
- Thyrotoxicosis
When would angina be most prominent if it is due to a lack of O2 to the myocardium?
- During activity the HR and BP rise putting strain on the heart
- Anxiety/emotional stress
- Can cause angina
What is “stable angina”?
Symptoms only on activity
What is the typical distribution of precordial pain?
- (retrosternal)
- Left chest
- Left arm
- Neck on occasion
- Abdomen in women
What is the character of angina?
- Often described as a “tight band” on the chest or heaviness
- Can radiate to mandible as well
What relieving factors are there for angina?
- GTN (rapid relief)
- Physical rest
What type of pain is typically not angina?
- Sharp stabbing pain
- Associated with movement
- Localised pinpoint site
- Superficial
- No pattern
- Begins AFTER exercise
- Long lasting
What might a sharp stabbing pain be?
- Pleuritic or pericardial
What is the differential diagnoses for chest pain?
- Cardiovascular causes
- Respiratory
- Musculoskeletal
- GI
What are the other cardiovascular causes of pain used in the differential?
- Aortic dissection
- Pericarditis
What are the respiratory causes for chest pain used in the differential?
- Pneumonia
- Pleurisy
- Peripheral PE
What are the musculoskeletal causes for chest pain used in the differential?
- Cervical disease
- Costochondritis
- Muscle spasm/strain
What are the GI causes for chest pain used in the differential?
- GORD
- Oesophageal spasm
- Peptic ulceration
- Biliary colic
- Chocystitis
- Pancreatitis
What symptoms ON EXERTION are in the history with myocardial ischaemia?
- Breathlessness
- Excessive fatigue
- Near syncope
What are the non modifiable risk factors for coronary artery disease?
- Age
- Gender
- Creed
- Family history and genetic factors
What are the modifiable risk factors for coronary artery disease?
- Smoking
- Lifestyle - diet and exercise
- Diabetes mellitus
- Hypertension (reducing BP reduces CV risk)
- Hyperlipidaemia (lowering reduces CV risk)
How is diabetes a modifiable risk factor?
Good glycaemic control reduces CV risk
What are the factors on examination, along with angina, that point towards CV
- Tar stains on fingers
- Obesity
- Xanthalasma
- Corneal arcus (both show hypercholesteraemia)
- Hypertension
- Abdominal aortic aneurysm arterial bruits, absent or reduced peripheral pulses
- Diabetic retinopathy
- Hypertensive retinopathy on fundoscopy
What signs of exacerbating or associated conditions exist with angina?
- Pallor or anaemia
- Tachycardia
- Tremor
- Hyper-reflexia of hyperthyroidism
- Ejection systolic murmur
- Plateau pulse of aortic stenosis
- Pansystolic murmur of mitral regurgitation
- Basal crackles, elevated JVP, peripheral oedema
What are the first investigations done on admission of stable angina?
- FBC
- Lipid profile and fasting glucose
- CXR (can rule out other causes)
What would be the next and most important step in the diagnosis?
- Electrocardiogram
What will an electrocardiogram be able to show evidence of?
- Past MI
- Left ventricular hypertrophy
What will show a past MI on an electrocardiogram?
- Pathological Q waves
What will show left ventricular hypertrophy on an electrocardiogram?
- High voltages
- Lateral ST segment depression or “strain pattern”
What is an ETT?
Exercise tolerance test
What does an exercise tolerance test allow?
- CV to be under stress
- Will show ST segment depression for positive test
What does a negative ETT NOT rule out?
- Coronary atheroma
- Negative at high workload means overall good prognosis
What is better than ETT in detection of coronary vascular disease, localisation of ischaemia and size of affected area?
- Myocardial perfusion imaging
What is bad about myocardial perfusion imaging?
- Expensive
- Involves radioactivity
- Sometimes unavailable
What is the process of myocardial perfusion imaging?
- Radionuclide tracer injected at peak stress and images taken
- Stress images compared to rest images
What will happen to the radionuclide tracer around healthy normal myocardium?
Will be absorbed
If the tracer is seen at rest but not after stress what is the diagnosis?
Ischaemia
If the tracer isn’t seen at rest or after stress what is the diagnosis?
Infarction
What other imaging techniques can be used to asses the coronary arteries?
- CTCA (coronary artery angiography)
When should invasive angiography be done during investigation?
- Early or strongly positive ETT
- Angina refractory to medical therapy
- Diagnosis unclear
- Young cardiac patients
- Occupation with risk (drivers)
What types of invasive angiography are there?
- Cardiac catheterisation
- Coronary angiography
What do the invasive angiographies allow?
- The extent of atheromatous disease and what treatment is best
- Whether medication alone or percutaneous coronary intervention is needed
What are the two types or percutaneous coronary intervention (PCI) are there?
- Angioplasty and stenting
- Coronary artery bypass graft (CABG)
What arteries are the arterial cannulas usually inserted into?
- Femoral or
- Radial
What is the path of the coronary catheters?
- Into the aortic root
- Introduced into ostium of coronary arteries where it enters
How are the images from cardiac catheterisation done?
- Radio opaque contrast injected down coronary arteries
What are the general measures taken in addressing the risk factors after a diagnosis is made?
- Control BP if high
- Control diabetes mellitus if hyperglycaemic
- Reduce cholesterol
- Alter lifestyle
What drugs can a stable angina sufferer be put on to reduce disease progression?
- Statins to reduce LDL cholesterol deposition
- ACE-I if increased CV risk
- Low dose aspirin (or clopidogrel if intolerant)
What drugs can be used to relieve angina symptoms?
- B blockers (anti arrhythmic)
- Ca2+ channel blockers
- Ik channel blockers
All to reduce HR
What is examples of Ca2+ channel blockers are used commonly?
- Diltiazem
- Verapamil
What is a new Ik channel blocker medication that reduces sinus node rate?
- Ivabridine
What else can calcium channel blockers do?
- Produce vasodilation
What Ca2+ channels cause vasodilation?
- Amlodipine
- Felodipine
What are nitrates used for with angina?
- Produce vasodilation
What types of nitrates are administered for angina?
- Sublingual buccal spray (GTN)
- Prolonged/short acting tablets
At what point is revascularisation considered?
When two anti anginals are used and no respite is gained
What types of PCI are there?
- Percutaneous transluminal coronary angioplasty
- Stenting
What is the process of PCI?
- Similar start to coronary angiography
- Cross stenotic lesion with guidewire inserted
- Atheroma plaque squashed into walls with a balloon and then stented
What drug treatment is taken following stenting?
- Aspirin and clopidogrel taken whilst endothelium covers the stent
Why does the endothelium need to cover the stent?
- Can be seen as foreign body
- Risk of thrombosis
What are the negatives of PCI?
- No evidence of prognosis improvement
- Small risk of procedural complication (0.1% death)
- Risk of restenosis with bare metal stents and drug eluding stents
What is the benefit of coronary artery bypass surgery (CABG)?
- 80% symptom free 5 years after op
- Prognostic benefit in some groups
Negative of CABG?
- High op risk
