Stable Angina Flashcards
What is the definition of angina?
Discomfort in chest and/or adjacent areas associated with myocardial ischaemia but without myocardial necrosis
What are the most common ways coronary blood flow to the myocardium is reduced?
Obstructive coronary atheroma (Very common)
Coronary artery spasm (Uncommon);
Coronary inflammation/arteritis (Very rare)
What are the uncommon reasons for having stable angina?
Uncommonly due to :
- coronary spasm or artery inflammation
- Reduced O2 transport (anaemia of any cause)
- Pathological increase in myocardial O2 demand (LVH - caused by severe hypertension, significant aortic stenosis and hypertrophic cardiomyopathy)
- Thyrotoxicosis - hypermetabolic state.
What is the effect of coronary atheroma on the onset of exercise?
Increased myocardial oxygen demand leads to myocardial ischaemia due to obstructed coronary blood flow - symptoms of angina arise
What situations might cause HR and BP to rise (and therefore myocardial oxygen demand)?
- Exercise
- anxiety/emotional
- cold weather
- stress
- after large meal
What is angina felt in the chest called?
Angina pectoris
What level of obstruction is present in the lumen in stable angina?
Obstructive if over 70% of lumen
How should the patient describe the site of the pain?
Retrosternal
How should the patient describe character of the pain?
tight band/pressure/heaviness
Where can the pain of angina radiate?
neck and/or into jaw, down arms
What are the releiving factors for angina?
Rest and GTN
When is the pain less likely to be angina?
- Sharp/‘stabbing’ pain; pleuritic or pericardial
- Associated with body movements or respiration.
- Very localised; pinpoint site
- Superficial with/or without tenderness.
- No pattern to pain, particularly if often occurring at rest.
- Begins some time after exercise
- Lasting for hours
What are the differential diagnoses for angina?
Cardiovascular disease
Aortic dissection (intra-scapular “tearing”), pericarditis
What are the differential diagnoses for angina?
Respiratory
Pneumonia, pleurisy, peripheral pulmonary emboli (pleuritic)
What are the differential diagnoses for angina?
Muscoskeletal
Cervical disease, costochondritis, muscle spasm or strain
What are the differential diagnoses for angina?
GI causes
- Gastro-oesphageal reflux
- oesophageal spasm
- peptic ulceration
- biliary colic
- cholecystitis
- pancreatitis
What is meant by dissection of aorta?
Inner layer of aorta tears
Blood surges through tear
Causes inner and middle layers of aorta to separate (dissect).
Define costochondritis
Inflammation of cartilage that connects rib to breastbone (sternum)
Pain caused by costochondritis might mimic that of a heart attack or other heart conditions
What are peptic ulcers?
Open sores that develop on inside lining of stomach and upper portion of small intestine
Define biliary colic
Pain due to gallstone temporarily blocking bile duct
Pain in right upper part of abdomen and can radiate to shoulder
Pain usually lasts from one to a few hours
Define cholecystitis
Inflammation of the Gall bladder
Myocardial ischaemia can occur without chest pain but other symptoms, what are these symptoms?
Breathlessness on exertion
Excessive fatigue on exertion for activity undertaken
Near syncope on exertion
More often in elderly or in diabetes mellitus: probably due to reduced pain sensation.
What is the canadian classification for angina severity?
- Ordinary physical activity does not cause angina, symptoms only on significant exertion.
- Slight limitation of ordinary activity, symptoms on walking 2 blocks or > 1 flight of stairs.
- Marked limitation, symptoms on walking only 1-2 blocks or 1 flight of stairs
- Symptoms on any activity, getting washed/dressed causes symptoms
What are the non-modifiable risk factors for angina?
- Age
- gender
- creed
- family history
- genetic factors
What are the modifiable risk factors for angina?
- Smoking
- Lifestyle - exercise and diet
- Diabetes mellitus (glycemic control reduces CV risk)
- Hypertension (BP control reduces CV risk)
- Hyperlipidaemia (lowering reduces CV risk)
What are typical signs of people with angina?
- Tar stains on fingers
- Obesity (centripetal, high waist to hip ratio, apple shape)
- Xanthalasma and corneal arcus (cholesterol deposit in the iris, hypercholesterolaemia)
- Hypertension
- Abdominal aortic aneurysm, arterial bruits, absent or reduced peripheral pulses
- Diabetic retinopathy, hypertensive retinopathy on fundoscopy
What are the exacerbating or associated conditions?
- Pallor of anaemia
- Tachycardia, tremor, hyper-reflexia of hyperthyroidism (overactive reflexes)
- Ejection systolic murmur, plateau pulse of aortic stenosis
- Pansystolic murmur of mitral regurgitation
- Signs of heart failure - basal crackles, elevated JVP, peripheral oedema
What are the relevant investigations for angina?
- Bloods
- CXR
- Electrocardiogram
- ETT (Exercise tolerance tests)
- Myocardial perfusion imaging
- CT coronary angiography
- Invasive angiography
What do you look out for when measuring bloods?
FBC
Lipid profile and fasting glucose
Electrolytes
Liver & thyroid tests are routine
Why would you order a chest X-ray for someone with angina?
Helps show any other causes of chest pain and can help show pulmonary oedema
In what percentage of cases in an electrocardiogram normal for someone with angina?
Over 50% of cases
What is the significance of pathological Q waves?
Prior myocardial infarction
How can you tell Left ventricular hypertrophy from an ECG?
High voltages, lateral ST-segment depression or “strain pattern”
What is a positive test for an ETT?
Symptoms of angina arise on exertion
What is a negative ETT indicative of?
Doesn’t exclude significant coronary atheroma
Shows good prognosis if workload is high
Why is moyocardial perfusion imaging superior to ETT in detection of CAD?
Better in localising ischaemia and assessing size of affected area
BUT - Expensive, involves radioactivity
During myocardial perfusion imaging - how is stress applied to the patient?
Excersize or pharmacological stress - nadenosine, dipyridamole or dobutamine
Vasodilators – work on areas that are not affected
How are the results from myocardial perfusino imaging interpreted?
Comparison of images at rest and after stress
Tracer seen at rest but not after stress = ischaemia
Tracer seen neither rest, or after stress = infarction
When would you use invasive angiography?
- Early or strongly positive ETT (suggests multi-vessel ds)
- Angina refractory to medical therapy
- Diagnosis not clear after non-invasive tests
- Young cardiac patients due to work/life effects
- Occupation or lifestyle with risk e.g. drivers etc
What are the different types of percutaneous coronary intervention?
Angioplasty and stenting
Coronary bypass graft (CABG) surgery
How is cardiac catheterisation / cornary angiography carried out?
Under local anaesthetic
Cannula is inserted into the femoral or radial artery
Coronary catheter is passed into the ostium of the coronary arteries.
Radio-opaque contrast injected down coronary arteries and visualised on X-ray.
(Coronary ostium - Opening of coronary arteries at root of aorta
Describe the dye used in invasive angiography.
Clear, watery, blood compatible, commonly called an X-ray dye
Iodinated - absorbs xrays – picture of lumen and not lumen walls
Iodine is normally clear
What are the general measures to control angina?
Blood pressure, cholesterol, lifestyle and diabetes mellitus
If the symptoms are not controlled after general measures and medical treatment, what are the next steps?
Revascularisation in symptoms are not controlled.
Percutaneous coronary intervention (PCI) & coronary artery bypass grafting (CABG)
What is the medical treatment that influences disease progression?
Statins - for high cholesterol (>3.5 mmol/l.)
Reduce LDL-cholesterol deposition in atheroma, reduce plaque rupture and ACS.
ACE inhibitors - increased CV risk and atheroma
Stabilise endothelium and reduce plaque rupture
Aspirin - 75mg or clopidogrel if intolerant to aspirin
may not directly affect plaque but does protect endothelium and reduces platelet activation/aggregation
What is the medical treatment that releives symptoms?
Beta blockers - achieve resting hr <60 bpm. Reduced myocardial work and have anti-arrhythmic effects.
Ca2+ channel blockers; achieve resting hr <60 bpm, produce
Central acting eg diltiazem/verapamil if ß-blockers C-I
Peripherally acting dihydropyridines eg amlodipine, felodipine produce vasodilation
Potassium channel blockers - achieve resting hr <60 bpm.
Ivabridine, new medication which reduces sinus node rate
Nitrates: Vasdilation - Used as short or prolonged acting tablets, patches or as rapidly acting sublingual GTN spray for immediate use.
What is the main procedure carried out in pericutaneous coronary intervention?
Pericutaneous transluminal coronary angioplasty and stenting (now in 95% of procedures)
How is the stent applied?
Similar process to coronary angiography - ateromaous plaque is squashed with balloon and stent
What medicine is used after placement of a stent?
Aspirin and clopidogrel - whilst endothelim covers the stent struts until it is no longer seen as a foreign body with associated risk of thrombosis
What is PCI effective for?
Symptoms but no evidence stating that it improves prognosis
What are the risks associated with PCI?
Death
MI
Emergency coronary artery bypass grafting
Restenosis
What is the best option for treatment of someone with diffuse multi-vessel coronary obstruction
Coronary artery bypass surgery
How do risks compare between pericutaneous coronary intervention and coronary artery bypass grafting?
Upfront risk > PCI
Death - 1.3%
Q-wave MI - 3.9%
(increase with comorbidity)
Good lasting benefit - 80% symptom free in 5 years
CABG - may give prognostic benefit in some subgroups
What vein do they normally use in CABG?
Long saphenous vein
What artery can they use in CABG?
Mammary artery
Why is the long saphenous vein reversed?
So that the valves travel in the correct direction
Where is the mammary artery placed?
Places the end of the artery beyond the area where the blockage is – usually lasts the lifetime of the patient
