Stable Angina Flashcards
What is the definition of angina
a discomfort in the chest and/or adjacent areas associated with myocardial ischaemia but without myocardial necrosis
What is the pathophysiology of myocardial ischaemia
Mismatch between supply of O2 and metabolites to myocardium and the myocardial demand for them.
What causes myocardial ischaemia (3)
Obstructive coronary atheroma (Very common)
Coronary artery spasm (Uncommon);
Coronary inflammation/arteritis (Very rare)
What are the uncommon causes of myocardial ischaemia (3)
Anaemia- reduced oxygen transport
Left ventricular hypertrophy
Thyrotoxicosis- excess of thyroid hormone in the body
When does myocardial oxygen demand increase
Situations where HR and BP rise: exercise, anxiety/emotional stress and after a large meal, cold weathee
What stage of Atherosclerosis does stable angina occur
Obstructive plaque >70% lumen
What stage of Atherosclerosis does acute coronary syndromes occur
Spontaneous plaque rupture & local thrombosis with degree or occlusion
What is essential in making the diagnosis
History:
Comes on during exertion
Common in individuals with high CV risk
Treatment is mainly symptomatic
What is essential to establish the characteristics of patients pain (4)
Site of pain (watch for patient gestures): retrosternal
Character of pain: often tight band/pressure/heaviness.
Radiation sites: neck and/or into jaw, down arms.
Aggravating e.g. with exertion, emotional stress
& relieving factors e.g. rapid improvement with GTN or physical rest.
What features make angina less likeky
- Sharp stabbing pain (pleuritic or pericardial)
- Associated with body movements or respiration
- Very localised; pinpoint
- Superficial with/or without tenderness
- No pattern to pain
- Begins sometime after exercise
- Lasting for hours
History of complaint of suspected angina (3)
Breathlessness on exertion
Excessive fatigue on exertion for activity undertake
Near syncope on exertion
How many stages are there in the Canadian Classification of angina severity
4
Stage 1 CCS
Ordinary physical activity does not cause angina, symptoms only on significant exertion.
Stage II CCS
Slight limitation of ordinary activity, symptoms on walking 2 blocks or > 1 flight of stairs.
Stage III CCS
Marked limitation, symptoms on walking only 1-2 blocks or 1 flight of stairs.
Stage IV CCS
Symptoms on any activity, getting washed/dressed causes symptoms.
Non-modifiable risks for coronary artery disease (5)
Age, gender, creed, family history and genetics
Modifiable risks for coronary artery disease (5)
Smoking Lifestyle and Diet Diabetes Hypertension Hyperlipidaemia
What do you look for to diagnose on examination (7)
Tar staining on fingers Obesity (centipedal) Hypertension Corneal arcus Xanthalasma Abdominal aortic aneurysm Diabetic retinopathy
Signs of exacerbating condition (7)
Pallor of anaemia Tachycardia Tremor Hyper-flexia of hyperthyroidism Murmur Aortic stenosis Signs of heart failure
Diagnosis (investigations) (7)
Blood CXR Electrocardiogram Exercise Tolerance Test Myocardial Perfusion imaging CT Scan/Angiography Invasive Angiography
What can the Blood investigations show (5)
FBC Lipid profile Fatsing Glucose Electrolytes Liver and Thyroid tests
What can the chest X-ray show
other causes of chest pain and pulmonary oedema
What does a ETT rely on
The ability for the patient to exercise enough to produce sufficient CV stress
What is a positive ETT
Symptoms
ST segment depression
Cons of ETT
Negative result does not rule CAD
What information can you get from myocardial perfusion imaging (3)
CAD
Localisation of ischaemia
Assessing size of area affected
Cons of MPI (2)
Expensive
requires radioactivity
What are the 2 types of stress that can be used in MPI
Exercise
Pharmacological
What drugs can be used as Pharmacological stresses for MPI (3)
Adenosine
Dipyridamole
Dobutamine
MPI tracer is seen at rest but not under stress
Ischaemia
MPI tracer not seen at rest or stress
Infarction
When is an Invasive angiography used (5)
Early or strong positive ETT Angina refractory to medical treatment Diagnosis not clear after non-invasive tests Young patients Occupation or lifestyle with risks
Percutaneous Coronary Intervention (PCI)
Angioplasty
Stenting
CABG
What is an angioplasty
A procedure carried to widen narrowed veins and arteries, typically arterial atherosclerosis
How is a cardiac catheterization carried out?
- Performed under local anaesthetic
- Arterial cannula is inserted into the femoral or radial artery
- Catheters passed to aortic root to ostium of coronary arteries
- Radio-opaque contrast is injected and visualised on X-Ray
What is used to visualise radio-opaque dye in cardiac catherization
X-ray
What image does a cardiac catheterization produce?
2D Lumenogram that shows dye passing through arteries
General measures for treatment (4)
BP, DM, cholesterol, lifestyle
Medical Treatment (8)
Statins ACEI Aspirin Beta blocker Calcium channel blockers IK channel blockers Nitrates K+ channel blockers
Role of statins
Reduce LDL-cholesterol
Role of ACEI
Stabilises endothelium and reduces risk of plaque rupture
Role of beta blocker
Reduces heart rate
Role of calcium channel blockers and examples
(diltiazem/verapamil)- central acting.
dihydropyridines e.g. amlodipine, felodipine (peripheral acting)
Reduces force of contraction
Role of IL blockers
Reduces sinus node rate (Ivabridine)
Role of nitrates
Vasodilators (GTN)
of K+ channel blockers
Nicorandil
Revascularisation treatment
CABG, PCI
Who would benefit the most from CABG
Stable angina
>70% stenosis in left main stem artery
Proximal three vessel
Two vessel CA (ejection fraction <50%)
