Angina Flashcards
What is the route of the coronary arteries?
Coronary arteries branch off the aorta
Left coronary - left circumflex and left anterior descending
Right coronary - right marginal
What is angina?
Is it more common in men or women and what is the mean age of presentation?
What is the most common cause?
What are the 3 typical angina symptoms?
Chest pain due to a mismatch of oxygen supply and oxygen demand in the coronary arteries.
It is usually caused by a limitation of supply of oxygen due to atherosclerosis which causes a narrowing of the arteries.
- More common in men
- Mean age of presentation = 59.
Symptoms
- Constricting, heavy chest discomfort (can radiate to neck, jaw, shoulders, arms)
- Symptoms brought on by exertion or emotional stress (big meals, cold weather)
- Pain relieved by GTN spray or on rest
All 3 features present = typical angina
2 features present = atypical angina
0-1 feature present = non-anginal chest pain
What are the predisposing factors of IHD?
- Age
- Cigarette smoking
- Family history
- Diabetes
- Hyperlipidemia
- HTN
- Kidney disease
- Obesity (on it’s own is unimportant)
- Physical inactivity (on it’s own unimpotant)
- Stress (on it’s own unimportant)
Exacerbating factors for angina?
decreased supply, increased demand and triggers
decreased supply
- anaemia
- hypoxia in lung disease
- polychythemia
- hypothermia, hypovolemia, hypervolemia
increased demand
- HTN as heart beats harder
- Tachycardia
- Valvular HD
- Hyperthyroidism
- Hypertrophic cardiomyopathy
Triggers
- Cold weather
- Heavy meals
- Emotional stress
What are some differential diagnosis of angina?
- Pericarditis or myocarditis
- Pulmonary embolism
- Chest infection
- Gastro-oesophageal - common disease
- MSK - common
- Psychological (anxiety) - common
Overview for management for angina?
- Reassurance
- Treat any underlying conditions - anaemia, thyrotoxicosis etc.
- Lifestyle changes & secondary prevention- smoking cessation, exercise, diet
- Advice for emergencies
- Medication
- GTN PRN
- aspirin daily if not CI, statin if needed, antihypertensive if needed.
- antianginal drugs (on another flash card) - Revascularisation if angina continues with medication
What different investigations are available for angina? (6)
Exercise stress testing
- Used to use a lot before
- Look for ST segment depression on ECG
- Patient experiences symptoms upon exercise
Myoview scan
- Combined CG and radioactive tracer
- Drug given to increase HR = gap in tracer showing ischaemia
- Ischaemia reverses when at rest
CT coronary angiography
- Scanner goes around heart in 1 breath
- Can rule in and out CHD
- Doesn’t provide information on the severity of the disease
Stress ECHO
- Stress drug given and we look for a reduction in pumping capacity and should return after stress agent is removed
- Not commonly done anymore
Perfusion MRI
- Very specific and good but not done in many places
- We can see which parts of the heart are affected and how bad the restriction is
Coronary angiogram
- If not responding to medical treatment well or one of the other tests are not conclusive
- Can also do test if symptoms are so bad they need revascularisation surgery
What 3 things do anti-anginal drugs aim to do?
- Reduce preload - Nitrates
- Reduce afterload by dilating arteries - CCBs
- Reduce HR - BBlockers
What is the first line pharmacological treatment for angina? (Example of drug?)
How do they work?
What are the side effects and contraindications for this group of drugs?
Beta blockers (atenolol or bisoprolol)
Reduce LV contractility (-ve inotropic)
Slow heart rate (-ve chronotropic)
Reduced myocardial oxygen demand so reduces symptoms
Side effects
- Bradycardia
- Peripheral constriction (cold hands and feet)
- Erectile dysfunction
- Tiredness, nightmares with older bblockers
Contraindications
- ASTHMA
How do nitrates work in treatment of angina?
(GTN/Isosorbide mononitrate) Nitrates are vasodilators on venous return so they work by increasing the capacity and decreasing preload
They have a direct dilating effect on coronary arteries
Decrease BP in higher doses
How to calcium channel blockers work in the treatment of angina? (Example of drug?) Side effects of this class of drug?
Amlodipine
- Vasodilator
- Reduces BP
Side effects?
- Postural hypotension
- Flushing
- Swollen ankles
How do antiplatelet agents work in the treatment of angina/angina complications?
Examples of antiplatelet therapies?
Risks associated with using these medications?
Antiplatelet therapy protects against platelet activation and acute thrombosis reducing risk of MI and sudden death.
- Low dose aspirin to reduce thrombus formations in almost all SIHD patients - reduces relative risk of non fatal MI by 20%
- Salicyclic acid
- COX inhibitor
- Reduces prostaglandin synthesis (thromboxane)
- Reduced platelet aggregation, anti-inflammatory
Can cause gastric bleeding
Why do we use statins in angina patients?
- Indicated for all of these patients
- Works in the liver on HMG CoA reductase and therefore, less LDL cholesterol synthesis
- Trials show that statin therapy reduces coronary death and non-fatal MI’s regardless of baseline low-density lipoprotein (LDL)-cholesterol
Why might we use ACEi in IHD/angina patients?
Who do we prescribe them to?
- ACE inhibitors result in a reduction in angiotensin II with an increase in bradykinin.
- These changes in the physiological balance between angiotensin II and bradykinin could contribute to reductions in LV and vascular hypertrophy, atherosclerosis progression, plaque rupture, and thrombosis through favourable changes in cardiac haemodynamics and improved myocardial oxygen supply and demand.
- Significant reductions in the incidence of acute MI, unstable angina, and need for coronary revascularisation in patients after MI with LV dysfunction, independent of aetiology
ACE inhibitors should be prescribed in all patients with IHD who also have hypertension, diabetes mellitus, left ventricular ejection fraction (LVEF) 40% or less, or chronic kidney disease, unless contraindicated.
Treatment of choice for treatment of acute episodes of angina?
Sublingual glyceryl trinitrate (GTN spray) - use prophylactically before activities which might induce angina attack and on onset of symptoms
effect within 5 mins, if no effect initially, spray again and if still no effect = hospital admission as could be MI
