angina pectoris Flashcards
definition
chest pain that is the product of transient myocardial ischemia.
Etiology – artherosclerotic (narrow artery), hypercoagulation, supply of O2 & myocardial demand imbalance.
pathogenesis
Ischemia happens when there is demand and supply disbalance
1. When only demand is ( dynamic changes )
2. Supply is impaired, demand not
3. Demand increase and supply decrease
4. Demand & supply both ↑ - Heart effects & bad regulation. Bad factor accompany with each other.
Main mechanism due to spasm of artery and transient hypercoagulation
- Spasm
a. hyperactivity of receptor in large and middle sized coronary artery cause general spasm of coronary system. spasm of these large trunk cause in blood and O2 supply
b. Disbalance of and receptor - receptor dilate coronary system in stress condition
c. Atherosclerotic plaque damage endothelium - Hypercoagulation - coagulation of artery depend on thrombocyte activation
classificaiton - stable angina
grade 1 2 3 4 - decubitus angina, nocturnal angina
- Stable
- occlusion caused by atheroma ( not spasm )
- 4 grades acc to tolerance to physical activity ( Canadian Cardiology Society )
- characterized by stereotypic characteristics, pain arises after a particular level of physical exertion is relieved by specific NG.
Grade 1
Pain in physical activity in higher than normal activity due to increase demand
Grade 2
Common attacks of angina which is walking 100- 500m , climbing > 1 floor, walking against frozen cold wind
Prominent angina when > 2 vessel affected , change in the lumen , stereotypic
Grade 3
Pain at rest, at night -> angina starts during REM sleep ( ↑ SNS ↑ demand )
Grade 4
Few patient survive till here , pain when walk < 100m , can‘t carry up themselves , can‘t do anything simple, typical rest angina attack
Decubitus variant and nocturnal 20-50 attacks /day may occur
- Decubitus angina – Due to changes of posture, increase preload to heart, attack.
- Noctural angina – This group is loss because majority of them dies.
Classification : Unstable angina
Unstable angina (Due to destabilizations of arthrosclerosis plug)
- due to dynamic spasm characterized by absence of stereotype-prolonged pain, severe, can occur in rest, decreased physical activities, need more tablets to relieve the pain.
a. Progressive exertional / accelerated angina
- patient > stable
- duration of attack/ year: 15-20
- tolerance to physical activity very short
- NG not so effective
b. New onset angina
- suddenly appear
- can‘t predict the outcome
c. Variant/ Prinzmetal angina
- appear only at rest and physical activity don‘t provoke it
- angina > prolonged
- > severe pain
- no absolute effect of NGclassification - unstable
clinical symptoms of coronary pain syndrome
Clinic of coronary pain syndrome
- Pain when low blood supply (energetic disbalance)
- In heart no pain receptor, only specific receptor baroreceptor, chemoreceptor, mechanoreceptor
- In ischemic zone, overactivity of receptor electrical function to brain reach thalamus and irradiate to cortex
- pain is transient
- Pain localised in the chest , substernal area
- Duration: never exceed 20-30 min normally 5-10 min, Duration of pain is >1 min & <20 min, pain less than 5 minutes is not angina pain
- Physical activity like walking, climbing, carrying heavy things, stress, ↑ eating volume cause SNS
- Nitroglycerin sublingual relieve pain in < 5 min at rest
- Irradiation to central part of the chest, left shoulder, scapula region, neck, jaw, arm, hand till 4th & 5th
- Character of pain: struggling, heaviness, squeezing, burning, sharp, and localised pain which can be shown by finger, Pressing, aching.
- Associated symptoms: headache, dizziness, inspiratory dyspnea, arrhythmic pulse, nausea, cold sweat, palpitation, weakness, fear of death
Pharmacological & stress testing: indication, c/i & evaluation of result
Pharmacological test
1. Positive effect
a. Nitroglycerin
b. Β-blockers - propranolol, metoprolol, atenolol, nadolol, and timolol.
c. Calcium antagonists
2. Negative effect
- Diperidamole and Curantile. Injection intravenously. - It will cause attack.
3. Cardiac catheterization with coronary arteriography - for direct visualization of the coronary arteries by injection radiographic contrast. used for coronary artery disease.
4. Cardioscintigraphy - thalium is injected into peripheral venous blood
5. Pharmacological stress - injection of vasodilator - normal vessels are dilated. Abnormal vessels show ischemia.they cannot dilate.
indications
Indications
- Angina refractory to medical therapy.
- Strongly positive exercise test.
- Angina occurring after myocardial infarction.
- When the diagnosis of angina is uncertain.
- to put diagnosis
- to know grades of angina
- checking of therapy effectiveness
- to check ability of patient with M.I
contraindications
- Myocardial infarction, fresh in 2 weeks
- Transmural.
- Unstable angina(new onset, stable, Prinzmetal)
- Acute/ chronic resp failure
- Acute/chronic cardiac failure
- Stenosis of aortic valve, fever, disease of joint
- Allergy for drug.
- ↑ BP (180/110), tachycardia
- Stroke and surgical operation of brain.
- any varaiant of acute fresh inflammation
- aneurysm of the heart
- serious arrythmia
- diseases of the joint
- episodes of thrombophlebitis
stress test (provocation test)
age - watt (bpm)
- don‘t need to wait demand supply disbalance
- e.g. step test, ergometry (walking, cycling), treadmill
- Provocation BP X HR at moment of investigation
Age Watt ( bpm )
20-30 - 170
30-40 - 150
40-50 - 150
50-60 - 140 - physical work done step by step in 2 variants
a. non stop – increasing in mechanical load
b. 1 min of rest after each step for old people - record ECG in next few minutes 2,3,4,5,10
- some people can reach submax level without changes in ECG
- inflammatory changes / dystrophy process in the heart check in ECG and clinical signs
Stress test (provocation test) : indications
- give artificial condition to test the heart function before angina occurs
Stress test (provocation test) : contraindication
- stress test for people > 60 yrs old not done
- no leg, weakness
Stress test (provocation test) : evaluation
Clinical prove of angina :
- if patient stop before or have sudden chest pain provoked by testing
- if BP < 25-30% stop test and if BP > 220/110 stop the test
- sensitivity of stress test, may be false and patient don‘t show problem in test
During stress test
a. direct signs of ischemia-classical pain episode, dyspnea, dizziness, cold sweat, decrease blood pressure
b. ECG
- ST depression
- abnormal shape of QRS complex
- appearance of transient pathological Q wave
- episode of transient ventricular arrhythmia
Stress echocardiography - based on principles as stress radionuclide ventriculography but an echocardiograph is used to produce the images of wall motion abnormalities.
general management of angina pectoris
- Nitrates – sublingual/IV
- nitroglycerin sublingual
- Dinitrate isosorbide – tablet
- NG in IV
- glyceryl trinitrate (GTN) spray /sublingual tabs, oral nitrate e.g. isosorbide mononitrate - β blockers
- Propanolol
- selective group, Atenolol
- Nebivalol - Ca channel blocker
- Verapamil, Diltiazem
- Ca antagonists: amlodipine
- Alteration of life style: stop smoking, encourage exercise, weight loss.
- Modify risk factors: diabetes, hypertension.
- Aspirin
- adding a K+ channel activator, e.g. nicorandil per os.
indication to surgical treatment
- 3rd class angina pectoris
- stenosis of > 75% of 3 coronary vessel
- no effect on drug
- patients who remain symptomatic despite optimal medical therapy & whose disease is not suitable for percutaneous transluminal coronary angioplasty
Prognosis
1st and 2nd grade angina pectoris have good prognosis but 3rd and 4th grade bad prognosis If recent onset exertional angina:
- Up to 1/3 experience symptom remission.
- Annual mortality is 2-3%.
- There is a 90% 8 year survival when angina is mild & stable.
Unstable angina has a worse prognosis, 30% suffering myocardial infarction /death within 3 months.
