3. IHD
Other names: coronary heart disease or coronary artery
disease(CAD)
Definition: Group of heart diseases in which there is an
imbalance between blood supply to the heart and oxygen
demand
4. IHD consists of:
- stable angina
- acute coronary syndromes(includes unstable angina,
STEMI, NSTEMI)
- It is a leading cause of death - 90 lakh deaths yearly
STEMI=ST elevation Myocardial infarction
NSTEMI=Non-ST elevation Myocardial Infarction
5. Etiology
Main cause of myocardial ischemia: Coronary artery occlusion
- Due to coronary atherosclerosis
Rare causes:
- Embolus
- vasculitis
- Vasospasm
- Shock
Risk factors for IHD - SAME as risk factors for
7. Modifiable risk factors
1. Hyperlipidemia: increase in serum cholesterol
โข High levels of Low density lipoprotein(LDL) - โbad
cholesterolโ
โข High-density lipoprotein(HDL) - โgood cholesterolโ
1. Hypertension: increase in systolic and diastolic blood
pressure
2. Cigarette smoking: most important avoidable cause of
atherosclerosis
3. Diabetes mellitus
10. Pathogenesis
Exposure to risk factors
โ
Formation of fatty streaks
โ
lipoprotein particles accumulate inside intima and macrophages enter
into the lesion
โ
macrophages ingest the lipoprotein and transform into "foam cells"
โ
11. Pathogenesis(...cont)
macrophages release cytokines and lead to smooth muscle
proliferation
โ
some foam cells die - formation of lipid-rich core
โ
fibrous tissue forms around lipid-laden macrophage - formation of fibrous
cap
โ
this fully-developed plaque/atheroma can undergo calcification
12. Pathogenesis(...cont)
โ
plaque can bulge into lumen of coronary artery and narrow it
โ
thrombosis can occur, leading to complete block of blood vessel and
causing acute coronary syndrome
13.
14. Parts of the plaque
1. Fibrous cap
2. Lipid core
3. shoulder
15. Stable plaque: thick cap, small core - unlikely to undergo rupture
High risk plaque: thin cap, large core - likely to undergo rupture
Complicated or advanced plaque: plaque which undergoes
complications like
16. Stable Angina or Angina pectoris
Definition: sudden and recurrent attacks of substernal chest
pain due to transient(short-lasting) myocardial ischemia
Causes:
โ obstruction of coronary blood flow
โ coronary vasospasm
โ coronary thrombosis
18. Clinical features
Classical or stable or exertional angina pectoris:
- Constricting discomfort or squeezing pain in front of the chest
- Radiates to left arm, neck, jaw and less commonly to the right
side
- Lasts for 2-5 minutes
- Levineโs sign: clenched fist held over chest
- Relieved by rest or sublingual glyceryl trinitrate
19.
20. Types of angina
โ Stable angina: occurs on exertion - 2-5 min
โ Unstable angina: occurs even at rest - >20 min
โ Refractory angina: angina not controlled by medical
therapy
โ Variant angina or Prinzmetal's angina: pain occurs
without exertion and at rest usually - due to coronary
vasospasm, commonly in women
24. Investigations
ECG:
- Normal when resting
- During an attack of angina, ECG shows signs of myocardial
ischemia, like ST segment depression or elevation, with or
without T-wave inversion
Exercise Tolerance Test(ETT) or exercise ECG:
- Done using treadmill
- ECG, BP and general condition are monitored
- NOT DONE for suspected MI
31. Treatment of angina
- Stop smoking
- Reduce body weight
- Regular exercise - but not extreme
- Avoid walking or exercise after a heavy meal or in cold
weather
- Anti-anginal drugs: Take sublingual nitrate before that any
exertion that may cause angina
32. ABCDE
A: Aspirin and Anti-anginal therapy
B: Beta-blocker and Blood pressure
C: Cigarette smoking and Cholesterol
D: Diet and Diabetes
E: Education and Exercise
33. 1) General measures
- correct risk factors
- treat HTN, DM
- reduce cholesterol levels through diet and drugs
- lifestyle modification: healthy diet and regular exercise
34. 2) Drug treatment:
Anti-anginal drugs:
5 groups
1. nitrates
2. Beta-blockers
3. Calcium channel blockers
4. Potassium channel openers
5. If channel antagonist
35. 1) Nitrates:
E.g: glyceryl trinitrate(GTN, nitroglycerine), isosorbide dinitrate
for prophylaxis and treatment
GTN spray or sublingual
36.
37. 2) Beta-blockers:
Reduce workload on heart
E.g:
- cardio-selective beta-blockers like atenolol, metoprolol
- non-selective: propranolol
38. 3) CCB:
E.g: nifedipine, amlodipine
4) Potassium channel opener:
E.g: nicorandil
5) If channel antagonist:
E.g: ivabradine
Other drugs:
Aspirin, clopidogrel: antiplatelet effect
Statins: to lower cholesterol levels
39. 3) Surgical treatment: revascularisation
- Percutaneous coronary intervention(PCI): placement of
stent to dilate the stenosed coronary artery
- Coronary artery bypass grafting(CABG)
44. Clinical features
- Prolonged cardiac pain: angina pectoris, radiating to left
shoulder, neck or arm
- Lasts for more than 20 minutes
- Does not respond to sublingual GTN
45. Other features like:
- nausea and vomiting
- breathlessness
- anxiety, fear of impending death
- collapse
- Pain may be absent in diabetics - called โsilent MIโ
47. Investigations
ECG changes:
- in STEMI: ST segment elevation, with Q wave and inverted T-wave
- NSTEMI: ST-segment depression, T-wave changes
48.
49.
50.
51. Cardiac enzymes or cardiac biomarkers:
- Creatine Kinase(CK-MB)
- Lactate Dehydrogenase(LDH)
- Cardiac Troponins: Troponin I(TnI), troponin T(TnT) - most
sensitive and specific for MI
54. Management of MI
- Admit in cardiac care unit
- General treatment( โ M O N A Cโ)
- Specific therapy
- Aftercare
55. - General treatment( โ M O N A C โ)
M: Morphine 2-4 mg quarter 5-10 minutes to control chest pain
O: Oxygen 4 L/min
N: Nitroglycerine sublingual or spray
A: Aspirin 160-325 mg to chew and swallow or
C: Clopidogrel 300mg oral
56. - specific therapy:
Thrombolysis or percutaneous coronary intervention(PCI)
Beta blockers: to reduce workload of heart
Treat complications like congestive failure and arrhythmias
