Coronary artery disease

• Ischemic heart disease( coronary artery disease)

Includes

Stable anginaAcute coronary syndromesSudden cardiac death due to arrythmiaChronic IHD with CHF

Acute coronary syndromes include:

Unstable anginaNon ST elevation MI( NSTEMI)Myocadial infarction with STE(STEMI)

Risk factors

Non modifiable risk factors:

AgeSexGenetics and familial predisposition

• Modifiable risk factors:

SmokingHeavy drinkingDiabetes mellitusHypercholesterolemia and hyperlipidemiaHypertensionObesity and sedentary lifestyleIncreased consumption of saturated fats and decreased intake of PUFA

Pathophysiology

•coronary arteries are obstructed due to athelesclerotic plaque formation

• In mild to moderate stenosis(narrowing) of coronary arteries patients are symptomless

• If >75% of lumen occlusion coronary arteris cannot dilate during increased physiological need

• T he artery can become partially blocked or narrowed, which reduces the flow of blood to the heart muscle. Reduced blood flow can cause chest pain, called angina pectoris, especially during physical activity or stress

•Plaque changes are the commonest initiating event in acute coronary syndrome- caused by the digestion of collagen cap of the atheroma by proteinases from macrophages. The exposed thrombogenic lipid and collagen initiate the coagulation cascade, causing thrombotic events

• This might lead to unstable angina or myocardial infarction

Angina pectoris

Angina pectoris is a painful or uncomfortable feeling that can occur when the blood supply to heart muscle is decreased.(ischemia)Can be a heaviness,a tightness, a pressureor burning sensation in the central chest The Pain May also be Felt in the shoulder,neck or along the jawatypical features may be fatigue ,nausea or indigestion,shortness of breath, sweating with or without chest pain

• Most of the time induced by physical activity • Subsides once the physical activity is stopped amnd/or nitrates

Types of angina

• Stable angina • Unstable angina

Stable angina

• Due to fixed coronary obstruction• Symptoms predictable and persistent over time

Case-I have been having exertional chest pain for the past 3 months.It is a central chest pain that radiates along the left upperlimb and occurs only if I exert. Walking about 500m will bring about the symptoms.This symptomatology has not changed over the past 3 months

Unstable angina

• Due to dynamic obstruction• Symptoms worsening over time

• Ex-I ve been having exertional chest pain for the past 1 month. Initially I got it with 1km walk and it was progressive over time. Now I get it even walking 10 feet

Myocardial infarction –heart attack

• Coronary vessel undergo complete obstruction due to plaque changes

• flow ceases in the coronary vessels beyond the occlusion

• The area of muscle that has either zero flow or so little flow that it cannot sustain cardiac muscle function

• Ischemia leads to infarction (ischemic cell death)• process is called a myocardial infarction.

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Progression of coronary plaque over time Clinical Findings

Acute Coronary SyndromesSudden Cardiac Death

Acute silent occlusive process

Angina pectoris

Thrombogenicrisk factors

Atherogenic risk factors

Endothelial dysfunction

20 years 60 yearsAge

Clinical features • Some can lead to sudden cardiac death • Chest pain is the most common symptom of a heart attack. Commonly chest pain

radiating to arms, shoulder, neck, teeth, jaw, belly area, or back.• The pain can be severe or mild. • Gastritis like symptoms • Heaviness of the chest

• The pain usually lasts longer than 20 minutes. Rest and nitrrates completely relieve the pain of a heart attack. Symptoms may also go away and come back.

• Other symptoms of a heart attack include:• Anxiety• Light-headedness, dizziness• Nausea or vomiting• Palpitations • Shortness of breath• Sweating,

• Some people (the elderly, people with diabetes, and women) may have little or no chest pain. Or, they may have unusual symptoms (shortness of breath, fatigue, weakness).

• A "silent heart attack" is a heart attack with no symptom

Types

• Subendocardial• transmural

Subendocardial vs. Transmural Myocardial Infarction

• Inner 1/3 or 1/2• Extend past territory of one artery

• Related to incomplete occlusion• Non-Q wave

• Distribution of one artery• Related to complete occlusion• Q-wave in ECG

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Complications of MI

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COMPLICATIONS OF INFARCTION

Ventricular Septal RupturePapillary Muscle Rupture

Ventricular Free Wall Rupture

Left Ventricular Thrombus

Deaths from MI

52%

19%

8%

21%

Prehospital

24 hours, in-hospital

48 hours, in-hospital

30 Days

Diagnosis

• ECG-ST depression, T inversion, ST elevation,Q waves ,loss of height of R wave

• Can diagnose type of MI, region affected by the ECG

Cardiac markers

• When heart muscle becomes irritated it may leak chemicals that can be measured in the blood. Levels of myoglobin, CPK, and troponin I and T

Treatment –acute

• Manage acute life threatening problems • Oxygen• Pain management-morphine• Antiplatelet drugs• Lipid lowering drugs• thrombolysis-drugs or angioplasty • Strict bed rest and liquid diet on D1

Treatment long term

• Feeding and physical activities restored gradually

• Life style modification• Angioplasty• CABG

Prevention is better than cure ...