Ischemic heart disease

Question 1

What is Ischemic Heart Disease (IHD)?

Answer 1

A condition where there is an inadequate supply of blood and oxygen to a part of the myocardium due to an imbalance between myocardial oxygen supply and demand. It is also known as Coronary Artery Disease (CAD).

Question 2

What is the main cause of IHD?

Answer 2

Mainly caused by atherosclerosis of the coronary artery.

Question 3

How many people did CAD affect globally in 2015, and how many deaths did it cause?

Answer 3

CAD affected 110 million people and resulted in 8.9 million deaths, accounting for 15.9% of all global deaths.

Question 4

How does atherosclerosis affect different organs?

Answer 4

In the heart, it leads to angina, MI, and sudden death; in the brain, it causes stroke and transient ischemic attack; in the limbs, it causes claudication and critical limb ischemia; in the kidneys, it narrows arteries, reducing blood flow.

Question 5

What is the progression of atherosclerosis?

Answer 5

It is a progressive inflammatory disorder with lipid-rich deposits (atheroma) in the arterial wall, which can remain asymptomatic until it disrupts tissue perfusion.

Question 6

What are the non-modifiable risk factors for atherosclerosis?

Answer 6

Age, male sex, and positive family history.

Question 7

Why are men at higher risk of atherosclerosis than women?

Answer 7

Men have lower estrogen levels, which increases LDL (bad cholesterol) and reduces HDL (good cholesterol), making them more susceptible to atherosclerosis.

Question 8

How does nitric oxide affect blood vessels?

Answer 8

Nitric oxide relaxes endothelium in blood vessels, aiding in vasodilation and blood flow regulation.

Question 9

What are the modifiable risk factors for atherosclerosis?

Answer 9

Smoking, hypertension, diabetes mellitus, hypercholesterolemia, obesity, physical inactivity, and alcohol use.

Question 10

How does smoking increase atherosclerosis risk?

Answer 10

Smoking increases inflammation, leading to LDL deposition, physical stress on arteries, and increased platelet aggregation.

Question 11

What are the symptoms of angina?

Answer 11

Symptoms include central/retrosternal chest pain described as “heavy,” “tight,” or “gripping,” and may range from mild ache to severe pain with sweating and fear.

Question 12

What is Prinzmetal’s angina, and who is more likely to experience it?

Answer 12

Prinzmetal’s angina is caused by artery spasms, typically at rest, and is more common in women.

Question 13

What are the classifications of angina according to the Canadian Cardiovascular Society?

Answer 13

Angina is classified as follows: 1. Typical angina: all three main features 2. Atypical angina: two out of three features 3. Non-anginal chest pain: one or less features

Question 14

What is the difference between typical, atypical, and non-anginal chest pain?

Answer 14

Typical angina meets all three criteria, atypical angina meets two, and non-anginal chest pain meets one or none of these criteria.

Question 15

What are the types of angina?

Answer 15

1. Stable Angina - occurs with activity or stress 2. Unstable Angina - occurs at rest, increases in frequency and severity 3. Refractory Angina - chronic angina unresponsive to treatment 4. Prinzmetal’s Angina - caused by a spasm in the coronary arteries, typically at rest

Question 16

How is stable angina characterized?

Answer 16

By central chest pain, discomfort, or breathlessness triggered by exertion or stress, relieved by rest.

Question 17

What activities commonly precipitate angina?

Answer 17

Physical exertion, cold exposure, heavy meals, and intense emotion. Less commonly, lying flat (decubitus angina) and vivid dreams (nocturnal angina) can trigger it.

Question 18

What is the significance of a 6–8-hour nitrate-free period in angina management?

Answer 18

This period prevents pharmacological tolerance to nitrates, maintaining their effectiveness.

Question 19

Why is lying down a possible trigger for angina?

Answer 19

Lying down (decubitus angina) increases venous return to the heart, potentially raising myocardial oxygen demand and triggering angina in susceptible individuals.

Question 20

What are common findings in a resting ECG of a patient with angina?

Answer 20

Often normal but may show reversible ST segment depression or elevation with or without T-wave inversion during symptoms.

Question 21

What are the main types of investigations for diagnosing IHD?

Answer 21

Resting ECG, exercise ECG, and coronary arteriography.

Question 22

What is the purpose of an ECG in diagnosing IHD?

Answer 22

To detect reversible ST segment depression or elevation, and T-wave inversion during symptoms.

Question 23

What is the purpose of coronary arteriography?

Answer 23

Provides detailed anatomical information on the extent and nature of coronary artery disease, especially when non-invasive tests do not confirm the cause of chest pain.

Question 24

What are antianginal drugs used in managing IHD?

Answer 24

Five main types: nitrates, beta-blockers, calcium antagonists, antiplatelet agents, and statins.

Question 25

How does glyceryl trinitrate relieve angina?

Answer 25

It acts on vascular smooth muscle to produce venous and arteriolar dilatation, reducing myocardial oxygen demand and relieving angina symptoms.

Question 26

How do beta-blockers help in managing IHD?

Answer 26

They reduce myocardial oxygen demand by lowering heart rate, blood pressure, and myocardial contractility.

Question 27

How do calcium channel blockers work in managing IHD?

Answer 27

They block calcium entry into vascular and myocardial cells, promoting vasodilation and reducing blood pressure and myocardial oxygen demand.

Question 28

What is the role of antiplatelet therapy in CAD?

Answer 28

To reduce the risk of adverse events like myocardial infarction, often using aspirin or clopidogrel.

Question 29

How does aspirin benefit patients with CAD?

Answer 29

Low-dose aspirin reduces the risk of adverse events like myocardial infarction by inhibiting platelet aggregation.

Question 30

What are the benefits of statins in CAD management?

Answer 30

Statins lower LDL cholesterol levels in the blood, reducing the risk of plaque buildup in arteries.

Question 31

What is the mechanism of potassium channel activators in IHD treatment?

Answer 31

They promote potassium efflux, hyperpolarize cell membranes, prevent calcium influx, reduce cardiac afterload, and increase coronary blood flow.

Question 32

What is the role of ivabradine in IHD management?

Answer 32

Ivabradine is an If channel antagonist that reduces heart rate without significantly affecting blood pressure, suitable for patients with heart failure.

Question 33

What is the recommended initial medical management for angina?

Answer 33

Start with low-dose aspirin, a statin, nitroglycerin (sublingual GTN), and a beta-blocker; add a calcium channel blocker or long-acting nitrate if necessary.

Question 34

When is revascularization considered in CAD?

Answer 34

When two or more drugs fail to achieve acceptable symptom control, revascularization like PCI or CABG may be pursued.

Question 35

What are the steps involved in Percutaneous Coronary Intervention (PCI)?

Answer 35

A guide-wire is passed across a coronary stenosis, a balloon is inflated to dilate the stenosis, and a stent is deployed to maintain vessel patency.

Question 36

What is Coronary Artery Bypass Grafting (CABG)?

Answer 36

A surgery where stenosed arteries are bypassed using internal mammary, radial arteries, or saphenous vein segments to restore blood flow.

Question 37

Why should intramuscular injections be avoided in angina management?

Answer 37

Poor skeletal muscle perfusion in angina patients increases the risk of painful hematoma formation at the injection site.