Ischemic heart disease Flashcards
What is Ischemic Heart Disease (IHD)?
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).
What is the main cause of IHD?
Mainly caused by atherosclerosis of the coronary artery.
How many people did CAD affect globally in 2015, and how many deaths did it cause?
CAD affected 110 million people and resulted in 8.9 million deaths, accounting for 15.9% of all global deaths.
How does atherosclerosis affect different organs?
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.
What is the progression of atherosclerosis?
It is a progressive inflammatory disorder with lipid-rich deposits (atheroma) in the arterial wall, which can remain asymptomatic until it disrupts tissue perfusion.
What are the non-modifiable risk factors for atherosclerosis?
Age, male sex, and positive family history.
Why are men at higher risk of atherosclerosis than women?
Men have lower estrogen levels, which increases LDL (bad cholesterol) and reduces HDL (good cholesterol), making them more susceptible to atherosclerosis.
How does nitric oxide affect blood vessels?
Nitric oxide relaxes endothelium in blood vessels, aiding in vasodilation and blood flow regulation.
What are the modifiable risk factors for atherosclerosis?
Smoking, hypertension, diabetes mellitus, hypercholesterolemia, obesity, physical inactivity, and alcohol use.
How does smoking increase atherosclerosis risk?
Smoking increases inflammation, leading to LDL deposition, physical stress on arteries, and increased platelet aggregation.
What are the symptoms of angina?
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.
What is Prinzmetal’s angina, and who is more likely to experience it?
Prinzmetal’s angina is caused by artery spasms, typically at rest, and is more common in women.
What are the classifications of angina according to the Canadian Cardiovascular Society?
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
What is the difference between typical, atypical, and non-anginal chest pain?
Typical angina meets all three criteria, atypical angina meets two, and non-anginal chest pain meets one or none of these criteria.
What are the types of angina?
- 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
How is stable angina characterized?
By central chest pain, discomfort, or breathlessness triggered by exertion or stress, relieved by rest.
What activities commonly precipitate angina?
Physical exertion, cold exposure, heavy meals, and intense emotion. Less commonly, lying flat (decubitus angina) and vivid dreams (nocturnal angina) can trigger it.
What is the significance of a 6–8-hour nitrate-free period in angina management?
This period prevents pharmacological tolerance to nitrates, maintaining their effectiveness.
Why is lying down a possible trigger for angina?
Lying down (decubitus angina) increases venous return to the heart, potentially raising myocardial oxygen demand and triggering angina in susceptible individuals.
What are common findings in a resting ECG of a patient with angina?
Often normal but may show reversible ST segment depression or elevation with or without T-wave inversion during symptoms.
What are the main types of investigations for diagnosing IHD?
Resting ECG, exercise ECG, and coronary arteriography.
What is the purpose of an ECG in diagnosing IHD?
To detect reversible ST segment depression or elevation, and T-wave inversion during symptoms.
What is the purpose of coronary arteriography?
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.
What are antianginal drugs used in managing IHD?
Five main types: nitrates, beta-blockers, calcium antagonists, antiplatelet agents, and statins.
How does glyceryl trinitrate relieve angina?
It acts on vascular smooth muscle to produce venous and arteriolar dilatation, reducing myocardial oxygen demand and relieving angina symptoms.
How do beta-blockers help in managing IHD?
They reduce myocardial oxygen demand by lowering heart rate, blood pressure, and myocardial contractility.
How do calcium channel blockers work in managing IHD?
They block calcium entry into vascular and myocardial cells, promoting vasodilation and reducing blood pressure and myocardial oxygen demand.
What is the role of antiplatelet therapy in CAD?
To reduce the risk of adverse events like myocardial infarction, often using aspirin or clopidogrel.
How does aspirin benefit patients with CAD?
Low-dose aspirin reduces the risk of adverse events like myocardial infarction by inhibiting platelet aggregation.
What are the benefits of statins in CAD management?
Statins lower LDL cholesterol levels in the blood, reducing the risk of plaque buildup in arteries.
What is the mechanism of potassium channel activators in IHD treatment?
They promote potassium efflux, hyperpolarize cell membranes, prevent calcium influx, reduce cardiac afterload, and increase coronary blood flow.
What is the role of ivabradine in IHD management?
Ivabradine is an If channel antagonist that reduces heart rate without significantly affecting blood pressure, suitable for patients with heart failure.
What is the recommended initial medical management for angina?
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.
When is revascularization considered in CAD?
When two or more drugs fail to achieve acceptable symptom control, revascularization like PCI or CABG may be pursued.
What are the steps involved in Percutaneous Coronary Intervention (PCI)?
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.
What is Coronary Artery Bypass Grafting (CABG)?
A surgery where stenosed arteries are bypassed using internal mammary, radial arteries, or saphenous vein segments to restore blood flow.
Why should intramuscular injections be avoided in angina management?
Poor skeletal muscle perfusion in angina patients increases the risk of painful hematoma formation at the injection site.
