Do you know that Ischemic heart disease (IHD) is the number one cause of death throughout the world? Today, we will explore the pathophysiology of ischemic heart disease and get to know how it develops in your heart. We will also learn the risk factors, causes, symptoms, diagnosis and treatment. The leading cause of ischemic heart disease is “blockage of coronary artery”. The chest pain is a hallmark sign of coronary artery disease. The pathophysiology of ischemic heart disease is an imbalance of oxygen supply and oxygen demand in the heart due to atherosclerosis formation in the coronary artery. You may be suspected of ischemic heart disease if you have had a history of diabetes mellitus, hypertension, smoking and a bad lifestyle.

1. Exploring Pathophysiology of Ischemic Heart
Disease: A Comprehensive Guide
Introduction
Do you know that Ischemic heart disease (IHD) is the number one cause of death
throughout the world? Today, we will explore the pathophysiology of ischemic
heart disease and get to know how it develops in your heart.
Heart disease is more common in the US. You will be shocked to know that one
person dies every 33 seconds in the United States from cardiovascular disease, as
per the CDC.
In 2017, about 126 million people were affected globally by Ischemic heart
disease.
As far as India is concerned, 28 million cases of IHD were found in 2016.
Ischemic heart disease means the death of heart cells (or cardiomyocytes) due to
obstruction or blockage in the coronary artery.

2. You know how the lifestyle is going at the current time. We all are trapped in oily
foods (junk food), processed food, physical inactivity, and long-time sitting jobs.
There would be obvious problems in your coronary artery.
You can understand the purpose of this post. I want to make you aware of this
cardiovascular disease.
In this post, there will be an in-depth discussion of the pathophysiology of
ischemic heart disease. You will also learn the risk factors, causes, symptoms,
diagnosis and treatment.
Let’s start this article.
What is ischemic heart disease exactly?
If we see the medical definition of ischemic heart disease, “it is a group of
clinical-pathological problems or syndrome due to an imbalance of oxygen (O2)
supply and oxygen demand to myocardium muscle (heart) that leads to myocardial
ischemia”.
The heart is a mechanical organ. You must have seen “water motor” in your house.
Our heart also works similarly. The heart acts as a water motor. That’s why it is
called a pumping organ.
The whole concept is based on O2 supply and O2 demand.
Usually, our heart muscle (or myocardium) needs a continuous supply of blood as
much as it demands.
If your heart muscles do not get enough blood supply as much as they require, it
causes necrosis or death of heart cells. It is called “Myocardial ischemia”.
In ischemia, there are three conditions involved –
● Decrease oxygen supply (hypoxemia)

3. ● Decrease nutrient supply
● Decrease washout of metabolic waste (means accumulation of waste
products)
The development of ischemia in the heart is called Ischemic heart disease. It is also
called “Coronary artery disease” or “coronary heart disease” because there is a
blockage in your coronary artery.
What is the leading cause of ischemic heart disease?
The leading cause of ischemic heart disease is “blockage of coronary artery”. The
coronary arteries are vessels that supply blood to your heart muscles.

4. Suppose you get any obstruction or blockage in your coronary artery. In that case,
it decreases the flow of blood towards the heart, and your heart muscles will start
damaging, which leads to ischemic heart disease.
You will have a coronary artery blockage when there is a deposition of plaque or
blood clot in a coronary artery called Atherosclerosis.
Here, the main culprit of coronary artery disease is atherosclerosis.
What is the pathophysiology of ischemic heart disease?
You know that atherosclerosis is a major problem in ischemic heart disease
pathophysiology.
You need to understand the pathophysiology of atherosclerosis, which means how
atherosclerosis forms in your body.
Normally, your blood vessels have a layer of semi-permeable membrane that is
made of endothelial cells. These cells are fenestrated, which helps to regulate the
exchange of fluid, nutrients, gases, and wastes (between the blood and tissues).
You should be happy because the endothelial cells of blood vessels act as a
protective layer. It releases various useful enzymes, hormones and other substances
to prevent blood clots, such as –
● Nitric oxide (NO) – dilates blood vessels
● PGI2 (prostacyclins) – stop platelet aggregation
● Heparin – prevents the formation of blood clot
● Thrombomodulin – prevent coagulation

5. When your endothelial cells become damaged, they stop secreting useful
substances like NO, PGI2, heparin, and thrombomodulin.
It generally happens if you have had a history of smoking, diabetes mellitus,
hypertension, ageing, stress, physical inactivity, exposure to viruses or other
microbes, etc.
These medical conditions or activities may start leaking nasty molecules (or
harmful substances) from endothelial cells in your blood, such as –
● LDL (low-density lipoproteins)
● Macrophage
● Cytokines such as TNF (tumour necrosis factor)
● Free radicals
● Growth factors
Mechanism of plaque formation
The formation of atherosclerosis starts with the formation of lipoprotein.
The lipoproteins are made up of lipids and proteins. In LDL, there is more
concentration of lipids and less quantity of protein. Due to the high LDL
concentration in lipids, it is sticky, which is not good for health. It is also called
Bad Cholesterol.
Whenever you have an endothelial injury, monocytes enter your intima (innermost
layer of blood vessel) and start secreting free radicals. These free radicals oxidize
the LDL molecules.
The oxidised LDL molecules attract more monocytes (WBCs), lymphocytes,
macrophages, LDL-C and smooth muscle cells. It makes foam cells.

6. Gradually, these foam cells become complex due to collagen deposition, making a
layer of fatty streaks in your artery.
Over time, this fatty streak developed into a fibrous cap, which is made up of
smooth muscle cells and connective tissues.
It is a mature plaque that bulges into your arteries.
The macrophages and t-lymphocytes are on the outer boundary of the fibrous cap,
making the plaque rupture and fissure.
This rupture plaque contributes to the accumulation and adhesion of platelets. The
platelets start sticking on the exposed or ulcerated area by platelet adhesion
reaction, and more platelets clump together. The process is called platelet
aggregation.
It forms a blood clot called Atheroma(fatty plaque).
This is the atherosclerosis pathophysiology. When you get deposition of this fatty
plaque in your artery, it is called Atherosclerosis.
It reduces or stops the blood flow in your coronary artery and causes coronary
artery disease.

7. How many types of atherosclerotic plaque?
Atherosclerotic plaque comprises fat, cholesterol, platelets, monocytes,
lymphocytes, smooth muscle cells and inflammatory cells (cytokines and growth
factors) that build up inside your artery.
You may have two types of atherosclerotic obstruction. It could be stable and
dynamic (or unstable) atheromatous plaque.
Initially, plaque is stable because it is gradually made in your arteries. It does not
move here and there. It narrows your arteries and decreases the blood flow towards
the heart. This stable plaque can be detectable and treatable.
The stable plaque becomes more vulnerable when it gets converted into a dynamic.

8. This dynamic plaque is unstable, which creates more disruption. This obstructive
unstable plaque may travel through wider to narrow arteries. It may completely
block your coronary artery or carotid artery.
The complete blockage of the coronary artery may cause a heart attack (or
myocardial infarction), and blockage of the carotid artery may lead to brain stroke.
Difference between stable and unstable plaque
Characteristics Stable plaque Unstable plaque
Dangerous Less dangerous More dangerous
Fibrous cap Thick (layer of fibrous
connective tissue)
Fragile
Foam cells Less More
Macrophages Less More
Fat or cholesterol Less More
What are the early signs of heart blockage?
When you get a blockage in your coronary artery, you will have chest pain.

9. This chest pain is a hallmark sign of coronary artery disease. You will have a
clenched fist over your chest, known as Levin’s Sign.
This pain may radiate to the left arm and shoulder. This medical condition is called
Angina Pectoris.
Angina pectoris can be of two types – stable and unstable angina.
In a stable angina, there is a 70% blockage of the coronary artery. You will feel
chest pain when you do physical work such as climbing upstairs, walking, running,
exercising, etc. It is also called Classical angina pectoris.
On the contrary, unstable angina may cause chest pain even at rest condition or
while sleeping. There could be 90% blockage or vasospasm of the coronary artery.
It is also called Prinzmetal or Variant angina pectoris.
When you have a 100% blockage (or complete blockage) of the coronary artery, it
could lead to Myocardial infarction or heart attack.
During heart attack, you may feel symptoms like –
● Severe chest pain that radiates to left arm and shoulder
● Shortness of breath
● Sweating
● Abnormal heart beating (palpitation)
● Anxiety
● Fatigue and weakness
● Nausea and vomiting

10. What are the risk factors of ischemic heart disease?
According to a study, smoking is a primary risk factor for ischemic heart disease.
Tobacco smoking contains nicotine that easily sticks to platelets and increases the
formation of atheromatous plaque in your artery
Along that, coronary artery disease is also associated with a history of following
medical conditions or bad lifestyles, such as –
● High blood pressure
● High blood cholesterol levels (high LDL)
● Uncontrolled diabetes (increased blood glucose level)
● Overweight or obesity
● Lack of physical activity
● Unhealthy diet (having oily or processed foods)
● Family history of heart disease
● Older age
What tests are done to diagnose ischemic heart disease?
Coronary artery blockage can be determined by various diagnostic tools such as –
● ECG – To find out STEMI
● Blood test – To determine the level of Trop T, LDH and CK-MB

11. ● Angiography – To visualize coronary artery blockage
● Myocardial perfusion scan or nuclear stress test – To determine heart
muscles or walls damage
Can ischemic heart disease be treated?
You may be suspected of ischemic heart disease if you have had a history of
diabetes mellitus, hypertension, smoking and a bad lifestyle.
If you struggle with chest pain while climbing stairs, walking, running or doing
any physical exertion. In that case, you need to consult your doctor.
You will have to get your diagnostic test done.
Suppose you have been diagnosed with ischemic heart disease. The treatment
algorithm for ischemic heart disease should be started in the following ways –
Non-medical therapy to prevent ischemic heart disease
First, you need to minimize your risk factors and improve your lifestyle.
● Stop smoking (if you are a smoker)
● Controlled your diabetes mellitus
● Controlled your blood pressure
● Weight loss
● Eat healthy food such as fruits, vegetables, low glycemic, non-oily, etc.

12. ● Start doing exercise or yoga regularly
Medical therapy to prevent ischemic heart disease
You may need to take medicines if non-medical therapy does not work. You have
to continue your non-medical treatment while taking medication for ischemic heart
disease.
You may be started following anti-anginal drugs –
● Antiplatelet drugs, such as aspirin and clopidogrel
● Nitrates, such as sublingual nitroglycerin tablet
● Beta blockers, such as propranolol, atenolol, metaprolol, bisoprolol,
nebivolol, etc.
● Calcium Channel Blockers, such as amlodipine, nifedipine, etc.
● Statins, such as atorvastatin, rosuvastatin, etc.
● ACE inhibitors, such as enalapril, ramipril, etc.
● Newer drugs, such as ranolazine, ivabradine, and trimetazidine
Surgery for unstable ischemic heart disease or myocardial infarction
Suppose there is a complete blockage in the coronary artery. In that case, you may
require surgery. There are two most trending surgeries for coronary artery diseases
–

13. 1. PTCA
PTCA means percutaneous transluminal coronary angioplasty.
Angioplasty is done if there is acute myocardial infarction (NSTEMI or STEMI) or
unstable (or variant) angina pectoris.
This procedure is used to widen narrow (or obstructed) coronary arteries. In this
surgery, a deflated balloon catheter is used in the femoral artery. This catheter is
inflated at the atherosclerotic plaque of the heart’s coronary artery, and then the
stent is placed.
This surgery is also called Balloon angioplasty.
2. CABG
CABG means coronary artery bypass grafting or coronary artery bypass surgery.
This procedure is used to prevent death from coronary artery disease.
It is an open heart surgery, where a narrow (or blocked) coronary artery of the heart
is bypassed. Surgeons use harvest veins or arteries to connect the aorta of the heart.
The harvest vein or artery can be cut from your other body parts, either from the
arms, chest, or leg.
Conclusion
The pathophysiology of ischemic heart disease is an imbalance of oxygen supply
and oxygen demand in the heart due to atherosclerosis formation in the coronary
artery.
It starts developing slowly and converts into devastating heart disease.
It could lead to an unexpected death by heart attack (or myocardial infarction).

14. This post taught us how atherosclerosis forms in our body and blocks the coronary
artery.
The increased blockage percentage in the coronary artery may be vulnerable to
you.
You should take care of your heart and minimize the risk factors contributing to
developing ischemic heart disease.
Please share this post if you find it informative.
FAQ
Q1. Can you live a long life with ischemic heart disease?
Sooner or later, you will have coronary artery disease if you are diabetic,
hypertension, smoker, obese and have a bad lifestyle. This coronary artery disease
decreases the survival rate and quality of life. You can increase the life span if you
reduce the risk factors that contribute to the development of ischemic heart disease.
Q2. Can you recover from ischemic heart disease?
Yes. Ischemic heart disease can be treated by lifestyle modification, controlling
medical conditions and taking medicines at the proper time.
Q3. Can 100 percent blockage be removed?
Surgery is the only option if there is 100% blockage in the coronary artery. The
surgery could be PTCA or CABG.
Q4. Is walking good for ischemic heart disease?
The risk of having a heart attack can be reduced by exercising regularly. Exercise
makes your heart strong. Pushing blood around the body is easier when your heart

15. is strong. You can keep your heart healthy by exercising aerobically, walking,
swimming, and dancing.
Q5. What is the first line of treatment for ischemic heart disease?
Beta-blockers (propranolol, atenolol, metoprolol, bisoprolol, nebivolol, etc.) are
considered first-line drugs for classical (or stable) angina pectoris. These drugs
help to reduce the workload and oxygen demand in the heart by decreasing heart
rate and heart pumping.
Read more post…