Diseases

Ischemic Heart Disease – a leading cause of death

Ischemic Heart Disease Posted On
Posted By SUMIT SHARMA

If you are dealing with heart disease, you are not alone. Presently, Ischemic heart disease (IHD) is the number one cause of death throughout the world. It is more common in the United States and other western counties. In the world, every minute, one person dies from heart disease. 

Ischemic heart disease

Generally, you all know the function of the heart. Our heart is made up of a stronger muscle – the myocardium, which pumps the blood and provides oxygen or nutrients to the tissue, organ, and other body parts. 

 

 

 

 

The blood is an essential component of your circulatory system that travelled in blood vessels. There are mainly two blood vessels – an artery (supply blood from the heart to other organs) and veins (supply blood from organs/tissue to the heart). 

The blood is supplied to the heart through a unique vascular system is called coronary blood vessels. Suppose you get any obstruction in your lumen of the coronary artery (blood vessels). Your heart or other vital organs won’t get enough blood supply that leads to cardiovascular disease

A classic example to understand this concept is the traffic road. Suppose your blood vessels are like a wide road or highway (artery or veins) that diverted into the different narrow streets like arterioles, venules, capillaries, and the coronary artery. 

But if anything is stuck in this pathway, you may have a severe medical problem called ischemia. 

Here, I am going to explain this medical condition – Ischemic heart disease in detail. Let’s start our topic.

 

What is Ischemic Heart Disease?

Ischemic Heart Disease is a group of clinical-pathological problems or syndrome. Due to an imbalance of O2 (oxygen) supply and O2 demand to myocardium muscle (heart), it leads to ischemia.

Ischemic heart disease

In other words, when you don’t get enough O2 (oxygen) supply or blood to your heart muscle. Then your heart muscles become damaged and stop the function of the heart. It results that pain occurs in your chest, which is known as angina

Moreover, it is also called coronary artery disease or coronary heart disease.

 

 

How is ischemia differs from isolated hypoxemia? Which is worse – hypoxia or ischemia?

The whole concept is based on O2 supply and O2 demand. It develops the condition when your heart muscle needs more O2 than it is getting. There is a slight difference between the condition of ischemia and isolated hypoxemia

In ischemia, there are three conditions involve –

  1. Decrease oxygen supply
  2. Decrease nutrients supply
  3. Decrease washout of metabolic waste (means accumulation of waste products)

 

But in Isolated Hypoxemia, only oxygen supply is reduced. That’s why ischemia is more dangerous.

 

What are the signs and symptoms of ischemia?

In ischemia, the heart is not getting enough oxygen supply. Due to this, you may feel heartburn and indigestion-like problems. You may also experience – 

  • Shoulder pain
  • Increase heart rate
  • Shortness of breath
  • Sweating
  • Tiredness
  • Nausea and vomiting

 

What is the most common cause of ischemic heart disease?

Ischemic heart disease (IHD) pathophysiology – 

IHD is more commonly involved in the left ventricle (left side of the heart). It is only developed by obstruction of lumen due to the formation of plaques.

At the early stages, it is a slightly fixed obstruction that does not produce ischemia. For ischemia, it should be blockage the lumen up to 70%.

According to the study, if you have a 70% blockage of lumen or artery. You will feel a problem in physical work like upstairs, walking, running, etc. Due to this blockage, your heart needs more oxygen and has to do more work and produce more cardiac output.

But if you have blockage of lumen or artery, more than 90%. It will create a problem even during rest. 

So, the formation of plaque in the coronary artery’s lumen is the leading cause of IHD. This plaque formation is known as Atherosclerosis

 

How atherosclerotic develop cardiovascular disorder?

Your blood vessels formed a layer of semi-permeable membrane of endothelial cells that regulates the exchange of fluid, nutrients, gases, and waste between the blood and tissues.

Naturally, endothelial cells release various substances which have numerous functions to prevent the endothelial area thrombogenic. 

Ischemic heart disease

 

  • Nitric oxide (NO) – dilates blood vessels
  • PGI2 (prostacyclins) – stop platelet aggregation
  • Heparin – prevention of the formation of the blood clot 
  • Thrombomodulin – prevent coagulation

 

But what happens when your endothelial cells become damaged. It stops the secretion of NO, PGI2, heparin, and thrombomodulin.

As a result, your LDL (low-density lipoproteins) molecules start leakage in the subendothelial area of the blood vessel. Then macrophage sticks to these areas.

After that, macrophages release a massive amount of cytokines such as TNF (tumour necrosis factor), free radicals, and growth factors. 

 

  • Cytokines draw more molecules of macrophages. 
  • Free radicles convert LDL to LDL-C, which is responsible for the inflammatory response. LDL-C is considered a strong predictor of cardiac events.
  • Growth factors are growth stimulators that multiply the smooth muscle cells. 

 

Eventually, these three nasty molecules help in the development of plaque. It develops in the form of foam cells (cholesterol + fat + LDL + LDL-C + macrophages + increase smooth muscles cells).

Over time, foam cells become complex due to collagen’s deposition below the endothelial layer. Then they started to develop necrosis that leads to cardiovascular disease.  

There are two types of atherosclerotic obstruction – stable atheromatous plaque and dynamic atheromatous plaque. Stable plaque becomes more vulnerable when it is converted into a dynamic.

In stable atheromatous plaque – They are

  1. thick fibrous cap (layer of fibrous connective tissue)
  2. less number of foam cells
  3. less number of macrophages
  4. less amount of fat or cholesterol

 

That sticks to the endothelial cell (blood vessel). But in dynamic atheromatous plaque

  1. a fragile fibrous cap
  2. more number of foam cells
  3. more number of macrophages
  4. more amount of fat or cholesterol

 

So, dynamic plaque can create more disruption because it can travel through wider to narrow arteries. They can block the small arteries that result in Myocardial infarction

 

How does Atherosclerosis form?

It is an essential contributing factor to develop plaque. It causes severe problems like Ischemic heart disease and other vascular diseases.

When plaque build-up inside your arteries is called Atherosclerosis. There are some stages in this mechanism of Atherosclerosis. 

 

Whenever erosion of the endothelium of blood vessels, it does not produce nitric oxide (NO)

Then fat will be exposed, and it became rupture and fissure.

The underlying basement membrane will be thrombogenic.

Platelets start to stick on this exposed area or ulcerated area. It is called platelet adhesion reaction.

But when platelets start releasing factors or more platelets releasing factors like ADH or AVP, 5-HT, epinephrine, procoagulant factor, and PF-4. Then platelets stick to the platelets. This is called Platelet aggregation.

 

What are the main risk factors of Ischemic Heart Disease?

According to the study, smoking is the main factor of Ischemic Heart Disease. Tobacco smoking can develop Ischemic Heart Disease because it contains nicotine and easily sticks to the platelets that favour the plaque.

Many other risk factors related to lifestyle and existing medical conditions – 

  1. High blood pressure
  2. High blood cholesterol levels
  3. Increase blood glucose level 
  4. Overweight or obesity
  5. Lack of physical activity
  6. Unhealthy diet 
  7. Stress
  8. Older age
  9. Family history 
  10. Race

 

Can ischemic heart disease be cured?

Generally, IHD can’t be cured, but various options help reduce a heart attack’s chances.

Medical treatment – 

Usually, statins are a fantastic drug to control cholesterol levels. Everyone knows statins reduce cholesterol level, but it also has an anti-inflammatory action on the plaque.

It means statins can inhibit the inflammatory activity in the plaque. Due to this, plaque will become more stable, and it will be less inflamed.

Even this claim now, statin does reduce not only the progression of plaque but also do plaque regression means it returns to normal condition.

 

Non-medical treatment – 

Ischemic Heart Disease is a condition of risk factors. You can control some risk factors to change the sedentary lifestyle. 

Firstly, you should stop smoking to prevent this disease. You should know about the nutrients which are taking in your food if you take maximum calories from the bad (junk) or high glycemic index foods. It will be a problem for you, like high cholesterol and obesity. 

Later on, it may develop severe heart disease, diabetes, and other vascular diseases. These are a chronic disease which is difficult to cure. It remains with your life if you do not change your lifestyle. 

 

Recommendations 

Our human body is like a machine, so it also requires some maintenance. 

I urge all of you. If you are 35 years old and more, you should undergo heart screening (ECG, ECHO etc.) at least once a year. If there is any blockage, then it can control earlier. 

We can prevent it easily by just cut cholesterol from the diet because prevention is better than cure. 

I hope you like this article on Ischemic Heart Disease.

 

 

 

 

 

 

Sources

1. Rachel Hajar. Risk Factors for Coronary Artery Disease: Historical Perspectives. Heart Views. 2017 Jul-Sep; 18(3): 109–114.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5686931/

2. Atherosclerosis. https://www.nhlbi.nih.gov/health-topics/atherosclerosis

3. Ian Loftus. Mechanisms of Plaque Rupture. https://www.ncbi.nlm.nih.gov/books/NBK534259/

4. Sanaz Keshavarz Shahbaz et al. Regulatory T cells: Possible mediators for the anti-inflammatory action of statins. Pharmacol Res 2019 Nov;149:104469

https://pubmed.ncbi.nlm.nih.gov/31577918/

5. Atsushi Shioiet al. Plaque Calcification During Atherosclerosis Progression and Regression. J Atheroscler Thromb 2018 Apr 1;25(4):294-303.

https://pubmed.ncbi.nlm.nih.gov/29238011/

 

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3 thoughts on “Ischemic Heart Disease – a leading cause of death
  1. vidhanshu

    It is quite relatable and everyone should take care of health…

    • SHARMAJI

      Thanks. Yes definitely every one should take care of health.

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