# Exercise as it relates to Disease/The effect that exercise has on Ischemic heart disease
## Background Information

Ischemic Heart Disease, more commonly known as Coronary Artery Disease or Coronary Heart Disease, is the current leading cause of death for men and women within the United States. The disease is the result of a build up of fatty plaque, made of cholesterol, which accumulates and solidifies to cause narrowing of the artery walls. This process is known as atherosclerosis. Atherosclerosis is damaging to the body as it can prevent sufficient blood supply from reaching the heart and other tissues, which reduces the amount of oxygen that these vital organs will receive. A lack of blood flow to the heart and muscles is termed ischemia.

## Risk Factors

The most common factors associated with Ischemic heart disease include:
* Smoking
* Diabetes
* High blood pressure
* Genetics (family history of heart disease)
* Obesity
* Age
* High levels of stress
* High levels of Low Density Lipoprotein cholesterol
* Low levels of High Density Lipoprotein cholesterol
These risk factors are found commonly among people with Ischemic heart disease, however, there have been reported cases of the disease without any of the standard risk factors.

## Symptoms
### Angina

Angina is the main symptom of Ischemic heart disease. It is regarded as a pressure or tightening in the chest which can cause acute or chronic pain, and is often triggered by stress.

### Shortness of Breath

Since your heart cannot pump the required amount of blood around the body, you may develop a shortness of breath and even fatigue when exertion is required.

### Myocardial Infarction

An artery that has been completely blocked with fatty plaque is extremely likely to cause a myocardial infarction, also known as a heart attack. The signs of a heart attack are generally seen through the former two symptoms, (Angina and a shortness of breath). However, a myocardial infarction can occur without any symptoms, and can be the first symptom of Ischemic Heart Disease.

## Diagnosis

Some of the most common diagnosing tests include:

### Electrocardiogram (ECG)

ECGs record the electrical activity of the heart, and can reveal changes within the heart beat that can display whether the heart is receiving enough oxygen. This can reveal a previous heart disorder, or any future heart problems that may be developing. However, in some cases the disease may not be recognised through an ECG reading.

### Exercise Stress Test

This is when the doctor will record heart beat readings (generally through ECG) whilst the patient is exercising. This is to examine the efficiency of the heart while under stress, to determine whether the heart is pumping enough blood and oxygen around the body.

### Echocardiograph

This test uses ultrasound readings to investigate the heart. Echocardiographs use sound waves, and can be useful in displaying any areas that may be damaged or diseased. This test is useful for isolating the areas of disease, as doctors will be able to hear which valves of the heart are weakened, or which parts of the heart are pumping the least blood. The downside to this examination is that it is very expensive.

## Treatment

Generally, the best treatment for any type of Heart Disease is lifestyle changes. This can include: Increasing exercise, quitting smoking, improving diet, etc.

### Exercise

Increasing the regularity of exercise can reduce the symptoms of Ischemic heart disease quite dramatically. It is the effect of exercise on vital organs, cardiovascular tissues and levels of low-density cholesterol circulating in the blood that have the most effect. Since atherosclerosis occurs slowly over time, exercise needs to be maintained for a long period of time in order to reduce the level of atherosclerosis within the valves. Due to increased blood and oxygen demand, the arteries will need to work harder and that blood being passed through these valves will gradually increase the size and efficiency of these arteries. Exercise allows beneficial changes to cholesterol in the blood, it does this by decreasing low density lipoprotein levels and increasing high density lipoprotein levels.

## References

* 1 2 3 4 5 6 Simon, H. (2012) 'Coronary Artery Disease' University of Maryland Medical Centre, retrieved from: http://umm.edu/health/medical/reports/articles/coronary-artery-disease
* ↑ American Heart Association (2014), 'Coronary Artery Disease - Coronary Heart Disease', retrieved from: http://www.heart.org/HEARTORG/Conditions/More/MyHeartandStrokeNews/Coronary-Artery-Disease---Coronary-Heart-Disease_UCM_436416_Article.jsp
* 1 2 3 4 Southern Cross Healthcare Group, (2013), 'Coronary Heart Disease - causes, symptoms, prevention', retrieved from: https://www.southerncross.co.nz/AboutTheGroup/HealthResources/MedicalLibrary/tabid/178/vw/1/ItemID/191/
* 1 2 3 4 5 6 7 Mayo Clinic (2014), 'Coronary Artery Disease', retrieved from: http://www.mayoclinic.org/diseases-conditions/coronary-artery-disease/basics/symptoms/con-20032038
* 1 2 Khot, et al. (2003), Prevalence of Conventional Risk Factors in Patients with Coronary Heart Disease, retrieved from: http://pmmp.cnki.net/Resources/CDDPdf/evd%5C200801%5CJAMA%5C%E9%9A%8F%E6%9C%BA%E5%AF%B9%E7%85%A7%E8%AF%95%E9%AA%8C%5Cjama200329008898.pdf
* 1 2 Greenland, et al. (2010) '2010 ACCF/AHA Guideline for Assessment of Cardiovascular Risk in Asymptomatic Adults'. Journal of the American College of Cardiology 56 (25): e50–103. doi:10.1016/j.jacc.2010.09.001
* 1 2 Taylor, et al. (2004) 'Exercise-Based Rehabilitation for Patients with Coronary Heart Disease: Systematic Review and Meta-analysis of Randomized Controlled Trials' doi:10.1016/j.amjmed.2004.01.009