# Exercise as it relates to Disease/Exercise during recovery from Myocardial Infarction

This page is a project for the unit Health Disease and Exercise.
Myocardial Infarction (or Heart Attack) is when blood flow to a part of your heart is blocked for a long enough time that part of the heart muscle is damaged or dies. Cardiovascular and Strength training is a known and proven treatment and recovery method following the onset of myocardial infarct increasing the contractibility and decreasing the risk of repeat attacks.

## Background
#### What is a Myocardial Infarction?

Myocardial Infarction, commonly know as a heart attack, is when blood flow to a part of your heart is blocked for a long enough time that part of the heart muscle is damaged or dies. There are numerous factors that can influence the onset of Myocardial infarction, but the main cause is a blockage of the Coronary Artery which brings oxygenated blood back to the heart.
The underlying cause of a heart attack is coronary heart disease (CHD).
Some people may not know they have CHD until they have a heart attack. For others, a heart attack can happen after weeks, months or years of treatment for CHD.
CHD is the slow build-up of fatty deposits on the inner wall of the arteries that supply your heart muscle with blood. These fatty deposits, called plaque, gradually clog and narrow the inside channel of the arteries. It is a process that begins early in life and continues over the years.

#### Risk Factors

A number of factors increase your risk of having a heart attack. These include:
Non-modifiable risk factors
* increasing age
* having family history of heart disease
Modifiable risk factors
* smoking - both active smoking and being exposed to second-hand smoke
* high blood cholesterol
* high blood pressure
* diabetes
* being physically inactive
* being overweight
* depression, social isolation and lack of quality support
Reducing or eliminating these risk factors can be helpful in reducing the risk of having a repeat heart attack.

#### Recovering from Myocardial Infarction

Recovering from a Myocardial infarction can be a long process, requiring you to make big changes in your life. A number of steps need to be taken in order to recover efficiently from Myocardial Infarction. These changes include modified diet, medications and an exercise program. Myocardial infarction's can alter an individual's responses to both maximal and submaximal exercise. Patients have a reduced level of cardiorespiratory fitness and a reduced oxygen transport capacity due to a diminished cardiac output (due to reduced contractile force of the left ventricle). Patients will also be taking a variety of medications, including beta-blockers, anti-coagulants, anti-arrhythmic drugs and vasodilators to decrease heart rate and blood pressure. These factors should be taken into account before any training program.

## Benefits of Exercise

There are several potential benefits to exercise training in patients following a heart attack. It has shown: to increase VO$_2$ max by an average of 20%; increase heart rate variability; reduce symptoms of angina; decrease blood platelet adhesiveness and blood viscosity; and increase vascular regeneration. Exercise has also shown improve psychosocial well-being. Exercise is known to improve cardiovascular health. Although nearly everyone can exercise safely after a heart attack, the intensity and duration of exercise depends upon the severity of your heart disease. Exercise in particular will increase the contractibility of the heart muscle following the stress of a heart attack, help to lower your risk of repeated infarct, reduce your risk of death from heart disease, and often increase your ability to exercise and be active. Overall recovery time can be improved and select individuals can return to a healthier active lifestyle sooner than previously anticipated.

## Resistance and Cardiovascular Training Guidelines
### Cardiac Rehabilitation

The Heart Foundation and the World Health Organization recommend that people who have had a heart attack, heart surgery, coronary angioplasty, angina or other heart or blood vessel disease attend an appropriate cardiac rehabilitation and prevention program. Supervised CR programs increase physical activity and may lead to a substantial reduction in mortality. Physical activity is a core component of CR programs and is recommended to patients after discharge

#### Phase 1

Phase 1 takes place while the patient is still in the hospital, consisting primarily of educational sessions and multiple short bouts of physical activity that typically range between 2 and 6 days, depending on the patient's progress. Early stages involve simple exposure to gravitational stress. This includes intermittent standing and sitting, followed rhythmic exercise involving large muscle groups, like walking, stair climbing and rowing.

#### Phase 2

Phase 2 is considered outpatient rehabilitation but involves a supervised exercise program that typically begins 1 to 4 weeks after hospitalization and lasts 1 to 12 weeks

#### Phase 3

Phase 3 is an unsupervised community-based, high-risk maintenance program that can go on indefinitely. Resistance exercise implemented during phase 3 is more typical of what one might recommend for the general aging population independent of heart disease.

##### Example of a Cardiac Rehabilitation Program

| Modes | Goals | Intensity/Frequency/Duration | Time to Goal |
| Aerobic Large muscle activities Arm/Leg ergonometry | Increase aerobic capacity Decrease BP and HR response to submaximal exercise Decrease submaximal myocardial VO$_2$ demand Decrease CAD risk factors | RPE 11-16/20 40-80% VO$_{2max}$ > 3 days /week 20-60min/session 5-10min of warm-up and cool-down activities | 4–6 months |
| Strength Circuit training | Increase ability to perform leisure and occupational activities Increase muscle strength and endurance | 30-40% 1RM (upper body), 50-60% 1RM (lower body) 2–3 days/week 2 -4 sets of 12-15 reps 8-10 different exercises Resistance gradually increased over time. | 4–6 months |
| Flexibility Upper and lower body ROM activities | Decrease risk of injury | Static stretches: hold for 10-30sec 2–3 days/week | 4–6 months |
Franklin, B.A.(2009) Myocardial Infarction(Ch. 6) in ASCM's Exercise Management for Persons with Chronic Diseases and Disabilities, pg 55.
Any training should be progressive, but more caution should be taken with certain exercises or machmes that mav result in increases in intrathoracic pressure that typically have been avoided in this group

## References

* ↑ http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001246/
* ↑ http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001246/
* ↑ http://www.medicinenet.com/heart_attack/article.htm
* ↑ http://www.heartfoundation.org.au/your-heart/cardiovascular-conditions/Pages/heart-attack.aspx
* ↑ http://www.heartfoundation.org.au/your-heart/know-the-risks/Pages/default.aspx
* ↑ http://www.uptodate.com/contents/patient-information-heart-attack-recovery
* ↑ http://circres.ahajournals.org/content/100/7/937.full.pdf+html
8. Ehlke, K., Greenwood, M.(2006) Resistance Exercise for Post-Myocardial Infarction Patients: Current Guidelines and Future Considerations. Strength and Conditioning Journal, 28(6), 56-62.
9. Sniehotta, F.F., Gorski, C. & Arau´jo-Soares, V.(2010)Adoption of community-based cardiac rehabilitation programs and physical activity following phase III cardiac rehabilitation in Scotland: A prospective and predictive study. Psychology and Health, 25(7), 839-854.
10. Franklin, B.A.(2009) Myocardial Infarction(Ch. 6) in ASCM's Exercise Management for Persons with Chronic Diseases and Disabilities, pg 55.

## External links

For further information on Myocardial Infarction and recovery visit:
Heart Foundation: Heart Moves Helping all Australians stay active for life
* http://heartmoves.heartfoundation.org.au/
Heart Foundation: Heart attack Facts
* http://www.heartattackfacts.org.au/