# Exercise as it relates to Disease/Preoperative exercise for CABG surgery and subsequent cardiovascular health
## Background
### What does surgery involve?

Coronary Artery Bypass Surgery or CABG involves redirecting heart blood flow around a narrow artery so that the blood can flow smoothly around the heart. This can potentially reduce the risk of a Myocardial Infarction (Heart Attack) from occurring. This is a major surgery and a thorough assessment should be undertaken before opting to have the surgery.

### CABG and Exercise

CABG is a medically proven way to improve mortality rates and provide an improved quality of life for patients(at least short term). Preoperative exercises and other lifestyle interventions provide important postoperative benefits for patients and hence can assist in maintaining or improving subsequent Cardiovascular (CV) health after CABG surgery. Some of these benefits include;
* reduced hospital stay
* decrease risk of pulmonary complications during surgery
* strengthen respiratory muscles
* Improve percerived quality of life pre and post surgery.
When determining the type of preoperative exercise a patient should undertake, an appropriate risk assessment procedure should be used to identify if there is a high risk of Postoperative Pulmonary complications.

## Types of Preoperative Exercise

| Type of exercise | Procedures |
| Inspiartory Muscle Training (IMT) | Patients should perform 5-7 30 minute sessions per week using a resistive breathing device and under supervision of an appropriately qualified physician |
| Low Intensity Exercise | Can be performed without supervision or with supervision (depending on risk factor). Light exercises such as stretching and going for easy walks or exercising on a stationary bike can be used. Number of sessions per week can vary between 2-5 depending on intensity of sessions. Very light Resistance training can also be performed. |

## Benefits of Preoperative exercise
### Inspiratory Muscle Training (IMT)

* Increase Respiratory Muscle Strength
* Increase Respiratory Muscle Endurance
* May decrease mortality
* Better pulmonary gas exchange before and after surgery
* Increase Maximal Inspiratory Pressures(MIPS)

### Low Intensity Exercise

* Improve physical and Mental Quality of Life
* Improve Blood Pressure
* Improve Heart function
* Increase V02 peak value
* Improve exercise tolerance

## Recommendations

It is recommended that patients who are undergoing CABG surgery should do some kind of light physical activity (PA) prior to their operation. PA can vary between light walks or rides, light resistance training, stretching and inspiratory muscle strengthening. Activity at a higher intensity has not been researched or trialled before, so higher intensity physical activity is not recommended before a CABG operation. It conjunction with PA other lifestyle changes can be made to improve health before the operation; this includes things such as;
* Practicing relaxation techniques
* Education about dealing with possible stresses that may arise
* Check up phone calls from hospital staff helps patients feel better and adhere to exercise programs.
* Diet supplementation such as Omega-3 fatty acids
Undertaking the above lifestyle changes prior to a CABG operation can provide patients with a postoperative advantage into the rehabilitation phase after the surgery. One of the most important benefits from preoperative exercise is the improved Quality of Life patients perceive to have following surgery, this can be the key to a longer term health benefit and lifestyle change.

## Further reading

* Australian Heart Foundation
* American Heart Association

## References

* ↑ D.S. Kehler. Master of Science. (2012) 33-92
* ↑ E. Hulzebos, P. Helders, N. Favie, R. De Bie, A.B. de la Riviere, N. Van Meeteren. Preoperative Intensive Inspiratory Muscle Training to Prevent Postoperative Pulmonary Complications in High-Risk Patients Undergoing CABG Surgery. JAMA 296(15); (2006) 1851-1857
* ↑ P. Weiner, F. Zeidan, D. Zamir, B. Pelled, J. Waizman, M. Beckerman, M. Weiner. Prophylactic Inspiratory Muscle Training in Patients Undergoing Coronary Artery Bypass Graft. World J. Surg. 22; (1998) 427–431
* ↑ K. Valkenet, I. van de Port, J. Dronkers, W. de Vries, E. Lindeman, F. Backx. The effects of preoperative exercise therapy on postoperative outcome: a systematic review. Clinical Rehabilitation 25; (2011) 99–111
* ↑ A. Hadj, D. Esmore, M. Rowland, S. Pepe, L. Schneider, J. Lewin and F. Rosenfeldt. Pre-operative Preparation for Cardiac Surgery utilising a Combination of Metabolic, Physical and Mental Therapy. (2006) 172-181
* ↑ S. Jack, M. West, M.P.W. Grocott. Perioperative exercise training in elderly subjects. Best Practice & Research Clinical Anaesthesiology 25; (2011) 461–472
* ↑ H. Arthur, C. Daniels, R. McKelvie, J. Hirsh, B. Rush. Effect of a Preoperative Intervention on Preoperative and Postoperative Outcomes in Low-Risk Patients Awaiting Elective Coronary Artery Bypass Graft Surgery: A Randomized, Controlled Trial. Ann Intern Med 133(4); (2000) 253-262
* ↑ http://www.heartfoundation.org.au/your-heart/cardiovascular-conditions/Pages/heart-attack.aspx
* ↑ http://www.heart.org/HEARTORG/