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Exercise as it relates to Disease/Exercise and Aortic Stenosis

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Aortic stenosis (AS) is an abnormal narrowing of the aortic valve in the heart.[1] The narrowing causes a restriction of blood flow to the aorta and an increase in blood pressure in the left ventricle (the chamber that supplies blood to the aorta).[2] The left ventricle has to increase its workload for the same cardiac output, which ultimately results in concentric hypertrophy (thickening) in the chamber walls, calcification and scarring of the valve and an overall thickening of the aortic valve. These changes can create abnormal heart sounds known as murmurs, which is the most common form of early detection of this disease. A healthy heart sounds very different to a heart with aortic stenosis. AS affects around 1 in 1000 people and is three times more prevalent in males than females.

Causes

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  • Genetic - The congenital heart condition Bicuspid aortic valve affects 2% of the population. The aortic valve is mildly deformed so blood flow across the valve is more turbulent. This increases wear and tear, creates scarring, calcification and reduced mobility in the valve.[3] This condition can cause AS and may require a heart valve transplant to prevent cardiac failure.[3]
  • Developed - Calcific aortic stenosis - a natural degenerative condition that occurs mostly in over 65yr olds and is the result of many years of lipid deposition, inflammation and calcification of the valve.
  • Rheumatic fever - This condition, caused by untreated bacteria can scar the valve resulting in the same aforementioned damage:[4] see above

Symptoms

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  • Breathlessness / Breathing issues worsened by physical activity[2]
  • Chest Pain (Angina) / Heart palpitations or murmur)[5]
  • Coughing at night when lying down in bed / Visual Problems [6]
  • Fainting / Fatigue[5]
  • In 4% of AS sufferers the first symptom is sudden death[7]

Treatment

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There is no known pharmacological way to treat AS directly.[4] The only guaranteed treatment is aortic valve replacement surgery.[8]

Exercise and Aortic Stenosis

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Exercise as a diagnostic tool

The most common diagnostic tools for AS are:[4]

  • Doppler echocardiography
  • Electrocardiogram
  • Chest radiograph

However recent research suggests that a non-invasive and cost effective form of diagnosis and monitoring is an Exercise stress test.[9] By creating a controlled environment where the patient's vital signs are closely monitored, medical practitioners can test the cardiovascular systems' reaction to exercise stress and then determine if the response (or lack of) is a serious threat to the patients wellbeing.[10] NB: Exercise stress tests for patients with severe or critical AS are not recommended or advised.[4][11]

Exercising with AS

If suffering from moderate, severe or critical AS, all competitive, high impact, and heavy resistance activities are dangerous and must be avoided to prevent sudden cardiac events or even death.[7] This is because the narrowing of the aortic valve has reached the stage where the blood cannot be pumped through effectively in a normal environment. Exercise involves increases in heart rate, blood pressure and cardiac output,[3] if the heart is already under strain, these increases can lead to a high risk of heart attack or similar event. If it is mild or asymptomatic AS then exercise can be beneficial. Aerobic based activities - running, walking, swimming, team sports; and resistance based activities - weights programs; will all help to keep the cardiovascular and muscular systems healthy. This can also help with comorbidities that will accelerate AS symptoms, like hypertension and obesity. If the patient can use exercise to maintain a medically desirable weight and keep their cardiovascular and musculoskeletal systems as healthy as possible they will be putting minimal additional strain on their heart thus helping to delay the need for an aortic valve replacement..

Exercise Recommendations for Mild/Asymptomatic AS

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Form of Exercise Benefits[12][13] Per week
Aerobic Strengthens heart and cardiovascular system. Lowers blood pressure. Improves circulation. Improves coronary risk profile. Decreases fat mass 3-5 times per week - 20-60min - if 10-30min intensity should be at 70-90%, if 30-60min intensity should be at 50-70%
Resistance Increases lean muscle - aiding in fat loss. Improves overall strength. Helps to increase aerobic ability. Decreased secondary heart disease risk. Reduced mortality rate in AS sufferers 1-3 times per week - 8-12 reps/ 1-2 sets

Persons with moderate AS will see the same benefits from aerobic conditioning however the frequency and length of the exercise must be lower than the above recommendation (around half) to maintain a safe working load. Resistance exercise is not recommended.[14]

Recommendations

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Those with AS need to be very aware of their class of severity before attempting any physical activity. For mild and asymptomatic sufferers, bi/tri-annual cardiologist visits to check the progress before continuing physical activity, as well as maintaining overall healthy weight and cardiovascular strength is crucial. The above recommendations are a guide for how often and how physically straining exercise should be for these persons. For moderate, severe and critical sufferers medical clearance before attempting any form of exercise and adhering strictly to the advice given is vital to avoid cardiac events that could end in death.

Further Reading

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What signs/symptoms to look out for with AS

Australian Heart Foundation - Active living

References

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  1. ↑ [The Royal Children's Hospital Melbourne. (December 2012). Aortic Stenosis AS. Retrieved from http://www.rch.org.au/cardiology/heart_defects/Aortic_Stenosis_AS/].
  2. ↑ a b [Heart Research Centre. (2011). Aortic Stenosis. Retrieved for http://www.betterhealth.vic.gov.au/bhcv2/bharticles.nsf/pages/Aortic_stenosis.]
  3. ↑ a b c [LiveStrong. (2013). Exercise & Bicuspid Aortic Valve. Retrieved from http://www.livestrong.com/article/465302-exercise-bicuspid-aortic-valve/].
  4. ↑ a b c d [Gian M. Novaro, The Cleveland CLinic - Disease Management Project. (n.d). Aortic Valve Disease. Retrieved from http://www.clevelandclinicmeded.com/medicalpubs/diseasemanagement/cardiology/aortic-valve-disease].
  5. ↑ a b [Wood, P. (1958). Aortic stenosis. The American Journal of Cardiology. 1(5), 553–571].
  6. ↑ Invalid <ref> tag; no text was provided for refs named HRC
  7. ↑ a b [Rome, J. (2010). Exercise restriction to prevent sudden death in congenital aortic stenosis].
  8. ↑ [Cribier, A. Eltchaninoff, H. Tron, C. Bauer, F. Agatiello, C. Nercolini, D. Tapiero, S. Litzler, P. Bessou, J. Babaliaros, V. (2006). Treatment of Calcific Aortic Stenosis With the Percutaneous Heart Valve : Mid-Term Follow-Up From the Initial Feasibility Studies: The French Experience. Journal of the American College of Cardiology, 47(6), 1214-1223.]
  9. ↑ [Amato, M. Moffa, P. Ramires, J. Werner, K. (2001). Treatment decision in asymptomatic aortic valve stenosis: role of exercise testing. Heart,86, 381-386.
  10. ↑ Invalid <ref> tag; no text was provided for refs named Exercise Test
  11. ↑ [Balady, G. Beasley, J. Bricked, T. Duvernoy, W. Froelicher, V. Gibbons, R. Mark, D. Mar wick, T. Mcallister, B. Thompson, P. Winters jnr, W. Yanowitz, F. (1997). ACC/AHA Guidelines for exercise testing: Executive summary. A report of the American College of Caridology/American Heart Association Task Force on Practice Guidelines (committee on exercise testing). Circulation, 96, 345-354.]
  12. ↑ [Medicinenet. (N.d). Aerobic exercise health. Retrieved from www.medicinenet.com/aerobic_exericse/article.htm].
  13. ↑ [Centre for Disease Control and Prevention. (2011). Why strength training? Retrieved from http://www.cdc.gov/physicalactivity/growingstronger/why/].
  14. ↑ [Livestrong. (2012). The best exercise if you have aortic heart disease. Retrieved from http://www.livestrong.com/article/325574-the-best-exercise-if-you-have-aortic-heart-disease/].
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