Understanding Heart Aging and Reversing Heart Disease

The heart is an amazing muscle that beats around 100,000 times a day. It is essentially a complex pump that is able to adjust blood pressure, flow, and volume in order to provide your body with all the blood it needs. Your heart is constantly adjusting to what you are doing and the state of your body. As you age, your heart adjusts to the needs of an older body. These adjustments come with trade-offs, leaving the heart more vulnerable to disease and other problems.

Your Heart's Job

Every day your heart must beat more than 100,000 times through more than 60,000 miles (if stretched end-to-end) of blood vessels. Your heart also must adjust the rate and force at which it pumps based on your activity level. As we age, changes in the body require that the heart adjusts how it works. For example, the buildup of fat in the arteries, known as atherosclerosis, causes the heart to work harder to pump all that blood through narrower tubes.

The Aging Heart

Heart disease is a leading cause of death. As we age, our heart compensates for clogged arteries by working harder and raising blood pressure. These changes put the heart at risk and impact our quality of life:

• Approximatetly 80% of heart disease deaths occur in people who are age 65 or older. 
• Between the ages of 25 and 80 years pulmonary function and aerobic capacity each decline by 40%
• In your 20s, the average maximum heart rate is 200 beats per minute, but drops as you get older. The average maximum heart rate for 70-year-olds is 150.
• Age-related changes in heart rate are seen most in maximal and exercise-induced heart rates with negligible changes in resting heart rate.

Aging Arteries

Arteries take oxygen-rich blood away from the heart and deliver it to the body. As we age, our arteries become stiffer and less flexible. This causes our blood pressure to increase. The heart has to adjust to the increase in blood pressure by pumping harder and changing the timing of its valves. These adjustments leave the heart more vulnerable. To stay young at heart, protect your arteries by:

• Exercising
• Controlling your blood pressure
• Watching your cholesterol

Thickening of the Left Ventricle

Researchers have noted that the wall of the left ventricle of the heart becomes thicker with age. This thickening allows the heart to pump stronger. As our blood vessels age, they become narrower, causing blood pressure to increase. The heart compensates for this by becoming stronger and pumping with more force. The heart may also become larger overall as a result.

Mitral Valve Function Can Deteriorate

Age-related changes in the mitral valve can cause mitral regurgitation — a condition in which the mitral valve fails to close completely, leading to regurgitation (leaking) of blood back into the left atrium as the left ventricle is contracting. Age-related mitral regurgitation is often fairly mild, but can become severe enough to require cardiac surgery.

Exercise Capacity Shrinks

As the heart ages, it becomes less able to respond rapidly to chemical messages from the brain. Researchers do not know exactly why the heart does not respond as fast to messages to speed up and adjust to increased activity. The result is the body cannot exercise as long or as intensely as before. This shows up as shortness of breath, a sign that oxygen-rich blood is not moving fast enough through the body because the lungs are trying to breathe in more oxygen.

"Sitting" Heart Rate Lowers

The heart rate of an older person while sitting is slower than a younger person (but the same when lying down). It is thought that this slower rate is from a decline in the heart-brain communication because fibrous tissue and fatty deposits have built up on the on nerves connecting the heart and brain. To compensate, the heart increases the volume of blood in circulation by raising the diastolic blood pressure.

The Heart Can't Squeeze as Tightly

Because of the increase in diastolic blood pressure, the heart also stretches larger each beat, giving a stronger pump in order to have a stronger contraction to pump the excess blood volume (called the Frank-Starling mechanism). But because of the greater diastolic pressure, the heart can't squeeze as tightly.

Keep Your Heart Healthy and Reverse Heart Disease

Your heart is only as healthy as your arteries. Work hard to keep your arteries healthy by:

• Controlling your blood pressure
• Improving your cholesterol
• Exercising
• Relaxing
• Learning heart-healthy nutrition