The Stream and the Sea by Melina Meza
In the past, we have written about using yoga for cardiovascular health, and we have talked about a variety of diseases of the CV system, such as heart attacks and irregular heart rhythms. But I have not shared with you an overview of the normal aging changes that specifically affect the heart and circulatory system of our bodies. Today, I intend to remedy that!Before I get into the specifics, I wanted to share an interesting story that makes generalizing about what to expect of our CV system as we age very challenging. I was chatting with one of my students yesterday after he returned to class from a 5-day cycling adventure in the San Juan Islands near Seattle. He is a fit 60-year old who cycles 4-5 days a week, 20-40 miles at a stretch. What blew him away about this trip was that the riders in their 70s were actually faster and stronger then most of the younger participants. My immediate thought was that they must have very robust cardiovascular function! So although I will paint a picture of what happens to the heart and circulation as we age, keep in mind that it can depend on a lot of factors, such as lifestyle (regular exercise, history of alcohol, cigarette or drug use), history of injury or infections (like Scarlet fever, which can damage heart valves), family history and genetic predispositions.Although aging itself does not cause heart disease, it is still considered a risk factor for all types of CV disease; the older you are, the more likely there will be a convergence of factors that will lead to the CV system’s dysfunction. So let’s look at the major areas of change that occurs as we age.Structural Changes: There is significant structural change in the heart and the blood vessels that occur over time, such as vascular stiffening of the blood vessels (what we sometimes refer to in lay press as hardening of the arteries), increased thickness of the wall of the heart (within normal limits), and fibrosis or stiffening of the heart muscle itself with aging, which can eventually lead to problems like heart failure.
Functional Changes: There are a number of functional changes and compensatory responses that the aging heart undergoes that diminish its ability to respond to increased workload during times of increased physical demands and leave it with less reserves if those kinds of demands go on for a while. Examples include a decrease in maximal heart rate and contractility, an increase in sympathetic signaling, and other technical changes in the filling and emptying of the heart.
Cardioprotection and Repair Processes: The specific heart mechanisms responsible for protection from injury and injury repair become increasingly defective with age, leading to the tendency for more adverse remodeling and increased dysfunction of the system as a whole.
Increased Cardiovascular Disease Incidence and Prevalence: There is a progressive increase in the prevalence of cardiovascular disease (CVD). Examples include such conditions as coronary artery disease (CAD), hypertension, and diabetes leading to the development of ischemic, hypertensive, or diabetic cardiomyopathy (diseases of the heart muscle).
Systemic Disease/Other Organ Systems: Aging-associated changes in other organ systems may affect cardiac structure and function, and thereby contribute to the development of problems such as heart failure. One example would be kidney disease having an impact on heart function over time.
Even with some of the changes described above (which you can read about in great detail in this NIH review article Aging-associated cardiovascular changes and their relationship to heart failure), there can be normal heart function in healthy older adults when they are at rest. But it is when we look at the heart and CV function while exercising that the changes start to show themselves. An overall decrease in exercise tolerance is evident in the progressive decline in one measure of aerobic fitness of the heart known as the VO2max, starting at the surprisingly early age range of 20–30 and falling by approximately 10% per decade. And, the rate of this decline progressively increases with age (although my student’s observation of septuagenarians would seem to contest this!).The folks at the NIH conclude that: “Aging results in an increase in cardiovascular disease and a decrease in cardiac reserve at the same time that the repair processes designed to deal with these problems become less active/effective. These factors combine to set the stage for heart failure [over time]. 1) Structurally, the heart thickens and stiffens with age resulting in the increased imposition of a number of functional demands. 2) Functionally, a number of changes which assist the resting heart to deal with the effects of aging cause significant functional deficits with exercise or stress, thereby lowering the cardiac reserve that the younger heart can call on to deal with disease or insult. 3) Finally, while the increased incidence of disease, less structurally efficient heart, and decreased cardiac reserve associated with aging would be well served by an effective repair system- this too declines with age.” They add that better understanding and continued discoveries into the normal aging of our hearts and circulatory systems may actually lead to better therapies to help treat and prevent conditions like heart failure in the future. But as we have reported on here in the past, yoga shows promise in many of the areas of change described above, for example the improvement in heart rhythms in those with irregular heart rhythms using yoga techniques (see Yoga and Heart Health: Tachycardia and Yoga and Heart Health: Atrial Fibrillation).Finally, keep in mind that for many of us, if we take reasonably good care of ourselves via exercise, a healthy diet, and regular checkups, our CV system may stay healthy enough, despite the changes of aging, to permit us to live active and engaged lives! See Heart Health and Yoga for an overview of how you can use yoga to foster cardiovascular health as you age.Subscribe to Yoga for Healthy Aging by Email ° Follow Yoga for Healthy Aging on Facebook ° Join this site with Google Friend Connect
