Old, old heart


  • Health
  • Sunday, 12 Jun 2005

AGE WELLBy DATUK DR AZHARI OSMAN

The heart is not immune to the ravages of time. Inevitably, an ageing heart will undergo changes that could spell trouble. 

I SOMETIMES wonder: had I known then what I know now, would I lead my life differently, at least in so far as a more healthy lifestyle is concerned. One of my patients once remarked: “The trouble with me doc, is that mentally I’m still 21, but the body is already 60; is that a bad thing?” 

That’s a tough one to answer, especially when he’s only 40. It was blindingly obvious that he, like me, is subject to the effects of the relentless march of time. Simply put, we are all growing older.  

Doctors are really no different from patients. True, the ageing process can accelerate any disease state. The question is, are we feeling older than our age?  

We start to “age” the moment we are born, and this process involves continuous biological changes involving cell multiplication, growth, repair and death. The heart is no exception, except that it is different from most other tissues in that heart muscles are unable to multiply – a distinction it shares with an elite group of body tissues like brain cells and egg cells in the ovaries.  

With age, the valves of the heart, such asthe aortic valve, stiffen due to calciumdeposits and the development of fibrous tissue. Over time, the valve can become narrowed and will not open well. Blood cannot be adequately ejected out from the heart.

Consider what the heart has to do – it beats on average 72 times per minute, 104,000 times per day and 2.5 billion times per lifetime. It is an effective pump, being able to send blood from your head to your toes by ejecting about six litres of blood a minute and all of 200 gallons in a day!  

Unfortunately, like anything else, it too is subject to wear and tear. Let’s take the first step and look at the structures of the heart that are subject to the ravages of ageing. It may seem deceptively simple but nothing could be farther from the truth. To be a pump, the heart has to be made up of muscles, valves which keep the blood flowing in one direction only, and finally a conduction system which is able to conduct small electrical currents to get the job done. The currents enable the heart to beat at a certain rate.  

The heart muscle is complex and laid down as three special layers arranged in various directions to enable the heart to contract powerfully. Any damage and these muscles are replaced by scar tissue. The muscle does not regenerate.  

When we age, three things can occur. The muscle fibres can become thicker, or be interspersed with non-muscle tissue fibres or in some cases, die and be replaced by scar tissue, which cannot contract. The heart muscle can thus become stiffer and when this happens, it can affect the contraction of the heart. If severe, patients can start to feel breathless and tired. Fortunately, this is uncommon in healthy individuals.  

Next is the conduction system of the heart. It is really special bundles of heart muscle with different electrical properties. You won’t find anything vaguely resembling wires in there!  

This conduction system ensures the heart beats at a regular rate and responds by beating faster during activities. The heart cannot stop beating even for a moment. If the heart stops beating for even three seconds, stopping blood supply to the brain as a result, you will immediately lose consciousness. A chilling thought.  

Changes to the electrical conduction system due to ageing can also occur. When this happens, the heart can beat very slowly at times. Patients are therefore unable to carry on their daily activities because they feel very tired and lethargic.  

So how low can the rate go down to? In healthy waking individuals, the normal heart rate is about 70 beats per minute (bpm). Those involved in competitive sports will have a slightly lower rate of about 60 bpm as a result of physical conditioning.  

But anything below 60 is considered too slow unless these individuals are on medications for high blood pressure, which can also slow down the heart rate.  

Treatment for this is usually by way of a device called a pacemaker, which kicks in whenever the heart rate is slower than it should be.  

Sometimes the heart electrical system can undergo changes, which result in a faster heartbeat. In addition, the rhythm may also be irregular. Patients normally complain of palpitations and when one checks the pulse, the heart beats at varying intervals each time, from one beat to the next.  

Doctors call this an irregularly irregular heart rate, or atrial fibrillation. It implies an increased risk of developing strokes, although this is small, at less than 1% risk per year. This condition affects about 1% of individuals above the age of 60 years and about 6% of individuals above the age of 80 years. Compare this incidence with that in the younger population, which is about 0.4%. This is in part due to the ageing process, and is more common in those with high blood pressure.  

In atrial fibrillation, the contraction in the smaller chambers of the heart is irregular and not forceful enough. As a result, tiny clots can actually form. The heart, as many of you know, has four chambers – two large and two small. Atrial fibrillation starts in the two smaller chambers of the heart. Patients with this condition may need to take drugs that make the blood thinner and therefore less likely to form clots. 

As the heart ages, changes can also involve the valves. The valves are fibrous tissues. They are not muscular. They are located between the heart chambers and large vessels and they allow the flow of blood in one direction.  

The valve that is most commonly affected by age is the aortic valve. Changes result in stiffening of the valve by calcium deposition and fibrous tissue. Over time, the valve can become narrowed and will not open well. Blood cannot be adequately ejected out from the heart.  

In severe cases, this forces the heart to work harder, making the muscles thicker. The blood supply to the important organs will subsequently be reduced, especially so when the heart has to beat at a faster rate.  

Patients with severe narrowing of the aortic valve can experience giddiness or even faint when they overexert themselves. Some may even get chest pains. Other valves may also be diseased over time, but usually they have been damaged by infection from youth.  

Finally we have another problem associated with ageing. This is the disease process called atherosclerosis. Although part of the ageing process, it can also occur at a younger age, especially when a person has risk factors for atherosclerosis. We are all very familiar with what they are.  

Atherosclerosis also contributes to the primary cause of hospital death in our country, which is coronary artery disease.  

As one grows older, the risk of developing coronary artery disease is much higher. In fact the Framingham Study in the US shows that the lifetime risk of a male over 40 years of age developing coronary artery disease is about 48%. Clearly, with increasing risk factors such as smoking, high cholesterol, hypertension, diabetes and so on, the likelihood of developing this disease is much higher.  

The question now is, if it is so much a part of ageing, how early does it start? During the days of the Vietnam and the earlier Korean wars, even young servicemen were found to have atherosclerosis. Autopsies carried out on casualties of war showed that artherosclerotic deposition had already begun to occur in the vessels of these “youngsters”, some as early as late teens and early 20s. At that time, this was earth shattering news. However as human conflict became more vicious, extracting increasing numbers of unfortunate children as casualties, it became more obvious that this process does not spare the vessels of the very young either.  

With that sobering note, I would like to end this story with the statement that perhaps the very people who should be reading this article, and who are most likely to benefit from it, are perhaps still too young to do so.  

Finally, I would like to say that it is not all doom and gloom as the as the sands of time sift by. An investment in a healthy lifestyle will provide good returns with age. Hopefully then, we will all have minds of 21 and bodies of 40 when we reach the age of 60 years!  

Would I lead my life differently then? It’s been much more fun the way it was! I must leave you with these parting words of wisdom by Woody Allen: “Life is really not so bad...when you consider the alternative.” 

 

  • This article is contributed by The Star Health & Ageing Panel, which comprises a group of panellists who are not just opinion leaders in their respective fields of medical expertise, but have wide experience in medical health education for the public.  

    The members of the panel include: Datuk Prof Dr Tan Hui Meng, consultant urologist; Dr Yap Piang Kian, consultant endocrinologist; Dr Azhari Rosman, consultant cardiologist; A/Prof Dr Philip Poi, consultant geriatrician; Dr Hew Fen Lee, consultant endocrinologist; Prof Sarimah Low, psychologist; Dr Nor Ashikin Mokhtar, consultant obstetrician and gynaecologist; Dr Lee Moon Keen, consultant neurologist; Dr Ting Hoon Chin, consultant dermatologist; Assoc Prof Khoo Ee Ming, primary care physician.  

    The Star Health & Ageing Advisory Panel provides this information for educational and communication purposes on.ly and it should not be construed as personal medical advice. Information published in this article is not intended to replace, supplant or augment a consultation with a health professional regarding the reader’s own medical care. 

    The Star Health & Ageing Advisory Panel disclaims any and all liability for injury or other damages that could result from use of the information obtained from this article. 


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