Tag Archives: heart

Just How Many Heartbeats Do We Get?

Talking recently about exercise and the heart, a really weird question came up. Sometimes those are the best questions, aren’t they?

Exercise makes the heart beat faster, so why doesn’t exercise wear the heart out faster? Why don’t you run out of heartbeats sooner if you spend a lot of time exercising? After all, the heart has a lot of moving parts – heart valves, blood vessels and muscle. These presumably wear out, like anything else, kind of like the 100,000-mile power train warranty on your car. After the warranty expires, you’re on your own …

So you Exercisers watch out, you might just shake something loose. Actually the heart is an absolute wonder of durable construction and last an astounding number of beats. Let’s play with some numbers.
How many beats do we get in a lifetime? If an individual averages 80 beats per minute, that’s 4,800 beats per hour, 115,200 beats per day, and more than 42 million per year, which calculates to roughly 3 billion if you live to age 72. When you think about them that way, heartbeats are the most precious commodity on the planet. Hate to waste ‘em.

Assume a really compulsive 40-year-old exerciser does something strenuous and aerobic five days a week for 30 minutes. He will drive his heart rate up to 160 beats per minute (220 – your age is maximum heart rate and we like to exercise at 65 to 85 percent of that).

The math works out to an extra 2,400 heartbeats per day on your exercise days. That is a 2 percent increase in heartbeats per day for those who are keeping count.

But exercisers have slow heart rates — not in the first week, but after a month or two. Let’s assume exercise brings your resting pulse down from 80 to 60 beats a minute, a pretty reasonable goal. The 72-year-old at the 60-pulse rate uses only 2.2 billion heartbeats. To put it another way, to use up 3 billion heart beats, at a pulse rate of 60, you have to live to age 95. Startling, isn’t it?

But lower pulse rate isn’t the whole story because your heart is living tissue, not a car. That’s a subtle distinction I know, but one that comes up every day in medical practice. A mechanic comes in with a cut hand that requires sutures. He thanks me for fixing it and I usually say, “you’re doing the hard part, I just got it pushed together. You are healing it.” A mechanic has to fix your car engine 100 percent or it won’t run properly. Cars can’t heal themselves, but people can.

Using your heart’s muscle makes it strong. You don’t wear tissue out by using it; you wear it out by not using it. So invest as little as 15 minutes a day in exercise and you will extend your warranty for more trouble-free years of body ownership. Get that pulse down to 50 and it takes 105 years to use up 3 billion heartbeats.

Take care

Dr B

The Proper Care and Feeding of Your Heart

Why should you invest a few precious heartbeats in learning something about your ticker?

Because of atherosclerosis and heart attacks – and because heart disease is still the No. 1 cause of death in this country.

Heart anatomyphoto © 2009 K Sandberg | more info (via: Wylio)

Most of us think the heart is the most important organ in your body. While this might spark a heated philosophical debate, the heart has a certain anatomic primacy based on the simple fact you can’t live without it, even for a few minutes. And few things will ruin your day more.

Most of the important organs in your body are designed with a certain redundancy, like airplanes having two spark plugs per cylinder. You have two kidneys, but can get by on one. You can lose more than half of your liver, just as much of your intestines, blood or lungs, and live, although not with all of that occurring simultaneously. Running on 50 percent function of most organs will leave you alive to fight again.

Ah, but the heart – there can be only one.

Conceptually, the heart is simple enough. It’s a variable speed pump. The faster it beats, the faster the blood goes round and round. It is actually kind of a double pump – one side pumps blood to the lungs, the other to the body. You have to be impressed by the build quality. Most hearts are good for 70+ years and more than 50 million cycles. Very few other things in the world, either living or inanimate, last 50 million cycles.

The heart is a lot like other pumps you know. Pumps, in general, don’t run on what they pump. Think about it – the oil pump in your car uses electricity to pump oil, and a pool pump uses the same to pump water. Similarly, the heart is not nourished by the blood inside the pump; rather, it is powered by the blood in vessels on the outside, namely the coronary arteries.

Given the coronary arteries’ well known propensity to plug up, perhaps the heart might have been better designed to get its nourishment from the blood inside.

But there are sound mechanical reasons why this can’t be. The first involves the heart’s thick muscular walls. There is no way for oxygen to passively diffuse across dense heart muscles in enough concentration to keep the heart alive, let alone beating.

Then there is the problem inherent in that whole beating thing. Blood leaves the heart in an intermittent flow (squirt-stop-squirt-stop). Most tissues, including the heart, don’t tolerate this type of flow. They need continuous flow. Getting this flow smoothed out is the job of the major arteries. These arteries have muscular walls that act as shock absorbers. They expand to absorb a slug of blood and then steadily contract to keep it moving. This works much like a water reservoir supplying water continuously to a town, even though rain is episodic.

Ah, but a heart is so much more than simple plumbing.

A heart’s got rhythm. Heart cells are a type of muscle cell, and like muscles everywhere, they contract. A specialized group of heart cells is a built-in pacemaker. This supplies the tempo. Everybody has to contract at once to get anything done. When they don’t, the heart sort of quivers and stops pumping, and that’s bad.

There can be either blood flow problems, rhythm problems or both from similar things. Atherosclerosis, or plugged coronary arteries, starves the heart cells. Sometimes these cells curl up and die. Sometimes they go electrically haywire and a rhythm disturbance occurs.

So the most important care and feeding of your heart are keeping good freshly oxygenated blood flowing through your coronary arteries. You have been prewired for this to happen. All you have to do is not screw it up. To do this simply means don’t do the stuff that clogs arteries.

• Do control your blood pressure
• Do control you weight
• Do control your cholesterol
• Do control your sugar if you have diabetes
• Do control your stress
• Do not smoke
• Do laugh as often as possible; it helps immunize against stress
• Do drink some red wine – it’s good for your heart and might also help with stress
• Do get some exercise, and for heaven’s sake, don’t suffer for it. If you do, the stress might cancel the benefit of the exercise.

So while hearts may continue to be a mystery to young lovers, you now have the necessary information to understand what makes them tick.

Take care,

Dr. B

Walking for Exercise

Walking for exercise is one of the most effective, inexpensive, enjoyable and safest activities you can do to stay healthy. Other than some comfortable footwear, you do not need any special equipment or nine other people to do it.

Trailnet-Walk-05photo © 2007 Trailnet | more info (via: Wylio)

Walking is so accessible – it can be right outside your front door or on a lunch break at work. You can go to other venues for a change of scenery, none of which adds any cost to the price of beneficial exercise.

And numerous studies demonstrate the enormous benefits of walking to people of all ages. The benefits are physical, mental and emotional.

As a physical exercise, it’s easier on the joints compared to high-impact sports or jogging. The speed is not as important as the duration of the activity. The cardiovascular benefit is most dependent on getting the heart rate up a little, but still in a safe range and sustaining that pace for 15 to 20 minutes. Actually, aerobic exercise can be very effective even in small installments. If you only have 5-10 minutes to walk several times a day, the cumulative benefit is comparable to the same sustained activity for 30 continuous minutes.

Research has shown that Americans walk less than people do in other countries. Studies have also shown that use of a pedometer or other movement-measuring device can be very helpful in measuring and stimulating people to be more active when they pay closer attention to the amount of their daily activity. Inexpensive pedometers ($25-50) or the more expensive motion sensors ($100) are fun tools to measure and track your progress.

The more you walk, the more calories that are burned and the easier it is to maintain weight. Toning the muscles provides overall stamina and significant cardiovascular benefits.

What may surprise some is the appetite suppressant effect of regular exercise. For serious dieters, the more active you are burning calories, the less restrictive with food you need to be. If the feeling of being deprived can be avoided, then staying with your food plan is more likely.

A regimen of regular walking can be a great stress reducer and relaxation tool. As any aerobic exercise burns calories, the increased circulation to the brain helps prevent memory loss, and it relieves physical and emotional tension. With relaxation, we can be more mindful and clear thinking about all things.

Since the evidence is overwhelming that walking helps so many aspects of your health, what are you waiting for? Let’s get moving!

– Dr. Bruce Kaler

Hardening of the Arteries and Other Blood Vessel Mischief

There is a point when discussing blood pressure, cholesterol or weight control that patients are genuinely perplexed about what causes what.

There is a very common notion that hard arteries or obesity both cause high blood pressure. It makes a certain amount of sense, when you think about it, but it’s unfortunately not true.

That’s why it’s well worth understanding this stuff as atherosclerosis is the leading cause of death and poor health in this country. As luck would have it, many cases of arteriosclerosis are fixable.

Heart coronary arteriesphoto © 2007 Patrick J. Lynch | more info (via: Wylio)

Atherosclerosis is commonly called “hardening of the arteries,” but the real problem is blockage of the arteries. Two hundred years ago, which in medicine might just as well be a million years, people dissecting dead bodies discovered arteries that were hard as pipe. These thick, hard walls were the result of calcified cholesterol plaques in the wall in arteries, thus the idea of “hardening of the arteries.”

We care a lot less about hardness than lousy blood flow. What happens when blood doesn’t flow? The body part turns black and dies – that’s bad.

So atherosclerosis means not enough blood to whatever the artery supplies – in the heart, no blood means a heart attack; in the brain, a stroke; in the kidneys, kidney failure. The list goes on, so we want to avoid atherosclerosis.

Many modifiable risk factors work through atherosclerosis to do their damage. High blood pressure (hypertension) beats up on the arteries by over pressuring them. That causes microscopic tears in the lining of the arteries. The body responds by causing an inflammatory reaction in the blood vessel. Over time this causes cholesterol to reinforce the walls of the vessel. In this case, the reinforcement causes trouble, namely atherosclerosis.

Cholesterol is another modifiable risk factor. By modifiable I mean something can be done about it. In general, the higher the cholesterol, the faster you develop atherosclerosis.

These days we understand that not all cholesterol is bad. There is bad cholesterol that plugs up your plumbing, like saturated fat. To make life more complicated, there are also several types of cholesterol particles. The good guys are called HDLs (high density lipoproteins), which are thought to bring cholesterol back from the plugged blood vessels, improving blood flow. LDLs are the bad guys. They are in the business of plugging blood vessels.

Good news – drinking wine increases your HDLs.

Smoking is another way to accumulate blood vessel damage as quickly as possible. There are chemicals and carbon monoxide in tobacco smoke that injure blood vessels. Once the vessels are injured, they are well on their way to becoming atherosclerotic.

Diabetes is a disease of uncontrolled or poorly controlled blood sugar. Blood sugar that is out of balance damages – you guessed it – the blood vessels. This results in high rates of inflamed and blocked arteries. This is a treatable condition, and careful control of blood sugar measurably reduces the rate of atherosclerosis.

Blood Vessel Model 3photo © 2005 Eina Jane | more info (via: Wylio)

No discussion of “hardening of the arteries” would be complete without mentioning obesity. It is readily apparent after a brief glance around any city in the country that obesity is at nearly epidemic levels. Obesity gets involved with hastening atherosclerosis in a variety of ways. Just being very overweight puts an additional load on the cardiovascular system. This alone can cause damage.

Obesity is also associated with type 2 diabetes. Often, people don’t get extra large eating only low-fat foods, so cholesterol-rich diets are also a factor.

These risk factors work together – smoking, high blood pressure, cholesterol and obesity cause a much greater risk when together in the same patient at the same time. The fancy name for this is metabolic syndrome. For those people, lifestyle changes are essential.

The good news is most of what plugs your plumbing is under your control. A doctor can help you with high cholesterol or blood sugar. You can help yourself by making good dietary choices and getting a little exercise. It might also be a good idea to throw the cigarettes away.

Take care,

Dr. B

‘Air goes in and out, blood goes round and round, and urine runs downhill’

Thus began one of my more entertaining lectures in medical school. At the time I was about half-way through medical school, so I just barely knew enough to know that this was a bit of an oversimplification. I laughed hard at the time, as did my classmates, but this got me thinking. There was a simple elegance to this concept, almost Zen-like. The human body was put together with a series of conceptually simple functional systems.

On that same note, here are some oversimplified health beliefs and the truth to them:

Air Goes In and Out
The lungs are in many ways like a tree. The trunk is the windpipe, the branches the bronchial tubes, and the leaves the alveoli. The leaves are where a tree goes about breathing. The trunk and branches are of little use without leaves. The leaves are the most sensitive parts of the system; serious tree diseases usually affect the leaves. In the body, we absolutely depend on free exchange of gases at the alveoli. Put toxin into them, and they are the first to go. The tree will eventually die.

Blood Goes Round and Round
Blood needs to circulate. If it doesn’t, stuff dies. If the blood that supplies the heart doesn’t go round and round, we call it a heart attack. In the brain, this is a stroke. We should do everything in our power to avoid blockages like these. Blockages are caused by excess: too much blood pressure or cholesterol, too much eating or smoking, too much weight or sugar, even too much work. It’s all about balance in life.

What Goes In Must Come Out
The first association that comes to mind is the digestive system. This, most simply, is a long tube where food goes in one end and waste comes out the other. A certain balance is implied – too much in and not enough out, and trouble will ensue. We also might use this to consider nutrition – good food in, good heath comes out. Calories also go in and must come out, otherwise you get bigger.

Use It or Lose It
This has application to almost every system. Our muscles must be used or they deteriorate. Spend a month in bed and even simple walking is a great effort. You must stay active if you wish to continue a vital life.

Our immune system is also a fan of this rule. Kids raised in too clean an environment have unstimulated immune systems that don’t work well. Two dogs keep a house dirty enough for proper development of the immune system. Asthma is rare in kids from two-dog households.

We are even finding mental exercise prevents deterioration of the mind. Risk for Alzheimer’s is lower the higher a person’s education level.

It is very easy to get caught in the details of “pop health talk” – the vitamin of the week, the micro nutrient of the moment, or a single exercise that will change your life. Maintaining good heath is actually rather simple and something you can do on your own without these fads: keep moving, keep breathing and strive for balance in your habits.

Take care,

Dr. B

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