One of the most fascinating vital organs in the body, a symbol of love, endearment, even of religious adoration, and still a mystery to most of us, is the heart. The marvelous facts about this restless, non-stop pump, are mind-boggling and a constant source of wonderment. Winning hearts, stealing hearts, breaking hearts (and for cardiac surgeons, mending hearts) are easier to understand and do, than to comprehend fully the wonders of this ceaselessly active, seemingly untiring, and unique contractile muscle in our body.
How large is our heart?
The size of the adult heart is about the volume of two hands clasping each other, with the fingers intertwined. In children, it is the size of the kid’s one fist. The heart is located, not to the left, as often thought of, but in the middle of your mid chest, enclosed in its own compartment, an envelope called pericardial sac, and located between the left and right chest cavity, where the left and right lungs are, respectively. Its tip is pointed slightly to the left.
Does the heart ever rest?
The heart beats about an average of 70 beats per minute, 4,200 an hour or about 100,800 times in one day, roughly about 36 million times in a year. In an average life span, the human heart will beat about 2.5 billion times. But contrary to what seems obvious, the heart rests for a split second in between beats. This happens between contractions, when the heart relaxes to accept more oxygenated blood from the lungs and prepares to pump blood out of its chambers again.
How powerful is the heart contraction?
The heart contraction is so powerful that it approximates the force one needs to give a tennis ball a hard and full squeeze with all your might. The cardiac muscles work twice as hard as the leg muscles of a person running full speed. The hydraulic force generated is necessary to propel rapidly the blood that circulates about 13 kilometers per minute, or 780 kilometers per hour, about four times the speed of the fastest racing car there is.
Will the heart beat on its own?
The muscle of the heart, unlike other muscles in our body, is a specialized one that beats on its own (automaticity) and one that has its own rhythm (rhythmicity), even when cut off from the body and lying on a surface. The isolated heart in this situation will beat continuously until its own residual energy is used up, which is within about 4 minutes. It then ceases movement.
What is the normal heart rate?
This varies from individual to individual, depending on the age, condition of the body, and the health of the person. A well-conditioned athlete may have a heart rate of 35 a minute and feel great, but this rate would cause almost all of us, non-athletes, to feel faint and pass out, or in the very least, feel very dizzy and weak. On the average though, the normal resting rate (medically speaking) is from 60 to 100 beats per minute. Anything below 60 is called bradycardia (too slow heart rate), and a rate higher than 100 is tachycardia (too fast a heart rate). Among children the range is between 90-120 beats a minute.
How much blood does a person have?
The adult human body has about 5.6 liters (6 quarts) of blood in the circulation. These 6 quarts completes a full round of circulation throughout the body about every 20 seconds. The blood travels a total of about 19,000 kilometers (12,000 miles) in 24 hours, which is about four times the distance from California to New York, or roughly five times the air miles from San Francisco to Manila. About one million barrels of blood is pumped by the heart in an average life span, a volume enough to fill more than three super tankers.
How does blood get oxygen and nutrition?
The nutrition and oxygen in the blood are used up by the tissues and cells. The used blood (now containing much less oxygen and more carbon dioxide, lactic acid and other “waste products”) travels back from the tissues and cells to lungs for oxygenation. Then blood goes to the heart for pumping to all organs, like the liver where toxins will be detoxified, to the kidneys that will filter the waste products and passed out through the urine, to the stomach and intestines where it will be replenished with new nutrition. The used blood then flows back to the lungs. After the oxygenation, the blood flows into the heart, ready to be pumped back into the circulation once again. And the cycle goes on.
How strong is our heart?
A healthy heart can take a lot of beating (no pun intended). It is one of the most powerful pumps in the world, even when compared to the mechanical ones built by man. Self-contained, self-propelled, energy-efficient, the heart works without stopping, and can survive grave insults and abuses we, humans, subject it to, day in and day out.
When is artificial heart used?
Mechanical (man-made artificial) heart is helpful as a bridge to heart transplantation, implanted temporarily (for a few weeks or so) while a transplant patient waits for a human donor heart, but not as a long-term, permanent, heart replacement. Obviously, of course, a suitable permanent mechanical heart with as close inherent features as those of the human heart is the ultimate goal of ongoing research around the world. When that day comes, a dying cardiac patient would not have to wait for a compatible donor to die before getting heart transplant. The cardiac surgeon then would simply ask the operating room nurse for the appropriate size artificial heart from the shelves (much like asking for a pacemaker today) to be implanted on the patient. By then too, coronary bypass, heart valve surgery, and most cardiac surgeries, would be a thing of the past, and the millions of lives lost annually around the globe today from severe and end-stage heart diseases would be saved. As a cardiac surgeon, I can’t wait for that dream to come true.
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The opinions, beliefs and viewpoints expressed by the author do not necessarily reflect the opinions, beliefs and viewpoints of the Asian Journal, its management, editorial board and staff.
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The main objective of this column is to educate and inspire people to live a healthier lifestyle to prevent illnesses and disabilities and achieve a happier and more productive life. Any diagnosis, recommendation, or treatment in our article are general medical information and not intended to be applicable to or appropriate for anyone. This column is not a substitute for your physician, who knows your condition well and who is your best ally when it comes to your health.
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Philip S. Chua, MD, FACS, FPCS, a Cardiac Surgeon Emeritus based in Northwest Indiana and Las Vegas, Nevada, is an international medical lecturer/author, Health Advocate, newspaper columnist, and chairman of the Filipino United Network-USA, a 501(c)3 humanitarian foundation in the United States. He was a recipient of the Indiana Sagamore of the Wabash Award in 1995, presented by then Indiana Governor, US senator, and later a presidential candidate, Evan Bayh. Other Sagamore past awardees include President Harry Truman, President George HW Bush, Muhammad Ali and Astronaut Gus Grissom (Wikipedia). Websites: FUN8888.com, Today.SPSAtoday.com, and philipSchua.com; Email: [email protected].
