The miracle of a heartbeat

Randy Riley - Contributing Columnist

Forty-six years ago, I was just beginning to learn the anatomy and physiology of the cardiopulmonary system.

It was April of 1970. I had just started working and studying for a career in respiratory therapy. The profession at that time was called “inhalation therapy.” It was the newest of all the health care specialty careers. At that time, Miami Valley Hospital had the reputation of being an excellent teaching hospital. They already had schools for nursing, lab technology and radiology. I was excited and thrilled to be part of their newest work/study program.

I was fascinated by the career and the way the entire healthcare team work together to save lives. I also remember being completely amazed by the miracle of strength and creation that is the human body.

Anyone who has ever taken a biology class in high school knows what the heart looks like and basically how it works. I still remember dissecting the heart of a fetal-pig and a frog in Mr. Barker’s biology class at Germantown High School. Even then, I was fascinated by both the simplicity and the complexity of the heart.

Most people think about the heart in poetic, romantic and musical ways. We have all heard phrases like; he gave her his heart and his heart would be forever broken. The world of music is filled with songs like; “Expressway to your heart,” and “Goodnight, sweetheart, goodnight.” With all of the feelings that are said to reside within the heart, it is little wonder that the heart has acquired a reputation for being where love lives and where love grows.

From a purely clinical point of view, your heart is about the size of your clinched fist. It lies near the center of your chest, angled slightly down to the left. The heart is nestled between the right lung and the left lung – almost like it is cushioned between two airbags. It rests just below the lower third of the sternum and lies just above the spinal column.

In the most simplistic of terms the heart is a four-chambered pump. The two chambers on the right side of the heart pump used blood to the lungs where carbon dioxide (one of the byproducts of metabolism) is exchanged for a fresh supply of oxygen (which is needed for life). The fresh blood coming from the lungs goes into the left side of the heart where it is then pumped to the entire body. This happens constantly. If it stops for just a few seconds, you will pass out.

That’s the circulation, or plumbing, part of the heart. But what makes this amazing little organ beat? Well, that piece of magic is caused by the work of the conduction (or electrical) system of the heart.

Nestled within the muscle of the upper right chamber of the heart is a clump of specialized tissue known as the Sinoatrial (SA) Node. The functioning of the SA Node is very complex, very technical. Basically, think about what makes a firefly be able to set its tail aglow. Think about what allows an electric eel to generate a charge of electricity strong enough to knock down a large animal. Somewhere in between these two examples, is the power of the SA Node.

The SA Node is the pacemaker of the heart. Anyone who has ever been shocked knows that the shock causes their muscles to contract. You can’t stop it from happening. Miraculously, nearly every second, the SA Node generates and discharges a small electrical charge that shocks the heart muscle, causing it to contract. The contraction (or squeeze) forces the blood that is within that chamber out to the next chamber or into an artery (think about milking a cow).

The electrical impulse that started in the SA Node will travel through both upper chambers of the heart, squeezing blood down through one-way valves into the lower chambers. The flow of the electrical impulse is then delayed ever so slightly near the middle of the heart at the Atrioventricular (AV) Node.

Before passing through the muscle of the lower two chambers, the electrical impulse is conducted between the two lower chambers along two bundles of conductive tissue (like electrical wiring) to the lowest part of the heart. The impulse then flows into the muscle of the heart causing the lower two chambers to contract and squeeze the blood up and out.

Think about holding a strong umbrella upside down. If is filled with fluid, and then closed, the fluid spills up and out. That’s basically how the heart is emptied of blood. One-way valves prevent the blood from flowing back into the heart.

While you read the previous few paragraphs, your heart beat about 100 times. Your heart beats about 100,000 times every day; nearly 40 million times a year; 3 billion times in a long-lived life. You never feel your heart get tired. If more blood flow is needed due to exercise or emotion, the heart simply beats faster.

The heart is a God-given miracle of design and function. There is peace and comfort in the regular beating and the sound of the human heart. An infant will cuddle and fall asleep on its mother’s chest while listening and being comforted by the sound of their mother’s heartbeat.

I apologize if all of this information about the heart sounds too medical and technical for a Tuesday in October, but, rest assured. There is magic and majesty in the heart. Despite what I know about the clinical part of the heart, I truly believe that, while love may start in the mind, it grows and develops in the heart. The heart can be broken and mended.

My heart was completely broken ten years ago when my son Danny died. Yet, it mended. Then, it was broken again last year when my grandson was diagnosed with cancer. Again, my heart was mended and healed by family and friends.

As of today, Debbie and I have been married for 29 years. She was gone last week on a “girls trip” to Florida. My heart ached while she was gone. It felt empty. It was like a piece of my heart was missing. Then she came home.

Even after 29 years of marriage, my heart will speed up and even flutter a little whenever Debbie takes my hand, squeezes it and tells me, “Goodnight, sweetheart, goodnight.” There is love and magic within our hearts.

Randy Riley is President of Council of Wilmington.

Randy Riley

Contributing Columnist