Be Heart Smart - Understand, Treat, and Prevent Coronary Heart Disease

CHAPTER 1

HEART BASICS: CORONARY HEART DISEASE, ACUTE CORONARY SYNDROME, AND HEART ATTACK

It was a typical Saturday. I was on call at a local hospital in suburban Houston, and since it was a quiet morning, I was catching up on some recent studies in a few medical journals. As an interventional cardiologist, I like to stay on top of the most up-to-date research and cutting-edge techniques that can help my patients. In the middle of reading an article, I got an urgent call to the emergency room. As I arrived, the ER doors swung open and paramedics wheeled in a patient—male, 45, chest pain, unconscious.

We transported him to the cardiac catheterization lab—the cath lab—to run tests to see what was happening with his heart. As we ran the imaging diagnostics, the patient flatlined again as he had done prior to arriving in the ER. We had to shock his heart multiple times to bring him back to life. The images told a worst-case scenario. He had a severe blockage in the most catastrophic spot—an artery cardiologists refer to as the “widowmaker.” The left anterior descending artery supplies blood to a large portion of the heart, and when it is blocked, it often results in sudden death.

When I realized the blockage was in the widowmaker, I thought about his wife, who had told me while sobbing in the ER that her husband was an airline pilot. I didn’t want her to become a widow that day, but I knew that her husband’s chances of survival were slim—few people who suffer a heart attack due to a blockage in the widowmaker make it out of the hospital alive. We immediately put the man on a ventilator and inserted a lifesaving mechanical balloon-pump device to help his heart pump more blood to his coronary arteries while we removed the blockage—a large blood clot—and placed a stent in the artery. With the stent in place, blood resumed flow to his heart, and it started beating normally again. Fortunately, his wife would not become a widow that day.

The following day we removed the ventilator, and when the airline pilot woke up, his chest pain was gone and his electrocardiogram (EKG) showed improvement. His wife was overjoyed to see him doing so much better, and a couple days later, he left the hospital. In time, he resumed his job as a pilot. Now I see him on a regular basis for follow-ups; his heart is healthy, and he feels great. The pilot defied death that day, but not everyone is so lucky.

THE NO. 1 KILLER

What is the No. 1 killer of both men and women in the United States? It isn’t cancer. It isn’t traffic accidents. It isn’t gun violence. It’s coronary heart disease (CHD). Every 43 seconds an American dies from a coronary event. That’s more than 2,000 deaths per day. And every year an estimated 735,000 Americans suffer a heart attack, also known as a myocardial infarction (MI), according to the American Heart Association (AHA).

The devastating and debilitating effects of CHD reach far beyond U.S. borders. CHD claims more lives worldwide than any other cause, and it is responsible for about one-third of all deaths in people over the age of 35. A 2014 World Health Organization study of 49 countries found that CHD was the culprit in over 4 million deaths that year.

If you or a loved one is living with CHD, you’re not alone. Roughly one-half of middle-aged men and one-third of middle-aged women have some form of CHD. According to a long-term research project known as the Framingham Heart Study, which followed more than 5,200 people between age 30 and 62 for over 40 years, the incidence of coronary events is generally higher in men than in women. After women complete menopause, however, the incidence of CHD tends to even out between the sexes.

Although coronary events are more common in older Americans, this insidious disease can take root in the body many years or even decades before old age. According to the most recent AHA estimates, 16.5 million people over age 20 currently show signs of the disease.

If your doctor has diagnosed you with coronary heart disease or if you’ve suffered a heart attack, you likely have a lot of questions: Why did this happen to me? What treatments are available? What can I do to prevent a heart attack?

One of the first things you should do to protect yourself from a coronary event is to learn as much as you can about the disease, its causes, risk factors, treatment options, and recommended lifestyle changes. With knowledge on your side, you and your doctor can make the best decisions for your heart health.

YOUR AMAZING HEART

Your heart is an amazing pump that beats more than 100,000 times a day, every day of your life. That adds up to about 2.5 billion beats in a lifetime. Although it weighs less than a pound and is only about the size of a fist, your heart handles one of your body’s most important processes: circulating blood throughout your body. Each minute, your heart pumps 1.5 gallons of blood, which adds up to over 2,000 gallons per day.

Located slightly left of center in the chest behind the breastbone, the heart has four chambers—two upper ones (the atriums or atria) and two lower ones (the ventricles). Divided in half by a thin membrane called the septum, the heart’s chambers work in concert to keep blood flowing in the following endless sequence:

The human heart can perform this continuous pumping action because it is a muscle, although it isn’t like the other muscles in your body. Composed of smooth tissue, the heart pumps involuntarily, meaning you never have to think about it. The other approximately 700 skeletal muscles in your body are composed of voluntary tissue, which means they are controlled consciously. For example, you have to consciously think about walking to engage your quadriceps, hamstrings, and other leg muscles. You have to make a conscious decision to raise a glass of water to your mouth to spark the contraction of your biceps. You have to will yourself to do a sit-up to fire up your abdominal muscles. But you don’t have to tell your heart to pump. It just keeps on beating.

The heart muscle also differs from skeletal muscles regarding healing and repair. Let’s say you’re playing in your company softball game, and it’s your turn at bat. The pitcher tosses a juicy strike to you and you swing with everything you’ve got, hitting a blistering line drive past the third baseman. You drop the bat and start running toward first base when—ouch!—you pull your hamstring. You have to sit on the bench the rest of the game with an ice bag on the back of your thigh. Almost immediately, inside your body, your cells shift into repair mode to begin the healing process on that hamstring. With rest and time, your hamstring will be as good as new and you’ll be back on the playing field.

Unfortunately, if you were playing in that same softball game and suffered a heart attack after you hit the ball, your cells wouldn’t rush into repair mode. The heart simply does not heal or regenerate tissue the way skeletal muscles do. This is why it is so important to try to avoid damage to the heart muscle.

THE CIRCULATORY SYSTEM

The heart is just one part of the body’s circulatory system, also known as the cardiovascular system. This system includes the lungs as well as blood vessels called arteries, veins, and capillaries. Arteries transport blood, oxygen, and nourishment from the heart to the body, and veins carry deoxygenated blood back to the heart. Tiny blood vessels called capillaries form connections between arteries and veins.

The circulatory system is vast. In fact, if you laid all the blood vessels in your body end to end, they would measure approximately 60,000 miles, more than twice the circumference of the earth or about 10 round trips from Los Angeles to New York City.

The circulatory system is similar to the nation’s highway system. Think of the blood vessels in your body as a complex network of one-way highways and roads. Oxygen-rich blood, which is bright red in color, travels through the arteries to the body’s organs. After nourishing the organs, the oxygen-depleted blood, now dark red, picks up waste and debris and returns to the heart via the veins. In between, capillaries act like bridges shuttling blood between the arteries and veins.

Your circulatory system can move blood through your body surprisingly quickly. Just like with real highways, the wider the artery, the faster traffic flows; the smaller the throughway, the slower it goes. On average, blood flows at about 3 to 4 miles per hour—average walking speed. If a nurse injects a drug into your arm, though, it can reach your brain in a matter of seconds.

All this internal circulation happens 24/7 every day of the year—whether you’re playing softball, watching TV on the couch, or reading a book.

CORONARY ARTERIES

Just like all the other organs in your body, your heart relies on oxygenated blood to work properly. Its supply of nourishment comes from two main coronary arteries that rise from the base of the aorta, the largest artery in the human body.

The two vessels that branch off...