The average healthy person has a resting heart rate between 60 and 100 beats per minute. The more athletic a person is, the lower his or her heart beat will be. Olympic swimmer Michael Phelps reportedly has a heart rate in the 30s, for example, because of his extraordinary physical conditioning.
When a heart muscle is exercised often, it pumps more efficiently. But when someone who doesn’t exercise regularly has a slow heart beat, it can be dangerous. This condition, called bradycardia, means the heart’s conduction system is not functioning properly. There are many reasons why it occurs, and treatments range from adjusting medication to placing a pacemaker, a device that tells the heart when to contract.
The heart beat is regulated by something called the sinus node, where the heart’s electrical impulses are generated. It’s known as the heart’s natural pacemaker, and when it doesn’t function correctly, it creates a condition called “sick sinus node.” A person with sick sinus node can experience dizziness, lightheadedness, fatigue, chest pain and in some cases, confusion or memory problems. “When the heart rate is very low, a person can become short of breath, a person can pass out,” says Dr. Maliakal Joseph Anto, chief of cardiology at Syosset Hospital in New York and assistant professor of medicine at Hofstra University. “It can be a fatal condition.”
[See: 17 Ways Heart Health Varies in Women and Men.]
Causes of a Slow Heart Beat
Slow heart beat can occur with age or as a result of damage from a heart attack or heart disease. Thyroid problems or sleep apnea can also be a trigger. And some people have a slow heart beat due to a genetic condition.
But, Anto says, “The number one cause is medications.” The first thing a doctor will do when a slow heart is detected is look at which medicines the patient is taking. Two of the most common culprits are the classes of heart medications called beta blockers and calcium channel blockers. Beta blockers, used for high blood pressure and chest pain, cause the heart to beat more slowly and gently to reduce blood pressure. Sometimes, the effect of beta blockers is that the heart beats too slowly. Calcium channel blockers, which stop calcium from penetrating cells of the heart and blood vessel walls, help lower blood pressure by widening blood vessels. That, too, can in some cases cause the heart to beat too slowly.
An initial step to address slow heart beat is to ensure a patient’s not on drugs such as beta blockers, calcium channel blockers or other prescriptions that could be affecting the heart beat. “You remove those medications and see if heart rate gets better,” says Dr. Ali Rahimi, a cardiologist with Kaiser Permanente Atlanta.
Pacemakers
If adjusting medication doesn’t work, doctors will consider placing a pacemaker, which is a small unit that generates electrical impulses to stimulate and regulate the heart beat. “Pacemakers can do absolute wonders,” Anto says. “Technology has advanced so much in the past 20 to 30 years.”
A pacemaker is a matchbook-sized, battery-powered device that’s placed under the skin in the chest, usually under the collarbone. The pacemaker has two parts, a pulse generator and wires that are attached to the heart wall. The surgical procedure can take an hour or two, and a pacemaker battery usually lasts between 5 to 15 years. When the battery runs out, the old pulse generator will be taken out, and a new one will be implanted.
Pacemakers work reliably, and once you put one in, “you can use any medication you want,” Anto says.
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Check Your Heart Rate
Knowing your heart rate can help monitor how fit you are, and it could also help spot a health problem.
Your resting heart rate is your heart pumping the least amount of blood your body needs because you’re not exercising. Babies and young children will have faster heart rates, often over 100 beats per minute. Starting at about age 10, children should have a heart rate similar to adults, between 60 and 100 beats per minute.
Activity trackers are a common way to figure out your rate. You can also check by placing two fingers on your wrists, side of your neck or top of the foot until you feel your pulse. Count the number of beats you feel in 60 seconds.
If your heart rate is less than 60, it’s a good idea to check in with a doctor, especially if you don’t regularly exercise.
Athlete’s Heart
So how do doctors know whether a person’s slow heart is caused by excellent physical conditioning — also called athlete’s heart — or from a problem in the electrical conduction?
Generally, cardiologists check a person’s weight and ask about his or her activity level. “If someone exercises, runs all the time, is very conditioned, their resting heart rate will be slower,” Rahimi says. “Someone who is an ultra-fit marathoner can have a heart rate in the 50s or the high 40s.” People who are in great physical shape often monitor their own heart rate with activity trackers, he adds.
Doctors have many ways to test the heart function and analyze blood flow through the arteries and to the heart. These include tests such as an exercise stress test, an echocardiogram or a coronary CT angiogram.
It’s also important to test the heart’s resilience. “The fitter you are, the quicker your heart rate will come back to normal after exercise,” Rahimi says. “In individuals who are not very fit, their heart rate will go up quick and take longer to come back to normal.”
[See: Easy Ways to Get 10,000 Steps per Day.]
If you’re unsure about the pace of your heart, or if you have symptoms such as dizziness or lightheadedness, visit your doctor for a check-up.
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Understanding What Causes a Slow Heart Rate originally appeared on usnews.com
