February is American Heart Month, with a focus on encouraging all of us to make heart-healthy choices to reduce cardiovascular disease risk. I thought that sharing some information about the heart, how it works and how to keep it healthy would be an appropriate way to celebrate.
Your heart started beating months before you were born and will continue to beat every second or so until it stops, signaling the end of your life. During your lifetime, your heart will probably beat more than 2 billion times, or about 100,000 times per day.
The major function of the heart is to pump blood to all of your tissues through the arteries and back again through the veins. The heart has four chambers: the left and right atria that receive blood from the veins and the left and right ventricles that pump blood into the arteries. The right ventricle pumps blood to the lungs to pick up oxygen and the left ventricle pumps oxygenated blood out to the rest of the body.
The activity of your heart will vary throughout the day. At rest your heart rate is low, typically around 70 beats per minute. Some athletes have resting heart rates that are much lower, owing to their bigger, stronger hearts.
But when you are active your heart beats faster and more forcefully to eject more blood to the working muscles. During intense exercise, a young person’s heart rate can go above 200 beats per minute and the amount of blood pumped can be five times higher than at rest.
The heart is made up mostly of muscle that functions similarly to the skeletal muscles you use to move your body. But cardiac muscle is different in that it can spontaneously contract when stimulated by a specialized area of the heart called the SA node or pacemaker. And unlike skeletal muscle, the heart is remarkably fatigue-resistant, meaning that it can contract repeatedly without needing a break.
In order to beat continuously, the heart needs a steady supply of oxygen which is delivered through coronary arteries, not from the blood inside the chambers of the heart. Normally, plenty of oxygenated blood gets through. But if the coronary arteries become narrowed through atherosclerosis, the accumulation of plaque in the vessels, blood supply can be limited.
This can lead to reversible symptoms like angina pectoris (chest pain), especially during exertion. If a clot forms in the narrowed vessel, blood flow can be blocked completely causing a myocardial infarction (heart attack). Heart disease can be managed using medications, angioplasty, or bypass surgery, but the best approach is to prevent the problem from occurring in the first place.
Taking care of your heart is one of the most important things you can do for your health. Like other muscles, regular exercise can make your heart larger and stronger to pump blood more effectively. Exercise also lowers your blood pressure and can help reduce your blood cholesterol, further reducing the risk of heart disease.
A diet that is low in salt and unhealthy fats, like trans fats, can help lower blood pressure and cholesterol, slowing the process of atherosclerosis and preventing heart failure, a condition in which the heart muscle becomes weak. Maintaining a healthy body weight and controlling blood glucose are also keys to a healthy heart.
More than anything, though, your heart likes to be active. So, celebrate American Heart Month by taking your heart for a walk every day.