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Taking Lyme disease to heart

Enjoy the great outdoors, but be on the lookout for disease-carrying pests.

Most summer insect bites can be forgotten as soon as the itching fades away. Not so with a bite from a tick harboring the bacteria that cause Lyme disease. The infection—which has potentially serious heart consequences—is transmitted via deer ticks most commonly found in wooded areas in the Northeast, mid-Atlantic, and parts of the Midwest.

Deer Tick

From tick bite to heart block

For most people, Lyme infection begins with a target-shaped rash where the tick attaches to the skin. If the infection is identified and treated with antibiotics at this stage, it usually does not progress. “Not all people have the expanding rash, and many don’t remember the tick bite,” says Dr. Allen Steere, a professor of rheumatology at Harvard Medical School, who first identified Lyme disease. In these cases, the first signs of the infection may be flu-like symptoms such as headache, joint pain, and fever.

If the infection is not caught early, the bacteria may infiltrate the nerves, joints, or heart tissue. The most common cardiac manifestation of Lyme infection is a malfunction of the heart’s electrical system that causes an abnormality known as atrioventricular nodal block (AV block). While mild AV block causes few symptoms, complete heart block prevents the conduction of electrical signals from the heart’s upper to lower chambers. This is a life-threatening situation that can cause cardiac arrest.

Who is at risk?

Athletic young men are most likely to report severe heart concerns, possibly because they’re slower to notice early symptoms of AV block because of their excellent heart function. The trend may also reflect who is outside and active in the summer. “Older people with atherosclerotic disease are less likely to be running in the woods,” says Dr. Steere. People who live in areas with high rates of infected deer are also at greater risk.

Getting treated

Two key tests are used to diagnose Lyme-related heart disease. The first is an electrocardiogram to identify AV block. The other is a blood test for antibodies to the disease-causing organism. However, your doctor may treat the heart block with a temporary pacemaker before the results of the blood test come back. Lyme infection responds very well to antibiotics and usually clears up without lasting damage after treatment. 

Preventing Lyme disease

  1. Apply insect repellant and wear protective clothing if you are in a tick-infested area.

  2. Always check your skin for ticks when you come inside.

  3. Learn to recognize the characteristic Lyme disease rash and see a doctor if it appears.

Posted by: Dr.Health

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