How can infections like Lyme disease lead to heart problems?

Recently, international rugby star Matt Dawson has made the headlines talking about how Lyme disease, spread by a tick bite, led to him needing two heart procedures.

Matt Dawson MBE

But how can infections, such as in rare cases Lyme disease, cause problems with our hearts?

A case of ‘itis’

In medicine, the letters ‘itis’ mean inflammation. For example the well-known malady tonsillitis, is caused by an infection in the small glands that sit on either side of the throat.

3D computer model of a virus

When infections — caused by viruses, bacteria or fungi — spread to the heart they can lead to inflammation here too, causing:

  1. Myocarditis — inflammation of the heart muscle
  2. Pericarditis — inflammation of the fluid sac that surrounds the heart
  3. Endocarditis — inflammation of the inner lining of the heart.

These conditions can often go unnoticed and do not always require medical treatment. Like with tonsillitis, the inflammation will go down once the body has fought off the infection.

When your heart’s rhythm goes wrong

In rare cases, these inflammatory conditions can damage the heart’s tissue leaving scars.

Within these scars, there often remain channels of living tissue that can form a short circuit around the scar, leading to electrical disturbances (arrhythmias or abnormal heart rhythms) that can stop the heart from beating normally and are potentially life threatening.

Finding a needle in a haystack

Doctors can prevent these disruptions by ablating (burning the areas of scarring responsible using radiofrequency energy).

However, first they need to find these problem channels amongst the scar tissue.

BHF-funded researchers at Imperial College London have created a new way of finding these channels, called Ripple Mapping and are carrying out a clinical study to find out if this technique can help doctors to more successfully treat these abnormal heart rhythms.

By funding research looking to make ablation more accurate the BHF aims to reduce the amount of people dying each year due to abnormal heart rhythms.

A twist in the tale

Strangely, the ticks which carry Lyme disease may also lead us to a cure for heart inflammation. Find out how a BHF Professor is teaching new bugs new tricks in the story below.