When Lyme bacteria reach your heart tissue, it can cause Lyme carditis, which affects your heart’s electrical system. Lyme carditis can lead to another condition called heart block, which happens when your heart beats too slowly. There are three types of heart block:
First-degree heart block: when the electrical signals reach the bottom chambers of your heart, called your ventricles, slower than usual.
Second-degree heart block: when the electrical signals either fail to reach the ventricles fully, or some of the signals cannot reach them at all.
Third-degree heart block: when none of the electrical signals can reach your ventricles.
Symptoms of Lyme carditis can include:
Dizziness or light-headedness
Fainting
Shortness of breath
Chest pains
Lyme carditis can be treated, usually through antibiotics. Some patients may also need a temporary pacemaker to keep the heart beating at a normal rate.