[Reversible complete heart block by re-infection with Borrelia burgdorferi with negative IgM-antibodies]

PAST HISTORY AND PHYSICAL EXAMINATION: A 38-year-old farmer presented at his general practitioner with dizziness. Physical examination was notable for a heart rate of 35 beats/min. The electrocardiogram (ECG) showed a complete (third degree) heart block with a bradycardic ventricular escape rhythm. The patient reported having had an rash on his right lower leg six weeks previously. After spreading centrifugally it had turned pale in its centre, then regressed and finally disappeared. After having been supplied with a temporary pacemaker in a county hospital the patient was transferred to our hospital.

The ECG showed pacemaker stimulation of the ventricle at about 60 beats/min. Without this stimulation the complete atrioventricular block persisted. Coronary heart disease was excluded by angiography and levocardiography revealed normal systolic left ventricular function. Serological findings were a positive titre of IgG-antibodies against Borrelia while the IgM titre was negative.

The heart block disappeared under antibiotic therapy with ceftriaxon within eight days, after first changing to transitory second and first-degree atrioventricular block, and the pacemaker was removed. The patient did not develop any neurological symptoms.

Cardiac involvement in Lyme disease can be the only manifestation of borreliosis. Possible reversibility under antibiotic therapy is an important aspect of diagnosis. In spite of atypical serology the combination of history, symptoms and serological findings will lead to the diagnosis Lyme disease.