AB0414 Heart block in the young: should we consider an inflammatory rheumatism?

Background Heart block in the young is uncommon and sometimes the etiology is not found. Several inflammatory rheumatic diseases can cause conduction disturbances. Some of them are well described, such as in patients with ankylosing spondylitis, but others are controversial. Ro autoantibodies have been traditionally associated with the development of neonatal lupus and congenital heart block. Recent research has demonstrated their physiopathological implication. Some investigators have tried to demonstrate the relationship between these autoantibodies and electrocardiographic abnormalities in adult patients with controversial results. Objectives To determine whether atrioventricular block (AVB) of unknown cause in young patients may be associated with an inflammatory rheumatism. Methods Retrospective observational study (1973-2011) at a university hospital with a referral area of 800000 inhabitants. The medical records of patients with pacemakers were reviewed from cardiology’s database: a total of 3359 patients. Patients under fifties with a heart block of unknown cause were selected: 24 patients. One was dead at the time of the study, and 3 refused to participate. The 20 remaining patients underwent an immunological study with antinuclear antibodies (AAN in HEp2 substrate) and extractable nuclear antigens (ENA) by immunoassay and immunoblot. A clinical interview was performed by a rheumatologist looking for signs and symptoms of inflammatory rheumatism. Results Twenty patients were included: 7 men (35%) and 13 women (65%). Mean age when they were reviewed was: 51 years ± 12 years (range: 28-70). Mean age at the time of pacemaker implantation was 37.5 ± 10 years (range: 17-49). The implantation causes were: complete AVB 14 patients (70%), advanced AVB 3 (15%), Wenckebach type 1 AVB (5%) and unknown AVB in 2 cases. Two patients had family history of autoimmune diseases: 1 rheumatoid arthritis and 1 autoimmune thyroiditis. A positive Ro52 patient without connective tissue disease and a Ro 60 positive patient diagnosed with systemic lupus erythematous were found; no other autoantibody was present. Another patient was diagnosed of ankylosing spondylitis (HLA B27 positive). The diagnosis of systemic lupus erythematous and ankylosing spondylitis were previous to the heart block. No signs or symptoms of inflammatory rheumatism were found in the other patients. The Schirmer test was abnormal in 5 (20%) patients. The 2 patients with systemic lupus erythematous and ankylosing spondylitis had sicca syndrome secondary to their underlying diseases. Conclusions Fifteen percent of patients had features of inflammatory rheumatic diseases: in 2 cases heart block occurred in a patient diagnosed with systemic lupus erythematous and another with ankylosing spondylitis. A third case with positive Ro52 antibodies was detected in a woman without connective tissue disease. Family history of autoimmune diseases was found in 2 patients. Anti Ro antibodies might be related to heart block in the young. It is recommended to purpose a clinical evaluation of the patients by a rheumatologist and an immunological study in order to clarify the origin of the heart block and to unmask other underlying pathologies. References Disclosure of Interest: None Declared