Heart block associated with spinocerebellar ataxia type 2

A 20-year-old man was discharged from the U.S. Army because of increasing gait abnormalities. One year later, he developed episodes of syncope secondary to high-degree atrial/ventricular block with periods of complete heart block and ventricular asystole. A permanent dual-chamber, rate-responsive cardiac pacemaker was implanted. At age 29 years, an abnormal expansion of the CAG trinucleotide repeat in the ataxin-2 gene on chromosome 12 was identified. This case suggests that cardiac conduction abnormalities should be included as part of the recognized clinical heterogeneity of spinocerebellar ataxia type 2.