CARDIAC INVOLVEMENT IN PROXIMAL MYOTONIC MYOPATHY

Proximal myotonic myopathy (PROMM) is a recently described autosomal d ominantly inherited disorder resulting in proximal muscle weakness, my otonia, and cataracts. A few patients with cardiac involvement (sinus bradycardia, supraventricular bigeminy, conduction abnormalities) have been reported. The cases of three relatives with PROMM (weakness of n eck flexors and proximal extremity muscles, calf hypertrophy, myotonia , cataracts) are reported: a 54 year old man, his 73 year old mother, and 66 year old aunt. All three presented with conduction abnormalitie s and one had repeated, life threatening, sustained monomorphic ventri cular tachycardia. This illustrates that severe cardiac involvement ma y occur in PROMM.