Clinical characteristics of sudden death victims in heritable (chromosome 1p1-1q1) conduction and myocardial disease

Objectives. The purpose of this study was to identify the clinical characteristics of family members at risk of sudden death.Background. The significance of sudden death in heritable cardiac disorders with delayed expression is incompletely understood. Additional insights come from a four-decade experience of seven generations of a family of German origin with autosomal dominant (chromosome 1p1-1q1) cardiac conduction and myocardial disease.Methods and Results. A total of 38 family members (20 males; 18 females) were identified with sudden death. Twenty-eight family members (mean age 48 ± 8 years) from earlier generations had no pacemaker at the time of sudden death. In this group, 15 subjects were asymptomatic prior to sudden death. Ten family members with sudden death, from later generations, had chronically implanted pacemakers for high grade atrioventricular block. This group was older (mean age 57 ± 2 years), with decreased functional status (New York Heart Association class II to IV), enlarged left atria, dilated left ventricles with reduced systolic function and documented ventricular fibrillation in three members. Twenty-eight family members with sudden death were descendants of sib lineages 2 or 6; 21 family members with sudden death were offspring of a parent who also suffered sudden death.Conclusion. Sudden death is an important late outcome in heritable (chromosome 1p1-1q1) cardiac conduction and myocardial disease. Pacemaker therapy is important for the treatment of symptomatic bradycardia, but it does not prevent sudden death. Family members who are beyond the third decade of life with reduced functional capacity, left ventricular dysfunction, pacemakers and who are the offspring of a parent with sudden death appear to be at greatest risk.