Sudden cardiac death with apparently normal heart

Background-Mechanisms of sudden cardiac death (SCD) in subjects with appare ntly normal hearts are poorly understood. In survivors, clinical investigat ions may not establish normal cardiac structure with certainty. Large autop sy series may provide a unique opportunity to confirm structural normalcy o f the heart before reviewing a patient's clinical history. Methods and Results-We identified and reexamined structurally normal hearts from a 13-year series of archived hearts of patients who had sudden cardia c death. Subsequently, for each patient with a structurally normal heart, a detailed review of the circumstances of death as well as clinical history was performed. Of 270 archived SCD hearts identified, 190 were male and 80 female (mean age 42 years); 256 (95%) had evidence of structural abnormalit ies and 14 (5%) were structurally normal, In the group with structurally no rmal hearts (mean age 35 years), SCD was the first manifestation of disease in 7 (50%) of the 14 cases, In 6 cases, substances were identified in seru m at postmortem examination without evidence of drug overdose; 2 of these c hemicals have known associations with SCD. On analysis of ECGs, preexcitati on was found in 2 cases. Comorbid conditions identified were seizure disord er and obesity (2 cases each). In 6 cases, there were no identifiable condi tions associated with SCD. Conclusions-In 50% of cases of SCD with structurally normal hearts, sudden death was the first manifestation of disease. An approach combining archive d heart examinations with detailed review of the clinical history was effec tive in elucidating potential SCD mechanisms in 57% of cases.