Simpson TF, Salazar JW, Vittinghoff E, et al. - This study was undertaken to investigate the relationship between QT-prolonging medications (QTPMs) and autopsy-defined sudden arrhythmic death (SAD) vs nonarrhythmic cause of sudden death. Between February 1, 2011, to March 1, 2014, researchers carried out a prospective countywide case-control study that involved World Health Organization–defined (presumed) SCD cases who underwent autopsy as part of the San Francisco Postmortem Systematic Investigation of Sudden Cardiac Death Study (POST SCD) to ascertain arrhythmic or nonarrhythmic cause, and control deaths due to trauma (hereinafter referred to as trauma controls) in San Francisco County, California. A sum of 629 individuals (mean [SD] age, 61.4 [15.7] years; 439 men [69.8%]) were recruited, 525 with presumed SCDs and 104 traumatic death controls. They applied multivariate regression to assess the association of QTPM with the risk of presumed SCD, autopsy-defined SAD, and non-SAD compared with trauma controls. These findings validate the correlation between QTPMs and presumed SCD; nevertheless, after autopsy, this risk was specific for nonarrhythmic causes of sudden death.