2. Material and methods

A retrospective study of a consecutive series of sudden death cases, registered within our department between 1963 and 2011, including the ECG records, Holter records from sudden death victims, autopsies, and the Death report by the relatives. The Chagas disease diagnosis was performed through serological studies, or a necroscopic study was performed in the cases of autopsies.

The date and time of death were collected from necropsy protocols and/or emergency clinical histories, as well as data obtained from relatives and witnesses.

Sudden cardiac death (SCD) is generally defined as a sudden and unexpected pulseless event, but noncardiac conditions need to be excluded before the occurrence of a primary cardiac event can be confirmed [13]. A case of established SCD is an unexpected death without obvious extracardiac cause, occurring with a rapid witnessed collapse, or if unwitnessed, occurring within 1 h after the onset of symptoms [13]. A probable SCD is an unexpected death without obvious extracardiac cause that occurred within the previous 24 h [13]. In any situation, the death should not occur in the setting of a prior terminal condition, such as a malignancy that is not in remission or end-stage chronic obstructive lung disease [13]. In our study, we included both established and probable SCD.

A total of 266 cases were analyzed; 56.7% of the subjects were male with an average age of 54.6 years, which were divided into four groups: Group A: Chagasic patients with sudden death, n = 38; Group B: non-Chagasic patients with sudden death, n = 58; Group C: Chagasic patients with non-sudden death, n = 89; and Group D: non-Chagasic patients with non-sudden death, n = 81.

The results were assessed using exploratory data analysis (EDA) and comparison of ratio differential. As the statistic validation rule, a p-value <0.05 was considered as statistically significant.
