Objective: Our aim was to identify electrocardiographic (ECG) changes related to exercise-induced sudden cardiac death (SCD).
Methods and Results: The Finnish Study of Genotype and Phenotype Characteristics of SCD (FinGesture) includes 3,989 consecutive sudden cardiac deaths in northern Finland between 1998 and 2012. Previously recorded ECGs were acquired manually from archives of Oulu University Hospital. A total of 647 SCD had a previously recorded ECG. In 276 of these cases the death was witnessed, and the activity at the time of death could be divided into either rest or physical exercise; in 40 (14%) cases SCD was exercise-related (PE group) and in 236 (86%) cases death took place at rest (R group). A total of 371 (57%) deaths were unwitnessed or the cases did not meet the criteria of either exercise or rest. Fragmented QRS (fQRS) complex in at least 2 consecutive leads within anterior leads (V1-V3) was more common in the exercise-group compared to rest-group (17/40, 43% vs. 51/236, 22%, p=0.005). Pathologic Q wave in anterior leads was somewhat more common in the PE group (9/40, 23% vs. 26/236, 11%; p=0.044). QRS duration, QTc interval or the prevalence of inverted T-waves did not differ significantly between the 2 groups.
Conclusions: Fragmented QRS complex in the anterior leads is associated with an increased risk of SCD during physical exercise.