Abstract 2563: Association of Cardiac Arrest With Early Repolarization Pattern in Competitive Athletes
Background. The ECG pattern of QRS-ST junction and ST segment elevation (“early repolarization”) in the inferior and lateral leads is frequently observed in athletes. Experimental investigations and clinical studies have suggested the potential arrhythmogenicity of this pattern.
Aim. To determine the prevalence of QRS-ST changes in inferior/lateral leads in a select group of competitive athletes without evidence of structural heart disease, who had resuscitated cardiac arrest (CA) or sudden death (SD).
Methods. We studied 21 athletes (19 CA, 2 SD; mean age 27 yrs, 5 females) and 365 healthy control athletes (mean age 29 yrs, 36 female) undergoing pre-partecipation screening for competitive sports. On the ECG we looked for: J point elevation (J wave) >0.05 mV above baseline level, slurred QRS complex (a gradual transition from QRS to ST segment) and ST segment elevation in inferior (II, III, aVF) and lateral leads (I, aVL, V4 to V6 ).
Results. J waves and/or QRS slurring and ST segment elevation were present in 10 of 21 cases (47.6%) and in 108 of 365 control athletes (29.5%, P=0.09); a significant difference between the 2 groups was found in inferior plus V4 to V6 leads (28.5% vs. 7.9%, P=0.007). QRS slurring alone was present in 28.6% of cases and in 7.6% of controls (P=0.006). ST segment elevation was less commonly observed among athletes with CA/SD than in controls and the pattern of J wave and/or QRS slurring without ST elevation was significantly more frequent in cases than in controls (38.1% vs 15.8%, P=0.04), particularly in infero-lateral leads (23.8% vs 2.4%, P=0.001). During a median follow-up of 36 months the incidence of recurrences of ventricular arrhythmias (Holter and ICD monitoring) was not significantly different in the 2 subgroups of CA subjects with and without an early repolarization pattern.
Conclusion. Our study showed a significantly higher prevalence of the pattern of J wave and/or QRS slurring without ST elevation in the athletes with CA/SD than in the controls. Nevertheless, among the CA group the presence of this pattern seems not to confer a higher risk for future malignant ventricular arrhythmias.