Analysis of 12-lead electrocardiogram in top competitive professional athletes in the light of recent guidelines.

BACKGROUND: One of the most important aims of modern sports cardiology is prevention of sudden cardiac death among athletes. Adequate pre-participation screening is a crucial part of prevention, however, current ACC, AHA or ESC guidelines are not uniform in this context. There is recently ongoing discussion on implementation of 12-lead ECG to the screening protocol.

AIM: To assess the prevalence of alterations of resting 12-lead ECG in a population of top-level professional athletes - members of the Polish Olympic Team - using recently accepted criteria.

METHODS: During the period of intensive training before the Summer Olympic Games in Beijing (2008), a 12-lead, resting ECG was performed in 73 members (20 women and 53 men) of the Polish Olympic Team. Commonly accepted criteria were used to assess the ECG, and alterations were divided into two groups according to recent publications: group I - 'benign', common - thought to be consistent with the athlete's heart syndrome (i.e.: sinus bradycardia, 1st degree atrioventricular block, early repolarisation, right bundle branch hemiblock, isolated signs of left ventricular hypertrophy); and group II - 'suspected', uncommon - which may occur due to organic heart disease (i.e. complete bundle branch block, ventricular arrhythmia, inverse T wave or pathological QRS axis deviation).

RESULTS: Completely normal ECG was present in 11% of those examined, common (group I) findings were observed in 65% and 'suspected' (group II) in 23%. The most commonly occurring 'benign' findings were bradycardia incomplete, right bundle branch block and isolated left ventricular hypertrophy, found in 75, 71 and 41%, respectively. From 'suspected' (group II) the most frequent was left posterior fascicular hemiblock, present in 10% of those examined; other findings were complete right bundle branch block, left atrial hypertrophy, inverse T waves and left anterior fascicular hemiblock in single cases.

CONCLUSIONS: 1. Most of the observed alterations in resting ECG of professional athletes belong to the 'common' group and result from adaptation to exercise. 2. Frequent occurrence of left posterior fascicular hemiblock, which is thought to be 'potentially malignant', requires further investigation.