EKG in athletes

this issue of NEJM has an article on role of cardiac screening pre-sports participation (see athlete screening preparticipation nejm 2013 in dropbox, or DOI: 10.1056/NEJMclde1311642. article presents differing views on the appropriate extent of screening, esp whether to use EKG as part of the screen, noting that:

--not common (around 100-150 young athletes die/yr in US), pales in comparison to numbers of youth who die from accidents, homicide, suicide, and even non-exercise assoc sudden death
--still obviously a very tragic event when it happens, typically unsuspected in apparently totally healthy, vigorous person
--everyone agrees to do pre-athletic screen with history/physical, best with standardized screen, assessing cardiac history of family and patient (eg  dizziness, fainting, chest pain, shortness of breath and palpitations during or after exercise, or a change in exercise tolerance).  but family history only picks up 16% and only 1/2 have antecedant symptoms prior to sudden death
--really important to focus on high school kids, since 65% of deaths in young athletes are in high school kids

so, you can read the pros and cons, but i thought i'd send along a reference from the british journal of sports medicine which has consensus criteria on the abnormal EKG in athletes (one issue with doing EKGs in these kids is the large number of false positives, leading to some unnecessary testing and unnecessary exclusion from sports) -- see athlete screening ekg br j sports med 2013 in dropbox, or doi:10.1136/bjsports-2012-092067

here is the summary table:

Table 1 Abnormal ECG findings in athletes

Abnormal ECG finding                      Definition

T-wave inversion                               >1 mm in depth in two or more leads V2–V6, II
                                                        and aVF, or I and aVL (excludes III, aVR and V1)

ST segment depression                      ≥0.5 mm in depth in two or more leads

Pathologic Q waves                            >3 mm in depth or >40 ms in duration in two or
                                                        more leads (except for III and aVR)

Complete left bundle branch block        QRS ≥120 ms, predominantly negative QRS
                                                        complex in lead V1 (QS or rS), and upright
                                                        monophasic R wave in leads I and V6

Intraventricular conduction delay          Any QRS duration ≥140 ms

Left axis deviation                             −30° to −90°

Left atrial enlargement                       Prolonged P wave duration of >120 ms in leads I
                                                        or II with negative portion of the P wave ≥1 mm in
                                                        depth and ≥40 ms in duration in lead V1
Right ventricular hypertrophy pattern    R−V1+S−V5>10.5 mm AND right axis deviation
                                                        >120°

Ventricular pre-excitation                    PR interval <120 ms with a delta wave (slurred
                                                        upstroke in the QRS complex) and wide QRS
                                                        (>120 ms)
Long QT interval*                                QTc≥470 ms (male)
                                                         QTc≥480 ms (female)
                                                         QTc≥500 ms (marked QT prolongation)
Short QT interval*                               QTc≤320 ms

Brugada-like ECG pattern                     High take-off and downsloping ST segment
                                                         elevation followed by a negative T wave in ≥2
                                                        leads in V1–V3

Profound sinus bradycardia                 <30 BPM or sinus pauses ≥ 3 s

Atrial tachyarrhythmias                         Supraventricular tachycardia, atrial-fibrillation,
                                                          atrial-flutter
Premature ventricular contractions        ≥2 PVCs per 10 s tracing

Ventricular arrhythmias                        Couplets, triplets and non-sustained ventricular
                                                          tachycardia

Note: These ECG findings are unrelated to regular training or expected
physiological adaptation to exercise, may suggest the presence of
pathological cardiovascular disease, and require further diagnostic evaluation.

*The QT interval corrected for heart rate is ideally measured with heart rates of
60–90 bpm. Consider repeating the ECG after mild aerobic activity for borderline or
abnormal QTc values with a heart rate <50 bpm.

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