Practice Update: Cardiology

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There are two initial considerations
during evaluation of an athlete with
electrocardiographic evidence of
ventricular pre-excitation, a finding char-
acterized by a shortened PR-interval
(<120 ms) and slurring of the initial QRS
complex, or “delta wave,” a pattern com-
monly referred to as Wolff-Parkinson-White
syndrome (WPW). The first is to exclude
concomitant structural (eg, hypertrophic
cardiomyopathy) or valvular (eg, Ebstein’s
anomaly) heart disease, thereby confirming
the presence of isolated WPW. The second
is to differentiate athletes with WPW pattern
from athletes with WPW syndrome. Ath-
letes with WPW pattern have pre-excitation
but no symptoms suggestive of arrhyth-
mia; athletes with WPW syndrome have
pre-excitation and symptomatic arrhyth-
mias involving their accessory pathway.
WPWpattern
All athletes with WPW pattern require risk
stratification for sudden cardiac death (SCD),
which can occur when rapid atrial fibrilla-
tion is conducted down the anterograde
accessory pathway at supraphysiologic
heart rates culminating in ventricular fibril-
lation. We utilize a step-wise approach to
SCD risk stratification. We begin by obtain-
ing serial electrocardiograms to document
persistence of the delta wave as intermit-
tent loss of pre-excitation implies a longer
accessory pathway refractory period
and lower SCD risk. Next, we proceed to
maximal effort exercise testing with the fol-
lowing technical considerations:
• Careful attention to lead placement and
application
• Use of a stationary bicycle rather than
treadmill to minimize motion artifact
• Use of 50 mm/sec paper speed to
enhance delta wave visualization and
diagnostic yield
An abrupt loss of the delta wave during the
physiologic tachycardia of exercise testing
places the athlete at low risk for SCD. In
these cases, the athlete can return to full
athletic participation with the understand-
ing that longitudinal follow-up is required
as symptomatic, albeit non-life threaten-
ing, arrhythmias may develop in the future.
If the delta wave persists throughout
exercise testing, we refer athletes for a
diagnostic electrophysiology study. Meas-
urement of the anterograde conduction
properties of the accessory pathway is
done by evaluating the shortest pre-excited
R-R interval (SPERRI) while in atrial fibrilla-
tion. A SPERRI of ≤250 ms indicates that
the accessory pathway can conduct rap-
idly and places the individual at increased
risk for SCD. We recommend that athletes
with high-risk pathways undergo catheter
ablation. In contrast, those with a SPERRI
of >250 ms are at low risk and can be
longitudinally followed without ablation as
described above.
WPW syndrome
Athletes with WPW syndrome and high-risk
pathways are referred for catheter ablation.
Catheter ablation of the accessory pathway
has high cure rates (95%–96%) when done
in experienced centers, with low risk (<1%)
of iatrogenic atrioventricular block during
ablation of septal accessory pathways.
Medical management with antiarrhythmic
medications is less effective, can hinder
athletic performance, and may have unde-
sired side effects, including arrhythmia.
Thus, medications are reserved for cases in
which catheter ablation is contraindicated.
Masters athletes
Management of an incidental finding of
WPW pattern in a Masters athlete (>35
years old) remains an area of uncertainty.
In theory, accessory pathway conduction
slows with age and older athletes may
inherently be at lower SCD risk given prior
decades of event-free survival. However,
there are no compelling primary data to
guide management. As such, we engage
with the athlete in a shared decision-mak-
ing process in which both conservative and
more aggressive options are presented
and discussed on a case-by-case basis.
My Approach to the
Athlete WithWolff-
Parkinson-White
Syndrome (WPW)
By Aaron L Baggish MD and Ankit B Shah MD, MPH
Dr Baggish is Assistant Professor of
Medicine, Harvard Medical School, and
Associate Director, Cardiovascular
Performance Program, Massachusetts
General Hospital, Boston, Massachusetts.
Dr Shah is Clinical and Research Fellow in
the Cardiovascular Performance Program,
Massachusetts General Hospital, Boston,
Massachusetts.
MY APPROACH 30
PRACTICEUPDATE CARDIOLOGY