Practice Update: Cardiology

MY APPROACH 30

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.

T here 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. www.practiceupdate.com/c/53487

PRACTICEUPDATE CARDIOLOGY