only one ventricular extrasystole ; no pauses exceeding two seconds ;
• Treadmill Stress Test ( Bruce protocol ) with good exercise tolerance ( 13m10s ; 15.5 METS , 94 % of agepredicted maximum heart rate ); no dysrhythmic or hypertensive response ; WPW pattern throughout the test ( exercise and recovery ); without changes suggestive of myocardial ischemia ( Figure 3 ). Since pre-excitation was maintained throughout the stress test and 24-hour Holter , suggesting a persistent conduction pathway , it was decided that a electrophysiological study be performed to analyze the electrical properties of the accessory pathway .
The electrophysiological study was performed with placement of catheters by right femoral access to the coronary sinus , right ventricular apex and His bundle . Pre-excitation was intermittent , requiring administration of adenosine during mapping , detecting an atrioventricular fusion signal in the posteroseptal region . Despite being a low-risk pathway , it was decided to perform ablation of the accessory pathway , obtaining immediate success criteria . No events were observed during the procedure .
Among post-discharge care , it was recommended not to exercise in the first 15 days after the intervention and resume professional activity in a gradual manner . The athlete resumed her competitive sport activity one month after the intervention .
Discussion
The present case illustrates a clinical situation with implications in athlete evaluation . In the presence of a WPW pattern on a 12-lead resting ECG of an asymptomatic athlete , the risk of degenerating into ventricular fibrillation should be stratified .
Figure 2 – 12-lead resting ECG with a typical WPW pattern : PR < 120ms , delta wave ( arrows ) and QRS > 120ms .
Figure 3 – 12-lead ECG at peak effort , maintaining the typical WPW pattern ( delta wave – arrows ).
Signs of high risk are :
• young age (< 30 years )
• pre-excitation persistence in the ECG at rest and during exercise
• shorter RR interval in pre-excited atrial fibrillation (< 250ms )
• different pre-excitation morphologies ( suggestive of multiple pathways ) and
• asymptomatic paroxysmal atrial fibrillation . 5 In this case , a transthoracic echocardiogram was performed on the athlete to exclude structural pathology , a stress test and 24-hour Holter to evaluate the persistence of the WPW pattern and identify significant dysrhythmias . This investigation is crucial since 40 to 50 % of patients with WPW , victims of sudden death , were asymptomatic prior to the event . 6
Since the athlete maintained the WPW pattern throughout the stress test and 24-hour Holter ( persistent pattern ), possibly indicating an accessory pathway with a short and potentially malignant refractory period , an electrophysiological study was performed . During the study , an accessory pathway was identified in the intermittent posteroseptal region ( low risk ), with the question remaining of whether or not to perform catheter ablation at the same operative time .
Being an athlete with the objective of increasing exercise intensity and volume ( predominantly dynamic ), ablation was performed due to the low risk of complications of the procedure and high success rate (> 95 %) when performed in reference centers .
The American Society of Cardiology 7 recommends an invasive electrophysiological study in asymptomatic athletes only if the accessory pathway is not considered low risk . According to the European Society of Cardiology 5 , risk stratification through a electrophysiological study is recommended in all athletes , regardless of the competitive level . While this discrepancy remains , it seems appropriate to us for all athletes with a WPW pattern be observed by an electrophysiologist for risk stratification purposes through the realization of an electrophysiological study . The decision for ablation must be made on a case-bycase basis after weighing the risks and benefits . Continue in page 25
Revista de Medicina Desportiva informa march 2018 · 11