Microvolt T-Wave Alternans as Predictor of Electrophysiological Testing Results in Professional Competitive Athletes
Methods: We prospectively studied 100 trained competitive athletes, including elite types (72/100), (mean age ± standard deviation: 26.1 ± 4.5 years). Forty-eight of them were wholly normal (Group A, mean age: 24.5 ± 8.5 years) and 52 of them had severe arrhythmias (Group B, mean age: 28.2 ± 11.5 years) and were symptomatic in 85% of cases for prolonged palpitations and syncope, but lacked any overt structural heart disease at standardized cardiological screening.
All athletes were evaluated with the microvolt T-wave alternans exercise–stress test, using the Heart Wave System with Microvolt Sensors. Group B underwent EPS to evaluate inducibility to sustained ventricular tachycardia (VT) during programmed electrical stimulation.
Results: In Group A, the mTWA outcome was determinate in 45 subjects (94%) and indeterminate in 3 (6%). No symptomatic event was reported in a follow-up of 36.1 months. In Group B, the mTWA test was positive in 7 symptomatic subjects (15%), indeterminate in 3 (7%), and negative for the remaining 42 subjects (76%). Forty-one of 42 negative mTWA subjects were also negative in the EPS test, without any syncope or sustained VT during 25.3 months of follow-up. In the positive mTWA test subjects, 5 (72%) were positive for inducibility of rapid sustained monomorphic VT in EPS, 1 was positive for severe sustained atrial tachyarrhythmias, and 1 refused EPS. We were able to pronounce a correct diagnosis of lymphocytic myocarditis for only 1 mTWA and EPS-positive subject. For the other 4 positive patients with arrhythmogenic micropathology, severe arrhythmic events were revealed in the follow-up and aggressive hybrid treatment was necessary.
Conclusion: Microvolt-TWA study seems to be a useful, noninvasive, and feasible tool for evaluating arrhythmic risk in the athletic population. The mTWA test showed a high negative predictive value, using both EPS and the follow-up observation for severe arrhythmic cardiac events as an endpoint. The positive predictive value was present in a limited number of cases that were, however, subjects with a high risk of sudden arrhythmic death.
Document Type: Research Article
Affiliations: 1: Department of Clinical Arrhythmia and Electrophysiology, San Donato Milanese Hospital, Milano 2: Sport Medicine Centre, University of Florence 3: University of Verona 4: Villa Bianca Hospital, Trento 5: Cardiology Department, Ferrari Hospital, Casarano, Lecce, Italy
Publication date: July 1, 2004