Letter to the Editor Prevalence and clinical meaning of isolated increase of QRS voltages in hypertrophic cardiomyopathy versus athlete's heart: Relevance to athletic screening ☆ Chiara Calore a , Paola Melacini a , Antonio Pelliccia b , Cinzia Cianfrocca c , Maurizio Schiavon d , Fernando M. Di Paolo b , Francesca Bovolato a , Filippo M. Quattrini b , Cristina Basso a , Gaetano Thiene a , Sabino Iliceto a , Domenico Corrado a, ⁎ a Department of Cardiac, Thoracic and Vascular Sciences, University of Padua, Italy b CONI, Institute of Sports Medicine and Science, Rome, Italy c Division of Cardiology, San Filippo Neri Hospital, Rome, Italy d Center for Sports Medicine and Physical Activity, Department of Social Health, Padua, Italy article info Article history: Received 22 May 2013 Accepted 30 June 2013 Available online xxxx Keywords: Athlete's heart Electrocardiogram Hypertrophic cardiomyopathy Screening Intensive athletic conditioning is associated with physiologic cardiac remodeling (known as “athlete's heart”), consisting of augmented left ventricular (LV) mass due to increase of both cavity dimension and wall thickness, which are reflected on the electrocardiogram (ECG) most frequently as an increase of QRS voltages [1,2]. Because of the par- tial overlap of ECG signs of LV hypertrophy, athlete's heart is often in the differential diagnosis with hypertrophic cardiomyopathy (HCM), which is the leading cause of sports-related cardiac arrest in young athletes. Patients with HCM have a variety of ECG abnormalities, including atrial enlargement, QRS left axis deviation, increase of QRS amplitudes, ST-segment and/or T-wave abnormalities, and pathologic Q waves [3]. According to the recommendations of the European Society of Cardiology, the ECG changes due to cardiac adaptation to physical exertion, predom- inantly the physiologic increase of QRS voltages, should not cause alarm and the athlete should be allowed to participate in competitive sports without additional evaluation [1]. Although this ECG interpretation approach offers the potential to lower the traditional high number of false-positives, whether and to what extent the increased specificity alter the ECG sensitivity for HCM remains to be established. The present study compared the ECG abnormalities associated with the LV remodeling of HCM (nondilated, hypertrophic LV) and that of athlete's heart (augmented LV mass due to increase of both cavity di- mension and wall thickness), with particular reference to the prevalence, clinical significance, and relevance to screening of the ECG pattern of iso- lated increase of QRS voltages. The main study objective was to evaluate the risk to miss a diagnosis of HCM by interpreting as normal the ECG pattern of isolated increase of QRS amplitude in highly trained athletes. The HCM population included 247 consecutive patients (181 males; age 39 ± 14 years, range 15–65 years). The diagnosis of HCM was based on the presence of a hypertrophied and nondilated left ventricle in the absence of other diseases that could produce the magnitude of hypertrophy evident. Echocardiographic criteria for diagnosis were a maximal LV wall thickness (LVWT) ≥ 15 mm in adult index patients and ≥13 mm in adult relatives [4,5]. The athlete's population included a series of 133 Caucasian healthy, highly trained athletes (116 males; age 27 ± 6 years, range 15–65 years) who fulfilled the echocardio- graphic criteria for augmented LV mass defined according to Devereux et al. as ≥134 g/m 2 in males and ≥110 g/m 2 in females [6]. Based on the ECG findings, HCM patients and athletes were grouped as follows: the “normal ECG group” (Group 1) presenting no evidence of any ECG abnormalities; the “isolated increase of QRS voltage group” (Group 2) exhibiting a pure increase of QRS amplitude according to the Sokolow– Lyon criterion [7] (but no other ECG abnormalities); and the “abnormal ECG group” (Group 3) showing ≥1 criteria for atrial enlargement, QRS axis deviation, complete bundle branch block, ST-segment or T-wave abnormalities, and pathologic Q wave (regardless of QRS voltages) [3,5,8]. A normal ECG (Group 1) and the pattern of isolated increase of QRS voltages (Group 2) were found in 4% and 2% of HCM patients, compared with 52% and 40% of athletes, respectively (P b 0.001) (Table 1). The combination of isolated increase of QRS voltages (Group 2) and non- voltage criteria (Group 3) showed a sensitivity of 96% (false negatives = 11) and a specificity of 52% (false positives = 64) in iden- tifying HCM. When Group 3 ECG abnormalities were used alone, there was a statistically significant (P b 0.001) increase of specificity to 92% (false positives = 11), associated with a non-significant (P = 0.35) International Journal of Cardiology xxx (2013) xxx–xxx ☆ All authors take responsibility for all aspects of the reliability and freedom from bias of the data presented and their discussed interpretation. ⁎ Corresponding author at: Inherited Arrhythmogenic Cardiomyopathy Unit, Department of Cardiac, Thoracic and Vascular Sciences, University of Padova Medical School, Via N. Giustiniani 2 35121 Padova, Italy. Tel.: +39 049 8212458; fax: +39 049 8212309. E-mail address: domenico.corrado@unipd.it (D. Corrado). IJCA-16547; No of Pages 4 0167-5273/$ – see front matter © 2013 Published by Elsevier Ireland Ltd. http://dx.doi.org/10.1016/j.ijcard.2013.06.123 Contents lists available at SciVerse ScienceDirect International Journal of Cardiology journal homepage: www.elsevier.com/locate/ijcard Please cite this article as: Calore C, et al, Prevalence and clinical meaning of isolated increase of QRS voltages in hypertrophic cardiomyopathy versus athlete's heart: Relevance to athletic screening, Int J Cardiol (2013), http://dx.doi.org/10.1016/j.ijcard.2013.06.123