RESUMEN
We describe the case of an ultra-marathon runner who finished first the "Spartathlon", a 246 km running race. The finishing time was the second fastest time ever in "Spartathlon". After finishing the race, the athlete suffered non-cardiac syncope and was administered intravenously 3 L of fluids for 5 hours. He underwent two echocardiographic assessments, one immediately after the finish of the race and the second 5 h later. Post-exercise fluid administration led to an increase in dimensions of all cardiac cavities, accompanied by a decrease in left ventricular (LV) end-diastolic interventricular septum thickness and posterior wall thickness of 0.1 cm. Dimensions and the respiratory profile of inferior vena cava improved after the race, reflecting alleviation of exercise-related hypovolaemia. Additionaly, LV global longitudinal strain improved, but right ventricular (RV) systolic function continued to deteriorate, mainly due to impairment of basal and medial RV free wall longitudinal strain. Study of this case offers a unique model for understanding the successive changes of cardiac structure and function following an ultra-marathon running race.
Asunto(s)
Carrera , Masculino , Humanos , Ecocardiografía , Ejercicio Físico , Ventrículos Cardíacos/diagnóstico por imagen , Diástole , Función Ventricular IzquierdaRESUMEN
The overwhelming majority of sports-related sudden cardiac deaths in mature athletes is attributed to coronary artery disease (CAD). Coronary plaques of mature athletes appear to be more calcified compared to sedentary individuals and thus may be more stable and less likely to be associated with an acute coronary event. Cardiac computed tomography (CT), including unenhanced CT for coronary artery calcium scoring (CACS) and contrast-enhanced coronary CT angiography, is characterized by very high negative predictive value to rule out CAD. Cardiac CT has been shown to have additional diagnostic value for detection of CAD in athletes over and above exercise electrocardiogram. Moreover, measurement of CACS possibly enables a more precise cardiovascular risk stratification of mature athletes. The main advantage of cardiac CT is its noninvasive nature. Although cardiac CT appears to increase the overall cost of cardiac examinations, this additional cost is much lower than the cost of unnecessary invasive coronary angiographies that would be performed in case of false positive results of exercise electrocardiograms. Radiation exposure may not be a major concern for the application of this modality to pre-participation screening of athletes, since recent technical advancements have resulted in low radiation dose of cardiac CT.Highlights Coronary computed tomography angiography can be used in pre-participation screening of mature athletes to increase the negative predictive value for excluding coronary artery disease.The identification of coronary artery calcium score = 0 in an athlete can improve risk stratification, since this athlete can be reasonably managed as an individual with low cardiovascular risk.
Asunto(s)
Atletas , Enfermedad de la Arteria Coronaria , Angiografía por Tomografía Computarizada/métodos , Angiografía Coronaria/métodos , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Humanos , Valor Predictivo de las Pruebas , Medición de RiesgoRESUMEN
Although previous studies suggest that prolonged intense exercise such as marathon running transitorily alters cardiac function, there is little information regarding ultramarathon races. Aim of this study was to investigate the acute impact of ultra-endurance exercise (UEE) on heart, applying advanced strain imaging. Echocardiographic assessment was performed the day before and at the finish line of "Spartathlon": A 246 Km ultra-marathon running race. 2D speckle-tracking echocardiography was performed in all four chambers, evaluating longitudinal strain (LS) for both ventricles and atria. Peak strain values and temporal parameters adjusted for heart rate were extracted from the derived curves. Out of 60 participants initially screened, 27 athletes (19 male, age 45 ± 7 years) finished the race in 33:34:27(28:50:38-35:07:07) hours. Absolute values of right (RV) and left ventricular (LV) LS (RVLS -22.9 ± 3.6 pre- to -21.2 ± 3.0% post-, p=0.04 and LVLS -20.9 ± 2.3 pre- to -18.8 ± 2.0 post-, p=0.009) slightly decreased post-race, whereas atrial strain did not change. RV and LV LS decrease was caused mainly by strain impairment of basal regions with apical preservation. Inter-chamber relationships assessed through RV/LV, LV/LA, RV/RA and RA/LA peak values' ratios remained unchanged from pre to post-race. Finally, UEE caused an extension of the systolic phase of cardiac cycle with concomitant diastole reduction (p<0.001 for all strain curves). Conclusively, ventricular LS strain as well as effective diastolic period slightly decreased, whereas atrial strain and inter-chamber relationships remained unchanged after running a 246-km-ultra-marathon race. These changes may be attributed to concomitant pre- and afterload alterations following UEE.
Asunto(s)
Ventrículos Cardíacos , Carrera de Maratón , Adulto , Diástole , Ecocardiografía/métodos , Atrios Cardíacos/diagnóstico por imagen , Ventrículos Cardíacos/diagnóstico por imagen , Humanos , Masculino , Persona de Mediana EdadRESUMEN
AIM: We aimed to investigate the main anthropometric, cardiorespiratory and haematological factors that can determine marathon race performance in marathon runners. METHODS: Forty-five marathon runners (36 males, age: 42 ± 10 years) were examined during the training period for a marathon race. Assessment of training characteristics, anthropometric measurements, including height, body weight (n = 45) and body fat percentage (BF%) (n = 33), echocardiographic study (n = 45), cardiopulmonary exercise testing using treadmill ergometer (n = 33) and blood test (n = 24) were performed. We evaluated the relationships of these measurements with the personal best marathon race time (MRT) within a time frame of one year before or after the evaluation of each athlete. RESULTS: The training age regarding long-distance running was 9 ± 7 years. Training volume was 70 (50-175) km/week. MRT was 4:02:53 ± 00:50:20 h. The MRT was positively associated with BF% (r = 0.587, p = 0.001). Among echocardiographic parameters, MRT correlated negatively with right ventricular end-diastolic area (RVEDA) (r = -0.716, p < 0.001). RVEDA was the only independent echocardiographic predictor of MRT. With regard to respiratory parameters, MRT correlated negatively with maximum minute ventilation indexed to body surface area (VEmax/BSA) (r = -0.509, p = 0.003). Among parameters of blood test, MRT correlated negatively with haemoglobin concentration (r = -0.471, p = 0.027) and estimated haemoglobin mass (Hbmass) (r = -0.680, p = 0.002). After performing multivariate linear regression analysis with MRT as dependent variable and BF% (standardised ß = 0.501, p = 0.021), RVEDA (standardised ß = -0.633, p = 0.003), VEmax/BSA (standardised ß = 0.266, p = 0.303) and Hbmass (standardised ß = -0.308, p = 0.066) as independent variables, only BF% and RVEDA were significant independent predictors of MRT (adjusted R2 = 0.796, p < 0.001 for the model). CONCLUSIONS: The main physiological determinants of better marathon performance appear to be low BF% and RV enlargement. Upregulation of both maximum minute ventilation during exercise and haemoglobin mass may have a weaker effect to enhance marathon performance. CLINICAL TRIAL REGISTRATION: www.ClinicalTrials.gov, identifier NCT04738877.
RESUMEN
AIM: The investigation of the pathophysiological determinants of cardiac changes following ultra-long duration exercise. METHODS: Twenty-seven runners who finished a 246 km running race were examined both before and after the finish of the race. Examinations included echocardiography and measurement of body weight and blood biochemical parameters. RESULTS: Exercise increased left ventricular end-diastolic interventricular septum thickness (LVIVSd) (p < 0.001) and posterior wall thickness (LVPWTd) (p = 0.001) and right ventricular end-diastolic area (p = 0.005), while reduced tricuspid annular plane systolic excursion (TAPSE) (p = 0.004). A minor decrease in the peak absolute values of both left ventricular (from -20.9 ± 2.3% to -18.8 ± 2.0%, p = 0.009) and right ventricular (from -22.9 ± 3.6% to -21.2 ± 3.0%, p = 0.040) global longitudinal strains occurred. There was decrease in body weight (p < 0.001) and increase in both circulating high-sensitivity troponin I (p = 0.028) and amino-terminal pro-B type natriuretic peptide (NT-proBNP) (p = 0.018). The change in the sum of LVIVSd and LVPWTd correlated negatively with percentage change of body weight (r = -0.416, p = 0.049). The only independent determinant of post-exercise NT-proBNP was pulmonary artery systolic pressure (r = 0.797, p = 0.002). Post-exercise NT-proBNP correlated positively with percentage changes of basal (RVbas) (r = 0.582, p = 0.037) and mid-cavity (RVmid) (r = 0.618, p = 0.043) right ventricular diameters and negatively with percentage change of TAPSE (r = -0.720, p = 0.008). Similar correlations with RVbas, RVmid and TAPSE were found for pulmonary artery systolic pressure. Post-exercise high-sensitivity troponin I correlated negatively with percentage change of body weight (r = -0.601, p = 0.039), but was not associated with any cardiac parameter. CONCLUSION: The main cardiac effects of ultra-long duration exercise were the decrease in left ventricular end-diastolic dimensions and increase in left ventricular wall thickness, as well as minimal dilatation and alteration in systolic function of right ventricle, possibly due to the altered exercise-related right ventricular afterload.
Asunto(s)
Ecocardiografía/métodos , Tolerancia al Ejercicio/fisiología , Cardiopatías/fisiopatología , Ventrículos Cardíacos/diagnóstico por imagen , Carrera/fisiología , Función Ventricular Izquierda/fisiología , Femenino , Estudios de Seguimiento , Ventrículos Cardíacos/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , SístoleRESUMEN
BACKGROUND: Noninvasive screening studies may identify hemodialysis (HD) patients at increased risk of sudden cardiac death. Interventions that improve the findings of such screening studies may reduce sudden cardiac death. STUDY DESIGN: Randomized and controlled clinical trial. SETTING & PARTICIPANTS: 59 HD patients were randomly assigned to an exercise training group (group A; 30 patients) or control group (group B; 29 patients). INTERVENTION: Group A participated in a 10-month supervised exercise training program during the HD sessions (3 times weekly). OUTCOMES: Each risk factor separately and the composite risk score. Patients were considered high risk according to the criteria (aerobic capacity: peak oxygen consumption [Vo(2)peak] < or = 14 mL/kg/min, left ventricular ejection fraction < or = 30%, SD of normal RR intervals [SDNN] < or = 70 milliseconds, positive T-wave alternans, or positive late potentials). Statistical analysis included a 2-group comparison of change scores and analysis of covariance adjusting for baseline. MEASUREMENTS: At entry and end of the study, Vo(2)peak and left ventricular ejection fraction were estimated, heart rate variability was calculated (measurement of SDNN, mean RR intervals), and the ratio between low- (LF) to high-frequency (HF) components (LF/HF) and late potentials and T-wave alternans were detected. RESULTS: Baseline measurements were similar between the 2 groups. At follow-up, 9 patients from group A and 20 from group B (P = 0.003) were considered high risk. The change in number of risk markers over time was significantly different between groups (-0.5 +/- 0.7 in group A versus 0.07 +/- 0.3 in group B; P < 0.001). Additionally, the change in Vo(2)peak over time was 3.5 +/- 3.2 in group A and -0.2 +/- 3.5 mL/kg/min in group B (P < 0.001), left ventricular ejection fractions were 3.4% +/- 3.9% and 0.2% +/- 7.7% (P < 0.05), SDNNs were 12.6 +/- 16.3 and -1.1 +/- 10.2 milliseconds (P < 0.001), and LF/HF ratios were 0.3 +/- 0.4 and -0.1 +/- 0.3 (P < 0.001), respectively. Change in numerical score of the signal-averaged electrocardiogram also was found to be statistically different (P < 0.05) between groups. LIMITATIONS: Clinical outcomes, including survival, were not assessed. CONCLUSIONS: Exercise training improves aerobic capacity and ameliorates some indicators of risk of sudden cardiac death in HD patients.
Asunto(s)
Fenómenos Fisiológicos Cardiovasculares , Terapia por Ejercicio/métodos , Fallo Renal Crónico/fisiopatología , Fallo Renal Crónico/terapia , Diálisis Renal , Muerte Súbita Cardíaca/prevención & control , Ejercicio Físico/fisiología , Prueba de Esfuerzo/métodos , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Factores de Riesgo , Factores de TiempoRESUMEN
The beneficial effects of chronic exercise training on lipoprotein metabolism include a considerable increase in serum high density lipoprotein-cholesterol and a reduction in serum triglyceride levels. These changes are mostly reported in athletes participating in dynamic sports, especially in the endurance ones. Diagnosis and treatment of dyslipidaemias in athletes should follow the main principles of management of dyslipidaemias for the general population, while specific considerations for athletes should be taken into account. Dyslipidaemias in athletes are usually characterized by a significant genetic predisposition. Clinicians who evaluate the lipoprotein profile of athletes should keep in mind the possibility of an illegal use of performance-enhancing drugs, which can influence lipoprotein metabolism. Lifestyle intervention should be the cornerstone of treatment of dyslipidaemias in athletes, but it should be tailored to the needs of individual athletic activity. Hypolipidaemic medications may not be well-tolerated by competitive athletes and should be reserved only for athletes with inadequate response to lifestyle measures. The treatment of dyslipidaemias in athletes should aim at reducing cardiovascular risk without compromising athletic performance.
Asunto(s)
Atletas , Dislipidemias/diagnóstico , Dislipidemias/terapia , Hipolipemiantes/uso terapéutico , Conducta de Reducción del Riesgo , Biomarcadores/sangre , Doping en los Deportes , Dislipidemias/sangre , Dislipidemias/etiología , Predisposición Genética a la Enfermedad , Estado de Salud , Humanos , Hipolipemiantes/efectos adversos , Metabolismo de los Lípidos/efectos de los fármacos , Lípidos/sangre , Sustancias para Mejorar el Rendimiento/efectos adversos , Factores de Riesgo , Resultado del TratamientoRESUMEN
BACKGROUND: The tilt test is used for the diagnosis of reflex syncope (RS) and is characterized by low sensitivity, especially in athletes. The objective of the study was the implementation of a novel diagnostic strategy for the tilt test without pharmacologic provocation in athletes based on haemodynamic criteria. METHODS: A passive tilt test for 30 min was performed in 132 athletes (53 with a history of RS, 79 without RS). Measurement of haemodynamic, heart rate variability (HRV) and baroreflex sensitivity parameters was performed. RESULTS: Tilt testing yielded 34% sensitivity and 94% specificity. Among negative tilt test responders, the ones with RS had increased heart rate (HR) (89 ± 11 vs 81 ± 10 bpm, p < 0.001), stroke index (SI) (40.2 ± 7.1 vs 35.5 ± 9.7 ml/m(2), p = 0.013), cardiac index (CI) (3.5 ± 0.6 vs 2.8 ± 0.8 l/(min·m(2)), p < 0.001) and decreased total peripheral resistance index (TPRI) (2230 ± 362 vs 2965 ± 725 dyne·s m(2)/cm(5), p < 0.001), low frequency component of HRV (76.2% (49.0-88.4) vs 79.7% (10.2-91.1), p = 0.045) during head-up tilt, compared with those without RS. Receiver-operating characteristic (ROC) curve analysis showed that among athletes with a negative tilt test the area under the curve (AUC) values were 0.727 (0.626-0.828) for HR (p < 0.001), 0.707 (0.611-0.804) for SI (p = 0.001), 0.847 (0.774-0.920) for CI (p < 0.001), 0.830 (0.754-0.905) for TPRI (p < 0.001). Further stratification of negative tilt test responders, characterizing their results as positive when TPRI <2800 dyne·s m(2)/cm(5) and CI >3 l/(min·m(2)), resulted in 85% sensitivity and 76% specificity. CONCLUSION: Our results provide supportive evidence that a novel stratification based on haemodynamic criteria can improve the sensitivity of the tilt test for the diagnosis of RS in athletes.
Asunto(s)
Atletas , Barorreflejo , Sistema Cardiovascular/inervación , Hemodinámica , Síncope/diagnóstico , Pruebas de Mesa Inclinada/métodos , Adolescente , Adulto , Área Bajo la Curva , Femenino , Humanos , Masculino , Posicionamiento del Paciente , Valor Predictivo de las Pruebas , Curva ROC , Reproducibilidad de los Resultados , Síncope/fisiopatología , Adulto JovenRESUMEN
OBJECTIVE: The investigation of the differences in orthostatic responses of individuals with a history of noncardiac syncope(NCS) between athletes and nonathletes. METHODS: A passive tilt test for 30min was performed in 133 athletes (54 with NCS, 79 without NCS) and 48 nonathletes (15 with NCS, 33 without NCS). We performed measurement of haemodynamic, heart rate variability and baroreflex sensitivity parameters. All comparisons were adjusted for age, gender and body mass index(BMI). RESULTS: Athletes with NCS had increased heart rate(HR) (90±11 vs 81±10bpm, p=0.001) and decreased total peripheral resistance index(TPRI) (2227±408 vs 2918±733dynesm2/cm5, p=0.039) and baroreflex effectiveness index(BEI) [70.16(37.42-89.71) vs 72.19(48.49-91.35)%, p=0.016] compared with athletes without NCS. After applying backward stepwise logistic regression analysis to predict history of NCS in athletes, the final model included age, gender, BMI, HR and TPRI. Nonathletes with NCS had increased HR (95±24 vs 83±11bpm, p=0.024) and TPRI (3744±1606 vs 2937±880dynesm2/cm5, p=0.030) and decreased stroke index(SI) (25.4±7.6 vs 33.0±7.5mL/m2, p=0.003) compared with nonathletes without NCS. After applying backward stepwise logistic regression analysis to predict history of NCS in nonathletes, the final model included SI and HR. Among individuals with NCS, athletes had increased SI and BEI and decreased HR and TPRI compared with nonathletes. Among individuals without NCS, a positive result of tilt test was less frequent in athletes compared with nonathletes (p=0.031). CONCLUSIONS: The possible main underlying mechanism for NCS during upright standing in athletes is the decreased TPRI, while the inadequate preservation of SI in nonathletes.
Asunto(s)
Atletas , Barorreflejo/fisiología , Presión Sanguínea/fisiología , Frecuencia Cardíaca/fisiología , Síncope/fisiopatología , Adolescente , Adulto , Estudios de Cohortes , Femenino , Humanos , Masculino , Persona de Mediana Edad , Síncope/diagnóstico por imagen , Pruebas de Mesa Inclinada/métodos , Adulto JovenRESUMEN
INTRODUCTION: Cardiovascular pre-participation screening (PPS) is recommended for the identification of athletes at risk for sudden cardiac death. However, there is currently no universally accepted screening protocol. METHODS: Two distinct PPS strategies were studied in a large cohort of Greek athletes (5 to 39 years old): PPS I, with routine 12-lead ECG and echo, in addition to personal and family history, and physical examination; and PPS II, without routine echo. PPS I (12,353 athletes) was performed from 1992 to 2002, and PPS II (9852 athletes) from 2003 to 2010. RESULTS: "Abnormal" findings were observed in 49.3% of the athletes (49.6% in PPS I and 48.9% in PPS II, p=0.299). Most of them were age- or exercise-related. Further evaluation was recommended for 8.3% of the athletes. Finally, 39 athletes (22 from PPS I) were excluded from competitive sports. Hypertrophic cardiomyopathy was found in 7 athletes. Other abnormalities were: dilated cardiomyopathy; complete heart block; coronary artery disease; Wolf-Parkinson-White syndrome; and severe hypertension. The ECG played a critical role in the exclusion of 13 athletes, compared to only one for echo. Both PPS methods revealed an almost equal incidence of findings. CONCLUSIONS: We suggest that the routine use of ECG alone is sufficient for the successful screening of athletes.
Asunto(s)
Enfermedades Cardiovasculares/diagnóstico , Muerte Súbita Cardíaca/prevención & control , Deportes , Adolescente , Adulto , Atletas , Enfermedades Cardiovasculares/diagnóstico por imagen , Niño , Preescolar , Diagnóstico Precoz , Femenino , Humanos , Masculino , Factores de Tiempo , Ultrasonografía , Adulto JovenRESUMEN
BACKGROUND: Diminished functional capacity is common in hypertrophic cardiomyopathy (HCM), although the underlying mechanisms are complicated. We studied the prevalence of chronotropic incompetence and its relation to exercise intolerance in patients with HCM. METHODS: Cardiopulmonary exercise testing was performed in 68 patients with HCM (age 44.8 ± 14.6 years, 45 males). Chronotropic incompetence was defined by chronotropic index (heart rate reserve)/(220-age-resting heart rate) and exercise capacity was assessed by peak oxygen consumption (peak Vo(2)). RESULTS: Chronotropic incompetence was present in 50% of the patients and was associated with higher NYHA class, history of atrial fibrillation, higher fibrosis burden on cardiac MRI, and treatment with ß-blockers, amiodarone and warfarin. On univariate analysis, male gender, age, NYHA class, maximal wall thickness, left atrial diameter, peak early diastolic myocardial velocity of the lateral mitral annulus, history of atrial fibrillation, presence of left ventricular outflow tract obstruction (LVOTO) at rest, and treatment with beta-blockers were related to peak Vo(2). Peak heart rate during exercise, heart rate reserve, chronotropic index, and peak systolic blood pressure were also related to peak Vo(2). On multivariate analysis male gender, atrial fibrillation, presence of LVOTO and heart rate reserve were independent predictors of exercise capacity (R(2) = 76.7%). A cutoff of 62 bpm for the heart rate reserve showed a negative predictive value of 100% in predicting patients with a peak Vo(2) <80%. CONCLUSIONS: Blunted heart rate response to exercise is common in HCM and represents an important determinant of exercise capacity.
Asunto(s)
Cardiomiopatía Hipertrófica/diagnóstico , Cardiomiopatía Hipertrófica/fisiopatología , Prueba de Esfuerzo/métodos , Tolerancia al Ejercicio/fisiología , Frecuencia Cardíaca/fisiología , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios ProspectivosRESUMEN
The purpose of this study was to evaluate the maximal oxygen uptake (Vo(2)max) values in soccer players as assessed by field and laboratory tests. Thirty-five elite young soccer players were studied (mean age 18.1 +/- 1.0 years, training duration 8.3 +/- 1.5 years) in the middle of the playing season. All subjects performed 2 maximal field tests: the Yo-Yo endurance test (T(1)) for the estimation of Vo(2)max according to normogram values, and the Yo-Yo intermittent endurance test (T(2)) using portable telemetric ergospirometry; as well as 2 maximal exercise tests on the treadmill with continuous (T(3)) and intermittent (T(4)) protocols. The estimated Vo(2)max values of the T(1) test (56.33 ml.kg(-1).min(-1)) were 10.5%, 11.4%, and 13.3% (p < or = 0.05) lower than those of the T(2) (62.96 ml.kg(-1).min(-1)), T(3) (63.59 ml.kg(-1).min(-1)) and T(4) (64.98 ml.kg(-1).min(-1)) tests, respectively. Significant differences were also found between the intermittent exercise protocols T(1) and T(3) (p < or = 0.001) and the continuous exercise protocols T(2) and T(4) (p < or = 0.001). There was a high degree of cross correlation between the Vo(2)max values of the 3 ergospirometric tests (T(2) versus T(3), r = 0.47, p < or = 0.005; T(2) versus T(4), r = 0.59, p < or = 0.001; T(3) versus T(4) r = 0.79, p < or = 0.001). It is necessary to use ergospirometry to accurately estimate aerobic capacity in soccer players. Nevertheless, the Yo-Yo field tests should be used by coaches because they are easy and helpful tools in the training program setting and for player follow-up during the playing season.
Asunto(s)
Prueba de Esfuerzo/métodos , Consumo de Oxígeno/fisiología , Fútbol/fisiología , Adolescente , Presión Sanguínea/fisiología , Frecuencia Cardíaca/fisiología , Humanos , Ácido Láctico/sangre , Resistencia Física/fisiología , Pruebas de Función RespiratoriaRESUMEN
BACKGROUND: Cardiac disorders constitute the most common causes of sudden cardiac death (SCD) and mitral valve prolapse (MVP) is one of the cardiac structural causes in young populations. The aim of this study was to evaluate some reliable non-invasive electrophysiological variables of SCD in young athletes with mild or moderate MVP and to compare them with their cardiorespiratory adaptations. DESIGN: The study population comprised of 40 amateur male soccer players, who were equally subdivided into those with (group A, aged 20.4+/-4.5 years) and without (group B, 18.4+/-2.4 years) MVP and 20 healthy age-matched sedentary individuals (group C). METHODS: All subjects underwent echo study for left ventricular mass index (LVMI) estimation, treadmill spiro-ergometric test for maximal oxygen uptake (VO2max) measurement and continuous ambulatory 24-h ECG recordings for arrhythmias detection and heart rate variability (HRV) analysis. Furthermore, groups A and B were also submitted to signal-averaged electrocardiogram for late potentials (LP) assessment and to submaximal exercise test for T-wave alternans (TWA) detection. RESULTS: Maximal oxygen uptake, LVMI and HRV index were enhanced in all athletes compared to group C (P<0.05). Resting QTc interval was significantly prolonged only in group B (by 3.7%) compared to C (P<0.05), whereas no significant difference was found between A and B. No positive LP or TWA were observed in all subjects. Significant correlation was found only between HRV index and VO2max in all groups. CONCLUSIONS: Athletes with mild or moderate MVP do not present any significant difference in non-invasive cardiac electrophysiological indices as well as in cardiorespiratory performance, compared to healthy ones. It seems that long-term exercise induced adaptations overlap any cardiac autonomic disorders in cases of mild-to-moderate MVP severity.