Heart dimensions may influence the occurrence of the heart rate deflection point in highly trained cyclists

OBJECTIVES: To determine whether the heart rate (HR) response to exercise in 21 highly trained cyclists (mean (SD) age 25 (3) years) was related to their heart dimensions. METHODS: Before performing an incremental exercise test involving a ramp protocol with workload increases of 25 W/min, each subject underwent echocardiographic evaluation of the following variables: left ventricular end diastolic internal diameter (LVIDd), left ventricular posterior wall thickness at end diastole (LVPWTd), interventricular septal wall thickness at end diastole (IVSTd), left ventricular mass index (LVMI), left atrial dimension (LAD), longitudinal left atrial (LLAD) and right atrial (LRAD) dimensions, and the ratio of early to late (E/A) diastolic flow velocity. RESULTS: The HR response showed a deflection point (HRd) at about 85% VO2MAX in 66.7% of subjects (D group; n = 14) and was linear in 33.3% (NoD group; n = 7). Several echocardiographic variables (LVMI, LAD, LLAD, LRAD) indicative of heart dimensions were similar in each group. However, mean LPWTd (p<0.01) and IVSTd (p<0.05) values were significantly higher in the D group. Finally, no significant difference between groups was found with respect to the E/A. CONCLUSIONS: The HR response is curvilinear during incremental exercise in a considerable number of highly trained endurance athletes-that is, top level cyclists. The departure of HR increase from linearity may predominantly occur in athletes with thicker heart walls. 



Ethnic differences in left ventricular remodeling in highly-trained athletes - Relevance to differentiating physiologic left ventricular hypertrophy from hypertrophic cardiomyopathy

ObjectivesThe purpose of this study was to evaluate ethnic differences in left ventricular (LV) remodeling between highly-trained athletes of African/Afro-Caribbean (black) and Caucasian (white) athletes.BackgroundThe upper limits of left ventricular hypertrophy (LVH) are established in white athletes and aid the differentiation of physiologic LVH from hypertrophic cardiomyopathy (HCM). However, there are few data regarding LV remodeling in black athletes, in whom deaths from HCM are more prevalent.MethodsBetween 2003 and 2007, 300 nationally ranked black male athletes (mean age 20.5 years) underwent 12-lead electrocardiogram and 2-dimensional echocardiography. The results were compared with 150 black and white sedentary individuals and 300 highly-trained white male athletes matched for age, size, and sport.ResultsBlack athletes exhibited greater LV wall thickness and cavity size compared with sedentary black and white individuals. Black athletes had greater LV wall thickness compared with white athletes (11.3 ± 1.6 mm vs. 10 ± 1.5 mm; p < 0.001). In absolute terms, 54 black athletes (18%) had LV wall thickness >12 mm compared with 12 white athletes (4%), and 3% of black athletes exhibited LV wall thickness ≥15 mm compared with none of the white athletes. Black athletes with LVH displayed an enlarged LV cavity and normal diastolic function.ConclusionsBlack athletes develop a greater magnitude of LVH compared with white athletes; therefore, extrapolation of conclusions derived from white athletes has the potential of generating false-positive diagnoses of HCM in black athletes

Cardiac dimensions over 5 years in highly trained long-distance runners and sprinters

Aims We assessed the changes in cardiac morphology between elite endurance-trained runners (n = 42) and elite sprinters (n = 34) over a 5-year period. In addition, we studied the relationship between heart size and maximum oxygen consumption (VO2 max). Methods At the beginning of 5 consecutive seasons, all athletes underwent an incremental running test to determine VO2 max and a color-coded pulsed Doppler examination to determine baseline echocardiographic variables. We hypothesized that cardiac morphology had reached its upper limit in elite athletes, and showed only minor changes during 5 years of regular training. Results Although all echocardiographic variables remained stable in nearly all sprinters studied, in the endurance runners (who presented higher cardiac cavity dimensions compared with sprinters), variations in heart morphology became evident from the third season, and were within established physiological limits. Conclusion Only 6 (17%) endurance runners and 3 (9%) sprinters showed a left ventricular internal diameter of > 60 mm (the threshold pathological value) at end diastole at some point during the observational period. Moreover, no statistically significant association was detected between changes in VO2 max and changes in heart size. After 5 years of intense training, the changes of the echocardiographic variables examined remained different between endurance runners and sprinters

Dilatación de la aurícula izquierda en deportistas de alta competición y electrofisiología auricular

Introduction and objectives: There are scarce data on left atrial (LA) enlargement and electrophysiological features in athletes. Methods: Multicenter observational study in competitive athletes and controls. LA enlargement was defined as LA volume indexed to body surface area ≥ 34mL/m2. We analyzed its relationship with atrial electrocardiography parameters. Results: We included 356 participants, 308 athletes (mean age: 36.4±11.6 years) and 48 controls (mean age: 49.3±16.1 years). Compared with controls, athletes had a higher mean LA volume index (29.8±8.6 vs 25.6±8.0mL/m2, P=.006) and a higher prevalence of LA enlargement (113 [36.7%] vs 5 [10.4%], P <.001), but there were no relevant differences in P-wave duration (106.3±12.5ms vs 108.2±7.7ms; P=.31), the prevalence of interatrial block (40 [13.0%] vs 4 [8.3%]; P=.36), or morphology-voltage-P-wave duration score (1.8±0.84 vs 1.5±0.8; P=.71). Competitive training was independently associated with LA enlargement (OR, 14.7; 95%CI, 4.7-44.0; P <.001) but not with P-wave duration (OR, 1.02; 95%CI, 0.99-1.04), IAB (OR, 1.4; 95%CI, 0.7-3.1), or with morphology-voltage-P-wave duration score (OR, 1.4; 95%CI, 0.9-2.2). Conclusions: LA enlargement is common in adult competitive athletes but is not accompanied by a significant modification in electrocardiographic parameters.Introducción y objetivos Existe poca información sobre la dilatación de la aurícula izquierda (AI) y los parámetros electrocardiográficos en deportistas. Métodos Estudio observacional multicéntrico en deportistas de competición y controles. La dilatación de la AI se definió como un volumen indexado por área de superficie corporal ≥ 34ml/m2. Se estudió su relación con parámetros electrocardiográficos auriculares. Resultados Se incluyó en total a 356 sujetos: 308 deportistas de competición (media de edad, 36,4±11,6 años) y 48 controles (49,3±16,1 años). Los deportistas de competición tenían un mayor volumen medio indexado de la AI (29,8±8,6 frente a 25,6±8,0ml/m2; p=0,006) y una mayor prevalencia de dilatación de la AI (113 [36,7%] frente a 5 [10,4%]; p <0,001), sin diferencias relevantes en cuanto a la duración de la onda P (106,3±12,5 frente a 108,2±7,7 ms; p=0,31), la prevalencia de bloqueo interauricular (40 [13,0%] frente a 4 [8,3%]; p=0,36) ni la puntuación Morphology-Voltage-P-wave duration (1,8±0,84 frente a 1,5±0,8; p=0,71). El entrenamiento competitivo se asoció de manera independiente con la dilatación de la AI (OR=14,7; IC95%, 4,7-44,0; p < 0,001), pero no con la duración de la onda P (OR=1,02; IC95%, 0,99-1,04), el bloqueo interauricular (OR=1,4; IC95%, 0,7-3,1) o la puntuación Morphology-Voltage-P-wave duration (OR=1,4; IC95%, 0,9-2,2). Conclusiones La dilatación de la AI es frecuente en deportistas de competición, pero no se acompaña de una modificación relevante en los parámetros electrocardiográficos.Sin financiaciónNo data JCR (2021)0.385 SJR (2021) Q3, 1499/2489 Medicine (miscellaneous)No data IDR 2020UE