Exercise-Induced Left Ventricular Remodeling Among Competitive Athletes

Abstract

E xercise-induced cardiac remodeling (EICR) refers to changes in cardiac structure and function that occur in response to exercise training. Numerous structural aspects of EICR (ie, athlete's heart) including ventricular chamber enlargement 1 and hypertrophy 2 have been described, and several key determinants of the EICR process including age, 3 sex, 4 ethnicity, 5 and sporting discipline 6,7 have been established. However, contemporary understanding of EICR is based largely on cross-sectional data derived from competitive athletes and instructive but relatively short duration longitudinal studies of recreational exercisers. 8,9 Therefore, the temporal progression of EICR among competitive athletes remains incompletely understood. See Clincial Perspective See Editorial by D'Silva and SharmaThe myocardial response to hemodynamic perturbation occurs in discrete phases in numerous settings. Specifically, physiological remodeling after 12 months of exercise training in previously sedentary people 9 and cardiac adaptations during pregnancy 10 occurs in different stages. In addition, numerous cardiac disease states are defined by phasic adaptations in myocardial structural and function. 11,12 Whether the EICR that occurs among competitive athletes develops in a phasic sequence remains unknown because of the lack of long-term longitudinal data. Determining the time course of EICR represents a critical step in further defining the myocardial response Background-Contemporary understanding of exercise-induced cardiac remodeling is based on cross-sectional data and relatively short duration longitudinal studies. Temporal progression of exercise-induced cardiac remodeling remains incompletely understood. Methods and Results-A longitudinal repeated-measures study design using 2-dimensional and speckle-tracking echocardiography was used to examine acute augmentation phase (AAP; 90 days) and more extended chronic maintenance phase (39 months) left ventricular (LV) structural and functional adaptations to endurance exercise training among competitive male rowers (n=12; age 18.6±0.5 years). LV mass was within normal limits at baseline (93±9 g/ m 2 ), increased after AAP (105±7 g/m 2 ; P=0.001), and further increased after chronic maintenance phase (113±10 g/m 2 ; P<0.001 for comparison to post-AAP). AAP LV hypertrophy was driven by LV dilation (ΔLV end-diastolic volume, 9±3 mL/m 2 ; P=0.004) with stable LV wall thickness (ΔLV wall thickness, 0.3±0.1 mm; P=0.63). In contrast, chronic maintenance phase LV hypertrophy was attributable to LV wall thickening (Δ LV wall thickness, 1.1±0.4 mm; P=0.004) with stable LV chamber volumes (ΔLV end-diastolic volume, 1±1 mL/m 2 ; P=0.48). Early diastolic peak tissue velocity increased during AAP (−11.7±1.9 versus −13.6±1.3 cm/s; P<0.001) and remained similarly increased after chronic maintenance phase. Conclusions-In a small sample of competitive endurance athletes, exercise-induced cardiac remodeling follows a phasic response with increases in LV chamber size, early diastolic function, and sy...

Global and regional cardiac function in lifelong endurance athletes with and without myocardial fibrosis

“…2CH: apical two chamber view; 4CH: apical four chamber view; APLAX: apical parasternal long axis view; E: early diastolic filling (E-wave); A: late diastolic filling (A-wave); E (cm/s): early diastolic velocity of mitral annulus; A (cm/s): late diastolic velocity of mitral annulus; S (l/s): systolic strain rate; E (l/s): early diastolic strain rate; A (l/s): late diastolic strain rate. Weiner et al, 2015) demonstrated that the magnitude of exercise-induced cardiac remodelling differs substantially across athletes. Genetic, epigenetic and environmental factors may contribute to the inter-individual differences of remodelling (Eijsvogels & Thompson, 2017).…”

Exercise-Induced Cardiac Remodeling

“…At study enrollment, these subjects exercised for ≤30 minutes, 3 times per week, and through a supervised, incremental exercise training program achieved a peak exercise regimen of 7 to 9 hours per week at the end of 1 year, in preparation for a marathon race. Therefore, it is noteworthy that these subjects were, on average, over 10 years older than the subjects of Weiner et al 9 and reached an exercise dose at the end of the study that reflected the baseline exercise dose of the subjects in the current cohort.…”

“…Although also reporting a phasic response to EICR, in contrast to Weiner et al, 9 Arbab-Zadeh et al 11 observed that in their population, the initial increase in left ventricular mass resulted from increased left ventricular wall thickness in a pattern of concentric hypertrophy in the first 6 to 9 months, with subsequent left ventricular dilatation at 9 to 12 months, producing the final picture of eccentric hypertrophy.…”

“…In this issue of Circulation: Cardiovascular Imaging, Weiner et al 9 addressed the subject of left ventricular remodeling in 12 healthy white male rowers with a mean age of 18±0.5 years over a follow-up period of 39 months. It is important to note that these subjects, before enrolment, exercised on average for 8.5 hours per week.…”

Cardiovascular benefits and risks across the physical activity continuum

“…High volumes of exercise training improve cardiovascular risk factors [42], and cause an initial increase in left ventricular chamber size followed by an increase in wall thickness during chronic exercise training [43].…”