What is normal in the female athlete’s heart?

This editorial refers to ‘Normal echocardiographic and electrocardiographic indices in young female athletes: a meta-analysis across sex, types of sports, races and ethnicities’ by N. Laurier et al., https://doi.org/10.1093/eurjpc/zwaf755. As women’s sports enter a period of unprecedented growth, increasing numbers of young female athletes are training and competing at intensities that rival those historically observed in men.1 Yet cardiovascular screening paradigms have not kept pace. Much of what clinicians rely on to distinguish physiological exercise-induced remodelling from pathology in athletes is derived from male-dominant cohorts, often without adequate representation of female athletes.2,3 This gap is clinically consequential: misclassification may lead to unnecessary restriction from sport or, conversely, missed disease at a time when participation, visibility, and long-term investment in women’s athletics are accelerating. More broadly, it reflects our incomplete understanding of the full spectrum of normal cardiovascular variation across sex, ancestry, and training exposure.4 Comprehension of these exercise-related cardiovascular indices and their mechanistic underpinnings is critical to guide more effective cardiovascular care for female athletes.5 In this issue of the European Journal of Preventive Cardiology, Laurier et al. address this unmet need through a meta-analysis of echocardiographic (ECHO) and electrocardiographic (ECG) parameters in young athletes.6 Drawing on data from nearly 12, 000 female athletes—predominantly in their early 20s (age range 18–35 years) and largely participating in endurance or mixed-discipline sports—and comparing findings with female non-athletes (n ∼ 500) and male athletes (n ∼14 000), the authors provide a timely synthesis of cardiac structural and electrical patterns in women. The cohort was predominantly White (approximately 80%), with more limited representation of athletes from other racial and ethnic backgrounds, a consideration that appropriately tempers generalizability and highlights the need for broader inclusion in future studies. Three principal observations from this meta-analysis merit emphasis. First, compared with female non-athletes, young female athletes demonstrate cardiac structural remodelling consistent with training adaptation, including higher indexed left ventricular end-diastolic volume and mass (each approximately 30% higher) and a lower resting heart rate (approximately 12 beats per minute lower). Second, when compared with male athletes, female athletes exhibit a distinct pattern of cardiac adaptation, characterized by lower left ventricular mass indices (approximately 20% lower) and a greater predominance of eccentric geometry—findings that reflect sex-specific scaling and remodelling patterns rather than an attenuated physiological response to training. Third, these structural and electrical differences occur in the context of preserved global cardiac performance, with broad overlap in measures of systolic and diastolic function and no signal of impaired myocardial function across groups. Normative values for many ECHO and ECG parameters have yet to be widely established, specific to the female athlete, as there has been a paucity of data; this meta-analysis aims to bring us closer to that target. Interestingly, the authors identified no significant differences in measured cardiovascular indices across endurance, mixed, and power sport categories in female athletes. This finding warrants cautious interpretation in light of prior literature describing sport-specific patterns of cardiac remodelling,2 further notable as cardiac remodelling can be observed after just a few months of intensive dedicated exercise training. The lack of difference in studied cardiovascular parameters across sport categorisation may indicate an incomplete knowledge of the exercise history of the studied athletes. The present data showcase numerous ECG and ECHO variables that can frame future investigations, however, given the small number of studies for each variable, the ability to inform normative values for female athletes overall or specifically for younger cohorts (despite the younger studied age) is limited. Importantly, self-reported race proportions (largely White cohort) and underrepresentation of sports of pure ‘power’ discipline (2.7% of total cohort) further limit the generalizability to inform normative values to populations not adequately represented in the study sample. The difference in left ventricular mass index between males and females is noted in the present study. These findings align with previous literature reporting female athletes maintain predominantly normal left ventricular geometry (81% in one large cohort), with eccentric remodelling being the predominant pattern when possible ‘physiologic adaptation to exercise’ is present.1,7 Finnochario and colleagues’ evaluation of 1083 elite athletes further supports these findings, demonstrating that females exhibit a lower left ventricular mass index (83 g/m2 vs. 101 g/m2) and higher rates of eccentric left ventricular hypertrophy compared to males (22% vs. 14%).8 Female athletes have previously been described to have less prevalent left ventricular hypertrophy by voltage criteria, more frequent anterior T-wave inversion on ECG and longer QTc intervals compared to males.7,9 The current study found self-identified Black female athletes have more T-wave inversion (unknown ECG localisation, a distinction with important implications for interpretation in athletes), though only 3 studies informed this statistic (White (5 studies), other races (0 to 1 studies each)), again highlighting the need for more data. While the authors were limited to analysing reported race from previously collected data, we have this opportunity to note that race, classification based on appearance/skin colour, and ethnicity, classification based on cultural identity, are sociopolitical and nonbiological constructs and lend toward bias in study design, results and data interpretation.10 Anterior ST elevation with T-wave inversion has been historically labelled the Black Athlete ECG Repolarisation Pattern. However, recent data looking at this pattern found that it is more common than previously described in athletes of other non-Black self-reported races, more common in sports with higher endurance and strength demands, and benign when absent accompanying high-risk features, possibly reflecting patterns of physiological adaptation rather than race-specific norms.11 Importantly, the recommended paradigm shift to a race-conscious framework acknowledges that race does not serve as a proxy for genetic variability, and that race-based screening approaches—such as differential ECG interpretation criteria for Black athletes (a group that continues to have a higher prevalence of false-positive ECG findings)—risk stigmatisation and unnecessary disqualification of athletes from underrepresented racial and ethnic groups. Finally, despite structural and ECG differences, ventricular performance was consistently preserved across female athletes. Measures of left ventricular systolic deformation and right ventricular systolic function—including global longitudinal strain and TAPSE—consistently fell within established normal ranges, reinforcing that exercise-related remodelling in females occurs in the context of preserved myocardial function. This meta-analysis provides clinically relevant insight into the cardiovascular phenotype of young female athletes (where a paucity of data exists!), though future studies are warranted before concrete normative values are determined (Figure 1). Future studies should investigate female athletes across the lifespan, incorporating comprehensive biologic variables, hormone status and additional women’s health history, as well as comparing ECG against ECHO findings and including longitudinal follow-up and outcomes data. These studies will aid in not only elucidating structural and electrical changes but also investigating the impact of age, hormones, genetics, ancestry, training status and other variables over time. Future scientific investigations are essential to increase accuracy in distinguishing physiological athletic remodelling from early pathological changes and to enhance individual risk stratification when testing is performed. Echocardiogram and electrocardiogram findings in female athletes vs. female non-athletes and male athletes. In summary, Laurier et al. provide a timely meta-analysis regarding structural and electrical cardiovascular parameters in young female athletes. The authors should be commended for their effort in highlighting important questions for the female athlete, recognising the need for more diverse athlete phenotype studies. Sincere gratitude is extended to Dr Jonathan H. Kim, MD, MSc from Emory University (Atlanta, Georgia, USA) for his detailed review of drafts of this editorial, including critical suggestions for structure, flow and content. Ufuk Vardar (MD (Conceptualization [equal]; Methodology [equal]; Visualization [equal]; Writing—original draft [lead]; Writing—review & editing [equal])), J. Sawalla Guseh (MD (Conceptualization [equal]; Visualization [equal]; Writing—review & editing [supporting])), and Elizabeth H Dineen (D.O. (Conceptualization [lead]; Visualization [equal]; Writing—original draft [supporting]; Writing—review & editing [lead])) J.S.G. is supported by the American Heart Association (19AMFDP34990046; SFRN awards 24SFRNCCN1276092, 25ISFRNCP1501445, 24SFRNPCN1284389). Other authors: None.