The electrocardiogram (ECG) is a non-invasive and cost-effective screening tool that is widely available and has been incorporated into many pre-participation screening programs for athletes. Despite historical criticisms regarding its suboptimal specificity, which could impact cost-effectiveness, the ECG remains a fundamental diagnostic method. Over the last 2 decades, significant research has focused on distinguishing pathological from physiological ECG patterns, the latter associated with the "athlete’s heart". The most recent guidelines for ECG interpretation in athletes include the International Criteria, published in 2017, which categorize ECG findings into common (training related), uncommon (training unrelated), and a "borderline" sub-group, with findings that do not necessitate further investigation when isolated. Premature ventricular beats (PVBs), although often overlooked, are a frequent cause of secondary investigations in athletes, especially when detected during exercise testing. Recent advances over the past decade have refined diagnostic methodologies, placing greater emphasis on morphological features, exercise relationships, and reproducibility, rather than solely on the count of PVBs. This evolution aims to enhance stratification for further investigations, such as cardiac magnetic resonance, which is crucial within this updated diagnostic framework, as it identifies pathologies causing sudden cardiac death during exercise. This review aims to provide a modern revision of the interpretation of ECGs and PVBs, incorporating a historical excursus to trace the evolution of these criteria. It is designed to offer clinicians a practical key for enhanced diagnostic precision in athlete screenings, reflecting both past insights and current advances.

The electrocardiogram (ECG) is a non-invasive and cost-effective screening tool that is widely available and has been incorporated into many pre-participation screening programs for athletes. Despite historical criticisms regarding its suboptimal specificity, which could impact cost-effectiveness, the ECG remains a fundamental diagnostic method. Over the last 2 decades, significant research has focused on distinguishing pathological from physiological ECG patterns, the latter associated with the "athlete’s heart". The most recent guidelines for ECG interpretation in athletes include the International Criteria, published in 2017, which categorize ECG findings into common (training related), uncommon (training unrelated), and a "borderline" sub-group, with findings that do not necessitate further investigation when isolated. Premature ventricular beats (PVBs), although often overlooked, are a frequent cause of secondary investigations in athletes, especially when detected during exercise testing. Recent advances over the past decade have refined diagnostic methodologies, placing greater emphasis on morphological features, exercise relationships, and reproducibility, rather than solely on the count of PVBs. This evolution aims to enhance stratification for further investigations, such as cardiac magnetic resonance, which is crucial within this updated diagnostic framework, as it identifies pathologies causing sudden cardiac death during exercise. This review aims to provide a modern revision of the interpretation of ECGs and PVBs, incorporating a historical excursus to trace the evolution of these criteria. It is designed to offer clinicians a practical key for enhanced diagnostic precision in athlete screenings, reflecting both past insights and current advances.