A case series of eight amateur athletes: exercise-induced pre-/syncope during the Zurich Marathon 2023.

Background: Marathon running poses unique cardiovascular challenges, sometimes leading to syncopal episodes. We present a case series of athletes who experienced pre-/syncope during the Zurich Marathon 2023, accompanied by elevated cardiac biomarkers. Case summary: Eight athletes (2 females, 6 males) aged 21-35 years, with pre-/syncope and various additional diverse symptoms such as dizziness and palpitations during the (half-)marathon, were admitted to two emergency departments in Zurich, Switzerland. Clinical evaluations included electrocardiogram, echocardiography, telemetry, coronary computed tomography (CT) scans, and cardiac biomarker assessments. High-sensitive troponin T (hs-cTnT) was elevated in all cases at initial assessment and returned to normal at follow-up. All athletes who received CT scans had normal coronary and brain CT results. None of the eight athletes had underlying cardiovascular disease. Renal function normalized post-admission, and neurological symptoms resolved within hours. Creatinine levels indicated transient acute kidney injury. A common feature was inexperience in running, inadequate race preparation, particularly regarding fluid, electrolyte, and carbohydrate intake, along with pacing issues and lack of coping strategies with heat. Discussion: From a clinician perspective, the case series highlights the challenge in the management of patients with a pre-/syncopal event during strenuous exercise and elevated cardiac biomarkers. Diverse initial symptoms prompted tailored investigations. Adequate training, medical assessments, and awareness of syncope triggers are essential for marathon participants. Caution and pacing strategies are crucial, especially among novices in competitive running. This information is pertinent given the growing popularity of marathon events and prompts a standardized diagnostic approach after these events.