Swimming-induced pulmonary edema (SIPE) linked to transient cardiac dysfunction and elevated biomarkers in open water swimmers.

Swimming-induced pulmonary edema (SIPE) is a poorly understood condition affecting athletes, particularly in open water events. While previous case reports have hinted at cardiac involvement, a comprehensive characterization of acute cardiac changes in SIPE patients has been lacking. Understanding these cardiac findings is crucial for accurate diagnosis, differentiating SIPE from other acute cardiac events, and guiding appropriate clinical management. This study addresses the gap by systematically evaluating cardiac function and biomarkers in a cohort of SIPE patients.

A prospective cohort study evaluated 45 patients with SIPE and 45 asymptomatic control swimmers participating in Sweden's largest open water swimming event, Vansbrosimningen, from 2022-2024. Participants underwent Transthoracic echocardiogram (TTE), electrocardiogram (ECG), and cardiac biomarker assessment (high-sensitivity cardiac troponin I, N-terminal pro-B-type natriuretic peptide) within two hours after swimming. A follow-up TTE was conducted within 12 months to assess the resolution of any observed cardiac pathology.

Cardiac assessments revealed significant differences between SIPE patients and controls. Systolic ventricular function on TTE was mildly impaired after swimming in 43% of SIPE patients compared to only 10% of controls (p=0.003). Systolic pulmonary artery pressure was also increased in 30% of SIPE patients, while none of the controls showed this increase (p=0.005). Notably, TTE pathology had improved at follow-up in all but one SIPE patient, indicating the transient nature of these changes. ECG findings post-swim showed no significant difference between groups (p=0.746).