CARDIAC FINDINGS IN SWIMMING-INDUCED PULMONARY EDEMA - IMPLICATIONS FOR ACUTE ASSESSMENT.

Abstract

Pathological cardiac findings have been described in case reports of patients with swimming-induced pulmonary edema (SIPE). To characterize cardiac findings in patients with SIPE. A cohort study evaluated patients with SIPE and asymptomatic swimmers (controls) participating in Sweden's largest open water swimming event, Vansbrosimningen, in 2022-2024. Transthoracic echocardiogram (TTE), electrocardiogram (ECG) and cardiac biomarkers were assessed within two hours after swimming and at follow-up within 12 months. In total, 45 patients with SIPE and 45 controls were included. Systolic ventricular function on TTE was mildly impaired after swim in 43% of patients and 10% of controls (p=0.003). Systolic pulmonary artery pressure was increased in 30% of patients but none of the controls (p=0.005). TTE pathology had improved at follow-up in all but one patient. Findings on ECG after swim showed no difference between groups (p=0.746). High-sensitivity cardiac troponin I after swim was increased in 67% of patients and 40% of controls (median 47 pg/ml vs 14 pg/ml, p<0.001). N-terminal pro-B-type natriuretic peptide was higher in patients than controls (median 169 pg/ml vs 65 pg/ml, p<0.001). Two patients with myocardial infarction concurrently with SIPE had clinically significant chest pain and high levels of cardiac troponin. In patients with SIPE, transient mildly affected cardiac function on TTE and a small to moderate elevation of cardiac biomarkers is likely to be found. ECG did not differ between groups. This study provides a reference of expected cardiac findings in patients with SIPE. clinicaltrials.gov: NCT05391737.