Study purpose: The aim of this study was to investigate the cardiopulmonary status in a competitive apnea diving team.
Design: This study was conducted with a cross-sectional study design in which subjects had to undergo a predefined series of cardiopulmonary examinations.
Subjects: Eight competitive apnea divers (mean age, 26.9 +/- 5.3 years) who were participating in international apnea diving contests.
Methods: Electrocardiographic, 2-dimensional echocardiographic, Doppler-echocardiographic, and oxymetric examinations were performed in each subject during an apnea test.
Results: Apnea diving experience was 2.5 +/- 0.58 years, with a training frequency of 8.9 +/- 6.0 dives per week. During an apnea test, mean apnea time was 4.5 +/- 0.96 minutes. While 2-dimensional echocardiography showed normal morphologic findings of cardiac dimensions and function, electrocardiography, and Doppler echocardiography revealed indicators suggesting the beginning of right ventricular strain.
Conclusions: We interpret the findings of our study as the onset of pulmonary hypertension resulting from repetitive pulmonary vasoconstriction together with severe hypoxia during apnea diving. We conclude that regular competitive apnea diving over a period of >2 to 3 years might carry a chronic cardiopulmonary risk that may lead from early functional changes to manifestation of pulmonary hypertension.