title: Cardiovascular changes during underwater static and dynamic breath-hold dives in trained divers.
abstract: Limited information exists concerning arterial blood pressure (BP) changes in underwater breath-hold diving. Simulated chamber dives to 50 m of freshwater (mfw) reported very high levels of invasive BP in two divers during static apnea (SA), whereas a recent study using a noninvasive subaquatic sphygmomanometer reported unchanged or mildly increased values at 10 m SA dive. In this study we investigated underwater BP changes during not only SA but, for the first time, dynamic apnea (DA) and shortened (SHT) DA in 16 trained breath-hold divers. Measurements included BP (subaquatic sphygmomanometer), ECG, and pulse oxymetry (arterial oxygen saturation, SpO₂, and heart rate). BP was measured during dry conditions, at surface fully immersed (SA), and at 2 mfw (DA and SHT DA), whereas ECG and pulse oxymetry were measured continuously. We have found significantly higher mean arterial pressure (MAP) values in SA (∼40%) vs. SHT DA (∼30%). Postapneic recovery of BP was slightly slower after SHT DA. Significantly higher BP gain (mmHg/duration of apnea in s) was found in SHT DA vs. SA. Furthermore, DA attempts resulted in faster desaturation vs. SA. In conclusion, we have found moderate increases in BP during SA, DA, and SHT DA. These cardiovascular changes during immersed SA and DA are in agreement with those reported for dry SA and DA.
authors: Dept. of Integrative Physiology, Univ. of Split School of Medicine, Soltanska 2, 21000 Split, Croatia.
authors: Toni
authors: T
authors: Breskovic
authors: Lovro
authors: L
authors: Uglesic
authors: Petra
authors: P
authors: Zubin
authors: Benjamin
authors: B
authors: Kuch
authors: Jasenka
authors: J
authors: Kraljevic
authors: Jaksa
authors: J
authors: Zanchi
authors: Marko
authors: M
authors: Ljubkovic
authors: Arne
authors: A
authors: Sieber
authors: Zeljko
authors: Z
authors: Dujic
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001049:Apnea / Q000097:blood / Q000503:physiopathology*; D001642:Bicycling; D015415:Biomarkers / Q000097:blood; D001794:Blood Pressure; D004242:Diving; D004562:Electrocardiography; D005260:Female; D006339:Heart Rate; D006801:Humans; D007101:Immersion; D019344:Lactic Acid / Q000097:blood; D016014:Linear Models; D008297:Male; D010092:Oximetry; D010100:Oxygen / Q000097:blood; D020127:Recovery of Function; D015656:Respiratory Mechanics; D019722:Sphygmomanometers; D013997:Time Factors; D055815:Young Adult
chemical_list: D015415:Biomarkers; D019344:Lactic Acid; D010100:Oxygen