Extravascular lung water and cardiac function assessed by echocardiography in healthy lowlanders during repeated very high-altitude exposure

INTERNATIONAL JOURNAL OF CARDIOLOGY

卷:332

Article

Lichtblau, Mona¹  Bader, Patrick R.¹  Carta, Arcangelo F.¹  Furian, Michael¹  Muralt, Lara¹  Saxer, Stephanie¹  Hartmann, Sara E.²  Rawling, Jean M.³  Poulin, Marc J.²  Bloch, Konrad E.¹  Ulrich, Silvia¹ 

[1] Univ Zurich Hosp, Dept Resp Med, Zurich, Switzerland

[2] Univ Calgary, Cumming Sch Med, Dept Physiol & Pharmacol & Hotchkiss Brain Inst, Calgary, AB, Canada

[3] Univ Calgary, Cumming Sch Med, Dept Family Med, Calgary, AB, Canada

关键词: High altitude;    Hypoxia;    Echocardiography;    Lung ultrasound;    Extravascular lung water;    B-lines;    Healthy;   

DOI  :  10.1016/j.ijcard.2021.03.057

来源: Elsevier

【 摘 要 】

Background: High-altitude pulmonary edema is associated with elevated systolic pulmonary artery pressure (sPAP) and increased extravascular lung water (EVLW). We investigated sPAP and EVLW during repeated exposures to high altitude (HA). Methods: Healthy lowlanders underwent two identical 7-day HA-cycles, where subjects slept at 2900 m and spent 4-8 h daily at 5050 m, separated by a weeklong break at low altitude (LA). Echocardiography and EVLW by B-lines were measured at 520 m (baseline, LA(1)), on day one, two and six at 5050 m (HA(1-3)) and after descent (LA(2)). Results: We included 21 subjects (median 25 years, body mass index 22 kg/m(2), SpO(2) 98%). SPAP rose from 21 mmHg at LA(1) to 38 mmHg at HA(1), decreased to 30 mmHg at HA(3) (both p < 0.05 vs LA(1)) and normalized at 20 mmHg at LA(2) (p = ns vs LA(1)). B-lines increased from 0 at LA(1) to 6 at HA(2) and 7 at HA(3) (both p < 0.05 vs LA(1)) and receded to 1 at LA(2) (p = ns vs LA(1)). Overall, in cycle two, sPAP did not differ (mean difference (95% confidence interval)-0.2(-2.3 to 1.9) mmHg, p = 0.864) but B-lines were more prevalent (+2.3 (1.4-3.1), p < 0.001) compared to cycle 1. Right ventricular systolic function decreased significantly but minimally at 5050 m. Conclusions: Exposure to 5050 m induced a rapid increase in sPAP. B-lines rose during prolonged exposures to 5050 m, despite gradual decrease in sPAP, indicating excessive hydrostatic pressure might not be solely responsible for EVLW-development. Repeated HA-exposure had no acclimatization effect on EVLW. This may affect workers needing repetitive ascents to altitude and could indicate greater B-line development upon repeated exposure. (c) 2021 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http:// creativecommons.org/licenses/by/4.0/).

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