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Kerkhof PLM, Handly N. Statistics at high-altitudes: Relevance for the interpretation of metrics that reveal cardiac morphology and performance. Echocardiography 2024; 41:e15797. [PMID: 38549393 DOI: 10.1111/echo.15797] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2024] [Accepted: 02/26/2024] [Indexed: 04/02/2024] Open
Abstract
Survey of four ratio-based metrics, commonly used to evaluate left ventricular performance. The numerator of each ratio is plotted against the corresponding denominator, implying that the slope of the colored line reflects the value of the ratio.9,11 Similar graphs can be constructed for the other cardiac compartments. Data sets obtained at various altitudes and defined with reference to sea level, based on Rao et al.6 Acronyms: E/A unitless ratio of the early (E) and late (A) diastolic wave peak velocities (cm/s); EDD, end-diastolic diameter (mm); EDV, end-diastolic volume (mL); EF, ejection fraction (%); ESD, end-systolic diameter (mm); ESV, end-systolic volume (mL); FS, fractional shortening (%).
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Affiliation(s)
- Peter L M Kerkhof
- Department of Radiology & Nuclear Medicine, Amsterdam University Medical Centers, VUmc location, Amsterdam, the Netherlands
| | - Neal Handly
- Department of Emergency Medicine, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA
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2
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Arrebola-Moreno AL, Casuso RA, Bejder J, Bonne TC, Breenfeldt Andersen A, Aragón-Vela J, Nordsborg NB, Huertas JR. Does Hypoxia and Stress Erythropoiesis Compromise Cardiac Function in Healthy Adults? A Randomized Trial. SPORTS MEDICINE - OPEN 2022; 8:137. [PMID: 36334130 PMCID: PMC9637068 DOI: 10.1186/s40798-022-00531-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Accepted: 10/20/2022] [Indexed: 11/07/2022]
Abstract
OBJECTIVES To investigate whether recombinant human erythropoietin (rHuEPO) injections during an altitude training camp impact heart function. METHODS Thirty (12 women) moderately trained subjects stayed at 2320 m altitude for 4 weeks while training. Subjects were randomized to placebo (isotonic saline) or rHuEPO (20 IU/kg body weight) i.v. injections. Transthoracic echocardiography imaging was acquired 3 days after arrival to altitude and prior to the first placebo or rHuEPO injection as well as one day after the last rHuEPO injection three weeks later. RESULTS rHuEPO did not alter cardiovascular morphology parameters, systolic or diastolic function. In the placebo group, altitude exposure improved left ventricle (LV) systolic function due to an increased twist angle but rHuEPO had no additional effects. Pulmonary arterial systolic pressure was unaffected in either group. Notably, rHuEPO hampered LV untwist rate without affecting LV early filling. CONCLUSION rHuEPO provided during mild altitude exposure does not cause any major effects on heart function. The observed alteration in LV untwist induced by rHuEPO is unlikely to have a meaningful clinical effect. Trial Registration Registered on www. CLINICALTRIALS gov (NCT04227665).
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Affiliation(s)
| | - Rafael A. Casuso
- grid.4489.10000000121678994Department of Physiology, Institute of Nutrition and Food Technology, University of Granada, Granada, Spain ,grid.449008.10000 0004 1795 4150Department of Health Sciences, Universidad Loyola Andalucía, Sevilla, Spain
| | - Jacob Bejder
- grid.5254.60000 0001 0674 042XDepartment of Nutrition, Exercise and Sports (NEXS), University of Copenhagen, Copenhagen, Denmark
| | - Thomas Christian Bonne
- grid.5254.60000 0001 0674 042XDepartment of Nutrition, Exercise and Sports (NEXS), University of Copenhagen, Copenhagen, Denmark
| | - Andreas Breenfeldt Andersen
- grid.5254.60000 0001 0674 042XDepartment of Nutrition, Exercise and Sports (NEXS), University of Copenhagen, Copenhagen, Denmark
| | - Jerónimo Aragón-Vela
- grid.4489.10000000121678994Department of Physiology, Institute of Nutrition and Food Technology, University of Granada, Granada, Spain
| | - Nikolai B. Nordsborg
- grid.5254.60000 0001 0674 042XDepartment of Nutrition, Exercise and Sports (NEXS), University of Copenhagen, Copenhagen, Denmark
| | - Jesús R. Huertas
- grid.4489.10000000121678994Department of Physiology, Institute of Nutrition and Food Technology, University of Granada, Granada, Spain
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Williams AM, Levine BD, Stembridge M. A change of heart: Mechanisms of cardiac adaptation to acute and chronic hypoxia. J Physiol 2022; 600:4089-4104. [PMID: 35930370 PMCID: PMC9544656 DOI: 10.1113/jp281724] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Accepted: 07/21/2022] [Indexed: 11/20/2022] Open
Abstract
Over the last 100 years, high-altitude researchers have amassed a comprehensive understanding of the global cardiac responses to acute, prolonged and lifelong hypoxia. When lowlanders are exposed to hypoxia, the drop in arterial oxygen content demands an increase in cardiac output, which is facilitated by an elevated heart rate at the same time as ventricular volumes are maintained. As exposure is prolonged, haemoconcentration restores arterial oxygen content, whereas left ventricular filling and stroke volume are lowered as a result of a combination of reduced blood volume and hypoxic pulmonary vasoconstriction. Populations native to high-altitude, such as the Sherpa in Asia, exhibit unique lifelong or generational adaptations to hypoxia. For example, they have smaller left ventricular volumes compared to lowlanders despite having larger total blood volume. More recent investigations have begun to explore the mechanisms underlying such adaptive responses by combining novel imaging techniques with interventions that manipulate cardiac preload, afterload, and/or contractility. This work has revealed the contributions and interactions of (i) plasma volume constriction; (ii) sympathoexcitation; and (iii) hypoxic pulmonary vasoconstriction with respect to altering cardiac loading, or otherwise preserving or enhancing biventricular systolic and diastolic function even amongst high altitude natives with excessive erythrocytosis. Despite these advances, various areas of investigation remain understudied, including potential sex-related differences in response to high altitude. Collectively, the available evidence supports the conclusion that the human heart successfully adapts to hypoxia over the short- and long-term, without signs of myocardial dysfunction in healthy humans, except in very rare cases of maladaptation.
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Affiliation(s)
- Alexandra M. Williams
- Department of Cellular and Physiological Sciences, Faculty of MedicineUniversity of British ColumbiaVancouverBCCanada
- International Collaboration on Repair DiscoveriesUniversity of British ColumbiaVancouverBCCanada
| | - Benjamin D. Levine
- Institute for Exercise and Environmental MedicineThe University of Texas Southwestern Medical CenterDallasTXUSA
| | - Mike Stembridge
- Cardiff School of Sport and Health SciencesCardiff Metropolitan UniversityCardiffUK
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Yang Y, Gao C, Yang T, Sha Y, Cai Y, Wang X, Yang Q, Liu C, Wang B, Zhao S. Vascular characteristics and expression of hypoxia genes in Tibetan pigs' hearts. Vet Med Sci 2021; 8:177-186. [PMID: 34561963 PMCID: PMC8788992 DOI: 10.1002/vms3.639] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Background Tibetan pigs have exhibited unique characteristics from low‐altitudes pigs and adapted well to the Qinghai‐Tibet Plateau. Objectives The current study was undertaken to investigate the hypoxic adaptation of heart in Tibetan pigs. Methods The hearts of Tibetan pigs and Landrace pigs raised at high or low altitudes were compared using 3D casting technology, scanning electron microscopy and real‐time quantitative PCR (qRT‐PCR). Results We found that the ratio of the major axis to the minor axis and the density of the heart were significantly higher in Tibetan pigs than in Landrace pigs (p < 0.05). Tibetan pigs had larger diameters and higher densities of arterioles than Landrace pigs (p < 0.05), and these features have a similar variation with the expression of vascular endothelial growth factor (VEGF). The cardiac expression levels of hypoxia‐inducible factor‐1α (HIF‐1α) and endothelial nitric oxide synthase (eNOS) were significantly higher in pigs reared at high altitudes than in those reared at low altitudes (p < 0.05). In contrast, Egl nine homolog 1 (EGLN1) had the opposite trend with respect to HIF‐1α and eNOS and was related to red blood cell (RBC) counts. Notably, the expressions of erythropoietin (EPO) and endothelial PAS domain‐containing protein 1 (EPAS1) were significantly higher in Landrace pigs kept at high altitudes than in the others (p < 0.05) and were associated with haemoglobin. Conclusions These findings show that the regulation of the heart function of Tibetan pigs in a hypoxic environment is manifested at various levels to ensure the circulation of blood under extreme environmental conditions.
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Affiliation(s)
- Yanan Yang
- College of Animal Science & Technology, Gansu Agricultural University, Lanzhou, P.R. China
| | - Caixia Gao
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, P.R. China
| | - Tianliang Yang
- College of Animal Science & Technology, Gansu Agricultural University, Lanzhou, P.R. China
| | - Yuzhu Sha
- College of Animal Science & Technology, Gansu Agricultural University, Lanzhou, P.R. China
| | - Yuan Cai
- College of Animal Science & Technology, Gansu Agricultural University, Lanzhou, P.R. China
| | - Xinrong Wang
- College of Animal Science & Technology, Gansu Agricultural University, Lanzhou, P.R. China
| | - Qiaoli Yang
- College of Animal Science & Technology, Gansu Agricultural University, Lanzhou, P.R. China
| | - Chengze Liu
- College of Animal Science & Technology, Gansu Agricultural University, Lanzhou, P.R. China
| | - Biao Wang
- College of Animal Science & Technology, Gansu Agricultural University, Lanzhou, P.R. China
| | - Shengguo Zhao
- College of Animal Science & Technology, Gansu Agricultural University, Lanzhou, P.R. China
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Magnani S, Mulliri G, Roberto S, Sechi F, Ghiani G, Sainas G, Nughedu G, Vargiu R, Bassareo PP, Crisafulli A. Systolic and Diastolic Functions After a Brief Acute Bout of Mild Exercise in Normobaric Hypoxia. Front Physiol 2021; 12:650696. [PMID: 33967823 PMCID: PMC8103167 DOI: 10.3389/fphys.2021.650696] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Accepted: 03/31/2021] [Indexed: 11/13/2022] Open
Abstract
Acute hypoxia (AH) is a challenge to the homeostasis of the cardiovascular system, especially during exercise. Research in this area is scarce. We aimed to ascertain whether echocardiographic, Doppler, and tissue Doppler measures were able to detect changes in systolic and diastolic functions during the recovery after mild exercise in AH. Twelve healthy males (age 33.5 ± 4.8 years) completed a cardiopulmonary test on an electromagnetically braked cycle-ergometer to determine their maximum workload (Wmax). On separate days, participants performed randomly assigned two exercise sessions consisting in 3 min pedalling at 30% of Wmax: (1) one test was conducted in normoxia (NORMO) and (2) one in normobaric hypoxia with FiO2 set to 13.5% (HYPO). Hemodynamics were assessed with an echocardiographic system. The main result was that the HYPO session increased parameters related to myocardial contractility such as pre-ejection period and systolic myocardial velocity with respect to the NORMO test. Moreover, the HYPO test enhanced early transmitral filling peak velocities. No effects were detected for left ventricular volumes, as end-diastolic, end-systolic, and stroke volume were similar between the NORMO and the HYPO test. Results of the present investigation support the hypothesis that a brief, mild exercise bout in acute normobaric hypoxia does not impair systolic or diastolic functions. Rather, it appears that stroke volume is well preserved and that systolic and early diastolic functions are enhanced by exercise in hypoxia.
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Affiliation(s)
- Sara Magnani
- Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy.,International PhD in Innovation Sciences and Technologies, University of Cagliari, Cagliari, Italy
| | - Gabriele Mulliri
- Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy.,International PhD in Innovation Sciences and Technologies, University of Cagliari, Cagliari, Italy
| | - Silvana Roberto
- Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy
| | - Fabio Sechi
- Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy
| | - Giovanna Ghiani
- Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy
| | - Gianmarco Sainas
- Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy
| | - Giorgio Nughedu
- Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy
| | - Romina Vargiu
- Department of Biomedical Sciences, University of Cagliari, Cagliari, Italy
| | - Pier Paolo Bassareo
- University College of Dublin, Mater Misericordiae University Teaching Hospital, Dublin, Ireland
| | - Antonio Crisafulli
- Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy.,International PhD in Innovation Sciences and Technologies, University of Cagliari, Cagliari, Italy
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Yuan F, Liu C, Yu S, Bian S, Yang J, Ding X, Zhang J, Tan H, Ke J, Yang Y, He C, Zhang C, Rao R, Liu Z, Yang J, Huang L. The Association Between Notching of the Right Ventricular Outflow Tract Flow Velocity Doppler Envelope and Impaired Right Ventricular Function After Acute High-Altitude Exposure. Front Physiol 2021; 12:639761. [PMID: 33868004 PMCID: PMC8047424 DOI: 10.3389/fphys.2021.639761] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Accepted: 02/26/2021] [Indexed: 01/25/2023] Open
Abstract
Introduction Pulmonary artery pressure (PAP) is increased and right ventricular (RV) function is well preserved in healthy subjects upon exposure to high altitude (HA). An increase in PAP may trigger notching of the right ventricular outflow tract Doppler flow velocity envelope (RVOT notch), which is associated with impaired RV function in patients with pulmonary hypertension. However, whether HA exposure can induce RVOT notch formation and the subsequent impact on cardiac function in healthy subjects remains unclear. Methods A total of 99 subjects (69 males and 30 females) with a median age of 25 years were enrolled in this study; they traveled from 500 to 4100 m by bus over a 2-day period. All subjects underwent a comprehensive physiological and echocardiographic examination 1 day before ascension at low altitude and 15 ± 3 h after arrival at HA. The RVOT notch was determined by the presence of a notched shape in the RVOT Doppler flow velocity envelope. The systolic PAP (SPAP) was calculated as Bernoulli equation SPAP = 4 × (maximum tricuspid regurgitation velocity)2+5 and mean PAP (mPAP) = 0.61 × SPAP+2. Cardiac output was calculated as stroke volume × heart rate. Pulmonary capillary wedge pressure (PCWP) was calculated as 1.9+1.24 × mitral E/e’. Pulmonary vascular resistance (PVR) was calculated as (mPAP-PCWP)/CO. Results After HA exposure, 20 (20.2%) subjects had an RVOT notch [notch (+)], and 79 (79.8%) subjects did not have an RVOT notch [notch (−)]. In the multivariate logistic regression analysis, the SPAP, right ventricular global longitude strain (RV GLS), and tricuspid E/A were independently associated with the RVOT notch. The SPAP, mPAP, PVR, standard deviations of the times to peak systolic strain in the four mid-basal RV segments (RVSD4), peak velocity of the isovolumic contraction period (ICV), and the peak systolic velocity (s’) at the mitral/tricuspid annulus were increased in all subjects. Conversely, the pulse oxygen saturation (SpO2), RV GLS, and tricuspid annulus plane systolic excursion (TAPSE)/SPAP were decreased. However, the increases of SPAP, mPAP, PVR, and RVSD4 and the decreases of SpO2, RV GLS, and TAPSE/SPAP were more pronounced in the notch (+) group than in the notch (−) group. Additionally, increased tricuspid ICV and mitral/tricuspid s’ were found only in the notch (−) group. Conclusion HA exposure-induced RVOT notch formation is associated with impaired RV function, including no increase in the tricuspid ICV or s’, reduction of RV deformation, deterioration in RV-pulmonary artery coupling, and RV intraventricular synchrony.
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Affiliation(s)
- Fangzhengyuan Yuan
- Institute of Cardiovascular Diseases of PLA, The Second Affiliated Hospital, Third Military Medical University (Army Medical University), Chongqing, China.,Department of Cardiology, The Second Affiliated Hospital, Third Military Medical University (Army Medical University), Chongqing, China
| | - Chuan Liu
- Institute of Cardiovascular Diseases of PLA, The Second Affiliated Hospital, Third Military Medical University (Army Medical University), Chongqing, China.,Department of Cardiology, The Second Affiliated Hospital, Third Military Medical University (Army Medical University), Chongqing, China
| | - Shiyong Yu
- Institute of Cardiovascular Diseases of PLA, The Second Affiliated Hospital, Third Military Medical University (Army Medical University), Chongqing, China.,Department of Cardiology, The Second Affiliated Hospital, Third Military Medical University (Army Medical University), Chongqing, China
| | - Shizhu Bian
- Institute of Cardiovascular Diseases of PLA, The Second Affiliated Hospital, Third Military Medical University (Army Medical University), Chongqing, China.,Department of Cardiology, The Second Affiliated Hospital, Third Military Medical University (Army Medical University), Chongqing, China
| | - Jie Yang
- Institute of Cardiovascular Diseases of PLA, The Second Affiliated Hospital, Third Military Medical University (Army Medical University), Chongqing, China.,Department of Cardiology, The Second Affiliated Hospital, Third Military Medical University (Army Medical University), Chongqing, China
| | - Xiaohan Ding
- Department of Geriatric Cardiology, Chinese PLA General Hospital, Beijing, China
| | - Jihang Zhang
- Institute of Cardiovascular Diseases of PLA, The Second Affiliated Hospital, Third Military Medical University (Army Medical University), Chongqing, China
| | - Hu Tan
- Institute of Cardiovascular Diseases of PLA, The Second Affiliated Hospital, Third Military Medical University (Army Medical University), Chongqing, China.,Department of Cardiology, The Second Affiliated Hospital, Third Military Medical University (Army Medical University), Chongqing, China
| | - Jingbin Ke
- Institute of Cardiovascular Diseases of PLA, The Second Affiliated Hospital, Third Military Medical University (Army Medical University), Chongqing, China.,Department of Cardiology, The Second Affiliated Hospital, Third Military Medical University (Army Medical University), Chongqing, China
| | - Yuanqi Yang
- Institute of Cardiovascular Diseases of PLA, The Second Affiliated Hospital, Third Military Medical University (Army Medical University), Chongqing, China.,Department of Cardiology, The Second Affiliated Hospital, Third Military Medical University (Army Medical University), Chongqing, China
| | - Chunyan He
- Institute of Cardiovascular Diseases of PLA, The Second Affiliated Hospital, Third Military Medical University (Army Medical University), Chongqing, China.,Department of Cardiology, The Second Affiliated Hospital, Third Military Medical University (Army Medical University), Chongqing, China
| | - Chen Zhang
- Institute of Cardiovascular Diseases of PLA, The Second Affiliated Hospital, Third Military Medical University (Army Medical University), Chongqing, China.,Department of Cardiology, The Second Affiliated Hospital, Third Military Medical University (Army Medical University), Chongqing, China
| | - Rongsheng Rao
- Department of Medical Ultrasonics, The Second Affiliated Hospital, Third Military Medical University (Army Medical University), Chongqing, China
| | - Zhaojun Liu
- Department of Medical Ultrasonics, The Second Affiliated Hospital, Third Military Medical University (Army Medical University), Chongqing, China
| | - Jun Yang
- Department of Medical Ultrasonics, The Second Affiliated Hospital, Third Military Medical University (Army Medical University), Chongqing, China
| | - Lan Huang
- Institute of Cardiovascular Diseases of PLA, The Second Affiliated Hospital, Third Military Medical University (Army Medical University), Chongqing, China.,Department of Cardiology, The Second Affiliated Hospital, Third Military Medical University (Army Medical University), Chongqing, China
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