scholarly journals Preliminary Study of Right Ventricular Dyssynchrony Under High-Altitude Exposure: Determinants and Impacts

2020 ◽  
Vol 11 ◽  
Author(s):  
Yuanqi Yang ◽  
Chuan Liu ◽  
Jingdu Tian ◽  
Xiaohan Ding ◽  
Shiyong Yu ◽  
...  
Keyword(s):  
Right Ventricular ◽  
High Altitude ◽  
Ventricular Dyssynchrony ◽  
Altitude Exposure ◽  
Exposure Determinants ◽  
Preliminary Study

Reversibility of electrophysiological changes induced by chronic high-altitude hypoxia in adult rat heart

2002 ◽  
Vol 282 (4) ◽  
pp. H1452-H1460 ◽  
Author(s):  
C. Chouabe ◽  
J. Amsellem ◽  
L. Espinosa ◽  
P. Ribaux ◽  
S. Blaineau ◽  
...  
Keyword(s):  
Right Ventricular ◽  
High Altitude ◽  
Current Density ◽  
Ventricular Hypertrophy ◽  
Right Ventricular Hypertrophy ◽  
Heart Weight ◽  
Altitude Hypoxia ◽  
Altitude Exposure ◽  
High Altitude Hypoxia ◽  
The Right

Recent studies indicate that regression of left ventricular hypertrophy normalizes membrane ionic current abnormalities. This work was designed to determine whether regression of right ventricular hypertrophy induced by permanent high-altitude exposure (4,500 m, 20 days) in adult rats also normalizes changes of ventricular myocyte electrophysiology. According to the current data, prolonged action potential, decreased transient outward current density, and increased inward sodium/calcium exchange current density normalized 20 days after the end of altitude exposure, whereas right ventricular hypertrophy evidenced by both the right ventricular weight-to-heart weight ratio and the right ventricular free wall thickness measurement normalized 40 days after the end of altitude exposure. This morphological normalization occurred at both the level of muscular tissue, as shown by the decrease toward control values of some myocyte parameters (perimeter, capacitance, and width), and the level of the interstitial collagenous connective tissue. In the chronic high-altitude hypoxia model, the regression of right ventricular hypertrophy would not be a prerequisite for normalization of ventricular electrophysiological abnormalities.

scholarly journals Changes in Subendocardial Viability Ratio With Acute High-Altitude Exposure and Protective Role of Acetazolamide

Hypertension ◽  
2013 ◽  
Vol 61 (4) ◽  
pp. 793-799 ◽  
Author(s):  
Paolo Salvi ◽  
Miriam Revera ◽  
Andrea Faini ◽  
Andrea Giuliano ◽  
Francesca Gregorini ◽  
...  
Keyword(s):  
High Altitude ◽  
Protective Role ◽  
Altitude Exposure ◽  
Subendocardial Viability Ratio

Reduction of ICa,Land Ito1Density in Hypertrophied Right Ventricular Cells by Simulated High Altitude in Adult Rats

1997 ◽  
Vol 29 (1) ◽  
pp. 193-206 ◽  
Author(s):  
Christophe Chouabe ◽  
Leon Espinosa ◽  
Pierre Megas ◽  
Abderrazak Chakir ◽  
Oger Rougier ◽  
...  
Keyword(s):  
Right Ventricular ◽  
High Altitude ◽  
Adult Rats ◽  
Ventricular Cells ◽  
Simulated High Altitude

scholarly journals Mechanisms of Memory Dysfunction during High Altitude Hypoxia Training in Military Aircrew

2016 ◽  
Vol 23 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Daniel A. Nation ◽  
Mark W. Bondi ◽  
Ellis Gayles ◽  
Dean C. Delis
Keyword(s):  
High Altitude ◽  
Situational Awareness ◽  
Neuropsychological Testing ◽  
Memory Retention ◽  
Memory Encoding ◽  
Memory Dysfunction ◽  
Critical Window ◽  
Altitude Exposure ◽  
Life Saving ◽  
Mechanisms Of Memory

AbstractObjectives: Cognitive dysfunction from high altitude exposure is a major cause of civilian and military air disasters. Pilot training improves recognition of the early symptoms of altitude exposure so that countermeasures may be taken before loss of consciousness. Little is known regarding the nature of cognitive impairments manifesting within this critical window when life-saving measures may still be taken. Prior studies evaluating cognition during high altitude simulation have predominantly focused on measures of reaction time and other basic attention or motor processes. Memory encoding, retention, and retrieval represent critical cognitive functions that may be vulnerable to acute hypoxic/ischemic events and could play a major role in survival of air emergencies, yet these processes have not been studied in the context of high altitude simulation training. Methods: In a series of experiments, military aircrew underwent neuropsychological testing before, during, and after brief (15 min) exposure to high altitude simulation (20,000 ft) in a pressure-controlled chamber. Results: Acute exposure to high altitude simulation caused rapid impairment in learning and memory with relative preservation of basic visual and auditory attention. Memory dysfunction was predominantly characterized by deficiencies in memory encoding, as memory for information learned during high altitude exposure did not improve after washout at sea level. Retrieval and retention of memories learned shortly before altitude exposure were also impaired, suggesting further impairment in memory retention. Conclusions: Deficits in memory encoding and retention are rapidly induced upon exposure to high altitude, an effect that could impact life-saving situational awareness and response. (JINS, 2017, 23, 1–10)

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