TY - JOUR
T1 - Effects of hypobaric hypoxia exposure at high altitude on left ventricular twist in healthy subjects
T2 - Data from HIGHCARE study on Mount Everest
AU - Osculati, Giuseppe
AU - Revera, Miriam
AU - Branzi, Giovanna
AU - Faini, Andrea
AU - Malfatto, Gabriella
AU - Bilo, Grzegorz
AU - Giuliano, Andrea
AU - Gregorini, Francesca
AU - Ciambellotti, Francesca
AU - Lombardi, Carolina
AU - Agostoni, Piergiuseppe
AU - Mancia, Giuseppe
AU - Parati, Gianfranco
PY - 2016/6/1
Y1 - 2016/6/1
N2 - Aims Previous studies investigating the effect of hypoxia on left ventricle focused on its global function, an approach that may not detect a selective dysfunction of subendocardial layers that are most sensitive to an inadequate oxygen supply. In the HIGHCARE study, aimed at exploring the effects of high altitude hypoxia on multiple biological variables and their modulation by an angiotensin receptor blocker, we addressed the effects of hypobaric hypoxia on both systolic and diastolic left ventricular geometry and function, focusing on echocardiographic assessment of left ventricle twist to indirectly examine subendocardial left ventricular systolic function. Methods and results In 39 healthy subjects, physiological and echocardiographic variables, including left ventricular twist and a simplified torsion-To-shortening ratio (sTSR), were recorded at sea level, at 3400 m, and at 5400 m altitude (Mount Everest base camp). Both left ventricular twist and sTSR were greater at 5400 m than at sea level (12.68 vs. 9.68 and 0.285 vs. 0.202, P <0.05 for both), were linearly related to the reduction in arterial oxygen partial pressure (P <0.01 for both), and were associated with significant changes in LV dimensions and contractility. No effects of angiotensin receptor blockade were observed on these variables throughout the study. Conclusion Our study, for the first time, demonstrates an increase in left ventricular twist at high altitude in healthy subjects exposed to high altitude hypoxia, suggesting the occurrence of subendocardial systolic dysfunction in such condition.
AB - Aims Previous studies investigating the effect of hypoxia on left ventricle focused on its global function, an approach that may not detect a selective dysfunction of subendocardial layers that are most sensitive to an inadequate oxygen supply. In the HIGHCARE study, aimed at exploring the effects of high altitude hypoxia on multiple biological variables and their modulation by an angiotensin receptor blocker, we addressed the effects of hypobaric hypoxia on both systolic and diastolic left ventricular geometry and function, focusing on echocardiographic assessment of left ventricle twist to indirectly examine subendocardial left ventricular systolic function. Methods and results In 39 healthy subjects, physiological and echocardiographic variables, including left ventricular twist and a simplified torsion-To-shortening ratio (sTSR), were recorded at sea level, at 3400 m, and at 5400 m altitude (Mount Everest base camp). Both left ventricular twist and sTSR were greater at 5400 m than at sea level (12.68 vs. 9.68 and 0.285 vs. 0.202, P <0.05 for both), were linearly related to the reduction in arterial oxygen partial pressure (P <0.01 for both), and were associated with significant changes in LV dimensions and contractility. No effects of angiotensin receptor blockade were observed on these variables throughout the study. Conclusion Our study, for the first time, demonstrates an increase in left ventricular twist at high altitude in healthy subjects exposed to high altitude hypoxia, suggesting the occurrence of subendocardial systolic dysfunction in such condition.
KW - High Altitude
KW - Hypobaric Hypoxia
KW - Left Ventricular Twist And Torsion
KW - Subendocardial Left Ventricle Function
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U2 - 10.1093/ehjci/jev166
DO - 10.1093/ehjci/jev166
M3 - Article
AN - SCOPUS:84978968113
VL - 17
SP - 635
EP - 643
JO - European Heart Journal Cardiovascular Imaging
JF - European Heart Journal Cardiovascular Imaging
SN - 2047-2404
IS - 6
ER -