0120 : Left ventricular mechanics at high altitude: 6 days on the top of Europe

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• 作者：Claire Maufrais¹ ; ^{claire.maufrais@hotmail.com" class="auth_mail" title="E-mail the corresponding author} ; Thomas Rupp² ; Pierre Bouzat³ ; Gré ; gory Doucende⁴ ; Samuel Verges¹ ; Sté ; phane Nottin⁵ ; Guillaume Walther⁵
• 关键词：pulmonay arterial hypertension ; hypoxia ; echocardiography ; ventricle ; mechanics
• 刊名：Archives of Cardiovascular Diseases Supplements
• 出版年：2016
• 出版时间：April 2016
• 年：2016
• 卷：8
• 期：3
• 页码：264
• 全文大小：50 K

文摘

To get insight into the underlying mechanisms of changes in left ventricular (LV) systolic and diastolic functions during several days in high-altitude hypoxia.

Methods and results

Resting evaluations of LV function and mechanics by 2D-strain echocardiography were performed on eleven subjects at sea level (SL_PRE), 3h±2h after helicopter transport to altitude (D0), at day 2 (D2), day 4 (D4) and day 6 (D6) at 4350 m and 5h±2h after return to sea level (SL_POST).

Subjects experienced acute mountain sickness (AMS) during the first days and systolic pulmonary arterial hypertension during the six days at high altitude. LV global systolic function, LV strains and LV synchrony were unchanged at high altitude. Peak twist was increased at 4350 m (p<0.05) and was normalized at SL_POST. Early filling decreased at high altitude with a nadir at D2 (SLPRE: 78±13cm.s-1; D2: 66±11cm.s-1, p<0.05) and was normalized at SL_POST. LV filling pressures index was decreased at high altitude with the minimum value obtained at D2 (SL_PRE: 4.7±1.2; D2: 3.4±0.6, p<0.05) and remained reduced at SL_POST.

Untwisting was delayed at high altitude (Percentage of untwist during isovolumic relaxation time at SL_PREvs D2: 39±31 vs 18±17%, respectively, p=0.08) and was normalized at SL_POST.

Conclusions

High-altitude exposure impaired diastolic function with the greatest effect observed at D2, concomitantly with the occurrence of AMS. The early filling impairments resulted from a decrease in LV filling pressure and a delayed LV untwisting, without changes in LV relaxation. During systole, a progressive increase in LV twist was observed from D0 to D6, probably acting as a compensatory mechanism to maintain ejection fraction and global cardiac performance during high-altitude hypoxia.

The author hereby declares no conflict of interest