Ventricular repolarization adaptation to abrupt changes in heart rate after microgravity simulation by 5-day head-down bed rest

• Type: Article in International Conference Proceedings Book
• Date: 2013

Authors

Bolea, J (Author) Other; Almeida, R (Author) FCUP; Pueyo, E (Author) Other; Laguna, P (Author) Other; Caiani, EG (Author) Other

Conference proceedings International

Title: European Space Agency, (Special Publication) ESA SP

Life in Space for Life on Earth

Aberdeen, 18 June 2012 through 22 June 2012

Indexing

Scopus - 1 Citation

Other information

Authenticus ID: P-009-69A

Abstract (EN): Microgravity exposure for long periods of time leads to body deconditioning and it increases the risk of experiencing life-threatening arrhythmias. The study of ventricular repolarization dependence on heart rate has been used to stratify patients according to their arrhythmic risk. The QTp adaptation to HR changes is characterized by M90 (90% of the adaptation). The QTp=HR, after compensation for the adaptation lag, is modeled using a set of regression functions (a, kind of slope of relationship). Subjects with lower orthostatic tolerance time showed a non significant decrease in the adaptation lag (M90 from 148 to 108 beats), which may be due to an extra deconditioning in the sympathovagal response. Nevertheless an increase in the QTp=HR adaptation lag (M90 from 108 to 117 beats with a p = 0.06) and a significant reduction in the slope (a from 0.53 to 0.35 with a p < 0.005), which in previous studies have been correlated with an increased arrhytimic risk, were observed for subjects with higher orthostatic tolerance time. © 2013 European Space Agency.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 5