Skip Navigation

European Heart Journal 1995 16(4):539-544;
Copyright © 1995 by the European Society of Cardiology.
This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrowRequest Permissions
Google Scholar
Right arrow Articles by ROCHE, F.
Right arrow Articles by LACOUR, J.-R.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by ROCHE, F.
Right arrow Articles by LACOUR, J.-R.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

© 1995 The European Society of Cardiology

Effects of exposure to hypoxia on the signal-averaged electrocardiogram in healthy subjects

F. ROCHE, J.-C. BARTIIÉLÉMY, R. ADAMEC*, A. GEYSSANT and J.-R. LACOUR+

University Hospital and Laboratoire de Physiologie, GIP Exercise Saint-Etienne, France;
*University Hospital Geneva, Switzerland
+University Hospital & Laboratoire de Physiologie Lyon, France

revised 18 August 1994; accepted 26 August 1994.

F. Roche, MD, Exploration Fonctionnelle, Centre Hospitalier et Universitaire Nord—-Niveau 6, F—-42055 Saint-Etienne Cedex 2, France.

Abstract

The effects of hypoxia on the signal-averaged ECG (SAECG) were investigated in 26 healthy active subjects with no suggestion of cardiac disease. The SAECG was recorded in each resting subject in normoxic and hypoxic normobaric conditions (inspired O2 fraction 20.7 vs 10.0%) which lowered resting arterial O2 saturation from 98.6 +0.6% to 77.7 ± 8%. Recordings from four subjects (three men) met the definition of abnormal late potentials at baseline; in all these subjects but one, who exhibited an improved but still abnormal QRS duration, these parameters returned to normal in hypoxic conditions. The duration of the filtered QRS was significantly reduced (from 107.6 ±13.2 to 101.6 ± 11.3 ms, P<001), the duration of the low amplitude signals in the terminal portion of the QRS <40 µ V (LAS) significantly decreased (from 26.5 ± 9.5 to 22.7 ± 7.9 ms, P<005) and the root mean square voltage in the last 40 ms (Term-RMS) increased non-significantly (from 55.8±40.2 to 69.1±38.3 µV, P=0.058). Hypoxia determined a higher (P<0.05) heart rate increase in subjects with abnormal records than in normal subjects.

These data could be related to a sympathic discharge. They suggest that: (1) variation in heart rate could affect the SAECG; (2) exposure to hypoxia improves SAECG parameters in healthy subjects, possibly related to sympathetic discharge; (3) abnormal records collected during sinus bradycardia could represent a type of false-positive expression of late potentials in young active adults.

Key Words: Signal-averaged electrocardiogram • normobaric hypoxia • ventricular late potentials


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?




Disclaimer:
Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.