[abstract] HUMAN ECG CHANGES IN REST AND EXERCISE DURING PROLONGED EXPOSURE TO INCREASED PRESSURE BREATHING NITROGEN-OXYGEN MIXTURES.

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[abstract] HUMAN ECG CHANGES IN REST AND EXERCISE DURING PROLONGED EXPOSURE TO INCREASED PRESSURE BREATHING NITROGEN-OXYGEN MIXTURES.

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Title: [abstract] HUMAN ECG CHANGES IN REST AND EXERCISE DURING PROLONGED EXPOSURE TO INCREASED PRESSURE BREATHING NITROGEN-OXYGEN MIXTURES.
Author: Schaefer, KE; Wilson, JW; Kligfield, PD; Harvey, C
Abstract: The electrocardiogram from 10 divers participating in 4 N2-02 saturation dives were analyzed. In all cases a decline in heart rate was observed upon compression to saturation depth; a slow adaptation and return of the heart rate toward normal was observed in those dives where the depth and the environmental parameters remained constant. Whenever excursion dives were performed, the heart rate responded by decreasing on deeper excursions and increasing on upward excursions. Decompression was uniformally accompanied by a rapid increase in heart rate resulting in a significant elevation in the post-dive period. Alterations in myocardial repolarization as evidenced by Q-T interval, ST and T wave changes were observed. Development of slight right ventricular conduction delay compatible with right ventricular strain was noted in 4 of the divers during the two deepest dives to 100 and 198 feet of seawater gauge pressure (FSWG). During the latter dive, nodal rhythms were observed in one diver with multiple premature ventricular contractions occurring in another man. These observations demonstrate definite hyperbaric effects on the pacemaker activity of the heart and myocardial depolarization and repolarization. Exercise tracings were obtained during 4 saturation dives. At the highest work load of 125 watts (V02=2.5 l/min), PAC's were observed in 2 out of 3 subjects at 198 FSWG. One diver who was well trained and physically active with no history of cardiovascular symptomatology developed at 3 different test at 125 watts PVC's. However no S-T segment changes associated with myocardial ischema were noted. This is the first case of exercise induced cardiac arrhythmia observed during saturation diving.
Description: Abstract of the Undersea and Hyperbaric Medical Society, Inc. Annual Scientific Meeting held May 12-13, 1976. Carillon Hotel, Miami Beach, FL (http:www.uhms.org)
URI: http://archive.rubicon-foundation.org/5246
Date: 1976

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  • UHMS Meeting Abstracts
    This is a collection of the published abstracts from the Undersea and Hyperbaric Medical Society (UHMS) annual meetings.

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