[abstract] MECHANISM OF DECREASED CORONARY AND SYSTEMIC BLOOD FLOW DURING HYPERBARIC OXYGENATION.

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[abstract] MECHANISM OF DECREASED CORONARY AND SYSTEMIC BLOOD FLOW DURING HYPERBARIC OXYGENATION.

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Title: [abstract] MECHANISM OF DECREASED CORONARY AND SYSTEMIC BLOOD FLOW DURING HYPERBARIC OXYGENATION.
Author: Savltt, MA; Elbeery, JR; Owen, CH; Rankin, JS; Camporesi, EM
Abstract: U.S.A. It is well known that hyperbaric oxygenation (HBO) decreases coronary blood flow (CBF) and cardiac output (CO), but the mechanism has not been defined. In order to determine whether this is a primary myocardial phenomenon, 10 chronically instrumented conscious dogs were studied during pharmacologic autonomic blockade. Left ventricular (LV) volume was measured with ultrasonic transducers, LV transmural pressure with micromanometers, CBF with Doppler flow probes, and coronary A-CS02 difference ([A-CS]D02) was calculated from direct LV and coronary sinus (CS) sampling. Data were recorded during control conditions and during multiple partial vena caval occlusions, at 1 ATA breathing air, and at 3 ATA on 100% 02. Oxygen was administered at pressure with a head-tent assembly. At 3 ATA Pa02 increased from 86±5 to 1374±201 mmHg (means±SD), while PaC02 and pH values were not statistically different. At 3 ATA, arterial 02 content increased from 13±4 vol% to 17±1 vol%, CS 02 content increased from 4±0 vol% to 10±1 vol%, CO decreased by 21±14%, CBF fell by 17±10%, and myocardial 02 consumption (MV02) decreased by 11±6% (all p<.05); [A-CS]D02 was unchanged (p=.10). In these autonomically blocked animals, HR did not decrease significantly at 3 ATA (from 112±19 to 106±22 bpm). Intrinsic myocardial function, as measured by the stroke work-end diastolic volume relationship 1, and myocardial energetics, as determined by the linear relationship between total myocardial Oxygen consumption and total mechanical energy expenditure (LV stroke work + LV pressure-volume product)2 were both unchanged from 1 ATA to 3 ATA 02 (p>.20). Thus, the diminished CBF and CO with HBO do not appear to be associated with primary alterations in myocardial energetic function. 1. Glover, D.D., et al.: Circulation, 1985; 71:994-1009. 2. Maier, G.W., et al.: Circulation, 1988; 78(Suppl 2):266.
Description: Abstract of the Undersea and Hyperbaric Medical Society, Inc. Annual Scientific Meeting held 6-11 June 1989. Hawaiian Regent Hotel, Honolulu, Hawaii, USA (http://www.uhms.org)
URI: http://archive.rubicon-foundation.org/6689
Date: 1989

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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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