Internal countershock produces myocardial damage and lactate production without myocardial ischemia in anesthetized dogs

Journal Article · Wed Apr 01 04:00:00 EST 1987 · Anesthesiology; (United States)

DOI:https://doi.org/10.1097/00000542-198704000-00005· OSTI ID:6518446

Gaba, D M; Maxwell, M S; Merlone, S; Smith, C

The global myocardial extraction of lactate was measured in 13 halothane anesthetized dogs to assess the effect of electric countershock applied directly to the heart. Seven animals received two countershocks of 30 delivered joules each, while six animals were not shocked but were atrially paced to a rate of 190-200, both with and without occlusion of the vena cava to produce a mean arterial pressure of 40-50 mmHg. All animals had substantially positive lactate extraction in the baseline state (36 +/- 10% for countershock group vs. 41 +/- 3% for pacing group). Myocardial lactate extraction reached a markedly negative nadir 2.5 min after countershock (-19 +/- 15%), but returned toward normal by 6 min (10 +/- 6%). Lactate extraction was not significantly changed from baseline in the pacing group. The relationship between changes in regional myocardial blood flow (radiolabeled microspheres) and post-countershock myocardial damage (technetium pyrophosphate uptake) was assessed in six dogs shocked as above. Mean myocardial blood flow was increased minimally immediately after countershock (0.78 +/- 0.08 ml X min-1 X g-1 vs. 1.16 +/- 0.3), but there was no difference in blood flow between damaged and undamaged tissue at either time point. The epicardial-to-endocardial ratio of blood flow was unchanged after countershock (0.97 +/- 0.05 vs. 0.99 +/- 0.08). There was no relationship between myocardial damage and either the absolute amount of blood flow after countershock (r = -0.03) or the change in blood flow compared with the pre-shock period (r = 0.01).

• Research Organization: Stanford Univ. School of Medicine, Palo Alto, CA
• OSTI ID: 6518446
• Journal Information: Anesthesiology; (United States), Journal Name: Anesthesiology; (United States) Vol. 4; ISSN ANESA
• Country of Publication: United States
• Language: English

Related Subjects

550901* -- Pathology-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ANIMALS
BIOSYNTHESIS
BLOOD FLOW
BLOOD PRESSURE
BODY
CARBOXYLIC ACID SALTS
CARDIOVASCULAR SYSTEM
DOGS
ELECTRIC SHOCK
HEART
ISOTOPE APPLICATIONS
ISOTOPES
LACTATES
MAMMALS
MICROSPHERES
MUSCLES
MYOCARDIUM
NECROSIS
ORGANS
OXYGEN COMPOUNDS
PATHOLOGICAL CHANGES
PHOSPHORUS COMPOUNDS
PYROPHOSPHATES
SYNTHESIS
TECHNETIUM ISOTOPES
TRACER TECHNIQUES
VERTEBRATES