Experimental study of the effect of autonomic nervous system on the transmural dispersion of ventricular repolarization under acute myocardial ischemia in vivo / 华中科技大学学报(医学)(英德文版)
Journal of Huazhong University of Science and Technology (Medical Sciences)
;
(6): 96-99, 2002.
Article
in English
| WPRIM
| ID: wpr-329173
ABSTRACT
The effect of the autonomic nerves on the transmural dispersion of ventricular repolarization (TDR) under acute myocardial ischemia in intact canine was investigated. Using the monophasic action potential (MAP) recording technique, MAPs of the epicardium (Epi), mid-myocardium (Mid) and endocardium (Endo) were recorded simultaneously by specially designed plunge-needle electrodes at the left ventricular free wall under acute myocardial ischemia in 12 open-chest dogs. MAPD90 and TDR among three myocardial layers as well as the incidence of the early afterdepolarization (EAD) before autonomic nervous stimulation and during autonomic nervous stimulation were compared. It was found that 10 min after acute myocardial ischemia, TDR was increased from 55 +/- 8 ms to 86 +/- 15 ms during sympathetic stimulation (P < 0.01). The TDR (53 +/- 9 ms) during parasympathetic stimulation was not significantly different from that of the control (55 +/- 8 ms) (P > 0.05). The EAD was elicited in the Mid of 2 dogs (16%) 10 min after acute myocardial ischemia, but the EAD were elicited in the Mid of 7 dogs (58%) during sympathetic stimulation (P < 0.01). It was concluded that (1) Sympathetic stimulation can increase the transmural dispersion of repolarization and induce early afterdepolarizations in the Mid under acute myocardial ischemia, which provide the opportunity for the ventricular arrhythmia developing; (2) Parasympathetic stimulation has no significant effect on the transmural dispersion of repolarization under myocardial ischemia.
Full text:
Available
Index:
WPRIM (Western Pacific)
Main subject:
Physiology
/
Autonomic Nervous System
/
Action Potentials
/
Ventricular Function
/
Myocardial Ischemia
/
Electric Stimulation
/
Heart Ventricles
/
Neuromuscular Junction
Limits:
Animals
Language:
English
Journal:
Journal of Huazhong University of Science and Technology (Medical Sciences)
Year:
2002
Type:
Article
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