Relationship between the U wave on electrocardiogram and the midmyocardium of the left ventricular wall.
- Author:
Cuntai ZHANG
1
;
Yuntian LI
;
Zaiying LU
;
Jie WU
;
Chen WANG
Author Information
- Publication Type:Journal Article
- MeSH: Action Potentials; drug effects; Animals; Anti-Arrhythmia Agents; pharmacology; Dose-Response Relationship, Drug; Electrocardiography; Endocardium; drug effects; physiology; Heart Ventricles; drug effects; Pericardium; drug effects; physiology; Rabbits; Sotalol; pharmacology; Ventricular Function
- From: Chinese Medical Journal 2002;115(4):509-512
- CountryChina
- Language:English
-
Abstract:
OBJECTIVETo investigate the relationship between the U wave on electrocardiogram and the midmyocardium in rabbit left ventricle free wall in vivo.
METHODSThe monophasic action potentials in the epicardium, midmyocardium, and endocardium of the left ventricle free wall were recorded simultaneously in 16 rabbits. The rabbits were then given an intravenous injection of Sotalol (1, 1.5 and 2.0 mg/kg) in 30 minutes intervals, and measurements were taken.
RESULTSIn the basic condition, there were no U wave on electrocardiogram. The U wave appeared after the intravenous Sotalol at 1.5 mg/kg, and the U wave became greater with increased dosage of intravenous Sotalol (2 mg/kg). The repolarization duration of the midmyocardium was prolonged longer than that of the epicardium and endocardium by Sotalol, and the repolarization duration of the epicardium coincided with the apex of the T wave, The repolarization duration of the midmyocardium coincided with the end point of the U wave.
CONCLUSIONThe U wave may originate from the delayed repolarization of the midmyocardium.
