Study of the relationship between apical rotation and apical myocardial structure in dogs by echocardiography

Abstract

Objective To detect the relationship between apical rotation and apical myocardial structure.Methods To observe the change of apical rotation,14 mongrel dogs were heated at apexes,and half and three quarter of apical wall thicknesses were destroyed according to their corresponding heating time.Ultrasonic tissue Doppler imaging was used to record the velocities of apical rotation.Computer programming was applied to calculate apical rotation according to the formulas of apical rotation calculation.Apical rotations were compared between before apical heating,half and three quarter of apical wall thicknesses destruction,respectively.Results Compared with the apical rotation before heating,apical rotation after half of apical wall destroyed decreased [(5.2±3.1)°vs (12.4±2.9)°,P＜0.001];but after three quarter of apical wall destroyed,the apical rotation increased [(7.3±3.6)°vs (5.2±3.1)°P＜0.01].Conclusions Outer part of apical myocardium was outer layer myocardium of which the damage leads to the decrease of apical rotation;inner part of apical myocardium was inner layer myocardium of which the damage leads to the increase of apical rotation to some extent. Key words: Echocardiography; Ventricular function; left ; Apical rotation