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Objective:To explore the changes of myocardial strain mechanics in healthy rabbits in the physiological condition by using speckle tracking echocardiography (STE) combined with adenosine stress.Methods:Twenty healthy rabbits underwent STE both at rest and during adenosine stress. The dynamic original images of 3 consecutive cardiac cycles of the standard views from the left ventricular (LV) short axis and apical long axis were acquired and analyzed by the Echo PAC workstation. The procedure was performed to obtain LV global longitudinal peak strain, global circumferential peak strain, and global radial peak strain both at rest and during adenosine stress.Results:There were no significant differences in heart rate and LV structural and functional parameters between baseline and adenosine stress ( P>0.05). After adenosine stress, LV global longitudinal peak strain and global circumferential peak strain increased significantly when compared with those at rest ( P<0.001), while LV global radial peak strain did not change significantly( P>0.05). Conclusions:Adenosine stress echocardiography combined with STE can be used to evaluate the characteristics of myocardial strain mechanics in rabbits in the physiological condition. This research provides reference value for the application of adenosine stress echocardiography in rabbit models with cardiovascular disease in future.
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Objective To evaluate the changes of left atrial (LA)functions in patients with constrictive pericarditis (CP)after pericardiectomy by two-dimensional speckle tracking echocardiography (STE).Methods A total of 41 patients with CP underwent echocardiography before and after pericardiectomy.The procedure was performed to obtain global LA longitudinal strain,the septal and lateral walls'longitudinal strain,including peak negative strain (NS),peak positive strain (PS),and total strain (TS),using speckle tracking echocardiography.Thirty-five healthy volunteers were recruited as controls. Results After pericardiectomy,global LA peak negative strain and total strain of CP increased significantly (P 0.05).And three components of LA longitudinal strain were still lower than normal (P <0.005).LA lateral wall's total strain,peak positive strain and peak negative strain improved apparently after pericardiectomy (P <0.005),only peak negative strain increased in LA septum (P < 0.01 ).Conclusions In the early postoperative period,LA reservoir and contractile function presented significant improvements,even notable in the lateral area when compared with septum.However,all three parts of LA function were still lower than normal.STE can regionally estimate LA functions in patients with CP after pericardiectomy.