Clinical Study Of Atrial Volume Tracking Technique Combined With Tissue Doppler Imaging On Atrial Volume And Synchronal Changes In Patients With Constrictive Pericarditis

Object:Constrictive pericarditis(CP)is a pericardial disease in which chronic inflammation causes thickening and calcification of the pericardium,resulting in restricted diastolic filling of the ventricles.Tuberculosis has been the leading cause of CP worldwide in the past.With the introduction of cardiac surgery and chest radiotherapy,the clinical spectrum of CP in developed countries has changed and TB remains the main cause of CP in developing countries.The clinical manifestations of CP are mainly bilateral lower limb edema,liver stasis,peritoneal effusion and abdominal distention.CP is easily misdiagnosed and missed clinically,and its course varies,with most having a chronic course.Echocardiography is currently the first choice in the diagnosis of CP.2D echocardiography can detect pericardial thickening,calcification and restricted ventricular diastolic motion,M-mode echocardiography can observe the "septal shudder" sign,and pulse doppler can detect changes in mitral and tricuspid flow spectra with respiration,as well as hepatic venous regurgitation and the rate of respiratory collapse of the inferior vena cava.Chronic CP often presents clinically with an enlarged left atrium,or even biventricular enlargement;and as CP progresses,there is a high incidence of atrial fibrillation in patients with constrictive pericarditis.Structural and functional changes in the atrium,such as atrial enlargement and the development of atrial fibrillation,are predictors of adverse cardiovascular events and affect patients’ quality of life,making surgery more difficult.Therefore,in this study,the atrial volume tracking technique was applied to investigate the left and right atrial volumes and functional changes in CP patients,as well as the tissue doppler technique was applied to evaluate atrial electric-mechanical activity conduction and intra-and inter-atrial asynchronous motion in CP patients,and to investigate the correlation between atrial volumes and atrial synchrony changes in CP patients.Method:Twenty-three patients with clinically diagnosed and surgically confirmed CP attending our hospital and Beijing Fu Wai Hospital from May 2018 to December 2021 were collected as the experimental group,and 23 age-matched healthy individuals were collected as the control group during the same period.The AVT technique was used to obtain the left and right atrial volume-time curves in the apical four-chamber and two-chamber heart views,and to obtain the left and right atrial volume indices in each time phase using body surface area correction,and to further calculate the functional parameters of the atria in each time phase.The atrial electrical-mechanical coupling time(P-A)was measured using the TDI technique in the apical fourchamber cardiac view at the lateral left atrial and septal side at the level of the mitral annulus and the lateral right atrial at the level of the tricuspid annulus,and the measured P-A time was used to further calculate the left intra-atrial asynchrony(TLA),the right intra-atrial asynchrony(TRA),and the asynchrony between the two cardiac chambers(TL-R).All the above parameters were taken as the average of three cardiac cycles.Results:Compared to the control group,the volumetric parameters:left and right atrial volume indices(LAVI,RAVI)in each temporal phase were significantly increased and functional parameters in each temporal phase were reduced in both left and right atria in the CP group,with statistically significant differences(P<0.05).The atrial electrical-mechanical coupling time(P-A)was prolonged in the CP group compared to the control group,and the intra-and interatrial asynchrony in the CP group(TLA,TRA,and TL-R)increased in the CP group compared to the control group,with statistically significant differences(P<0.05).Pearson correlation analysis showed that the correlation between changes in atrial electro-mechanical conduction parameters,synchrony and changes in atrial volumes was not significant in the CP group(P>0.05).Conclusion:The left and right atria of CP patients underwent structural,functional and electrical remodeling,which were manifested as increased atrial volume,decreased ejection fraction,and delayed atrial electromechanical conduction.AVI and TDI techniques can accurately evaluate the changes in left and right atrial volume and function as well as the changes in atrial synchronization in patients with CP.