Three-dimensional Speckle Tracking Imaging For Assessing Left Atrial Function In Paroxysmal Atrial Fibrillation Patients With Hypertension

Objective: To measure the left atrial volume,strain,and synchronization of patients in paroxysmal atrial fibrillation with and without hypertension by three-dimensional speckle tracking imaging(3D-STI),and investigate the changes of left atrial function.Methods: A total of 71 patients with paroxysmal atrial fibrillation(PAF)were selected,of which 35 were paroxysmal atrial fibrillation with hypertension group(PAF-HT(+)),36 were paroxysmal atrial fibrillation group(PAF-HT(-)),according to the left atrial diameter index(LAI),36 patients in PAF-HT(-)were further divided into the left atrial non-enlarged group(LAI ? 2)and the left atrial enlarged group(LAI >2).And 36 healthy volunteers who were roughly matched in gender and age were selected as the control group.Body surface area(BSA)was calculated from height and weight.Two-dimensional echocardiography was used to measure the left atrial diameter(LAD),left ventricular end-diastolic diameter(LVEDd),inter ventricular septum(IVS),and left ventricular posterior wall(LVPW),biplane Simpson's method to measure left ventricular ejection fraction(LVEF),calculate left ventricular mass(LVM)and left ventricular mass index(LVMI),LVM = 0.8×1.04×[(IVS+LVPW+LVDd)3-LVDd3]+0.6,LVMI=LVM/BSA.Pulse Doppler was used to measure the early diastolic(E)and late diastolic(A)transmitral valve peak velocities,and E/A was calculated.Tissue Doppler was used to measure the early diastolic(Em)tissue velocity of the mitral valve annulus,and calculated E/Em.Collect full-volume three-dimensional images to obtain 3D-STI parameters: maximal left atrial volume(LAVmax),minimal left atrial volume(LAVmin),and pre-atrial contraction volume(LAVpa);global longitudinal strain(GLS)and global circumferential strain(GCS);peak time of longitudinal strain(TLS)and peak time of circumferential strain(TCS).Calculate maximal left atrial volume index(MaxLAVi),minimal left atrial volume index(MinLAVi),and pre-atrial contraction volume index(PaLAVi),LAVi = LAV/BSA;left atrial ejection fraction(LAEF),active left atrial emptying fraction(a-LAEF)and passive left atrial emptying fraction(p-LAEF);standard deviation of longitudinal strain peak time(TLS-SD)and standard deviation of circumferential strain peak time(TCS-SD).The differences in left atrial function betweenthe three groups were analyzed and compared.Results:(1)Compared with the control group,the LAD of PAF-HT(+)and PAF-HT(-)increased,and the LAD was higher in PAF-HT(+)than in PAF-HT(-)(P<0.05).(2)IVS,LVPW,E/Em,and LVMI in the group of PAF-HT(+)were higher than those in the control group and PAF-HT(-),and the E/A was lower than those in the control and PAF-HT(-).The differences were statistically significant(P<0.05).(3)The left atrial volume index(MaxLAVi,MinLAVi,PaLAVi)of the PAF-HT(-)and PAF-HT(+)were higher than those of the control group,and the above indexes increased more significantly in PAF-HT(+)group(P<0.05).(4)Compared with the control group,the LAEF,a-LAEF,and p-LAEF in the PAF-HT(-)and PAF-HT(+)were reduced,and the LAEF of PAF-HT(+)group was lower than that in PAF-HT(-).The differences were statistically significant(P<0.05);there were no statistically significant differences in a-LAEF and p-LAEF between the PAF-HT(+)and PAF-HT(-)(P>0.05).(5)Compared with the control group,the PAF-HT(+)and PAF-HT(-)had lower GLS and GCS,and the standard deviation of strain peak time increased(P<0.05);Compared with the control group,GLS and GCS in PAF-HT(+)decreased,and the standard deviation of strain peak time increased(P<0.05).(6)The left atrial non-enlarged group and the left atrial enlarged group had lower GLS and GCS than the control group,and the differences were statistically significant(P<0.05),but the left atrial non-enlarged group and the enlarged group were not statistically significant(P>0.05).Compared with the control group,TLS-SD and TCS-SD in the left atrial enlargement group increased,and the difference was statistically significant(P<0.05).Conclusions: The left atrial function of patients with paroxysmal atrial fibrillation decreased,and the degree of impaired left atrial function was significantly different in patients with and without hypertension.Among them,patients with hypertension had more severe left atrial function than patients without hypertension.When the left atrial geometry is normal in PAF patients,the left atrial function is already impaired.3D-STI can accurately and sensitively analyze left atrial volume,left atrial wall strain and synchronization of patients with atrial fibrillation,quantitatively evaluate changes in left atrial function,and provide a basis for clinical diagnosis and treatment.