The Study Of Energy Loss In Left Heart Obtained By Vector Flow Mapping In Patients With Atrial Fibrillation

Background Atrial fibrillation(AF),the most frequent among long lasting arrhythmias,may result in severe complications,including thromboembolic stroke,heart failure and higher mortality,which were associated with the remodeling of cardiac structure and function by AF.At present,a lot of research focused on the change of cardiac structure and diastolic and systolic function,while little study into intracardiac flow pattern,whose change was happening prior the aforementioned change.Therefore,there is importantly clinical significance that explores the change of intracardiac flow pattern in patients with AF.Aims The present study aims to quantify the left atrial(LA)and left ventricular(LV)flow energy loss(EL)in patients with AF in sinus rhythm and successfully sustained sinus rhythm after radiofrequency catheter ablation(RFCA)by vector flow mapping(VFM),and explores the effect on LA and LV flow pattern by AF and successful RFCA.Methods 1.The present study enrolled 54 patients with AF(AF group)who were going to take RFCA in our hospital,and 29 age-and sex-matched healthy volunteers(controls).Patients in AF group were enrolled in RFCA group who completed follow-up of all thransthoracic echocardiographic examiantions and did not suffer from reccurence of sustained atrial arrhythmias within one yeas.2.Transthoracic echocardiographic examination was performed in sinus rhythm during perioperative period within 24h to 72h in AF group,and RFCA group would accept another two examinations of transtroracic echocardiography at 3 and 6 month after operation.LA and LV structure and function parameters were evaluated by thransthoracic echocardiography.Switch to VFM configuration,two-dimensional color Doppler cineloop images were collected in the standard apical four-chamber view.Using workstation,LV EL in basal(B),middle(M)and apical(A)segment and LA EL were assessed at isovolumetric contraction phase(T1),early systolic phase(T2),late systolic phase(T3),early diastolic phase(T4)and atrial systolic phase(T5).3.The difference of general informations and two-dimentional echocardiographic parameters and EL would be analysesed between AF group and controls,RFCA group and controls,baseline,3 month and 6 month in RFC A group.Results 1.Compared with controls(29 people),except BSA and BMI,the difference of general information had not statistical significance in AF group(54 people)and RFCA group(37 people).2.AF group vs.controls,LA EL was significantly decreased at T2,T3 and T5(all P<0.01);LV EL in basal segments at every phases were significantly increased,and the same trend in every segments at T4 and T1 A,T2A(all P<0.05).3.AF group vs.controls,LVEDd,LVPW,IVS,LVMI and LVmax,LVmax were obviously elevating(P<0.01),while LVEF did not present significant difference(P=0.49);LAVImax,LAVIpre and LAVImin were significantly increasing,at the same time,LATEF and LAAEF were obviously decreasing(all P<0.001);E/A and E/e'were apprarently increasing,while A and e'were decreasing(all P<0.05).4.In RFCA group,as for LA EL,compared with baseline,it was no apparent change in 3 and 6 month at every phases(all P>0.05);while compared with conrols,it was significantly decreasing at T1 and T4 in 6 month(both P<0.05).As for LV EL,except for T2M and T3M,it was significantly decreasing in other segments and phases in 3 month compared with baseline(all P<0.05);except for T2B and T3B,there was no statistically significant difference compared with controls.5.In RFCA group,3 month vs.baseline,there was no apparent change in LV and LA structure and systolic function parameters;while E,E/A,DT were significantly decreasing(all P<0.05).6 month vs.baseline,LVEDd,LVmax,LVMI,LAVImax were obviously reducing,and LAAEF was increasing(all P<0.05).Conclusion VFM revealed obviously impaired LA EL and LV EL in patients with AF.RFCA did not recovery the change of LA EL after 6 months,meaning the sustained abnormality of LA flow pattern.LV EL was significant improvement at 3 months post RFCA,which meant that successful RFCA was able to effectively reverse the abnormality of LV flow pattern by AF...