Assessment Of Left Ventricular Systolic Function And Mechanical Synchrony Using Real-Time Three-Dimensional Echocardiography: A Clinical Study

Clinical Studies of Left Ventricular Systolic Function and Mechanical SynchronyUsing Real-Time Three-Dimensional EchocardiographyPartⅠMethodological Study Of Real Time Three-DimensionalEchocardiography In Assessing Global And Segmental Left Ventricular SystolicFunctionBackground:Recent developments with high resolution real time three-dimensionalechocardiography (RT3DE) facilitate the acquisiton of high quality images and theanalysis of global and segmental volume-time curves (VTCs).ObjectiveTo evaluate (1) the accuracy of left ventricular (LV) volume quantification usingoffline three dimensional system compared with radionuclide ventriculography inheart failure (HF), and (2) to evaluate the feasibility of direct evaluation of global andsegmental left ventricular volume by biplane method using online three-dimensionalsystem in HF, and (3) to compare the sensitivity of detecting LV systolic asynchronyby online and offline three dimensional systems.Methods and Results:Twenty HF patients underwent RT3DE, offline quantification of global LVvolume and LVEF were compared with radionuclide ventriculography. The LVvolume and LVEF were of no difference between RT3DE and radionuclide results (P> 0．05) with moderate correlation (r = 0．6847, P < 0．01) , despite the relativeinaccuracy of 2D echocardiography results (2D-EF 37．73%±7．27%, LVEF byradionuclide ventriculography 31．34±7．81, P < 0．01) . Then online(QLab 4．0) andoffline (Tomtec LV analysis CRT 1．0) quantification of global and segmental LVsystolic function were used in 20 HF patients and 20 normal subjects, the end systolictime reaching minimal segmental volume (Tmsv) for 16 segments were obtained bythe two 3D analysis system. Compared with offline multiplane 3D methods, online3DBiplane methods could rapidly quantify LV global volume and LVEF as well asoffline 3D methods in both HF patients and normal subjects (P > 0．05) . By offline 3Dsystem, the standard deviation of Tmsv (Tmsv-SD% ) and the difference between the latest Tmsv and the earliest Tmsv (Tmsv-Dif%) were higher in HF patients(for 16segments: Tmsv-SD% 6．44±3．55, Tmsv-Dif% 22．8±14．1) than normal subjects(for 16 segments: Tmsv-SD% 4．41±0．99, Tmsv-Dif% 14．97±3．44, P < 0．05) ,however, by the online QLab system, the Tmsv-SD% and Tmsv-Dif% are of nodifference in HF patients(for 17 segments: Tmsv-SD% 1．10±0．34, Tmsv-Dif% 3．91±1．01) and normal subjects (for 17 segments: Tmsv-SD% 0．83±0．22, Tmsv-Dif%2．57±0．51, P>0．05) .ConclusionBoth online and offline 3D methods could accurately evaluate LV volume andLVEF in HF patients, in which online method was more rapidly. But only offlineRT3DE system could sensitively detect the segmental LV systolic asynchrony in heartfailure patients over normal subjects. PartⅡAssessment of Left Ventricular Systolic Function and MechanicalSynchronicity in Normal Subjects Using Real Time Three DimensionalEchocardiographyBackground:Real time three-dimensional echocardiography ( RT3DE) is a novel techniquecurrently being investigated in the evaluation of left ventricular contraction patternsby analyzing global and segmental volume-time curves (VTCs). However, thephysiological time course curves of normal subjects have not been studied yet.ObjectiveTo explore the normal LV segmental volume-time changes by RT3DE over thecardiac cycle, and to get the range of Tmsv-SD% and Tmsv-Dif% in normal subjects.MethodsFifty-nine healthy subjects underwent RT3DE and the data were analyzed offlineby two independent observer. Tmsv-SD% and Tmsv-Dif% were evlatuated for all 16segments, 12 segments not including the apex, basal 6 segments and middle 6segments.ResultsTmsv% in all 16 segments were of no difference within normal subjects(16-segment Tmsv-SD% 4．25%±1．02%, Tmsv-Dif%4．79%±3．48%; 12-segmentTmsv-SD% 4．36%±1．19%,Tmsv-Dif%; basal-6-segment Tmsv-SD%4．51 %±1．42% 15．50 %±11．79 % , Tmsv-Dif% 14．60 %±3．62 % ; middle-6-segmentTmsv-SD%4．19%±1．37%, Tmsv-Dif% 11．70%±3．57%). The result of Tmsv-SD%and Tmsv-Dif % were comparable both for Interobserver and intraobservermeasurements.ConclusionThe segmental systolic motion are synchronous in normal subjects , Tmsv-SD%,Tmsv-Dif% results are low and stable in normal subjects. PartⅢAssessment Of Left Ventricular Systolic Function And MechanicalAsynchrony In Heart Failure And Ventricular Conduction Disturbances UsingReal Time Three Dimensional Echocardiography: a clinical studyBackground:Left ventricular mechanical dyssynchrony is frequently observed in chronic heartfailure patients. Volume-time curves determined by real time three-dimensionalechocardiography could be used to identify geometric and time-course changes of leftventricular segments in selected patients underwent CRT therapy. However, thepathological changes of time-course curves in isolated ventricular conductiondisturbances and in heart failure population have not been studied yet.ObjectiveTo evaluate the LV systolic asynchrony in isolated ventricular conductiondisturbances, as well as in heart failures patients with or without ventricularconduction disturbances.Methods116 patients underwent RT3DE, including 32 isolated ventricular conductiondisturbances patients (GROUP A, 17 with CLBBB, 10 with CRBBB+LAH, 5 others),44 heart failure patients with narrow QRS complex (GROUP B, 17 with ischemiccardiomyopathy, 20 with dilated cardiomyopathy and 7 with hypertension), and 40heart failure with ventricular conduction disturbances (12 CLBBB /28 non-CLBBB,18 ischemic/ 22 non-ischemic cardiomyopathy). The Tmsv-SD% and Tmsv-Dif%were compared among different groups and subgroups, and the relationship ofsegmental Tmsv% with 3D-EF, QRS interval, type of ventricular conductiondisturbances and heart diseases were evaluated within and among groupsResults1．Patients with isolated wide QRS complex have higherTmsv-SD%, higher Tmsv-Dif% and lower 3DEF(P <0．05) , especially inisolated CLBBB patients(16 segmental Tmsv-SD% 4．90±1．89 P < 0．01,Tmsv-Dif% 17．2±6．3, P< 0．01) .2．In most isolated CLBBB patients, the earliest Tmsv were found in anterior wall and post interventricular septum. Relative Lower LVEF,shorter QRS interval and worse asynchrony were found in patients withmost delayed Tmsv located in the inferior or posterior wall comparedwith those located in the anterior interventricular septum (IVS).3．In HF patients with CLBBB, Tmsv-SD% and Tmsv-Dií% werehigher than other subgroup. In all CLBBB patients, a liner correlationwas found between 3D-EF and LV systolic asynchrony determined byTmsv-SD% and Tmsv-Dif%(16 segmental Tmsv-SD% 7．47±3．85, P <0．001, Tmsv-Dif% 26．17±16．37, P < 0．01) .4．HF patients with narrow or wide QRS complex, have higherTmsv-SD% and Tmsv-Dif% than normal subjects. (16 segmentalTmsv-SD% r =-0．6216 P < 0．001, Tmsv-Dif% r =-0．5077 , P < 0．01)5．In all HF patients, a liner correlation was found between 3D-EFand LV systolic asynchrony determined by Tmsv-SD% and Tmsv-Dif%.By multiple regression analysis, LVEF determined by RT3DE was theonly independent factor of LV systolic asynchrony. (16 segmentalTmsv-SD% r =-0．4913, P < 0．0, Tmsv-Dif% r =-0．4819, P < 0．0)6．Different shapes of volume-time curves were found betweenanterior and posterior IVS, with various relationship with QRS interval,3D-EF and LV synchronicity, which indicated different role of segmentmovement between the two adjacent segments.7．In ischemic HF subgroups, the most delayed Tmsv in theposterior wall indicated a relative preserved LVEF and less obvious LVasynchrony.ConclusionLV mechanical asynchrony could be detected by RT3DE in either HF orventricular conduction disturbances patients, which were more severe in HF patientswith wide QRS complex. LVEF determined by RT3DE was the only independentfactor of LV systolic asynchrony. The reduced cardiac function and abnormalventricular conduction patterns may support a possible cause-and-effect relationshipbetween ventricular conduction disturbances and HF.