| Objective: To evaluate left atrial function and study its relationship withthe left ventricular function in patients with dilated cardiomyopathy and thosewith hypertrophic cardiomyopathy by the application of the single cardiaccycle real-time three-dimensional echocardiography (sRT-3DE).Methods:1Subjects: This study presented twenty healthy volunteers as subjects, whohad no history of hypertension and heart disease in the past, and there was noheart disease found in laboratory examination, ultrasound, ECG exam andphysical examinations. This group involved twenty patients (12males and8females), with an average age of (54.76±16.21) years; twenty patients were inthe DCM group. All of them received treatments in our hospital from October2010to April2012and were diagnosed with sinus heart rate, exclusive of therheumatic heart disease, conge-nital heart disease, ischemic cardiomyopathyand other cardiovascular diseases. It involved twenty patients (11males and9females), with an average age of (58.80±18.92)years; The HCM groupscreened twenty patients (14males and6females), with an average age of(53.71±14.12)years, who received treatment in our hospital from October2010to April2012. All of the cases were diagnosed with sinus heart rate andrheumatic heart disease, congenital heart disease, ischemic cardiomyopathyand other cardiovascular diseases were excluded.2Apparatuses and methods: Acuson SC2000, the color doppler ultrasonicdiagnostic apparatus, was employed with the adult cardiac probe of4Z1c,frequency of1~4.0MHz, frame rate>20volume/s, and depth of16cm; grayscale three-dimensional fan angle was90×90degrees. Application of sRT-3DE to measure the function of the left heart:①Imageacquisition: The patients had left lateral decubitus and were connected to theECG; then the probe was placed on the apex and the standard apical fourchamber view was obtained; the gain was adjusted until a clear image wasobtained; press the "4D" button on the display, and it was displayed on thescreen that apical four chamber view, three chamber view and left ventricularshort axis view formed three orthogonal planes; the right side of srceenshowed four heart cavity volume image; all the targets should be covered inthe sampling volume by adjusting the direction of sound beams; press thecollecting key to obtain the images of three consecutive heartbeat cycle, andthen repeat the steps to collect the left ventricular image of sRT-3DE in aheartbeat cycle.②The data processing: The left ventricular4D analysissoftware was employed, and the intima of left ventricular end-systolic orend-diastolic was automatically identified by software according to the ECG;adjust it manually for more suitable position. Their left ventricularend-systolic volume (LVESV),end-diastolic volume (LVEDV) and ejectionfraction (LVEF) were obtained and the time-volume curves of left ventricularwere automatically generated by sRT-3DE. Left atrial function parameterswere obtained in the apical four chamber view, two chamber view and threechamber view plane by manual when the endocardial surface could be shownmost clearly. Then software could automatically generate the relatedparameters like LAVmax, LAVmin and LVEF as well as the time-volumecurve of left atrium. In2D mode, left ventricular longitudinal and fourchamber view were obtained and three consecutive heartbeat cycle image wasstored, to obtain the parameters: left atrial maximal anteroposterior diameter(LAD) and left ventricular end diastolic maximum anteroposterior diameter(LVDD). The method of Simpson's was used to obtain left atrial maximumvolume (LAVmax), minimum volume (LAVmin) and left ventricular ejectionfraction (LVEF). Mitral valve ring movement spectrum was measured in DTImode to get a peak velocity of early diastole of mitral valve (E '); samplingvolume was placed at mitral valve to measure forward flow peak velocity of early diastole of mitral valve (E) in PWD mode, and then E/E 'value wascalculated.Results:1DCM group(1) Compared with control group, there were changes in left atrial function;the difference was statistically significant (P <0.05). It was shown that thefunctions of the conduit and the auxiliary pump were reduced and savingfunction was enhanced.(2) Compared with control group, left ventricular systolic and diastolicfunctions were both reduced with significant reduction in the systolic function;the difference was statistically significant (P <0.05); the change in left atrialfunction was correlated to decrease in left ventricular diastole.2HCM group(1) Compared with control group, there were changes in left atrial function;the difference was statistically significant (P <0.05). It was shown thatconduit function was reduced while saving function and auxiliary pumpfunction were enhanced.(2) Compared with control group, there was no significantly statisticaldifference in left ventricular systolic function in the DCM group (P>0.05).The reduction in diastolic function of the DCM group was correlatd with leftatrial function (P <0.05).3There was significantly statistical difference in the change of left atrialfunction between HCM and DCM group, which showed that auxiliary pumpfunction was enhanced while the conduit function was reduced in left atriumin HCM group; the conduit function and the auxiliary pump function of leftatrium were all reduced in the DCM group; the saving functions of both weresignificantly enhanced with a more significant function in DCM group.4There was significant correlation between parameters of LAVmax measuredby2DE and sRT-3DE (P<0.01).Conclusions:1The conduit function and auxiliary pump function in left atrium were reduced in the DCM group while the savings function was increased. Thesaving function and auxiliary pump function of the HCM group wereincreased while the conduit function was reduced. There was significantcorrelation between reduced left atrial function and changed left ventriculardiastolic function in both groups．2There was significant correlation between parameters of LAVmax measuredby2DE and sRT-3DE (P<0.01). |
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