| Objective: Fetal cardiac arrhythmias are common in clinic.Some serious cardiac arrhythmias can lead to fetal edema, heart failure and even death. Cardiac auscultation can only determine whether the fetal heart rate is regular, but can’t determine the nature of it. Fetal electrocardiogram are vulnerable to the interference of pregnant ecg signals, and it’s not easy to acquire the atrial activity signals. Fetal echocardiography is a recently developed new technology, which can not only judge the condition of cardiac structure and function but also detect fetal heart rhythm. Pulse doppler and M-type echocardiography can intuitively reflect the fetal atrial and ventricular time order and the relationship between the activation sequence and detect fetal heart rate according to the type.This topic further discusses the effect of doppler spectrum and M-type ultrasound in the detection of fetal heart rate through the doppler spectrum and M-type ultrasonic detection of fetal heart rate.Methods:1 The object of studyThe research objects were chosen from the pregnant women who came to the Hebei province children’s hospital inpatient and outpatient obstetrics to receive conventional ultrasound and fetal echocardiography from January 2014 to February 2015.This study randomly selected 240 cases of pregnant women aged 19 to 35 years old, and the average(26.26±2.15) years of age, gestational age16~41weeks, the average(30.10±6.22) for weeks. The fetal cardiac structure and rhythm of the heart of their fetus were normal. 240 cases of fetus in 16 cases of paroxysmal room premature beat.2 The instruments and methodsInstruments: the American Voluson E8 color doppler ultrasonic diagnostic instrument. RAB-4-8-D convex side probe, the frequency of 1.91~7.77 MHz, 4 C-D convex array probe, the frequency of 1.5~4.6 MHz, M6 C convex array plane array probe, the frequency of 2.6~7.77 MHz. Pregnant women took supine or lateral position. First the routine prenatal ultrasound examination of the fetus was carried out, and then transferred to fetal heart examination condition. The standard section used involve: fetal abdominal transverse section, four-chamber view, left and right ventricular outflow tract aspect,three-vessel-trachea view,the aorta and ductus bow section, upper and inferior vena cava long axis plane and some non-standard aspects.According to gestational age,the study was divided into three stages(16 ~ 21 weeks,22~32 weeks and33~41 weeks), a total of 240 random cases of fetus were tested, 60 cases(16~21 weeks),100cases(22~32 weeks) and 80 cases(33 ~41weeks) were tested separately. Trial for each case using fetal M-type ultrasonic spectrum, inferior vena cava, hepatic vein spectrum, left ventricular flow spectrum, superior vena cava,and aorta spectrum detection of fetal heart rate. If you took the image which could clearly reflect the atrial ventricular activity rhythm,the test is successful,and recorded the number of successful cases correspondently.In the fetus of 22 weeks gestational age or above, select normal heart rhythm,structure without cardiac malformation fetus. Check each fetal with hepatic vein spectrum, left ventricular flow spectrum measurement fetal AV conduction time(from atrium to ventricle), the VA value(the time period between ventricular contraction to the cardiac cycle and atrial contraction). And use these data for statistical analysis.For 16 cases of premature beat, clonic room with hepatic vein spectrum detection, the spectrum change was observed.Using SPSS13.0 statistical software for analysis. Compare the success rate of the 5 ways of testing via chi-square test,P<0.05.The difference was statistically significant, and then compared the groups of two,P<0.005.The difference was statistically significant; Use the hepatic vein spectrum and left ventricular flow spectrum measurement of AV and VA value by x ±S. Conduct the comparison of two methods with paired test,P<0.05 and we concluded the difference was statistically significant.Results:1 Atrioventricular rhythm detection results: in the two phases of 16 ~ 21 and 22~32 weeks, I detected 160 cases of fetus using the M-type ultrasound, hepatic vein and left ventricular flow detection. The success rate of the three kinds of methods had no statistically significant difference, and the detection rate was high. The checkout success rate differences among the three methods and inferior vena cava,superior vena cava, and aorta were statistically significant, and the detection rate of the two methods was low. A total of 80 cases of fetus of33~41weeks were detected. The success rate obtained by the hepatic vein spectrum, spectrum detection, the left ventricular inflow outflow was no statistically significant difference, and the two methods detection rates were both high.Compared with other three methods, the success rate was statistically significant.The detection rate obtained by M-type ultrasonic spectrum, superior vena cava and inferior vena cava and the ascending aorta spectrum was of no statistical significance. The success checkout rate was low.2 The measurement results of fetal cardiac conduction time:75 cases of fetus(fetal gestational age≥22weeks) were successfully measured with the two methods.The AV value of Hepatic vein spectrum measurement was(85.53± 9.34) ms,VA value was(333.1±26.42) ms, the left ventricular inflow outflow spectrum measurement of AV value was(121.59±9.47) ms, VA value was(287.6±35.73) ms.Compare the values of Hepatic vein spectrum of AV and left ventricular flow spectrum and there were obvious difference(t=26.73, P<0.05).The difference acquired by VA value comparison between Hepatic vein spectrum and left ventricular inflow outflow spectrum was statistically significant(t=10.98,P<0.05).3 16 cases of paroxysmal room premature beat fetal hepatic vein spectrum had the typical change, room contraction waves appear in advance, A waveform becames wide.Conclusions:1 M type ultrasound in the 16~32weeks of fetal atrioventricular rhythm detection rate was higher, the operation was simple, image was clear; 33 ~ 41 weeks due to the interference factors more test success rate was low.2 hepatic vein spectrum in 16~41 weeks, high success rate of detecting fetal atrioventricular rhythm. Hepatic vein blood flow and ultrasound beam direction Angle were easy to adjust to the parallel,simple operation, good quality of frequency spectrum. room wave A reverse, atrial rhythm shows especially clear. Premature diagnosis was more sensitive to room. But its measured AV value is not suitable for atrioventricular conduction time measurement.3 the left ventricular inflow outflow spectrum in 16~41 weeks,high success rate of detecting fetal atrioventricular rhythm. Left ventricular outflow section accessible inflows,the operation was simple, spectrum band narrower, the boundary was clear,Measurement of atrioventricular conduction time AV accuracy was high, measuring value was reliable, of great value to diagnosis atrioventricular block.4 Inferior vena cava spectrum, three vessels vena cava in cross section and the ascending aorta spectrum in 16~41 weeks of detecting fetal atrioven- tricular rhythm success rate was low, operation time, spectrum image quality was poor. |
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