Two-dimensional Ultrasonic Examination And Analysis Of Doppler Flow Spectra Of Superior Vena Cava In Healthy Adults

Purpose: To obtain perfect pathway of examining superior vena cava(SVC) and analyze the flow spectra of SVC and investigate the changes of Doppler spectra of SVC flow with respiratory and cardiac cycles in healthy adults by two-dimensional and pulsed Doppler ultrasonography. Materials and methods: Fifty-six healthy volunteers (thirty males,twenty females,average age was 32.6 years old)without history of heart or lung diseases were selected by random. Their physical examination of the heart, lung and echocardiography were normal. We employed Acuson. 128XP110 computed sonography and selected V4c probe. Respiratory signals were recorded by Acuson heat-sensitive nasal thermistor. We detected SVC through the planes of right supraclavicular fossa, apical five-chamber and infra-xiphoid four-chamber planes respectively . The displaying rates of SVC on various planes and the depths of detection were recorded. ECG was connected simultaneously. We measured diameters of SVC and bi-lateral 1NVs and the length of SVC during respiratory cycles. Doppler spectra of SVC were obtained through the planes of right supraclavicular fossa. Results: The displaying rates of SVC through different planes were different in normal adults. The displaying rates through the planes of right 4 supraclavicular fossa, apical five-chamber and infra-xiphoid four-chamber planes were 96.43%.. 89.3 % and 82.1% respectively. The displaying rate through the plane of right supraclavicular fossa was higher than that through infra-xiphoid four-chamber plane (P<0.05) ,and was not obviously different from that ofapical five-chamber plane(P>0.05). The displaying lengths through different planes were all different. The displaying length of SVC through the plane of right supraclavicular fossa was the longest, while that through the apical five-chamber plane was the shortest. The displaying length of SVC through the plane of the infra-xiphoid four-chamber plane was between the former and the latter( 56.49?.91mm.. 22.05?. 37mm.. 28.29?. 83mm) In respiratory cycles, the measured diameters of SVC in this team through the different planes were different. During the inspiratory phase, the diameters through the planes of right supraclavicular fossa, apical five-chamber and infra- xiphoid four-chamber planes were 16.00?. 11mm.. 13.71 ?2. 34mm and 11.43 ?. 05mm respectively. During the expiratory phase, the diameters through the planes of right supraclavicular fossa, apical five-chamber and infra-xiphoid four-chamber planes were 9.41?.63mm.. 8.91?.78mm and 6.61?1. 14mm respectively. The angle between the sound beam and flow through right supraclavicular fossa plane was smaller than 10 degrees. In respiratory cycles,the direction of SVC flow was deviate from the probe,which was showed as blue laminar flow with color Doppler. The blood flow filled the lumen of SVC frilly. The spectra of SVC were made up of two bigger forward waves and a few smaller reversal waves with the pulsed wave Doppler. Forward waves were named as systole S wave and diastole D wave. Reversal waves were named as atrium contraction AR wave and ventricle contraction VR wave. The S velocities of S wave and D wave during inspiratory phase were higher than those during expiratory phase(P