3D printing technique applied in vaginoplasty: A case report.

Background: We present the first case report of the treatment of congenital vaginal atresia by 3D-printed patient-specific vaginal scaffold from China. Case presentation: A 17-year-old female patient was referred to our department for treatment of congenital vaginal atresia and complications arising from previous failed operations. Pelvic examination was conducted to understand the morphological characteristics and severity of stenosis, and based on which we designed our prototypes of vaginal scaffold using software UG NX10.0. We finally obtained our patient-specific mold, which was 50 mm in length, 28 mm in diameter, 2 mm of thickness with a whole weight of 7.6 g, and it was made of polycaprolactone. After removing scar tissues caused by vaginal stenosis, an 8 cm long artificial tunnel was created, and then the polycaprolactone (PCL) vaginal mold was placed and sutured. The patient had no discomfort after surgery and was discharged 3 days after the surgery. Follow-up for 1 year after surgery, through hysteroscopy and colposcopy, it was found that the cervix was smooth, the vaginal wall was covered with stratified squamous epithelium, and the vaginal wall was soft and lubricated, which was close to a normal vagina. The incompletely absorbed mold was taken out one year after the operation. Hysteroscopy and colposcopy were performed one year and two years after the mold was taken out. The vagina was unobstructed and the length was about 12 cm. The appearance of the vaginal wrinkles was normal. The patient's quality of sexual life was good. Conclusion: Our team tried to treat congenital vaginal atresia by 3D-printed patient-specific vaginal scaffold, which can effectively reduce patient complications and reduce patient pain. Through long-term follow-up, we found that this technique has achieved favorable results and improved the patient's quality of sexual life.

SUCCESSFUL RESOLUTION OF NUTCRACKER SYNDROME WITH 3D PRINTED PEEK EXTRAVASCULAR STENT IN AN ADOLESCENT BOY.

Three-dimensional printed polyetheretherketone (PEEK) extravascular stent was applied to treat a 14-year-old boy with nutcracker syndrome. Digital subtraction angiography revealed a segment of the left renal vein (LRV) with reduced contrast filling immediately before its inflow into the inferior vena cava, and high-pressure gradient. The three-dimensional reconstruction model demonstrated that the LRV and the duodenum were contracted at the aortomesenteric angle, resulting in LRV compression from the abnormal high-level duodenal compartment. When duodenum courses between the abdominal aorta and superior mesenteric artery (duodenal interposition), the LRV entrapment occurs even at <90 aortomesenteric degrees. Three-dimensional printed PEEK extravascular stent was chosen to elevate the superior mesenteric artery and lower the duodenum position, thus relieving LRV compression. This extravascular application has significant advantages over open surgery, endovascular stenting and artificial vessel procedures with expanded polytetrafluoroethylene. It provides better cellular vitality by ensuring soft tissue proliferation. By reducing external acceleration and centrifugal force, a three-dimensional printed PEEK extravascular stent reduces adverse side effects. Such a stent has a distinctive personalized design, good stiffness, and durability that allows blood vessel growth, preventing stent migration and thrombosis. Therefore, it is suitable for both adult and pediatric patients. According to the abdominal ultrasound and multi-slice computed tomography scan, the postoperative follow-up results were satisfactory one year after surgery. The patient felt well, the blood flow in the LRV was not obstructed, and the blood flow velocity was average. The external stent was in place.

Preliminary application of three-dimensional printing in congenital uterine anomalies based on three-dimensional transvaginal ultrasonographic data.

BACKGROUND: The three-dimensional (3D) printing technology has remarkable potential as an auxiliary tool for representing anatomical structures, facilitating diagnosis and therapy, and enhancing training and teaching in the medical field. As the most available diagnostic tool and it is routinely used as the first approach in diagnosis of the uterine anomalies, 3D transvaginal ultrasonography (3D-TVS) has been proposed as non-invasive "gold standard" approach for these malformations due to high diagnostic accuracy. Despite holding promise of manufacturing 3D printed models based on 3D-TVS data, relevant reports about 3D-TVS derived gynecological 3D printing haven't been reported to the best of our knowledge. We found an opportunity to explore the feasibility of building 3D printed models for the abnormal uterus based on the data acquired by 3D-TVS. METHODS: The women suspected with congenital uterine anomalies (CUAs) were enrolled in the study. The diagnose of CUAs were made by 3D-TVS scanning and further confirmed under the hysteroscopy examination. One volunteer with normal uterus was enrolled as control. All subjects underwent 3D-TVS scanning for 3D printing data collection. Acquired images were stored and extracted as DICOM files, then processed by professional software to portray and model the boundary of the uterine inner and outer walls separately. After the computer 3D models were constructed, the data were saved and output as STL files for further surface restoration and smoothing. The colors of endometrium and uterine body were specified, respectively, in the print preview mode. Then the uncured photosensitive resin was cleaned and polished to obtain a smooth and transparent solid model after printed models were cooled down. RESULTS: 3D printing models of normal uterus, incomplete septate uterus, complete septate uterus, uterus didelphys and unicornuate uterus were produced on ultrasonographic data of 3D-TVS. CONCLUSIONS: Our research and practice made the first try in modeling CUAs successfully based on ultrasonographic data entirely, verifying that it's a feasible way to build 3D printed models of high-quality through 3D-TVS scanning.

A minimally invasive alternative for the treatment of nutcracker syndrome using individualized three-dimensional printed extravascular titanium stents.

BACKGROUND: This study was designed to evaluate the clinical and radiographic outcomes of patients with nutcracker syndrome (NCS) who were treated with three-dimensional printing (3DP) extravascular titanium stents (EVTSs). The 3DP EVTS was expected to release the hypertension of the left renal vein (LRV) produced by its compression between the superior mesenteric artery (SMA) and the aorta without causing any complications. METHOD: The pre-operative kidney model of each patient was printed out to enable surgical planning. After that, the EVTS was designed based on the LRV's primitive physiologic structure using computer-aided design software, and each stent was printed out with a precision setting of 20 µm. Seventeen patients who had been suffering from NCS underwent laparoscopic 3DP EVTS placement. The surgical procedure was designed for the placement of EVTS, taking great care in positioning and fixing the stent. Surgical data, which included patient demographic characteristics as well as pre- and post-operative test results, were collected and analyzed. RESULTS: The mean duration of surgery was 75 ±â€Š9 min, and the mean blood loss was 20 ±â€Š5 mL. Computed tomography examinations revealed that the pre- and post-operative angle between the SMA and the aorta ranged from 18.7°â€Š±â€Š4.3° to 48.0°â€Š±â€Š8.8° (P < 0.05); in patients with left varicocele, the mean diameter of the left spermatic vein ranged from 3.7 ±â€Š0.5 to 1.3 ±â€Š0.2 mm (P < 0.05). Moreover, Doppler ultrasound examinations showed that the peak velocity of blood flow at the hilar area ranged from 12.4 ±â€Š3.3 to 18.5 ±â€Š3.4 cm/s (P < 0.05). No side effects were observed in the 24 to 42 months following surgery. CONCLUSION: The findings after 2 years of follow-up suggest that the 3DP EVTS is a safe and effective minimally invasive alternative for the treatment of NCS.

Aortic stiffness evaluated by echocardiography in female patients with Takayasu's arteritis.

OBJECTIVES: The aim of this study was to evaluate the aortic stiffness (AS) in young female patients with Takayasu's arteritis (TAK) and comparable controls by measuring carotid-femoral PWV (PWVcf) using echocardiography with pulse wave Doppler. The clinical feasibility and reproducibility of this echocardiographic method were also investigated. METHODS: Twenty-five TAK female patients (mean age 28.3±6.2 years) and 25 strictly matched healthy controls were included according to rigorous inclusion and exclusion criteria. The PWVcf of all subjects were measured by echocardiography based on the principle that PWVcf could be calculated by pulse wave spreading distance divided by the transmit time. Reproducibility of the echocardiographic measured PWVcf were performed randomly in 15 TAK patients and 15 healthy controls. RESULTS: The patients with TAK had a higher PWVcf value measured by echocardiography, compared with healthy controls (8.37±2.23 vs. 6.46±1.15 m/s; p<0.001). The echocardiographic measured PWVcf was significantly dependent on the TAK (p=0.003), age (p=0.032) and pulse pressure (p=0.025). PWVcf did not correlate with the echocardiographic measured cardiac systolic and diastolic parameters and the laboratory variables in TAK patients (p>0.05 for all). The intra- and inter-observer coefficients of variation were low and the Bland-Altman plots indicated a satisfactory reproducibility. CONCLUSIONS: Our results indicated that AS in female patients with TAK is increased, which may predict a higher cardiovascular risk. This manifestation is prior to the impairment of cardiac diastolic function. This elevated AS can be detected by echocardiographic measured PWVcf with a good reproducibility.

Effects of race and sex on cerebral hemodynamics, oxygen delivery and blood flow distribution in response to high altitude.

To assess racial, sexual, and regional differences in cerebral hemodynamic response to high altitude (HA, 3658 m). We performed cross-sectional comparisons on total cerebral blood flow (TCBF = sum of bilateral internal carotid and vertebral arterial blood flows = QICA + QVA), total cerebrovascular resistance (TCVR), total cerebral oxygen delivery (TCOD) and QVA/TCBF (%), among six groups of young healthy subjects: Tibetans (2-year staying) and Han (Han Chinese) at sea level, Han (2-day, 1-year and 5-year) and Tibetans at HA. Bilateral ICA and VA diameters and flow velocities were derived from duplex ultrasonography; and simultaneous measurements of arterial pressure, oxygen saturation, and hemoglobin concentration were conducted. Neither acute (2-day) nor chronic (>1 year) responses showed sex differences in Han, except that women showed lower TCOD compared with men. Tibetans and Han exhibited different chronic responses (percentage alteration relative to the sea-level counterpart value) in TCBF (-17% vs. 0%), TCVR (22% vs. 12%), TCOD (0% vs. 10%) and QVA/TCBF (0% vs. 2.4%, absolute increase), with lower resting TCOD found in SL- and HA-Tibetans. Our findings indicate racial but not sex differences in cerebral hemodynamic adaptations to HA, with Tibetans (but not Han) demonstrating an altitude-related change of CBF distribution.

New method for noninvasive quantification of central venous pressure by ultrasound.

BACKGROUND: The central venous pressure (CVP) is essential for assessing the cardiac preload and circulating blood volume in clinic. The invasive CVP measurement by central venous catheter has been reported with various complications. The aim of this study was to develop a new noninvasive method for quantification of CVP by ultrasound. METHODS AND RESULTS: Seventy-six patients who had their CVP monitored for intraoperative or postoperative management were recruited. By accurate location of the collapse point of the internal jugular vein and the center of the right atrium using ultrasound imaging, the height of the fluid column between those 2 points was measured as the noninvasive CVP (CVPn). A total of 118 measurements were performed and compared with the invasive CVP (CVPi). Linear correlation analysis revealed a significant correlation between CVPi and CVPn (preoperative measurements, r=0.90; P<0.01 and postoperative measurements, r=0.93; P<0.01). Bland-Altman plots showed a good agreement between CVPi and CVPn with the mean difference of 0.22 mm Hg (preoperative measurements) and -0.09 mm Hg (postoperative measurements), respectively. CONCLUSIONS: The new noninvasive CVP quantification method based on the location of both the collapse point of internal jugular vein and the center of right atrium by ultrasound could be used as a reliable approach for monitoring the hemodynamic status in clinic.

Noninvasive method for measuring local pulse wave velocity by dual pulse wave Doppler: in vitro and in vivo studies.

OBJECTIVES: To evaluate the validity and reproducibility of a noninvasive dual pulse wave Doppler (DPWD) method, which involves simultaneous recording of flow velocity of two independent sample volumes with a measurable distance, for measuring the local arterial pulse wave velocity (PWV) through in vitro and in vivo studies. METHODS: The DPWD mode of Hitachi HI Vision Preirus ultrasound system with a 5-13MHz transducer was used. An in vitro model was designed to compare the PWV of a homogeneous rubber tubing with the local PWV of its middle part measured by DPWD method. In the in vivo study, local PWV of 45 hypertensive patients (25 male, 49.8±3.1 years) and 45 matched healthy subjects (25 male, 49.3±3.0 years) were investigated at the left common carotid artery (LCCA) by DPWD method. RESULTS: In the in vitro study, the local PWV measured by DPWP method and the PWV of the homogeneous rubber tubing did not show statistical difference (5.16 ± 0.28 m/s vs 5.03 ± 0.15 m/s, p = 0.075). The coefficient of variation (CV) of the intra- and inter- measurements for local PWV were 3.46% and 4.96%, for the PWV of the homogeneous rubber tubing were 0.99% and 1.98%. In the in vivo study, a significantly higher local PWV of LCCA was found in the hypertensive patients as compared to that in healthy subjects (6.29±1.04 m/s vs. 5.31±0.72 m/s, P = 0.019). The CV of the intra- and inter- measurements in hypertensive patients were 2.22% and 3.94%, in healthy subjects were 2.07% and 4.14%. CONCLUSIONS: This study demonstrated the feasibility of the noninvasive DPWD method to determine the local PWV, which was accurate and reproducible not only in vitro but also in vivo studies. This noninvasive echocardiographic method may be illuminating to clinical use.

Ultrasound study of carotid and cardiac remodeling and cardiac-arterial coupling in normal pregnancy and preeclampsia: a case control study.

BACKGROUND: Cardiovascular adaptions, such as cardiac and uterine spiral arterial remodeling, and aortic arterial stiffening during pregnancy have been extensively investigated, while the interactions between the elastic artery and the left ventricle are poorly understood. This study was to evaluate the cardiac-arterial coupling in both normal pregnancy and preeclampsia using ultrasound techniques. METHODS: Twenty-three preeclamptic women with no antihypertensive treatment prior to admission, and 40 age- (27.2 ± 3.0 y vs. 29.1 ± 5.7 y, p = 0.0805) and gestational week- (35.6 ± 3.4 wk vs. 34.8 ± 3.6 wk, p = 0.3573) matched normotensive pregnant women were included. All women signed informed consent. All were nulliparas, had singleton pregnancies, and had no other risk factors for arterial stiffening. Carotid and cardiac ultrasound was performed using a MylabTwice ultrasound unit (Esaote, Italy). Cardiac and carotid remodeling and their associations were analyzed. Left ventriculo-carotid coupling was characterized by the ratio between the arterial elastance (Ea) and the left ventricular systolic elastance (Ees). Follow-up study was performed 16-20 months after parturition. RESULTS: Left ventricular and carotid arterial remodeling was seen more frequently in preeclamptic women than in normal pregnant controls (96% vs. 40%, 82% vs. 48%, both p < 0.0001). The relative carotid arterial wall thickness showed no significant difference between the two groups. However, the carotid cross-sectional area, a surrogate for carotid arterial mass, was significantly greater in preeclampsia than that in normal controls (11.23 ± 0.17 mm2 vs. 8.58 ± 1.88 mm2, p < 0.00001). Carotid arterial stiffness and intima-media thickness correlated significantly with cardiac diastolic function parameters and blood pressures (p < 0.05). Both Ea and Ees were significantly greater in preeclampsia, compared with values in normal pregnant controls (Ea: 2.41 ± 0.57 mmHg/ml vs. 1.98 ± 0.46 mmHg/ml, p = 0.0005; Ees: 11.68 ± 9.51 m/s2 vs. 6.91 ± 6.13 m/s2, p = 0.002). However, there was no significant difference in the left ventriculo-carotid coupling index, Ea/Ees, between the two groups. Carotid remodeling persisted in both preeclamptic women and normal pregnant controls 16-20 months after parturition. CONCLUSIONS: Significant cardiac and carotid remodeling and similar left ventriculo-carotid coupling were observed in both preeclampsia and normal pregnancy. Carotid remodeling may persist postpartum. Further studies with larger populations are needed to confirm these findings.

Evaluation of carotid artery elasticity changes in patients with type 2 diabetes.

BACKGROUND: Type 2 diabetes is one of the most common causes of cardiovascular disease as it causes arterial stiffness changes. The purpose of this study is to characterize, in vivo, carotid arterial structural and functional changes by applying radio frequency and X-strain ultrasound techniques. METHODS: Ninety-one subjects were assigned into two groups; a diabetes group and a control group. Structural and functional changes in the common carotid arterial wall were investigated by quality intima-media thickness (QIMT), quality arterial stiffness (QAS), and X-strain analysis with a Mylab Twice ultrasound instrument. The relationships among variables between the two groups were analyzed in this study. RESULTS: There was no significant difference in carotid IMT (626.5 ± 169.1 µm vs. 568.5 ± 122.6 µm, P = 0.1506) between two groups. Pulse wave velocity (PWV) and stiffness index (ß) were remarkably greater (8.388 ± 3.254 m/s vs. 7.269 ± 1.332 m/s; 12.51 ± 14.16 vs.9.279 ± 2.871), while compliance coefficient (CC) decreased significantly in the diabetes group (0.802 ± 0.3094 mm2/Kpa vs. 0.968 ± 0.3992 mm2/Kpa) (P < 0.05). The displacement difference of radial (RD-D), longitudinal (LD-D) and rotation (ROT-D) directions were significantly different between two groups' comparison (P = 0.0212, P = 0.0235 and P = 0.0072, respectively). The time of circumferential peak strain difference (CS-DT) and the time of radial peak strain rate (RSR-T) were found to be significantly different between the two groups (341.9 ± 77.56 ms vs. 369.0 ± 78.26 ms, P = 0.0494; 142.7 ± 22.43 ms vs. 136.2 ± 30.70 ms, P = 0.0474). CS-TD and RSR-T were also found to be positively correlated with CC value (r = 0.3908, P < 0.005 and r = 0.3027, P = 0.0326, respectively). Finally, PWV was negatively correlated with CC with (r = -0.6177, P < 0.001). CONCLUSIONS: In type 2 diabetes, the functional changes in CCA can be identified using the methods presented in this article earlier than the structural changes. Arterial stiffness values provided by QAS and X-strain analysis can be used as indicators of CCA functional lesions in patients with type 2 diabetes.

Maternal carotid remodeling and increased carotid arterial stiffness in normal late-gestational pregnancy as assessed by radio-frequency ultrasound technique.

BACKGROUND: The adaption of elastic arteries to transient increase in hemodynamic load in normal pregnancy (NP) remains controversial. The purpose of this study was to investigate the NP carotid remodeling and regional arterial stiffness before and after parturition. METHODS: Fifty-one NP women and 30 age-matched non-pregnant women were included. All women underwent right common carotid artery (RCCA) measurements with MylabTwice ultrasound instrument (Esaote, Italy). Carotid intima-medial thickness (IMT), pulse wave velocity (PWV, m/s), distensibility coefficient (DC, 1/KPa), α, ß, augmentation index (AIx, %) and carotid arterial pressure were obtained by the newly developed ultrasound vascular wall tracking methods: automatic QAS (Quality Arterial Stiffness) and QIMT (Quality Intima-Medial Thickness) Follow up study was performed. RESULTS: Compared to the non-pregnant controls, the arterial pressures were significantly increased and RCCA diameter was significantly enlarged in late gestational NP women. Twenty months after parturition, carotid diameter, DC, AIx, PWV and arterial wall tension were significantly decreased and had no significant difference with those in non-pregnant controls. CONCLUSIONS: Carotid arterial remodeling and stiffening could be seen in the normal pregnant women, which seems to be a physiological adaption and could be recovered post partum. QIMT and QAS together could provide a comprehensive assessment of the maternal carotid arterial changes during pregnancy.

Mechanism study of pulsus paradoxus using mechanical models.

Pulsus paradoxus is an exaggeration of the normal inspiratory decrease in systolic blood pressure. Despite a century of attempts to explain this sign consensus is still lacking. To solve the controversy and reveal the exact mechanism, we reexamined the characteristic anatomic arrangement of the circulation system in the chest and designed these mechanical models based on related hydromechanic principles. Model 1 was designed to observe the primary influence of respiratory intrathoracic pressure change (RIPC) on systemic and pulmonary venous return systems (SVR and PVR) respectively. Model 2, as an equivalent mechanical model of septal swing, was to study the secondary influence of RIPC on the motion of the interventriclar septum (IVS), which might be the direct cause for pulsus paradoxus. Model 1 demonstrated that the simulated RIPC had different influence on the simulated SVR and PVR. It increased the volume of the simulated right ventricle (SRV) when the internal pressure was kept constant (8.16 cmH2O), while it had the opposite effect on PVR. Model 2 revealed the three major factors determining the respiratory displacement of IVS in normal and different pathophysiological conditions: the magnitude of RIPC, the pressure difference between the two ventricles and the intrapericardial pressure. Our models demonstrate that the different anatomical arrangement of the two venous return systems leads to a different effect of RIPC on right and left ventricles, and thus a pressure gradient across IVS that tends to shift IVS left- and rightwards. When the leftward displacement of IVS reaches a considerable amplitude in some pathologic condition such as cardiac tamponade, the pulsus paradoxus occurs.

Simultaneous beat-by-beat investigation of the effects of the Valsalva maneuver on left and right ventricular filling and the possible mechanism.

Although the influence of the Valsalva maneuver on the heart and circulatory system has been investigated, the mechanism of intrathoracic pressure influencing cardiovascular function is unclear. To test our hypothesis that the interaction between the anatomy-determined partially-intrathoracic system and the fully-intrathoracic system might explain those issues and help to disclose the mechanism, we used the Hitachi dual pulse wave Doppler echocardiographic apparatus to investigate simultaneously the beat-by-beat influence of 40-mmHg Valsalva maneuver on left and right cardiac ventricular filling in 30 male adult volunteers. The mitral and tricuspid blood inflow velocity spectra during the Valsalva maneuver were recorded simultaneously. The peak velocity (PV), velocity-time integral (VTI) and inflow volume (IV) of each cycle were measured or calculated. The PV, VTI and IV of the left heart remained unchanged at the first beat after the Valsalva maneuver onset (compared with those at rest, p>0.1) and then decreased gradually to the lowest at the 11±1.2th beat (range, 9th to 12th beat). Simultaneously, the PV, VTI and IV of the right heart decreased significantly (p<0.05) at the first cycle, decreased rapidly to the lowest at the 6±0.8th beat (range, 4th to 7th beat) and then increased gradually to the 9±1.3th beat (range, 8th to 10th beat). These results suggest that the left heart and right heart have different physiological responses to the Valsalva maneuver. These could be explained by our hypothesis, the interaction between the partially-intrathoracic system and the fully-intrathoracic system, which might help to disclose the mechanism of how intrathoracic pressure influences the heart and circulatory system.

The mechanics of left ventricular filling during the strain phase of the valsalva maneuver in healthy subjects.

BACKGROUND: The aim of this study was to investigate the mechanical changes in left ventricular filling during the strain phase of the Valsalva maneuver in healthy subjects. METHODS: Thirty healthy volunteers were recruited to undertake the Valsalva maneuver at a load of 40 mm Hg for 10 seconds. Parameters of left ventricle filling were determined by echocardiography at baseline and at the first and second beats during the strain phase. RESULTS: Compared with baseline values, the E, E/A ratio, E/esep ratio and E/elat ratio parameters all increased at the first beat (P < 0.05). Compared with the first beat values, the E, E/A ratio, E/esep ratio and E/elat ratio parameters all decreased at the second beat (P < 0.05). The results demonstrate that left ventricular filling decreases at the second beat during the strain phase of the Valsalva maneuver. Positive intrathoracic pressure decreases left-side heart and pulmonary vessel transmural pressure while increasing blood vessel resistance, which explains the decrease in left ventricular filling. CONCLUSIONS: The results provide a new understanding of the underlying mechanical mechanism of the Valsalva maneuver, indicating that it should be performed clinically at a lower load and shorter strain time to avoid adverse events.

Value of the echocardiographic suprasternal view for diagnosis of patent ductus arteriosus subtypes.

OBJECTIVES: The purpose of this study was to explore the value of the transthoracic echocardiographic suprasternal view in the diagnosis of patent ductus arteriosus subtypes. METHODS: Sixty-five patients with a patent ductus arteriosus were examined using transthoracic echocardiographic suprasternal and parasternal views before ductus arteriosus closure. Diameters of the aortic and pulmonary sides of the ductus arteriosus were measured, and subtype diagnoses were made. The results were compared with those from digital subtraction angiography. RESULTS: The mean diameters ± SD of the aortic side of the ductus arteriosus were 8.31 ± 2.76, 10.87 ± 3.26, and 11.15 ± 3.29 for the parasternal view, the suprasternal view, and digital subtraction angiography, respectively, whereas the diameters of the pulmonary side were 5.69 ± 2.82, 5.75 ± 2.63, and 6.09 ± 2.78 mm. Of the 65 cases, 12, 19, and 19 were the funnel-type patent ductus arteriosus as evaluated with the parasternal view, the suprasternal view, and digital subtraction angiography. Detection on the parasternal view was lower than that on the suprasternal view (χ(2) = 5.14; P < .025). CONCLUSIONS: The diameter of the aortic side of a patent ductus arteriosus can be accurately detected on the superasternal view, which would be helpful for diagnosis of patent ductus arteriosus subtypes.

New method for quantifying and correcting underestimated cardiac Doppler blood flow velocities: in vitro and in vivo studies.

This study was aimed to quantify the underestimation of cardiac Doppler measurements and to explore a method for correction. A dual pulse wave (PW)/Doppler tissue imaging (DTI) mode echocardiographic technique was used in the in vitro and in vivo studies. In the in vitro experiment, we have demonstrated how cardiac valvular motion might interfere with blood velocity estimation using conventional Doppler. When examining the participants, we observed that adding valvular annulus velocity to determine the relative velocity between blood and valvular annulus would result in an increment of 9.3 ± 1.3 cm/s and 6.3 ± 0.9 cm/s for aortic and pulmonary blood flow, 12.8 ± 1.9 cm/s and 8.9 ± 1.4 cm/s for mitral E and A wave, 12.9 ± 1.8 cm/s and 10.2 ± 2.4 cm/s for tricuspid E and A wave. The underestimations of the Doppler measurements markedly influence the hemodynamic parameters commonly used in the clinical practices and researches. This study provides a quantitative method for the correction and would make the Doppler measurement accurate.

Multidirectional myocardial systolic function in hemodialysis patients with preserved left ventricular ejection fraction and different left ventricular geometry.

BACKGROUND: Multidirectional myocardial strain analysis can provide mechanistic insight into the ventricular systolic function and pathophysiology. The aim of this study was to assess the multidirectional systolic function of the left ventricle (LV) and its relationship to LV geometry in hemodialysis patients with preserved left ventricular ejection fraction (LVEF). METHODS: A total of 98 end-stage renal disease patients (age 46 ± 10 years, 60% men) with preserved LVEF (≥50%) on a maintenance hemodialysis program and 18 healthy volunteers were enrolled. The patients were divided into non-hypertrophic groups (classified as normal LV geometry and concentric remodeling) and hypertrophy groups (classified as eccentric and concentric hypertrophy) according to their LV geometries assessed from LV mass/height(2.7) and relative wall thickness in combination. Multidirectional strain analysis was performed by two-dimensional speckle tracking echocardiography. RESULTS: Myocardial systolic strain (longitudinal and circumferential) and stress-corrected midwall fraction shorting (sc-MWFS) were lower in the hypertrophy groups compared with non-hypertrophic groups. Longitudinal strain and strain rate were even lower in the concentric hypertrophy group than the eccentric hypertrophy group (-15.5 ± 2.2% versus -17.8 ± 2.6%, P = 0.001; -0.7 ± 0.2 versus -0.9 ± 0.2s(-1), P = 0.016). Impaired longitudinal strain correlated with higher LV mass index (LVMI), relative wall thickness, pre-dialysis systolic blood pressure (SBP), calcium-phosphate product and lower sc-MWFS (all P < 0.0001) and weakly correlated with higher interdialytic weight gain (P = 0.004). Using multivariate linear regression, the independent predictors of LV longitudinal strain were pre-dialysis SBP, LVMI, relative wall thickness and sc-MWFS. There were no differences in LVEF and myocardial function in radial direction among all groups. CONCLUSIONS: In hemodialysis patients with LV hypertrophy, myocardial function was impaired not only in longitudinal direction but also in circumferential direction despite preserved LVEF. Low longitudinal strain is related to LV hypertrophy, concentric geometry and pre-dialysis blood pressure.

Double-chambered left ventricle in echocardiography.

In this article, we describe a double-chambered left ventricle (LV) in a 37-year-old man. Its accessory chamber attached to the inferior and posterior wall of LV, and had normal systolic contraction without any regional wall motion abnormality. A double-chambered LV was suspected on echocardiography and confirmed by cardiac computed tomography scanning and cardiac magnet resonance imaging. Our aim is to accentuate the value of echocardiography in this rare anomaly

Quantitative assessment of maternal common carotid artery mechanics using velocity vector imaging in pre-eclampsia.

OBJECTIVE: Velocity vector imaging (VVI) is widely used to quantify cardiac mechanical deformation. This study sought to determine whether VVI could be used to evaluate the stiffness of maternal peripheral arteries in women with pre-eclampsia. STUDY DESIGN: Twenty-four women with pre-eclampsia and 34 normotensive pregnant women were recruited. Longitudinal and circumferential peak velocity, strain and strain rate of the right common carotid artery (CCA) were measured. All measurements were averaged from three consecutive cardiac cycles and expressed as mean ± standard deviation. RESULTS: Longitudinal velocity, strain and strain rate of the anterior and posterior walls of the CCA were significantly lower in women with pregnancy-induced hypertension compared with normotensive pregnant women [velocity: 0.22 ± 0.09 cm/s vs 0.29 ± 0.09 cm/s (p<0.01) and 0.24 ± 0.10 cm/s vs 0.34 ± 0.13 cm/s (p<0.01); strain: 8.50 ± 4.92% vs 12.2 ± 6.21% (p<0.01) and 10.11 ± 5.02% vs 14.21 ± 6.48% (p<0.05); strain rate: 1.62 ± 1.14 s(-1) vs 2.24 ± 1.13 s(-1) (p<0.05) and 1.91 ± 0.99 s(-1) vs 2.45 ± 0.97 s(-1) (p<0.05)]. Similar results were also found for circumferential velocity, strain and strain rate of the anterior and posterior walls, and the interior and exterior lateral walls of the CCA. CONCLUSIONS: Stiffness of the maternal CCA was significantly greater in women with pre-eclampsia compared with normotensive pregnant women. VVI may have potential for quantitative assessment of vascular mechanical deformation in the clinical setting.