A 63-Year-Old Male with D-Transposition of the Great Arteries Who Had an Early Form of the Arterial Switch Operation

We describe a 63-year-old male who appears to have undergone an early form of the arterial switch operation for D-transposition of the great arteries performed in the mid-1960s.We review the clinical and imaging data that support our conclusion.He had a diagnostic cardiac catheterization which demonstrated severe pulmonary hypertension responsive to epoprostenol and oxygen.Our case may represent one example of the experimental surgical work done prior to Dr.Adibe Jatene’s description of thefirst successful arterial switch performed in 1975.

Case Report: Surgical Correction of Transposition of the Great Arteries with Aortopulmonary Window

Introduction:Transposition of the great arteries(TGA)with aortopulmonary window is a rare type of congenital heart disease with limited experience.We reported a neonate aged 25 days receiving the arterial switch operation and assisted with extracorporeal membrane oxygenation.Conclusion:TGA with aortopulmonary window can be safely correctly with the arterial switch operation.

Response of colloidal liquids containing magnetic holes of different volume densities to magnetic field characterized by transmission measurement

This paper systematically investigates the response of colloidal liquids containing magnetic holes of different volume densities to magnetic field by conventional transmission measurements. It finds that the enhancement in the transmission of such a colloidal liquid under a magnetic field exhibits a strong dependence on the volume density of magnetic holes. A linear increase in the maximum enhancement factor is observed when the volume density of magnetic holes is below a critical level at which a maximum enhancement factor of ~150 is achieved in the near infrared region. Once the volume density of magnetic holes exceeds the critical level, a sharp drop of the maximum enhancement factor to ~2 is observed. After that, the maximum enhancement factor increases gradually till a large volume density of ~9%. By monitoring the arrangement of magnetic holes under a magnetic field, it reveals that the colloidal liquids can be classified into three different phases, i.e., the gas-like, liquid-like and solid-like phases, depending on the volume density of magnetic holes. The response behaviour of colloidal liquids to magnetic field is determined by the interaction between magnetic holes which is governed mainly by their volume density. A phase transition, which is manifested in the dramatic reduction in the maximum enhancement factor, is clearly observed between the liquid-like and solid-like phases. The optical switching operations for colloidal liquids in different phases are compared and the underlying physical mechanisms are discussed.

A Rare Case of Late LAD Reimplantation after Arterial Switch Operation

Arterial switch operation(ASO)is a complex neonatal operation in which transfer of the coronary arteries origins is the key to success.Coronary events after a successful ASO are not uncommon.We describe a rare case of a child who underwent an ASO in the neonatal period with one coronary(LAD)described as atretic left in place.At age seven,he developed myocardial ischemia due to retrograde flow with a steal phenomenon from the LAD into the pulmonary artery.The patient underwent a late LAD reimplantation.This case underscores that even very small ostia should be translocated at the time of ASO.

3.0T MR Coronary Angiography after Arterial Switch Operation for Transposition of The Great Arteries-Gd-FLASH Versus Non-Enhanced SSFP.A Feasibility Study

Background:Patency of the coronary arteries is an issue after reports of sudden cardiac death in patients with transposition of the great arteries(TGA)operated with arterial switch(ASO).Recent studies give rise to concern regarding the use of ionising radiation in congenital heart disease,and assessment of the coronary arteries with coronary MR angiography(CMRA)might be an attractive non-invasive,non-ionising imaging alternative in these patients.Theoretically,the use of 3.0T CMRA should improve the visualisation of the coronary arteries.The objective of this study was to assess feasibility of 3.0T CMRA at the coronary artery origins by comparing image quality with non-contrast CMRA in ASO TGA patients to healthy age-matched controls,and by comparing image quality with non-contrast CMRA to contrast enhanced CMRA in the patient group.Material and methods:Twelve patients,9-15 years(mean 11.9 years,standard deviation 1.5 years),and 12 age-matched controls(mean 12.7 years,standard deviation 1.7 years)were examined with 3D balanced steady-state free precession(SSFP).Nine of twelve patients had Gadolinium-enhanced fast low-angle shot(Gd-FLASH)performed after SSFP.Image quality at the coronary artery origins was evaluated subjectively with a 10 cm figurative visual analogue scale(fVAS)and objectively by signal-to-noise and contrast-to-noise ratio(SNR,CNR).Results:All,but one,coronary artery origins were identified.No significant difference in image quality scores was found between patients and controls with SSFP(mean values 6.5 cm—9.1 cm in patients and 7.0 cm—8.0 cm in controls,p-values>0.1).With SSFP,intra-observer fVAS mean score was 6.7 cm—8.6 cm and with Gd-FLASH 7.7 cm—8.7 cm.CNR was higher with Gd-FLASH(p<0.03).Intra-observer agreement index(AI)with SSFP was moderate-to-good(0.43–0.71)and with Gd-FLASH good(0.64–0.79)in all origins.Inter-observer AI was good in the left main stem(LMS)with SSFP(0.65).With Gd-FLASH inter-observer AI was good in LMS(0.78)and moderate(0.5)in the left anterior descending artery,but lacking in the other origins though with a good agreement on Bland-Altman plots.Conclusions:Our findings indicate a better,more reproducible image quality with Gd-FLASH than with non-contrast SSFP CMRA on 3.0T for evaluation of the coronary artery origins in ASO TGA children and adolescents.

Systematic review and meta-analysis of outcomes of anatomic repair in congenitally corrected transposition of great arteries

BACKGROUND Treatment of congenitally corrected transposition of great arteries(cc-TGA)with anatomic repair strategy has been considered superior due to restoration of the morphologic left ventricle in the systemic circulation.However,data on long term outcomes are limited to single center reports and include small sample sizes.AIM To perform a systematic review and meta-analysis for observational studies reporting outcomes on anatomic repair for cc-TGA.METHODS MEDLINE and Scopus databases were queried using predefined criteria for reports published till December 31,2017.Studies reporting anatomic repair of minimum 5 cc-TGA patients with at least a 2 year follow up were included.Metaanalysis was performed using Comprehensive meta-analysis v3.0 software.RESULTS Eight hundred and ninety-five patients underwent anatomic repair with a pooled follow-up of 5457.2 patient-years(PY).Pooled estimate for operative mortality was 8.3%[95%confidence interval(CI):6.0%-11.4%].0.2%(CI:0.1%-0.4%)patients required mechanical circulatory support postoperatively and 1.7%(CI:1.1%-2.4%)developed post-operative atrioventricular block requiring a pacemaker.Patients surviving initial surgery had a transplant free survival of 92.5%(CI:89.5%-95.4%)per 100 PY and a low rate of need for pacemaker(0.3/100 PY;CI:0.1-0.4).84.7%patients(CI:79.6%-89.9%)were found to be in New York Heart Association(NYHA)functional class I or II after 100 PY follow up.Total re-intervention rate was 5.3 per 100 PY(CI:3.8-6.8).CONCLUSION Operative mortality with anatomic repair strategy for cc-TGA is high.Despite that,transplant free survival after anatomic repair for cc-TGA patients is highly favorable.Majority of patients maintain NYHA I/II functional class.However,monitoring for burden of re-interventions specific for operation type is very essential.

Coronary Artery Anomalies in D-Transposition of the Great Artery Following Arterial Switch Operation

Background:The survival rate of patients following arterial switch operation(ASO)exceeds 95%,but coronary artery anomalies(CAA)contribute to a 2%incidence of sudden cardiac arrest later in life.Therefore,we aimed to assess abnormal findings of coronary arteries in post-ASO patients.Methods:Coronary computed tomography angiography(CCTA)is performed on post-ASO patients who meet institutional criteria.Intraoperative findings of coronary artery patterns were retrospectively reviewed and categorized using the Leiden classification system.Coronary artery anomalies were detected by CCTA and associations with coronary artery compromise were explored.Results:Forty-three patients who had CCTA with a median age of 15.6 years(12–21.3 years)were included in the study.Unusual coronary patterns were identified in 20(46%)patients before ASO.CCTA identified 25 CAA in 22 patients(eleven with prepulmonic course,nine with interarterial course,three with acute take-off angle,and two with significant stenosis).Postoperative CAA was more common in patients with unusual coronary patterns(90%vs.17.4%;p<0.001).Nine patients experienced chest pain and two patients required coronary artery bypass graft.A common ostium of RCA and LAD or LMCA were associated with significant chest pain(OR 14.3%,95%CI 2.5 to 82.3).Conclusions:Coronary artery anomalies in post-ASO are common.All post-ASO patients should have coronary artery imaging before participating in competitive sport and when they reach adolescence.Patients with unusual preoperative coronary artery patterns should undergo coronary artery imaging when feasible.Follow-up imaging studies are indicated in patients with post-operative coronary artery abnormalities.

ARTERIAL SWITCH OPERATION FOR COMPLETE D-TRANSPOSITION OF THE GREAT ARTERIES: SURGICAL RESULTS AND ANALYSIS

Objective To review and analyze the surgical results of arterial switch operations in complete D-transposition of the great arteries （TGA）. Methods A total of 113 patients underwent arterial switch operation from Jan. 2001 to Dec. 2005. There were 60 patients with transposition of the great arteries and intact ventricular septum （TGA/IVS） and 53 patients with transposition of the great arteries and ventricular septal defect （TGA/VSD）. The lowest body weight was 2. 3 kg and the smallest age was 6 h. The arterial switch operation was performed under deep hypothermia with circulatory arrest and low-flow perfusion. Results The total mortality was 9. 73%. There were 5 deaths in TGA/IVS （8.3%）, 6 deaths in TGA/VSD （ 11.3% ）. With the development of surgical technique, peri-operative management and cardiopulmonary bypass, the total mortality significantly decreased from 16. 65% in the early times to 5. 5% lately. Conclusion The vital risk of the operation is coronary artery malformation. The incidence of coronary artery malformation is higher in TGA/VSD than in TGA/ [VS. The positional relationship of the great arteries does not affect the results of the operation. The arterial switch operation should be prevented when the pressure ratio between the left and right ventricle is less than 0.6, otherwise it is great likely to cause severe low cardiac output postoperatively.

Investigation of the risk factors associated with early mortality of the rapid two-stage arterial switch operation

Objective To investigate the risk factors associated with early mortality of the rapid two-stage arerial switch operation,which has a significantly higher overall mortality than that of ASO procedure for D-TGA with an intact ventricular septum. Methods The data we reviewed involving patients who underwent rapid two-stage switch operations from September,2002 to September,2007 in our center,13 patients were male and 8

Near field coupling to shielded cable due to switching operation in substation

It is vital to study the electromagnetic coupling to shielded cable for improving electromagnetic antiinterference ability of secondary equipment in a substation.As a hybrid of method of moment(MoM)and transmission line method,a frequency domain model is put forward to study the near field coupling to shielded cable due to the switching operation in substation.Compared with the results of EMTP,the proposed method has been proven correct.Furthermore,this method overcomes the disadvantage of EMTP,which is only applicable for transient analysis of parallel conductors.As an example,the presented method is applied to evaluating the electromagnetic interference(EMI)to the shielded cable,whose shield is grounded at both ends,due to the switching operation in 500 kV air insulation substation(AIS).

Analysis of Conducted Disturbance via Current Transformer Due to Switch Operation of GIS Disconnector in UHV Substation

The characteristics of conducted disturbances via current transformer(CT)caused by switch operations in 1000 kV UHV substations are studied in this paper.Since the broadband circuit models might have limitations on the stability and accuracy for CT conducted disturbance simulation,a frequencydomain simulation method without circuit synthesis is proposed based on VFTC spectrum and CT transfer characteristics.To improve VFTC simulation accuracy,both the bushing radiation loss and frequency-dependent earth impedance are taken into consideration.Transfer characteristics of three types of windings for the 1000 kV GIS CT are ingeniously measured from a combination of fast and slow impulse tests.Through conducted disturbances simulations in UHV Wuhu substation,bushing radiation loss is found to have a suppression effect on the highfrequency response but the effect of frequency-dependent earth impedance can be ignored.As a result,the maximum amplitude of 84.5 A for the conducted disturbance is obtained,thus a fast damped oscillatory wave immunity test with no lower than Level 4 from IEC standard is suggested to test the anti-interference performance of the secondary equipment in UHV substation.

Comparative analysis of early and middle outcomes of the arterial switch operation in children with complete transposition of the great arteries with ventricular septal defect and severe pulmonary artery hypertension

Background The best age for the arterial switch operation （ASO） in complete transposition of great arteries with ventricular septal defect is usually considered to be within six months. This is because of severe pulmonary arterial hypertension and pulmonary arterial obstructive pathological changes. There are few reports on ASO surgery in children older than three years old. Methods We studied 41 children, including 24 males and 17 females, from January 2010 to December 2011. They were divided into three groups by operation age; 15 patients were 〈1 year old, 13 were 1-3 years old, and 13 were 〉3 years old. Associated cardiac abnormalities included patent ductus arteriosus in six cases, atrial septal defect in five cases, and mitral regurgitation in two cases. All the patients had echocardiography before the operation. Seventeen patients underwent a coronary computed tomography examination and five patients underwent right heart catheterization. All ASO surgeries were performed under inhalation anesthesia and hypothermic cardiopulmonary bypass. Results Three operative deaths occurred. Two were in the 〈1 year old group, who died from severe postoperative low cardiac output. The other was two years old and died of postoperative multiple organ failure. There was no significant difference in postoperative mortality and the recent mid-term survival rate among the three groups. Thirty-eight cases were followed up for an average of 11.2 months, ranging 6-20 months. One seven years old patient died of acute diarrhea and electrolyte disturbance arrhythmia caused by food poisoning. Three patients more than three years old still had residual pulmonary arterial hypertension. Conclusion Children older than three years old can still undergo the ASO procedure, but residual pulmonary hypertension is present.

Surgical Treatment of Complete Transposition of the Great Arteries in Newborn

INTRODUCTION Complete transposition of the great arteries （TGAs）is a common cyanotic congenital heart defect,with an incidence rate of 0.02%,accounting for 5-7% of congenital heart diseases.[1] After birth,infants with TGA largely rely on ventricular septal defect （VSD）,atrial septal defect （ASD）,and patent ductus arteriosus （PDA）to sustain life.Without systemic-pulmonary shunt and surgical correction,these infants will probably die on the day after birth.

Dual-Mode Low Power Pipelined ADC with Pre-charged Switched Operational Amplifier

This paper describes a 12-bit 40-MS/s and 8-bit 80-MS/s dual-mode low power pipelined analog-to-digital converter （ADC）. An improved multiplying digital-to-analog converter is used to provide the dual-mode operation. A pre-charged fast power-on switched operational amplifier is used to reduce the power consumption of the pipelined ADC to 28.98 mW/32.74 mW at 40 MHz/80 MHz sampling rates. The ADC was designed in a 1.8-V 1P6M 0.18-μm CMOS process. Simulations indicate that the ADC exhibits a spurious free dynamic range of 90.24 dB/58.33 dB and signal-to-noise-and-distortion ratio of 73.81 dB/47.85 dB at 40 MHz/80 MHz sampling frequencies for a 19-MHz input sinusoidal signal.

Reconstruction of a new pulmonary artery in arterial switch operation

Background:This study was undertaken to evaluate the new method for the reconstruction of the pulmonary artery in arterial switch operation(ASO).Methods:A total of 108 consecutive infants with congenital heart disease were treated with ASO in our department between January 2004 and June 2012.The new pulmonary arterial root was reconstructed with a fresh autologuos pericardium which was clipped pants­like with continuous mattress suture of 6-0 Prolene thread.Patients were reexamined consecutively at 3 and 6 months and 1,2 and 6 years after discharge.The pulmonary arterial blood velocity was measured by continuous Doppler during systole.The pulmonary flow of healthy children of same age was also measured in the control group.Simplified Bernoulli formula was used to calculate the pressure gradient via the pulmonary artery for determining whether there was pulmonary stenosis.Results:In this series,96 infants survived after the surgery and 88 were followed up with a mean peirod of(22±4)months.No pulmonary stenosis was detected with the simplified Bernoulli formula.Conclusion:No pulmonary stenosis was detected with the simplified Bernoulli formula.

A Mach-Zehnder interferometer electro-optic switch with ultralow voltage-length product using poled-polymer/silicon slot waveguide

By using poled-polymer/silicon slot waveguides in the active region and the Pockels effect of the poled-polymer,we propose a kind of Mach-Zehnder interferometer(MZI) electro-optic(EO) switch operated at 1 550 nm.Structural parameters are optimized for realizing normal switching function.Dependencies of switching characteristics on the slot waveguide parameters are investigated.For the silicon strip with dimension of 170 nm×300 nm,as the slot width varies from 50 nm to 100 nm,the switching voltage can be as low as 1.0 V with active region length of only 0.17–0.35 mm,and the length of the whole device is only about 770–950 μm.The voltage-length product of this switching structure is only 0.17–0.35 V·mm,and it is at least 19–40 times smaller than that of the traditional polymer MZI EO switch,which is 6.69 V·mm.Compared with our previously reported MZI EO switches,this switch exhibits some superior characteristics,including low switching voltage,compact device size and small wavelength dependency.