Differential Adaptation of Biventricular Myocardial Kinetic Energy in Patients With Repaired Tetralogy of Fallot Assessed by MR Tissue Phase Mapping.

BACKGROUND: The myocardial kinetic energy (KE) and its association with pulmonary regurgitation (PR) have yet to be investigated in repaired tetralogy of Fallot (rTOF) patients. PURPOSE: To evaluate the adaptation of myocardial KE in rTOF patients by tissue phase mapping (TPM). STUDY TYPE: Prospective. POPULATION: A total of 49 rTOF patients (23 ± 5 years old; male = 32), 47 normal controls (22 ± 1 year old; male = 29). FIELD STRENGTH/SEQUENCE: 3-T/2D dark-blood three-directional velocity-encoded gradient-echo sequence. ASSESSMENT: Left and right ventricle (LV, RV) myocardial KE in radial (KEr ), circumferential (KEø ), longitudinal (KEz ) directions. The proportions of KE in each direction to the sum of all KE (KErøz ): %KEr , %KEø , %KEz . PR fraction. STATISTICAL TEST: Student's t test, multivariable regression. Statistical significance: P < 0.05. RESULTS: In rTOF group, LV KEz remained normal in systole (P = 0.565) and diastole (P = 0.210), whereas diastolic LV %KEz (62% ± 14% vs. 72% ± 7%) and systolic LV %KEø (9% ± 6% vs. 20% ± 7%) were significantly decreased. The KEr and %KEr of both ventricles significantly increased in the rTOF group (RV in diastole: 6 ± 3 vs. 3 ± 1 µJ and 54% ± 13% vs. 27% ± 7%). The rTOF group exhibited significantly higher RV/LV ratios of %KEr (systole: 1.3 ± 0.3 vs. 1.0 ± 0.3) and %KEø (systole: 1.6 ± 0.8 vs. 1.0 ± 0.3) and significantly lower ratios of %KEz in systole (0.7 ± 0.2 vs. 1.0 ± 0.1) and diastole (0.5 ± 0.2 vs. 0.9 ± 0.1). In multivariable regression analysis, the RV peak systolic KErøz , RV systolic KEz , and LV diastolic %KEø were independently associated with PR fraction in the rTOF group (adjusted R2  = 0.479). DATA CONCLUSION: In rTOF patients, the adaptation of the KE proportion occurred earlier than that of the KE amplitude, and the biventricular balance of %KE was disrupted. PR may cause differential KE adaptation in RV and LV. TPM-derived KE may be useful in investigation of myocardial adaptation in rTOF patients. EVIDENCE LEVEL: 2 TECHNICAL EFFICACY: Stage 3.

Glut5 Knockdown in the Nucleus Tractus Solitarii Alleviates Fructose-Induced Hypertension in Rats.

BACKGROUND: Several studies have suggested mechanisms whereby excessive fructose intake increases blood pressure (BP). Glucose transporter 5 (GLUT5) is a fructose transporter expressed on enterocytes, and its involvement in the nucleus tractus solitarius (NTS)-modulated increase in BP following fructose intake remains unclear. OBJECTIVES: Herein, we investigated whether NTS Glut5 knockdown (KD) can alleviate fructose-induced hypertension in rat models. METHODS: Male Wistar-Kyoto rats (6-8 weeks old; average weight: 230 g) were randomly assigned into 4 groups [control (Con), fructose (Fru), fructose + scrambled (Fru + S), and Fru +  KD]. The Con group rats had ad libitum access to regular water, and the other 3 groups were provided 10% fructose water ad libitum for 4 weeks (2 weeks before lentiviral transfection in the Fru + S and Fru + KD groups). Glut5 short hairpin RNA was delivered into the NTS of rats using a lentivirus system. Fructose-induced hypertension was assessed via the tail-cuff technique, a noninvasive blood pressure measurement approach. GLUT5-associated and other insulin signaling pathways in the NTS of rats were assessed using immunofluorescence and immunoblotting analyses. We evaluated between-group differences using the Mann-Whitney U test or Kruskal-Wallis 1-way ANOVA. RESULTS: Compared with the Fru + S group, the Fru + KD group had reduced sympathetic nerve hyperactivity (48.8 ± 3.2 bursts/min; P < 0.05), improved central insulin signaling, upregulated protein kinase B (AKT; 3.0-fold) and neuronal NO synthase (nNOS; 2.78-fold) expression, and lowered BP (17 ± 1 mmHg, P < 0.05). Moreover, Glut5 KD restored signaling dependent on adenosine 5'-monophosphate-activated protein kinase and reduced fructose-induced oxidative stress 2.0-fold, and thus decreased NAD(P)H oxidase in p67-phox 1.9-fold within the NTS. CONCLUSIONS: Fructose-induced reactive oxygen species generates in the NTS of rats through GLUT5 and receptor for advanced glycation end products signaling, thus impairing the AKT-nNOS-NO signaling pathway and ultimately causing hypertension.

Comparable long-term results of the extracardiac conduit total cavopulmonary connection in heterotaxy to non-heterotaxy patients.

BACKGROUND: Fontan operation in heterotaxy patients has been associated with high mortality. We studied whether adoption of the extracardiac conduit (EC) total cavopulmonary connection (TCPC) in heterotaxy demonstrated comparable results to non-heterotaxy population. METHODS: A retrospective medical record review of 35 consecutive patients with heterotaxy and 70 consecutive patients without heterotaxy syndrome who underwent EC TCPC between 2000 and 2018 was performed. RESULTS: In the 35 heterotaxy patients, 30 were right and 5 were left atrial isomerism. Anomalies of venous return included bilateral superior vena cava in 20 (57.1%), separated hepatic vein in 8 (22.9%), interrupted inferior vena cava in 3 (8.6%), total anomalous pulmonary venous return in 7 (20%), and partial in 2 patients (5.7%). All patients underwent EC TCPC under beating-heart cardiopulmonary bypass except in four patients (11.4%) cardioplegic arrest was needed for cardiac repair. The surgical mortality rate was lower in heterotaxy patients (0% vs. 5.7%; p = 0.299) but statistically not significant. The follow-up ranged from 2 months to 17.8 years (mean 9.4 ± 5.6 years). At 15 years, there was no significant difference between the heterotaxy and non-heterotaxy patients regarding the long-term survival (70% vs. 78.6%; p = 0.443), freedom from reoperation (81.9% vs. 96.5%; p = 0.057), and postoperative arrhythmia (17.1% vs. 7.1%; p = 0.174). CONCLUSIONS: EC TCPC can be performed in heterotaxy patients with comparable early and late results to the non-heterotaxy population. However, the late morbidities regarding the Fontan circulation needs careful follow-up.

Prazosin improves neurogenic acute heart failure through downregulation of fibroblast growth factor 23 in rat hearts.

Bilateral nucleus tractus solitarii (NTS) lesions, possibly caused by enterovirus 71 infection, cause severe neurogenic hypertension, leading to acute heart failure (HF), pulmonary edema, and death within hours. Alpha-adrenergic blockers attenuate blood pressure and ameliorate HF and pulmonary edema, thereby prolonging survival time. However, the molecular mechanisms of these blockers are not clear. In this study, we investigated these mechanisms in a rat model of 6-hydroxydopamine (6-OHDA)-induced HF. Sprague-Dawley rats were treated with prazosin 10 min after the microinjection of 6-OHDA into the NTS. Immunohistochemistry and dihydroethidium (DHE) staining were used for analysis. In the cardiac tissue of 6-OHDA-induced HF, in situ expression of tumor necrosis factor-alpha (TNF-α), fibroblast growth factor-23 (FGF23), and FGF receptor 1 (FGFR1) increased, but in situ expression of Vitamin D receptor (VDR) decreased. DHE staining revealed several heart cells with high reactive oxygen species production. Prazosin treatment decreased TNF-α, FGF23, and FGFR1 expression in the heart of rats with 6-OHDA-induced HF. It also prevented cardiomyopathy caused by 6-OHDA-induced bilateral NTS lesions by inhibiting the FGF23-FGFR1 pathway and downregulating TNF-α expression. In situ, FGF23, FGFR1, VDR, superoxide, and TNF-α in the heart were found to be involved in acute HF in our rat model of 6-OHDA-induced bilateral NTS lesions. These findings are potentially useful for treating fatal enterovirus 71 infection-induced NTS lesions and HF.

Performance of the EuroSCORE II Model in Predicting Short-Term Mortality of General Cardiac Surgery: A Single-Center Study in Taiwan.

Background: The latest European System for Cardiac Operative Risk Evaluation (EuroSCORE) II is a well-accepted risk evaluation system for mortality in cardiac surgery in Europe. Objectives: To determine the performance of this new model in Taiwanese patients. Methods: Between January 2012 and December 2014, 657 patients underwent cardiac surgery at our institution. The EuroSCORE II scores of all patients were determined preoperatively. The short-term surgical outcomes of 30-day and in-hospital mortality were evaluated to assess the performance of the EuroSCORE II. Results: Of the 657 patients [192 women (29.22%); age 63.5 ± 12.68 years], the 30-day mortality rate was 5.48%, and the in-hospital mortality rate was 9.28%. The discrimination power of this new model was good in all populations, regardless of 30-day mortality or in-hospital mortality. Good accuracy was also noted in different procedures related to coronary artery bypass grafting, and good calibration was noted for cardiac procedures (p value > 0.05). When predicting surgical death within 30 days, the EuroSCORE II overestimated the risk (observed to expected: 0.79), but in-hospital mortality was underestimated (observed to expected: 1.33). The predictive ability [area under the curve (AUC) of the receiver operating characteristic (ROC) curve] and calibration of the EuroSCORE II for 30-day mortality (0.792) and in-hospital mortality (0.825) suggested that in-hospital mortality is a better endpoint for the EuroSCORE II. Conclusions: The new EuroSCORE II model performed well in predicting short-term outcomes among patients undergoing general cardiac surgeries. For short-term outcomes, in-hospital mortality was better than 30-day mortality as an indicator of surgical results, suggesting that it may be a better endpoint for the EuroSCORE II.

Serial Cardiopulmonary Exercise Testing in Patients after Extracardiac Conduit Total Cavopulmonary Connection for Single-Ventricle Hearts: An Observational Study.

OBJECTIVE: To analyze the aerobic fitness and evolution of exercise tolerance in patients with single-ventricle physiology after total cavopulmonary connection (TCPC) with an extracardiac conduit (ECC). STUDY DESIGN: This retrospective cohort study included patients with previous ECC-TCPC who underwent cardiopulmonary exercise testing (CPET) between September 2010 and September 2019. Patients who completed at least 2 tests (≥6 months apart) with adequate levels of effort were recruited for the serial CPET evaluation. RESULTS: We identified 70 patients (50% male) with a mean age of 6.45 ± 5.14 years at ECC-TCPC and 15.67 ± 5.03 years at the initial CPET. The peak oxygen consumption (peak VO2) to predicted value (peak PD) was 55.90 ± 16.81%. Twenty of the 70 identified patients (50% male) were recruited for serial analysis. The average number of CPETs was 2.6 per patient. The average duration from the first CPET to the last CPET was 3.64 years. The peak VO2 and PD increased slowly, with mean rates of 38.77 ± 129.01 mL/min and 1.66 ± 6.40%, respectively, during the study period. CONCLUSIONS: Although the patients had lower exercise tolerance after ECC-TCPC compared with their normal peers, exercise tolerance appears to have been preserved over the adolescent period in those who underwent serial testing after ECC-TCPC.

Gabapentin Reduces Blood Pressure and Heart Rate through the Nucleus Tractus Solitarii.

BACKGROUND: Oral and intravenous gabapentin can markedly attenuate blood pressure (BP) in hypertensive rats. The nucleus tractus solitarii (NTS) is the primary integrative center for cardiovascular control and other autonomic functions in the central nervous system. However, the signaling mechanisms involved in gabapentin-mediated cardiovascular effects in the NTS remain unclear. We investigated whether the nitric oxide synthase (NOS) signaling pathway was involved in gabapentin-mediated BP regulation in the NTS of spontaneously hypertensive (SHR) rats. METHODS: SHR rats were anesthetized with urethane at age 10-12 weeks. Arterial pressure and heart rate (HR) were monitored through a femoral artery catheter. For stereotaxic intra-NTS microinjection, the dorsal surface of the medulla was exposed by limited craniotomy. We observed that unilateral microinjection of gabapentin into the NTS whether to change dose-related BP and HR. Then, unilateral microinjection of gabapentin into the NTS before and after N(ω)-nitro-L-arginine methyl ester (L-NAME) treatment whether to change blood pressure and heart rate. RESULTS: Unilateral microinjection of gabapentin into the NTS produced prominent dose-related depressor and bradycardic effects in SHR rats. The cardiovascular effects of gabapentin were attenuated by the prior administration of the NOS inhibitor, L-NAME. CONCLUSIONS: Gabapentin modulated central BP and HR control in the NTS of SHR rats in this study through NOS signaling.

Involvement of Endothelial Nitric Oxide Synthase Activation in Midkine-Mediated Central Hypotensive Effects.

The growth factor midkine (MK) has been implicated in various biologic and pathologic events. It has been shown that the peripheral influence of MK on cardiovascular regulation is due to an influence on the renin-angiotensin system (RAS). The nucleus tractus solitarii (NTS) is the primary integrative center for cardiovascular control and other autonomic functions in the central nervous system. However, the signaling mechanisms involved in MK-mediated cardiovascular effects in the NTS remain unclear. In this study, we investigated whether the RAS and/or N-methyl-D-aspartate (NMDA) receptor-calmodulin-endothelial nitric oxide synthase (eNOS) signaling pathways were both involved in MK-mediated blood pressure (BP) regulation in the NTS of Wistar-Kyoto (WKY) rats. Intra-NTS microinjection and immunoblot analysis were used to evaluate the signal pathway. WKY rats were anesthetized with urethane. Unilateral microinjection of MK (600 fmol) into the NTS produced a dose-dependent decrease in BP and heart rate (HR). The depressor effects were observed before and after microinjection of the angiotensin-converting enzyme (ACE) inhibitor lisinopril (2.4 fmol), or the angiotensin receptor blockers (ARB) inhibitor valsartan (7.5 pmol). However, lisinopril and valsartan did not diminish the MK-mediated cardiovascular effects in the NTS. Microinjection of the NMDA receptor antagonist MK801 (1 nmol) or the NOS inhibitor N-nitro l-arginine methyl ester (L-NAME), (33 nmol), into the NTS attenuated the MK-induced hypotensive effects. Pretreatment with an eNOS inhibitor N5-iminoethyl-l-ornithine (L-NIO) (6 nmol) attenuated the MK-induced hypotensive effects. In this study, the data showed that MK might play a role in central cardiovascular regulation in the NTS. These results suggest that MK decreased BP and HR in the NTS probably acting via the NMDA receptor-calmodulin-eNOS signaling pathway.

Early and intermediate-term results of the extracardiac conduit total cavopulmonary connection for functional single-ventricle hearts.

BACKGROUND/PURPOSE: Fontan operation has evolved from atriopulmonary connection to total cavopulmonary connection (TCPC) due to its advantages in terms of hemodynamics and reduction of atrium-related complications. We analyzed the early and intermediate-term results of extracardiac conduit TCPC (EC-TCPC) procedure in patients with functional single ventricle to investigate the risk factors of surgical mortality and intermediate failure. METHODS: Retrospective review of the medical records of 88 consecutive patients with functional single ventricle who underwent EC-TCPC from 2000 to 2013 was conducted. RESULTS: The follow-up was 100% complete, ranging from 3 months to 13 years (mean 7.0 ± 3.8 years). There were two (2.3%) hospital and 18 (20.4%) late deaths. The estimated event-free survival rates at 1 year, 5 years, and 10 years were 90.6%, 89.3%, and 77.2%, respectively. On univariate analysis, fenestration was the only risk factor for surgical mortality (p = 0.027). On multivariate analysis, the significant atrioventricular valve regurgitation was the only risk factor for intermediate failure (p = 0.017). CONCLUSION: The clinical results of EC-TCPC in patients with functional single ventricle were satisfactory. The patients who needed fenestration during operation had higher risk of surgical mortality. Significant atrioventricular valve regurgitation had negative impact on intermediate survival.

Fontan Operation in a Patient with Severe Hypoplastic Right Pulmonary Artery, Single Ventricle, and Heterotaxy Syndrome.

Assessment of the pulmonary circulation status including pressure, resistance, size, and absence of anatomical distortion, is crucial to the successful Fontan operation. Most patients are found to have acceptable pulmonary arteries after previous palliation, although some degree of distortion is not uncommon. However, in rare instances, some patients have only one functioning lung with another pulmonary artery seriously hypoplastic or atretic. For theses patients, completion of a Fontan operation will be challenging. We reported a 17-year-old girl with a single ventricle and heterotaxy syndrome and only her left lung functioning, who underwent one-lung Fontan operation with a satisfactory result.

Morphometrics predicts the differential regurgitant fraction in bilateral pulmonary arteries of patients with repaired tetralogy of fallot.

In patients with repaired tetralogy of Fallot (rTOF), the regurgitant fraction (RF) in left pulmonary artery (LPA) and right pulmonary artery (RPA) is usually unequal. The morphometrics may play a crucial role in this RF discrepancy. Cardiovascular MR of 79 rTOF patients and 20 healthy controls were retrospectively enrolled. Forty-four from the 79 patients were matched in age, sex and body surface area to the 20 controls and were investigated for: (1) phase-contrast flow of main pulmonary artery (MPA), LPA, and RPA; (2) vascular angles: the angles between the thoracic anterior-posterior line (TAPL) with MPA (θM-AP), MPA with RPA (θM-R), and MPA with LPA (θM-L); (3) cardiac angle, the angle between TAPL and the interventricular septum; (4) area ratio of bilateral lung and hemithorax regions. Compared with the 20 controls, the 44 rTOF patients exhibited wider θM-AP, sharper θM-L angle, and a smaller θM-L/θM-R ratio. In the 79 rTOF patients, LPA showed lower forward, backward, and net flow, and greater RF as compared with RPA. Multivariate analysis showed that the RF of LPA was negatively associated with the θM-L/θM-R ratio and the age at surgery (R2 = 0.255). Conversely, the RF of RPA was negatively associated with the left lung/left hemithorax area ratio and cross-sectional area (CSA) of LPA, and positively associated with CSA of RPA and MPA (R2 = 0.366). In rTOF patients, the RF of LPA is more severe than that of RPA, which may be related to the vascular morphometrics. Different morphometric parameters are independently associated with the RF of LPA or RPA, which may offer potential insights for surgical strategies.

Pulmonary artery intimal sarcoma: a case report and literature review.

Pulmonary artery intimal sarcoma is a rare disorder arising from the intima of the pulmonary artery. Histopathology reveals that it is a tumour cell of mesenchymal origin. The signs and symptoms include chronic shortness of breath and other features of right ventricular failure, which mimic chronic pulmonary thromboembolism. The definitive diagnosis can rarely be made based on the symptoms and signs alone, and other investigations including echocardiography, computed tomography, magnetic resonance imaging (MRI), and positron emission tomography (PET) are often required. The gold standard for diagnosis is tissue biopsy. The mainstay for treatment is surgery, and complete surgical resection with endarterectomy provides survival benefit. According to recent evidences, however, multimodal treatment provides better survival outcomes than monotherapy such as surgery alone. Despite the newer upcoming treatment strategies, patients with pulmonary intimal sarcoma continue to have a poor prognosis. We present a case of pulmonary artery intimal sarcoma and review the literature associated with the disease.

Noninvasive methods of accurately diagnosing in children anomalous origin of the left coronary artery from the pulmonary trunk.

BACKGROUND: Anomalous origin of the left coronary artery from the pulmonary trunk is a rare congenital heart defect. Cardiac catheterization remains the standard means of diagnosis. Our purpose in this study is to emphasize the importance of assessing the electrocardiogram when making the diagnosis, in addition to taking note of transthoracic echocardiographic findings. We also analyzed the sensitivity of each parameter under investigation. METHODS AND RESULTS: Between June, 1999, and March, 2007, we studied 9 patients, 6 males and 3 females, with a mean age of 3.02 years, in whom anomalous origin of the left coronary artery from the pulmonary trunk was suspected subsequent to transthoracic echocardiographic examination. We examined their electrocardiograms, and undertook cardiac catheterization. In all patients, the transthoracic echocardiogram had shown retrograde flow into the pulmonary trunk, with the left coronary artery arising from pulmonary trunk, along with a dilated right coronary artery, or intercoronary collateral vessels. In 8 patients, the electrocardiogram showed deep Q wave in leads I and aVL, with depression of the ST segments over lead V4 through 6, or inversion of the T waves in leads I, II, and aVL. In the remaining patient, the electrocardiogram showed incomplete right bundle branch block. Later, cardiac catheterization confirmed the diagnosis in 8 patients, but the other patient was shown to have the right coronary artery arising from the pulmonary trunk. CONCLUSIONS: By combining transthoracic echocardiography with study of the electrocardiogram, it is possible to provide accurate evaluation of anomalous origin of the left coronary artery from the pulmonary trunk.

A potentially fatal complication during subclavian vein catheterization in an infant with congenital heart disease-puncture to pulmonary artery directly: a case report.

The most frequent and acute complications of subclavian vein catheterization are arterial puncture to the subclavian artery and pneumothorax. We report an arterial puncture directly to the pulmonary artery in infant during subclavian vein catheterization.

Successful repair of neonatal tricuspid regurgitation due to chordae rupture.

Neonatal rupture of the chordae of tricuspid valve with severe regurgitation is rare and disastrous. We report on a full-term female neonate presented with cyanosis caused by severe tricuspid regurgitation (TR) due to anterior leaflet chordal rupture. After initial stabilization by prostaglandin E1 infusion, successful early repair was achieved with artificial chordae implantation. The unique pathophysiology and the therapeutic strategy of this situation will be described.

Hemopericardium from right atrial laceration in a newborn.

We report the case of a newborn who suffered right atrial laceration during delivery. To our knowledge, there has been no previous report of blunt injury causing right atrial laceration with hemopericardium complicated by cardiac tamponade in the perinatal period.

Performance of European system for cardiac operative risk evaluation in Veterans General Hospital Kaohsiung cardiac surgery.

BACKGROUND: The European System for Cardiac Operative Risk Evaluation (EuroSCORE) model is a widely-used risk prediction algorithm for in-hospital or 30-day mortality in adult cardiac surgery patients. Recent studies indicated that EuroSCORE tends to overpredict mortality. The aim of our study is to evaluate the validity of EuroSCORE in Veterans General Hospital Kaohsiung (VGHKS) cardiac surgery including a number of different surgical and risk subgroups. METHODS: From January 2006 to December 2009, 1,240 adult patients who underwent cardiac surgery in VGHKS were included in this study. The study was followed the guidelines of the Ethics Committee of Kaohsiung Veterans General Hospital, Taiwan. Both additive and logistic score of all patients were calculated depending on the formula in the official EuroSCORE website. The entire cohort, different surgical type and risk stratification subgroups were analyzed. Model discrimination was tested by determining the area under receiver operating characteristic (ROC) curve. Model calibration was tested by the Hosmer-Lemeshow chi-square test. Clinical performance of model was assessed by comparing the observed and predicted mortality rates. RESULTS: There were significant differences between the VGHKS and European cardiac surgical populations. The additive score and logistic score for the overall group were 7.16% and 12.88%, respectively. Observed mortality was 10.72% overall, 5.68% for isolated coronary artery bypass grafting (CABG), 4.67% for the mitral valve only and 4.25% for the aortic valve only group. The discriminative ability EuroSCORE was very good in all and various surgical subgroups, with area under the ROC curve from 0.75 to 0.87. The addictive and logistic models of EuroSCORE showed excellent accuracy, 0.839 and 0.845, respectively. Good calibration power was recognized by p value higher than 0.05 for the entire cohort and all subgroups of patients except for isolated CABG. The logistic EuroSCORE model overestimated mortality to different degrees in the various subgroups, indicating that the logistic EuroSCORE needs to be recalibrated by a factor about 0.55 for uncomplicated surgery and low-risk groups, and 0.85 for high-risk patients with original additive score more than six. CONCLUSION: EuroSCORE is simple and easy to use. In the present study, the model demonstrated excellent accuracy in all and various surgical subgroups in VGHKS cardiovascular surgery populations. Good calibration ability in all and different risk categories was identified except for isolated CABG group. Recalibration factors of 0.55 and 0.85 were suggested for the various operative subgroups and risk categories.

Role of multi-slice and three-dimensional computed tomography in delineating extracardiac vascular abnormalities in neonates.

BACKGROUND: Recent advances in multi-slice computed tomography (MSCT) and three-dimensional computed tomography (3D CT) provide good-resolution images and short scan time for complete diagnosis of congenital heart disease (CHD). In the present study, we found that MSCT rapidly provides clinically relevant information for diagnosing extracardiac vascular anatomy in neonates with CHD. It is less invasive, necessitating only minimum or no sedation and a relatively small amount of contrast material. These advantages are crucial, especially for critically ill neonates. METHODS: Between January 2007 and December 2008, MSCT scans were conducted on 41 neonates who were admitted to our neonatal intensive care unit. All the neonates were suspected to have complex CHD after an initial echocardiography examination. The scans were focused on detecting extracardiac vascular anatomy and abnormalities. All the image data sets were sent to image processing workstations for multiplanar interactive viewing and 3D reconstruction. RESULTS: High-resolution MSCT scan images were obtained from 41 patients. Reported indications and findings of extracardiac abnormalities and related structural anatomy pertaining to congenital heart disease from MSCT and 3D CT findings were confirmed by clinical and surgical findings by a team of multidisciplinary congenital heart disease specialists. CONCLUSION: Based on clinical and surgical confirmation of the MSCT scan results from a multidisciplinary congenital heart disease specialist team, we concluded that adequate information on CHD, specifically that regarding extracardiac abnormalities of the anatomy, can be obtained and MSCT can be used to replace cardiac catheterization.

Ventilator-associated pneumonia after pediatric cardiac surgery in southern Taiwan.

BACKGROUND AND PURPOSE: To determine the frequency, risk factors, associated pathogens, and outcomes of ventilator-associated pneumonia (VAP) after pediatric cardiac surgery. METHODS: This was a retrospective review of the medical records of patients younger than 18 years with congenital heart disease (CHD) who underwent cardiac surgery from January 2005 to December 2007. Patients were categorized into 2 groups: with and without VAP. RESULTS: Of 100 patients, 13% acquired VAP. Most patients (85%) who developed VAP were infants younger than 1 year. Patients with complex CHD were more likely to develop VAP than patients with simple CHD (chi(2) = 7.69; p < 0.03). Two independent and modifiable risk factors were identified: prolonged use of mechanical ventilation (adjusted odds ratio [AOR], 15.196; 95% confidence interval [CI], 2.158-107.2) and prolonged use of a central venous catheter (AOR, 7.342; 95% CI, 1.054-51.140). The cardiopulmonary bypass time and duration of chest tube drainage were not risk factors. The development of VAP increased pediatric intensive care unit duration of stay (p < 0.006), duration of hospital stay (p < 0.001), and mortality rate (p < 0.001). Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus were the most common pathogens isolated from endotracheal aspirate. CONCLUSIONS: VAP is common after congenital heart surgery. Physicians must pay special attention to infants with complex CHD because they are at high risk for the development of VAP after congenital heart surgery. Shortening the duration of mechanical ventilation and central venous catheter placement are critical factors for reducing the risk for VAP.

Influence of pulmonary regurgitation inequality on differential perfusion of the lungs in tetralogy of Fallot after repair: a phase-contrast magnetic resonance imaging and perfusion scintigraphy study.

OBJECTIVES: The purpose of this study was to evaluate the influence of pulmonary regurgitation inequality on differential perfusion of the lungs in tetralogy of Fallot (TOF) after repair. BACKGROUND: Asymmetry of lung perfusion is one of the best predictors of outcome in TOF after repair. A recent phase-contrast magnetic resonance imaging (PC-MRI) study found prominent regurgitation inequality between the bilateral pulmonary arteries in TOF after repair. METHODS: Forty-three TOF post-repair patients (median age = 51 months, 31 men) received PC-MRI and 99mTc-labeled macroaggregates of albumin perfusion scintigraphy (PS) in the same day. We took PC-MRI measurements of forward flow volume (FFV), backward flow volume (BFV), and net flow volume (NFV) (NFV = FFV - BFV) and regurgitation fraction (RF) (RF = BFV/FFV) at the left and right pulmonary arteries (LPA and RPA). The differential perfusion of the left lung (L%) (L% = left lung/left + right lung) as calculated by NFV ratio, by FFV ratio of PC-MRI, and by PS were compared. RESULTS: The discrepancy between L% by NFV versus L% by PS was affected by the severity of RF of LPA (r = -0.51, p = 0.001); agreement between L% by NFV versus L% by PS was good (intraclass correlation coefficient [Ri] = 0.87) if RF of LPA <0.4 (n = 23) but downgraded (Ri = 0.51) and underestimated the L% (median of error = -14%, range = -25.3% to 5.5%) if RF of LPA > or =0.4 (n = 20). In contrast, agreement between L% by FFV versus L% by PS was high and unaffected by RF of LPA (Ri = 0.94, 0.92, respectively). CONCLUSIONS: While integrating PC-MRI of pulmonary artery as a comprehensive MRI evaluation of TOF after repair, conventional NFV ratio method tended to underestimate the left lung perfusion and may lead to unnecessary intervention. The FFV ratio method should be used for precise assessment of differential lung perfusion.