Review and Assessment of Material, Method, and Predictive Modeling for Fiber-Reinforced Polymer (FRP) Partially Confined Concrete Columns.

The repairing and strengthening of concrete structures using external and internal partial confinements are inevitable in the construction industry due to the new standards and rapid developments. The conventional materials and methods of confinement are unable to meet modern safety and functional standards. The fiber-reinforced polymer (FRP) enhances the strength and ductility of deteriorating and new concrete columns by reducing lateral confinement pressure and resistance against seismic shocks. The precise methods of partial confinement are inevitable for effective FRP-concrete bonding, durability, and cost-effectiveness under different loading conditions and to cope with external environmental factors. Predictive modeling and simulation techniques are pivotal for the optimization of confinement materials and methods by investigating the FRP-concrete novel confinement configurations, stress-strain responses, and failure modes. The novel materials and methods for concrete columns' partial confinement lack high compressive strength, ductility, chemical attack resistivity, and different fiber orientation impacts. This review provides an overview of recent confinement materials, novel methods, and advanced modeling and simulation techniques with a critical analysis of the research gaps for partial FRP confinement of concrete columns. The current challenges and future prospects are also presented.

Python data odyssey: Mining user feedback from google play store.

Context: The Google Play Store is widely recognized as one of the largest platforms for downloading applications, both free and paid. On a daily basis, millions of users avail themselves of this marketplace, sharing their thoughts through various means such as star ratings, user comments, suggestions, and feedback. These insights, in the form of comments and feedback, constitute a valuable resource for organizations, competitors, and emerging companies seeking to expand their market presence. These comments provide insights into app deficiencies, suggestions for new features, identified issues, and potential enhancements. Unlocking the potential of this repository of suggestions holds significant value. Objective: This study sought to gather and analyze user reviews from the Google Play store for leading game apps. The primary aim was to construct a dataset for subsequent analysis utilizing requirements engineering, machine learning, and competitive assessment. Methodology: The authors employed a Python-based web scraping method to extract a comprehensive set of over 429,000+ reviews from the Google Play pages of selected apps. The scraped data encompassed reviewer names (removed due to privacy), ratings, and the textual content of the reviews. Results: The outcome was a dataset comprising the extracted user reviews, ratings, and associated metadata. A total of 429,000+ reviews were acquired through the scraping process for popular apps like Subway Surfers, Candy Crush Saga, PUBG Mobile, among others. This dataset not only serves as a valuable educational resource for instructors, aiding in the training of students in data analysis, but also offers practitioners the opportunity for in-depth examination and insights (in the past data of top apps).

Prediction of dementia based on older adults' sleep disturbances using machine learning.

BACKGROUND: The most common degenerative condition in older adults is dementia, which can be predicted using a number of indicators and whose progression can be slowed down. One of the indicators of an increased risk of dementia is sleep disturbances. This study aims to examine if machine learning can predict dementia and which sleep disturbance factors impact dementia. METHODS: This study uses five machine learning algorithms (gradient boosting, logistic regression, gaussian naive Bayes, random forest and support vector machine) and data on the older population (60+) in Sweden from the Swedish National Study on Ageing and Care - Blekinge (n=4175). Each algorithm uses 10-fold stratified cross-validation to obtain the results, which consist of the Brier score for checking accuracy and the feature importance for examining the factors which impact dementia. The algorithms use 16 features which are on personal and sleep disturbance factors. RESULTS: Logistic regression found an association between dementia and sleep disturbances. However, it is slight for the features in the study. Gradient boosting was the most accurate algorithm with 92.9% accuracy, 0.926 f1-score, 0.974 ROC AUC and 0.056 Brier score. The significant factors were different in each machine learning algorithm. If the person sleeps more than two hours during the day, their sex, education level, age, waking up during the night and if the person snores are the variables that most consistently have the highest feature importance in all algorithms. CONCLUSION: There is an association between sleep disturbances and dementia, which machine learning algorithms can predict. Furthermore, the risk factors for dementia are different across the algorithms, but sleep disturbances can predict dementia.

Innovative parallel synthesis of 5-nonanone and furfural from lignocellulosic biomass accompanied by deep economic analysis.

An integrated strategy is developed to utilize all three primary components (cellulose, hemicellulose, and lignin) of lignocellulosic biomass for the coproduction of hydrocarbon fuel (5-nonanone) and bio-chemicals (furfural and high purity lignin). After biomass fractionation, (1) 5-nonanone is produced with high yield of 89% using cellulose-derived γ-valerolactone (GVL), which can potentially serve as a platform molecule for the production of liquid hydrocarbon fuels for the transportation sector; (2) furfural, a valuable platform chemical, is produced using hemicellulose; and (3) production of high-purity lignin, which can be used to produce carbon foams or battery anodes. Separation subsystems are designed to effectively recover the solvents for reuse in the conversion processes, which ultimately improves the economic feasibility of the integrated process, resulting in achieving lower minimum selling price (MSP) of $5.47 GGE-1 for 5-nonanone compared to market price. Heat pump is introduced to perform heat integration, which reduces utility requirements more than 85%. Finally, a wide range of techno-economic analysis is performed to highlight the major cost and technological drivers of the integrated process.

Evaluation of magnesium sulfate as an adjuvant in sub-Tenon anesthesia for cataract surgery: A prospective, randomized controlled trial.

Purpose: To evaluate the efficacy, safety, and satisfaction for the use of adjuvant; magnesium sulfate (MgSO4) in sub-Tenon anesthesia for cataract surgery. Methods: This single centered randomized, double blind trial was held in 2021 after approval of ethical committee at the Eye Hospital, Riyadh, Saudi Arabia. Cataract patients to be operated using local anesthesia were randomly assigned to two groups; Group magnesium sulfate (MS) received 50 mg/0.5 ml of magnesium sulfate and Group normal saline (NS) received 0.5 ml of normal saline added to the standard mixture, respectively. Absence of eyelid dropping and akinesia of the globe at different time after anesthesia were considered as ineffective anesthesia. The age and sex-adjusted generalized estimating equation (GEE) analysis was carried out. Complications, patient's and surgeon's satisfaction were also compared. Results: Each group had 100 cataract patients. Effectiveness of block was not significantly different in two groups (adjusted odds ratio, 0.90; 95% confidence interval [CI], 0.62, 1.31; P = 0.594). The likelihood of "no eye-opening" significantly increased with time (adjusted odds ratio, 1.26; 95% CI, 1.18-1.34; P < 0.001). Subconjunctival bleeding was significantly higher in the MS versus NS Group (36 of 98 [36.7%] vs. 11 of 102 [10.8%], P < 0.001). Chemosis was not significantly different between the groups (P = 0.95). Patient's satisfaction score was very good (9/10) but slightly higher in NS group than MS (P = 0.001) while surgeon's satisfaction score was similar in both groups (P = 0.149). Conclusions: Although safe, adding 50 mg of magnesium sulfate did not improve the effect of sub-Tenon anesthesia for cataract surgery. Risk of subconjunctival bleeding was higher in cataract patients operated using MgSO4 compared to those managed with the conventional sub-Tenon anesthetic.

Breaking barriers: a statistical and machine learning-based hybrid system for predicting dementia.

Introduction: Dementia is a condition (a collection of related signs and symptoms) that causes a continuing deterioration in cognitive function, and millions of people are impacted by dementia every year as the world population continues to rise. Conventional approaches for determining dementia rely primarily on clinical examinations, analyzing medical records, and administering cognitive and neuropsychological testing. However, these methods are time-consuming and costly in terms of treatment. Therefore, this study aims to present a noninvasive method for the early prediction of dementia so that preventive steps should be taken to avoid dementia. Methods: We developed a hybrid diagnostic system based on statistical and machine learning (ML) methods that used patient electronic health records to predict dementia. The dataset used for this study was obtained from the Swedish National Study on Aging and Care (SNAC), with a sample size of 43040 and 75 features. The newly constructed diagnostic extracts a subset of useful features from the dataset through a statistical method (F-score). For the classification, we developed an ensemble voting classifier based on five different ML models: decision tree (DT), naive Bayes (NB), logistic regression (LR), support vector machines (SVM), and random forest (RF). To address the problem of ML model overfitting, we used a cross-validation approach to evaluate the performance of the proposed diagnostic system. Various assessment measures, such as accuracy, sensitivity, specificity, receiver operating characteristic (ROC) curve, and Matthew's correlation coefficient (MCC), were used to thoroughly validate the devised diagnostic system's efficiency. Results: According to the experimental results, the proposed diagnostic method achieved the best accuracy of 98.25%, as well as sensitivity of 97.44%, specificity of 95.744%, and MCC of 0.7535. Discussion: The effectiveness of the proposed diagnostic approach is compared to various cutting-edge feature selection techniques and baseline ML models. From experimental results, it is evident that the proposed diagnostic system outperformed the prior feature selection strategies and baseline ML models regarding accuracy.

Anesthesia management of ophthalmic surgery for patient with suspected/confirmed COVID-19 -Saudi Anesthesia Society guidelines.

The outbreak of the novel coronavirus (COVID-19) has been declared a global pandemic. With a mortality rate reaching up to 5%, healthcare professionals treating patients with COVID-19 are at a significantly higher risk for exposure themselves. Given the rapidly progressing rate of COVID-19, there is an urgent need for developing guidelines within each specialty. This article discusses guidelines specifically for anesthesiologists dealing with ophthalmic surgeries with suspected or confirmed COVID-19 patients. Anesthesiologists always work in the proximity of the patient's face while performing either ocular regional anesthesia or while managing the airway in the process of intubation/extubation. Within these guidelines, the emphasis is provided on thorough preoperative screening to identify COVID-19 patients and to prevent the exposure of healthcare staff by following standard personal protective equipment (PPE) precautions.

Comparative efficacy of mitigation techniques for the detoxification of Prunus persica (L.) from selected pesticide residues.

Fruits are the valuable and important components of human diet. Among them, Prunus persica is a rich source of different minerals and dietary fibers. In Pakistan, the total annual production of P. persica is approximately 837,000 tons. In order to enhance agricultural yield and quality, the plant protection agents are employed during fruit production. Ultimately, this in turn leads to the incorporation of pesticide residues in fruits. In present study, an effort has been made for the determination of three selected pesticide residues, i.e., chlorpyrifos (CPF), difenoconazole (DFN), and carbendazim (CRB) in samples of P. persica collected from Swat territory. Samples were analyzed through high performance liquid chromatography (HPLC). Results revealed the occurrence of all three pesticides in studied samples; however, levels of CPF and DFN were found to be higher than MRLs. Moreover, the effects of different mitigation techniques revealed that highest reduction of CPF, DFN, and CRB (86%, 97%, 89%) residues was obtained by treatment with 10% CH3COOH followed by 10% NaCl (74%, 78%, 84%). The lowest reduction was obtained by treatment with 10% solution of NaOH (52%, 55%, 63%).

Comparison of topical oxybuprocaine and intravenous fentanyl in pediatric strabismus surgery.

PURPOSE: To compare the outcomes such as postoperative nausea/vomiting, analgesic requirements, and hospital stay following the use of topical oxybuprocaine hydrochloride 0.4% or intravenous (IV) fentanyl in children undergoing strabismus surgery. METHODS: This was a prospective cohort study. Children operated under general anesthesia for strabismus were given topical oxybuprocaine hydrochloride 0.4% (Group T) and IV fentanyl (Group F) before surgery. The episodes of nausea/vomiting, pain score, requirement of additional analgesia during postoperative period, and duration of hospital stay were compared in two groups. RESULTS: There were 47 children in Group T and 59 children in Group F. The median pain score in two groups were 2.38 (25% quartile; 2.0) and 3.00 (25% quartile; 3.00), respectively. The difference was significant (K W P < 0.03). The episodes of nausea/vomiting in two groups were in 2 and 6 children in Group T and Group F, respectively. The median hospital stay of children of Group T and Group F were 242 and 285 min, respectively. The difference was not statistically significant (P = 0.22). CONCLUSIONS: Using intraoperative topical oxybuprocaine drops, one can achieve better analgesic outcomes and reduce risk of nausea and vomiting compared to intravenous opioid analgesics and therefore, the hospital stay could also be marginally reduced.

Comparison of Olive Tipped and Conventional Steven's Cannula for Sub-Tenon Ophthalmic Anesthesia.

PURPOSE: To compare the efficacy of the olive tipped (OT) cannula to the conventional Steven's cannula for sub-Tenon block (STB) before cataract surgery. METHODS: This prospective, randomized, double-masked compared STB delivered in cataract surgery patients with an OT cannula or a conventional Steven's cannula (ST). Outcome variables included the akinesia score and lid movement scores at 5 and 10 min. The patient perception of pain during delivery of the STB and surgery were also compared between groups. Surgeon satisfaction with anesthesia was compared between groups. P <0.05 was statistically significant. RESULTS: There were sixty patients in each group. The age between groups was not statistically different (P = 0.4). The body mass index was higher in the ST group compared to the OT group (P < 0.001). The akinesia score at 5 and 10 min did not differ between groups (P = 0.07 and P = 0.6, respectively). The patient perception of pain during STB and surgery were similar between groups (P = 0.1 and P = 0.06, respectively). There were six patients with mild chemosis and redness in the OT group and 15 patients in the ST group. CONCLUSION: An OT cannula is equally effective as the conventional Steven's cannula for delivering STB anesthesia before cataract surgery.

Mutations of the human interferon alpha-2b (hIFNα-2b) gene in low-dose natural terrestrial ionizing radiation exposed dwellers.

Natural terrestrial ionizing radiations emerge from uranium deposits and can impact human tissues by affecting DNA bases which constitute genes. Human interferon alpha-2b (hIFNα-2b) gene synthesizes a protein which exhibits anticancerous, immunomodulatory, anti-proliferative and antiviral properties. This research aimed to find out hIFNα-2b gene mutations for those residents who were chronically exposed to low-dose natural terrestrial ionizing radiations. The gene amplifications was done through PCR technique and gene mutations were identified by bioinformatics in order to conclude as to how mutations identified in hIFNα-2b gene sequences will lead to alterations in the hIFNα-2b protein in radiation exposed residents. The range of radiation dose exposure was 0.4383-4.55832 (mSv/y) for the selected radiation exposed locations which were having uranium mineralization. Mutations (24%) in hIFNα-2b gene shows that some of the radiation exposed inhabitants were having a modulated immune response. The CBC (Complete Blood Count) parameters: WBC (White Blood Cells), MCH (Mean Corpuscular Hemoglobin), MCHC (MCH Concentration) and PLT (Platelets) on average were below the normal range in 24% radiation exposed subjects who were having hIFNα-2b gene mutations. Immunomodulation is observed by the mixed trend of either lymphocytosis or lymphopenia and neutropenia or neutrophilia in the exposed population. Thus, a radioactive exposure from uranium can affect the immune system and can induce mutations.

Influence of GlideScope assisted endotracheal intubation on intraocular pressure in ophthalmic patients.

BACKGROUND: Traditional Macintoch laryngoscopy is known to cause a rise in intraocular pressure (IOP), tachycardia and hypertension. These changes are not desirable in patients with glaucoma and open globe injury. GlideScope is a video laryngoscope that functions independent of the line of sight, reduces upward lifting forces for glottic exposure and requires less cervical neck movement for intubation, making it less stimulating than Macintosh laryngoscopy. AIM: The aim was to assess the variations in IOP and hemodynamic changes after GlideScope assisted intubation. MATERIALS AND METHODS: After approval of the local Institutional Research and Ethical Board and informed patient consent, 50 adult American Society of Anesthesiologist I and II patients with normal IOP were enrolled in a prospective, randomized study for ophthalmic surgery requiring tracheal intubation. In all patients, trachea was intubated using either GlideScope or Macintoch laryngoscope. IOP of nonoperated eye, heart rate and blood pressure were measured as baseline, 1 min after induction, 1 min and 5 min after tracheal intubation. RESULTS: IOP was not significantly different between groups before and after anesthetic induction and 5 min after tracheal intubation (P = 0.217, 0.726, and 0.110 respectively). The only significant difference in IOP was at 1 min after intubation (P = 0.041). No significant difference noted between groups in mean arterial pressure (P = 0.899, 0.62, 0.47, 0.82 respectively) and heart rate (P = 0.21, 0.72, 0.07, 0.29, respectively) at all measurements. CONCLUSION: GlideScope assisted tracheal intubation shown lesser rise in IOP at 1 min after intubation in comparison to Macintoch laryngoscope, suggesting that GlideScope may be preferable to Macintosh laryngoscope.

Mutations of the human interferon alpha-2b (hIFN-α2b) gene in occupationally protracted low dose radiation exposed personnel.

Ionizing radiations impact human tissues by affecting the DNA bases which constitute genes. Human interferon alpha 2b gene synthesizes a protein which is an important anticancerous, immunomodulatory, anti-proliferative and antiviral protein. This study was aimed to identify interferon alpha-2b mutations as a consequence of the use of occupational chronic low dose radiation by hospital radiation exposed workers. A molecular analysis was done in which DNAs were extracted from blood samples from radiology, radiotherapy and nuclear medicine workers. The gene was amplified through polymerase chain reaction and further genetic data from sequencing results analyzed by bioinformatics tools in order to determine as to how mutations in interferon alpha 2b sequences will lead to changes in human interferon alpha-2b protein. A total of 41% gene mutations was detected among all radiation exposed workers in which higher percentage (5.4%) of base insertion mutations and 14% frameshift mutations were found in radiology workers. The chronic use of low dose of radiations by occupational workers has a significant correlation with mutational effects on interferon alpha 2b gene, further evident by depressed interferon alpha levels in serum. This can lead to depressed immunity in radiation exposed workers. Hematological profiling of this group also showed hyperimmune response in the form of lymphocytosis.

Clinical review of obstructive primary cardiac tumors in childhood.

OBJECTIVES: This study aims to examine the long-term outcomes of conservative management compared with surgical resection for obstructive and nonobstructive primary cardiac tumors in children. DESIGN: A 20-year retrospective review of primary cardiac tumors seen in the right ventricular outflow tract (RVOT) and left ventricular outflow tract (LVOT) in children at The Hospital for Sick Children, Toronto, Canada. Student's t-tests and Fisher's exact chi-square were used to compare outcomes between the conservatively managed vs. surgical resection groups and the obstructive vs. nonobstructive tumor groups. RESULTS: Between 1990 and 2010, we identified 130 children with intracardiac tumors among 52 937 (2.5 per 1000 children, 95th confidence interval: 2.1-2.9 per 1000). Thirty-six children (28%) had at least one cardiac tumor in the RVOT (n = 13) or LVOT (n = 23). Of those, 14 children had peak outflow gradients of >20 mm Hg at the diagnostic echocardiogram (median age at diagnosis: 4 days, range 0 days-6 months; mean follow-up: 7.8 ± 4.5 years). Rhabdomyoma was the most common tumor 27/36 (75%). Twelve (33%) patients underwent surgical repair vs. 24 patients who were observed only. There was no difference in survival. Patients who had surgery tended to be sicker (intubated at diagnosis 4/12, 33% vs. 1/23, 4%, P = .04). There were no deaths in either group. One child required reoperation for severe aortic insufficiency, and only one child in the observation group had residual obstruction at most recent follow-up. CONCLUSIONS: Primary cardiac tumors in childhood obstructing the RVOT or LVOT are uncommon findings after birth and may be managed nonsurgically in most cases.

Comparison of metal and flexible sub-Tenon cannulas.

PURPOSE: To compare metal posterior, flexible posterior, and flexible medium sub-Tenon cannulas for akinesia and anesthesia. SETTING: King Khaled Specialist Eye Hospital, Riyadh, Saudi Arabia. DESIGN: Prospective blind randomized comparison. METHOD: Patients having cataract surgery under sub-Tenon block received a mixture of bupivacaine and lidocaine with hyaluronidase. The patients were divided into 3 groups based on whether a metal posterior sub-Tenon cannula, flexible posterior sub-Tenon cannula, or flexible medium sub-Tenon cannula was used. Pain during injection, akinesia, anesthesia, and complications were recorded. RESULTS: The study enrolled 159 patients. The akinesia score, superior oblique muscle activity, lid movements, and pain during injection were significantly lower in the metal posterior cannula group 2 minutes after injection (P=.002, P=.008, P=.097, and P=.001, respectively); there was no significant difference at 4 minutes, 6 minutes, 8 minutes, and 10 minutes. The incidence of intraoperative pain was low in all groups (P=.607). Chemosis was significantly less in the flexible posterior cannula group (P=.003); however, there was no significant difference in the site of chemosis (P=.460). There was no significant difference in the incidence, site, or severity of subconjunctival hemorrhage (P=.087, P=.072, and P=.331, respectively). No serious complications occurred. CONCLUSIONS: Rigid posterior, flexible posterior, and flexible medium cannulas produced effective and equivalent anesthesia. The flexible cannulas may be safer than the rigid cannulas. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.

Comparison of levobupivacaine 0.5% or bupivacaine 0.5% both in a mixture with lidocaine 2% for superficial extraconal blockade.

PURPOSE: To evaluate the quality and efficacy of Peribulbar blockade for superficial extraconal anesthesia with levobupivacaine 0.5% versus bupivacaine 0.5%, both combined with lidocaine 2% for patients undergoing phacoemulsification. MATERIALS AND METHODS: In this prospective, double blind study, 150 patients were randomly divided into two groups: group-1 received a Peribulbar block (PB) with a mixture of evobupivacaine 0.5% and lidocaine 2% while group-2 received a PB with a mixture of bupivacaine 0.5% and lidocaine 2%. The block was performed by insertion of a short needle (15 mm) in infra-temporal space just above inferior orbital notch. An initial volume of 6 9 ml of either mixture was injected until total upper eyelid drop. Akinesia score was assessed at 2, 5, and 10 min after the block. The degree of pain was assessed by a verbal rating scale immediately after block, at the end of surgery and 4 h postoperatively. The patients and surgeons were asked to rate their satisfaction level of the quality of block postoperatively. Data were analyzed with the unpaired, two-tailed t-test and the Chi-square test as appropriate. P < 0.05 was considered statistically significant. RESULTS: There were no significant differences between groups with respect to the akinesia score (P = 0.2) at 2, 5, and 10 min, the number of supplementary injections (P = 0.84) and initial and total required volume of local anesthetics (P = 0.80 and 0.81, respectively). There was no significant difference between the groups regarding surgeon and patient satisfaction (P = 0.53 and P = 0.74, respectively). Similarly the verbal rating scales assessed at three different occasions were not significantly different between the groups (P > 0.05 all cases). The need for additional intra-operative topical anesthetic was also similar between the groups. (P = 0.69). CONCLUSIONS: Superficial extra-conal block with a mixture of levobupivicaine 0.5% and lidocaine 2% or bupivicaine 0.5% and lidocaine 2% provides similar block quality and efficacy.

A novel method for laryngeal mask airway size selection in paediatric patients.

CONTEXT: The successful use of the laryngeal mask airway in children partly depends on the correct selection of size. Most anaesthesiologists rely on the weight-based table which is often difficult to remember. A simple method allowing an adequate choice of the correct size may be highly desirable. OBJECTIVES: To test the hypothesis that the size of the external ear (pinna) of the child may be used as proxy for the required size of laryngeal mask airway. DESIGN: A descriptive study. SETTING: King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia. PATIENTS: Two hundred and ten paediatric patients aged 6 months to 15 years, of either sex, American Society of Anesthesiologists (ASA) 1-2 and scheduled for routine ophthalmological procedures from 1 March to 31 December 2010. Emergency cases, patients with a full stomach or with a history of any oropharyngeal lesion other than tonsillar hypertrophy were excluded. MAIN OUTCOME MEASURES: The size of the external ear was measured with a ruler in vertical and horizontal dimensions in the first 30 patients, and visually evaluated for the remaining patients. For all, the nearest corresponding size of partially inflated laryngeal mask airway was chosen and inserted after induction. The correct placement was assessed using predefined criteria. RESULTS: Insertion and good ventilation was achieved in 196 (93.3%) on first attempt. Fourteen patients (6.7%) required a second attempt and the main reason for failure was an audible leak because of smaller size. CONCLUSION: Choosing the size of the laryngeal mask airway in children according to the size of the external ear was associated with a success rate of 93% which is comparable with that reported in the literature when the tables are used. This simple method may allow a rapid choice of the correct size of laryngeal mask airway and may eliminate the need to remember different tables or formulae.

Influence of RV restrictive physiology on LV diastolic function in children after tetralogy of Fallot repair.

BACKGROUND: Restrictive right ventricular (RV) physiology is a common finding after tetralogy of Fallot repair. Via diastolic ventricular interaction, RV filling characteristics may influence left ventricular (LV) filling. The aim of this study was to analyze the effect of RV diastolic physiology on LV diastolic properties. METHODS: This was a retrospective study including 112 pediatric patients after tetralogy of Fallot repair who underwent full echocardiographic evaluations. Restrictive RV physiology was defined as the presence of end-diastolic forward flow in the main pulmonary artery as detected in at least three consecutive cardiac cycles. RV and LV diastolic function was assessed by analyzing mitral or tricuspid inflow patterns, pulmonary venous flow traces, and pulsed tissue Doppler velocities at the tricuspid and mitral annuli. RESULTS: The mean age at the time of study was 12.9 ± 3.2 years. Restrictive RV physiology was identified in 58 of 112 patients (52%). Patients with RV restriction had larger right atrial and RV dimensions, as well as increased left atrial length and left atrial indexed volume compared with nonrestrictive patients. No differences were found in LV dimensions. Although parameters reflecting early LV diastolic filling (mitral E velocity, lateral annular E' velocity, isovolumetric relaxation time, and E/E' ratio) were not different between the restrictive and nonrestrictive patients, those reflecting late filling were different, with a significantly higher pulmonary venous A-wave reversal velocity and duration in the restrictive group (P < .001). Also, the difference between pulmonary venous A-wave reversal and mitral valve A-wave duration was higher in the restrictive group (P = .0007). CONCLUSIONS: End-diastolic forward flow in the main pulmonary artery is associated with larger RV dimensions in pediatric patients with postoperative tetralogy of Fallot. The presence of end-diastolic forward flow was not associated with other differences in RV diastolic parameters but with more pronounced pulmonary venous reversals and larger left atrial size. This indicates that ventricular diastolic interaction affects LV filling pressures.