Sensory ataxic polyneuropathy unmasking late-onset urea cycle defect.

A 63-year-old man with type 2 diabetes mellitus, alcohol consumption in moderation, and three episodes of hepatic encephalopathy presented with symmetrical lower limb distal weakness, sensory ataxia, thickened palpable nerves, mood disturbances for seven years, and a family history of schizophreniform disorders. Nerve conduction studies showed demyelinating sensorimotor polyradiculoneuropathy. CSF analysis showed mild albumino-cytological dissociation. MRI brain and lumbosacral plexus showed thickened fifth cranial nerves and lumbosacral roots. He was treated with steroids for a provisional diagnosis of chronic inflammatory polyneuropathy and became encephalopathic. EEG showed triphasic waves. Serum ammonia was 201 micrograms/dL. Further evaluation suggested ornithine transcarbamylase (OTC) deficiency. The patient underwent hemodialysis with a low protein diet, rifaximin, and sodium benzoate, with subsequent recovery.

3D visualization system and standard operating microscope for ease of visualization and surgeon comfort during phacoemulsification surgery.

PURPOSE: To compare the ease of visualization and comfort of the surgeon during phacoemulsification surgery using NGENUITY® 3D (NG) visualization system and standard operating microscope (SOM). METHODS: In this prospective, randomized, single-blind, single-center study, patients undergoing phacoemulsification surgery by one of the five surgeons were randomly assigned to two groups based on the visualization modality-NG and SOM. Ease of visualization and comfort of the surgeon was assessed using a 27-parameter in-house Surgeon Comfort Score questionnaire. RESULTS: A total of 224 phacoemulsification with intraocular lens implantations were performed in senile immature cataract (SIMC, n = 174) and mature cataract patients (MC, n = 50). Surgeon's ease of visualization (4.92-5.00) and hand-eye coordination score (4.97-5.00) were comparable between the NG- and SOM-groups. Postoperative neck discomfort was lower in both the groups, with a relatively lower discomfort in the NG-group (score: 1.04 vs 1.56). The Spearman rank correlation coefficient (r) between illumination of the operation theatre room and the surgical field revealed a weak negative correlation for most of the patients in the NG-group, and a positive correlation for patients in the SOM-group. No correlation was obtained between brightness of the surgical field and comfort with the surgical field brightness. CONCLUSIONS: Similar ease of visualization was experienced by the surgeons using NG- and SOM-system. Neck discomfort postsurgery was numerically lower in the NG-group, although not significant. Additionally, the NG-system permitted the safe performance of phacoemulsification using a lower surgical field illumination.

Mebendazole plus lomustine or temozolomide in patients with recurrent glioblastoma: A randomised open-label phase II trial.

Background: Recurrent glioblastoma (GBM) has dismal outcomes and limited treatment options. Mebendazole (MBZ) has activity in glioma both in-vivo and in-vitro, and is well tolerated in combination with lomustine (CCNU) and temozolomide (TMZ). In this study, we sought to determine whether the addition of MBZ to CCNU or TMZ would improve overall survival (OS) in recurrent GBM. Methods: In this phase II randomized open-label trial, adult patients with ECOG PS 0-3, with recurrent GBM who were not eligible for re-radiation, were randomized 1:1 to the CCNU-MBZ and TMZ-MBZ arms. CCNU was administered at 110 mg/m2 every 6 weeks with MBZ 800 mg thrice daily and TMZ was administered at 200 mg/m2 once daily on days 1-5 of a 28 days cycle with MBZ 1600 mg thrice daily. The primary endpoint was OS at 9 months. A 9-month OS of 55% or more in any arm was hypothesized to warrant further evaluation and a value below 35% was too low to warrant further investigation. OS was analyzed using intention to treat (ITT) and per-protocol (PP) analyses. Per-protocol analysis was used for safety analysis. Clinical Trials Registry-India number, CTRI/2018/01/011542. Findings: Participants were recruited from 14th March 2019 to 18th June 2021, 44 patients were randomised on each arm. At 17.4 months, 68 events for OS analysis had occurred, 33 in the TMZ-MBZ and 35 in the CCNU-MBZ arm. The 9-month OS was 36.6% (95% CI 22.3-51.0) and 45% (95% CI 29.6-59.2) in the TMZ-MBZ and CCNU-MBZ arms respectively, in the ITT population. ECOG PS was the only independent prognostic factor impacting OS (HR-0.48, 95% CI 0.27-0.85; P = 0.012). Grade 3-5 adverse events were seen in 8 (18.6%; n = 43) and 4 (9.5%; n = 42) patients in the TMZ-MBZ and CCNU-MBZ arms respectively. There were no treatment related deaths. Interpretation: The addition of MBZ to TMZ or CCNU failed to achieve the pre-set benchmark of 55% 9-month OS. This was probably due to 28.6% of patients having poor PS of 2-3. Funding: Brain Tumor Foundation (BTF) of India, Indian Cooperative Oncology Network (ICON), and India Cancer Research Consortium (ICRC) under ICMR (Indian Council of Medical Research).

Identification and management of young infants with possible serious bacterial infection where referral was not feasible in rural Lucknow district of Uttar Pradesh, India: An implementation research.

BACKGROUND: Based on World Health Organization guidelines, Government of India recommended management of possible serious bacterial infection (PSBI) in young infants up to two months of age on an outpatient basis where referral is not feasible. We implemented the guideline in program setting to increase access to treatment with high treatment success and low resultant mortality. METHODS: Implementation research was conducted in four rural blocks of Lucknow district in Uttar Pradesh, India. It included policy dialogues with the central and state government and district level officials. A Technical Support Unit was established. Thereafter, capacity building across all cadres of health workers in the implementation area was done for strengthening of home based newborn care (HBNC) program, skills enhancement for identification and management of PSBI, logistics management to ensure availability of necessary supplies, monitoring and evaluation as well as providing feedback. Data was collected by the research team. RESULTS: From June 2017 to February 2019 there were 24,448 live births in a population of 856106. We identified 1302 infants, aged 0-59 days, with any sign of PSBI leading to a coverage of 53% (1302/2445), assuming an incidence of 10%. However, in the establishment phase the coverage was 33%, while it was 85% in the implementation phase. Accredited social health activists (ASHAs) identified 81.2% (1058/1302) cases while rest were identified by families. ASHAs increased home visits within first 7 days of life in home based newborn care program from 74.3% (2781/3738) to 89.0% (3128/3513) and detection of cases of PSBI from 1.6% (45/2781) to 8.7% (275/3128) in the first and last quarter of the project, respectively. Of these 18.7% (244/1302) refused referral to government health system and 6.7% (88/1302) were treated in a hospital. Among cases of PSBI, there were 13.3% (173/1302) cases of fast breathing in young infant aged 7-59 days in whom referral was not needed. Of these 147 were treated by oral amoxicillin and 95.2% (140/147) were cured. Among those who needed referral, simplified treatment was given when referral was refused. There were 2.9% (37/1302) cases of fast breathing at ages of 0-6 days of which 34 were treated by simplified treatment with100% (34/34) cured;66.5% (866/1302) were cases of clinical severe infection of which 685 treated by simplified treatment with94.2% (645/685)cured and 09 died;17.3% (226/1302) cases of critical illness of which 93 were treated by simplified treatment, as a last resort, 72% (67/93) cured and 16 died. Among 255 cases who either did not seek formal treatment or sought it at private facilities, 96 died. CONCLUSION: Simplified treatment for PSBI is feasible in public program settings in northern India with good cure rates. It required system strengthening and supportive supervision.

An integrative assessment of the diversity, phylogeny, distribution, and conservation of the terrestrial reptiles (Sauropsida, Squamata) of the United Arab Emirates.

In the present study we use an unprecedented database of 5,535 distributional records to infer the diversity, ecological preferences and spatial distribution of the 60 species of terrestrial reptiles of the United Arab Emirates (UAE), and use the 57 native species to test the effectiveness of the protected areas' network in conserving this unique vertebrate fauna. We infer a time-calibrated phylogeny with 146 species of squamates and 15 genes including all UAE terrestrial reptile species to determine the phylogenetic diversity (PD) and evolutionary distinctiveness (ED) of the native species and to compare it with the distribution of the hotspots of native species richness. The results of this study indicate that the sampling effort is remarkable, covering 75% of the country's territory representing nearly the entire climatic space of the UAE defined by the mean annual temperature and the total annual precipitation, as well as the multivariate climatic space defined by a principal component analysis (PCA). Species richness is highest in the northeast of the country, in a transitional area from sandy desert to the mountainous terrain of the Hajar Mountains. The highest PD of a single square cell of 10 arc-minutes grid is of 2,430 million years (my) of accumulated evolutionary history and the strong correlation between PD and species richness suggests that the raw number of species is a good surrogate to quantify the evolutionary history (i.e., PD). The species with the highest values of ED are those in families represented by only one species in the UAE. Finally, the assessment of the UAE protected areas shows that, despite their relevance in protecting the terrestrial reptiles, they do not offer adequate protection for some threatened species. Therefore, a reassessment of some of the protected areas or the creation of species specific conservation action plans are recommended in order to ensure the preservation of the unique diversity of UAE terrestrial reptiles.

Highly selective peroxisome proliferator-activated receptor δ (PPARδ) modulator demonstrates improved safety profile compared to GW501516.

Compound 1 regulates significantly fewer genes than the PPARδ modulator, GW501516. Both compounds are efficacious in a thermal injury model of muscle regeneration. The restricted gene profile of 1 relative to GW501516 suggests that 1 may be pharmacoequivalent to GW501516 with fewer PPAR-related safety concerns.

Effect of compositional heterogeneity on dissolution of non-ideal LNAPL mixtures.

The extent of dissolution of petroleum hydrocarbon fuels into groundwater depends greatly on fuel composition. Petroleum fuels can consist of thousands of compounds creating different interactions within the non-aqueous phase liquid (NAPL), thereby affecting the relative dissolution of the components and hence a groundwater plume's composition over long periods. Laboratory experiments were conducted to study the variability in the effective solubilities and activity coefficients for common constituents of gasoline fuels (benzene, toluene, p-xylene and 1,2,4-trimethylbenzene) (BTX) in matrices with an extreme range of molar volumes and chemical affinities. Four synthetic mixtures were investigated comprising BTX with the bulk of the NAPL mixtures made up of either, ethylbenzene (an aromatic like BTX with similar molar volume); 1,3,5-trimethylbenzene (an aromatic with a greater molar volume); n-hexane (an aliphatic with a low molar volume); and n-decane (an aliphatic with a high molar volume). Equilibrium solubility values for the constituents were under-predicted by Raoult's law by up to 30% (higher experimental concentrations) for the mixture with n-hexane as a filler and over-predicted by up to 12% (lower experimental concentrations) for the aromatic mixtures with ethylbenzene and 1,3,5-trimethylbenzene as fillers. Application of PP-LFER (poly-parameter linear free energy relationship) model for non-ideal mixtures also resulted in poor correlation between experimentally measured and predicted concentrations, indicating that differences in chemical affinities can be the major cause of deviation from ideal behavior. Synthetic mixtures were compared with the dissolution behavior of fresh and naturally weathered unleaded gasoline. The presence of lighter aliphatic components in the gasoline had a profound effect on estimating effective solubility due to chemical affinity differences (estimated at 0.0055 per percentage increase in the molar proportion of aliphatic) as well as reduced molar volumes (estimated at -0.0091 in the activity coefficient per unit increase in molar volume, mL/mol). Previously measured changes in activity coefficients due to natural weathering of 0.25 compares well to 0.27 calculated here based on changes in the chemical affinity and molar volumes. The study suggests that the initial estimation of the composition of a fuel is crucial in evaluating dissolution processes due to ideal and non-ideal dissolution, and in predicting long term dissolution trends and the longevity of NAPL petroleum plume risks.

Evaluation of Outcome of Orthodontic Treatment in Context to Posttreatment Stability: A Retrospective Analysis.

INTRODUCTION: One of the main aims of orthodontic treatment is the improvement of esthetics along with enhancement of functions of the orofacial regions. Complications are observed even after final completion of the orthodontic treatment due to relapse and loss of stability. Hence, we retrospectively analyzed angle class I malocclusion cases to study the correlation of outcome of orthodontic treatment and posttreatment stability. MATERIALS AND METHODS: A total of 100 patients were included in this retrospective analysis, which accounted for the patients reporting to the department of orthodontics from 2013 to 2015 with angle class I malocclusion. Pretreatment, posttreatment, and postretention casts of the patients were made and analyzed. The Richmond et al criteria was used to evaluate peer assessment rating (PAR) index and Little irregularity index, followed by scoring with American weight. Measurement of Pearson's coefficient was done to calculate the p-value. p-value of less than 0.05 was considered as significant. RESULTS: No significant amount of alteration was seen in the systematic errors of Little index and PAR index, while casual errors were also within the normal range. While comparing the PAR index at pretreatment and posttreatment phases, statistically significant results were obtained, whereas in case of Little index at same time intervals, scores showed nonsignificant results. CONCLUSION: Even after delivering ideal orthodontic treatment, stability of the treatment is still not ensured until unless posttreatment follow-up is properly maintained.

Diagnostic features of Angle's Class II div 2 malocclusion.

STATEMENT OF PROBLEM: A thorough knowledge of the salient features of malocclusion makes the practitioner to come to a proper diagnosis and to formulate proper mechanotherapy. It also helps to predict the prognosis, prior to the onset of treatment process. Among the various malocclusions, Class II div 2 occurs the least often. The literature review does not clearly describe the classical skeletal and dental features of Angle's Class II div 2 malocclusion. PURPOSE OF STUDY: The aim of this study is to describe the unique features of Angle's Class II division 2 malocclusion. MATERIALS AND METHODS: A total of 612 pre-treatment records (study models and cephalograms), with age ranging from 14 to 25 years, were obtained from the hospital records of Drs Sudha and Nageswar Rao Siddhartha Institute of Dental Sciences. Among these samples, 317 were Class II div 1 and 295 were Class II div 2. The lateral cephalograms were analyzed by using Kodak software and the arch width analysis was calculated by using digital vernier calipers. RESULTS: Student's t test was used for the study. On the cephalograms, the vertical skeletal measurements and few of the dental variables showed a significant difference. On the plaster models, the maxillary transverse measurements revealed a notable discrimination between the groups. CONCLUSION: Angle's Class II div 2 malocclusion has a marked horizontal growth pattern with decreased lower facial thirds, palatally inclined upper anteriors, and remarkably increased transverse maxillary arch dimensions.

Protective effect of alpha glucosyl hesperidin (G-hesperidin) on chronic vanadium induced testicular toxicity and sperm nuclear DNA damage in male Sprague Dawley rats.

The study was conducted to evaluate the vanadium-induced testicular toxicity and its effect on sperm parameters, sperm nuclear DNA damage and histological alterations in Sprague Dawley rats and to assess the protective effect of G-hesperidin against this damage. Treatment of rats with vanadium at a dose of 1 mg kg bw(-1) for 90 days resulted in significant reduction in serum testosterone levels, sperm count and motility. Further, a parallel increase in abnormal sperm morphology and adverse histopathological changes in testis was also associated with vanadium administration when compared to normal control. Moreover, sperm chromatin dispersion assay revealed that vanadium induces sperm nuclear DNA fragmentation. A marked increase in testicular malondialdehyde levels and decreased activity of antioxidant enzymes such as superoxide dismutase and catalase indicates vanadium-induced oxidative stress. Co-administration of G-hesperidin at a dose of 25 and 50 mg kg bw(-1) significantly attenuated the sperm parameters and histological changes by restoring the antioxidant levels in rat testis. These results suggested that vanadium exposure caused reduced bioavailability of androgens to the tissue and increased free radical formation, thereby causing structural and functional changes in spermatozoa. G-hesperidin exhibited antioxidant effect by protecting the rat testis against vanadium-induced oxidative damage, further ensures antioxidant potential of bioflavonoids.

Comparison of canine retraction by in vivo method using four brands of elastomeric power chain.

OBJECTIVE: To investigate the amount of space closure by movement of canines into the extraction spaces using four brands of elastomeric power chains (EPCs) by intraoral application with pre-adjusted appliance for 6 weeks. MATERIALS AND METHODS: The sample size calculation was based on the studies of Boester and Johnston and also with repeated measures analysis of variance (ANOVA) continuous data for force degradation, standard deviation of 24.9 g, and also from a pilot study, which totaled to around 17 patients with a mean age of 20 ± 2 years and receiving fixed orthodontic treatment that required retraction of canines into the premolar extraction spaces in all four dental arch quadrants. Four brands of EPCs, namely the Ormco, 3M Unitek, Rocky Mountain, and Highland, which were closed-link with five loops delivering less than or equal to 250 g were used. The rates of canine retraction were measured between the attachment points on the canine bracket hook and first molar hook using a Mitutoyo Digital Vernier Caliper at the time of first application, after 3 weeks of use, and at the end of 6 weeks of use, and were subjected to statistical calculations. RESULTS: The distances recorded from canine retraction were similar with slight differences noticed in the four brands of EPCs. However, no statistically significant difference was observed in relation to the EPCs. CONCLUSION: Although all brands of the EPCs produced space closure of canines, it was observed that not much of a significant difference existed among the products tested.

The synthesis, characterisation and in vivo study of a bioceramic for potential tissue regeneration applications.

Hydroxyapatite (HAP) is a biocompatible ceramic that is currently used in a number of current biomedical applications. Recently, nanometre scale forms of HAP have attracted considerable interest due to their close similarity to the inorganic mineral component of the bone matrix found in humans. In this study ultrafine nanometre scale HAP powders were prepared via a wet precipitation method under the influence of ultrasonic irradiation. The resulting powders were compacted and sintered to form a series of ceramic pellets with a sponge-like structure with varying density and porosity. The crystalline structure, size and morphology of the powders and the porous ceramic pellets were investigated using advanced characterization techniques. The pellets demonstrated good biocompatibility, including mixed cell colonisation and matrix deposition, in vivo following surgical implantation into sheep M. latissimus dorsi.

Sperm DNA fragmentation assay by sperm chromatin dispersion (SCD): correlation between DNA fragmentation and outcome of intracytoplasmic sperm injection.

PURPOSE: The aim of the present study was to investigate the relationship between sperm DNA fragmentation index (sDFI) and outcome of intracytoplasmic sperm injection (ICSI). METHODS: All the patients were divided into two groups based on sperm DNA fragmentation analysis by the sperm chromatin dispersion (SCD) method. A total of 237 patients were in the DNA fragmentation normal group (sDFI ≤ 30 %), and 140 patients were in the DNA fragmentation abnormal group (sDFI ≥ 30 %). The relationship of sDFI with the outcome of ICSI was analyzed. RESULTS: A significant difference in semen parameters was observed between the DNA fragmentation normal and abnormal groups [count, motility and morphology (p < 0.05)]. However, no significant difference was seen between the number of oocytes retrieved and fertilization rates between the two groups, whereas the number of embryos progressed to day 3 and the blastocyst formation rate in the remaining embryos after transfer were significantly more in the DNA fragmentation normal group (p < 0.05). A significant negative correlation was noted between DFI values of more than 30 % and number of pregnancies and deliveries (p < 0.05). A higher DFI was also associated with increased abortion rates. CONCLUSIONS: In the present study, sperm with DNA fragmentation showed a negative correlation with semen parameters. Further, sperm with damaged DNA have potential adverse effects on embryo progression, clinical pregnancy rate, and ongoing pregnancies.

Causes, outcome and prevention of abandonment in retinoblastoma in India.

BACKGROUND: The high-cure rates of 90% in retinoblastoma are not replicated in developing countries due to late presentation and poor compliance to treatment. The present study takes a closer look at causes of abandonment of therapy and effectiveness of counselling in reducing abandonment. PROCEDURE: A retrospective study of children with retinoblastoma registered at our centre from March 2008 through August 2011. RESULTS: Fifty (49.50%) of 101 children registered for treatment abandoned therapy. Abandonment rates were significantly higher in rural as compared to urban children (P = 0.02). There was no significant difference in rate of abandonment between stages or laterality of disease and other socio-demographic factors. Telephone calls were more effective than letters in tracing patients (31.2% vs. 2.4%). Major reasons cited behind abandonment were financial problems (30%) and unwillingness to enucleate (20%). Of the 12 children who returned and were retreated 6 (50%) died of progressive disease. Nineteen (73%) of those who did not return died at home. Abandonment rates steadily declined from 71.42% in 2008 to 16.66% in 2011 (P = 0.01) due to effective pre-abandonment counselling by a support team under the National Retinoblastoma Registry of India from 2009. CONCLUSIONS: Abandonment rates for children with retinoblastoma continue to be unacceptably high. Rural background, financial constraints and hesitancy to enucleate were important causes behind abandonment. Outcome of patients who abandoned treatment was uniformly dismal. Inclusion of support team and intensified initial counselling helped in improving compliance.

Toll-like receptors and diabetes complications: recent advances.

Diabetes mellitus (DM) is a disease with constellation of metabolic aberrations resulting in debilitating complications. The prevalence of DM worldwide was 2.8% (171 million people) in 2000 and estimated to be at 4.4% (366 million people) in 2030. DM is a major risk factor for heart, kidney diseases, and lower limb amputations. Emerging in vitro and in vivo data suggest that systemic inflammation plays a role in the pathogenesis of DM complications via innate immune receptors. Toll-like receptors (TLRs) are key innate immune receptors that mediate the inflammatory responses in DM. There are no reviews that collectively summarize and examine the detrimental role of TLRs in the manifestation of DM complications namely heart disease, nephropathy, neuropathy, and wound healing. Thus, in this review, we will provide summaries of the TLR expression and activation and elucidate their role in propagating inflammation seen in DM complications.

Synthesis of N4 donor macrocyclic Schiff base ligands and their Ru (II), Pd (II), Pt (II) metal complexes for biological studies and catalytic oxidation of didanosine in pharmaceuticals.

A series of tetraaza (N(4) donor) macrocyclic ligands (L(1)-L(4)) were derived from the condensation of o-phthalaldehyde (OPA) with some substituted aromatic amines/azide, and subsequently used to synthesize the metal complexes of Ru(II), Pd(II) and Pt(II). The structures of macrocyclic ligands and their metal complexes were characterized by elemental analyses, IR, (1)H &(13)C NMR, mass and electronic spectroscopy, thermal, magnetic and conductance measurements. Both the ligands and their complexes were screened for their antibacterial activities against Gram positive and Gram negative bacteria by MIC method. Besides, these macrocyclic complexes were investigated as catalysts in the oxidation of pharmaceutical drug didanosine. The oxidized products were further treated with sulphanilic acid to develop the colored products to determine by spectrophotometrically. The current oxidation method is an environmentally friendly, simple to set-up, requires short reaction time, produces high yields and does not require co-oxidant.

Noninsulin-dependent diabetes mellitus: effects on sperm morphological and functional characteristics, nuclear DNA integrity and outcome of assisted reproductive technique.

The aim of the study was to compare the semen characteristics and nuclear DNA fragmentation in spermatozoa of diabetic and nondiabetic men undergoing assisted reproduction and correlate them with pregnancy outcome. Semen characteristics and nuclear DNA fragmentation were analysed using computer-aided semen analysis system and sperm chromatin dispersion assay (SCD), respectively. Spermatozoa from diabetic patients showed significantly lower progressive (Type A) motility (14.64 ± 9.60 versus 17.99 ± 11.51, P < 0.02) and increased nuclear DNA fragmentation (37.05 ± 12.68 versus 21.03 ± 10.13, P < 0.001). Furthermore, a positive correlation was observed in diabetic patients in terms of blastocyst formation rate (38.13% versus 55.46%, P < 0.001), pregnancy rate (28.57% versus 46.34%, P < 0.001) and miscarriage rate (50.0% versus 24.56%, P < 0.001). The higher percentage of sperm DNA damage because of oxidative stress seen in diabetic patients may be responsible for the poor embryonic development and pregnancy outcome in these individuals.

Effect of dilute gelatine on the ultrasonic thermally assisted synthesis of nano hydroxyapatite.

A series of nano hydroxyapatite-gelatine composites with different dilute solutions of gelatine concentrations were synthesized by a thermally assisted low-power ultrasonic irradiation method. The gelatine hydroxyapatite, (Gel-HAP) nanoparticles were prepared using Ca(NO(3))(2) and KH(2)PO(4) in the presence of gelatine in an aqueous solution. The synthesised products were heat treated between 100 and 400°C. The effect of the addition of gelatine on the nucleation and growth of synthesised nano HAP was investigated. Characterisation was performed using X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and Fourier transform infrared spectroscopy (FT-IR). The characterisation results indicate that gelatine has been appended to the nano HAP forming regular spherical shaped crystals of nano sized Gel-HAP.

Electrocardiographic measurements of regional atrial fibrillation cycle length.

BACKGROUND: Differences in atrial fibrillation (AF) cycle length (CL) between the left (LA) and right (RA) atrium and coronary sinus (CS) may help separate paroxysmal from persistent AF and identify patients most likely to respond to pulmonary vein isolation, but has not been measured noninvasively. METHODS AND RESULTS: We developed methods to estimate regional intraatrial AF CL from the surface electrocardiogram (ECG) in 20 patients with persistent AF and 10 patients with paroxysmal AF prior to ablation. Intraatrial AF CL was measured near the LA appendage, mid-CS, and lateral RA. In simultaneous filtered ECG, AF CL was estimated using autocorrelation. The mean of ECG-derived AF CL in leads V5, I, and aVL was used to estimate LA CL; leads aVF, II, and III for CS CL; and V1, V2, and aVR for RA CL. ECG CL estimates for the LA, CS, and RA had R(2) > 0.91 versus measured CL (all P < 0.001). Though magnitudes of left-versus-right AF CL gradients were small in this series, the ECG predicted the direction of gradients in 62% of measurements (P < 0.05). When the gradient was >10 ms, the direction was accurately predicted in eight of 11 patients. The accuracy of AF CL estimates was not adversely affected by AF type or LA dilatation (< or =40 or >40 mm). The ECG-estimated AF-CL showed high 5-minute temporal stability (P < 0.001 each chamber). CONCLUSIONS: Left and right atrial AF CL, and their gradients, can be accurately determined from the ECG using autocorrelation analysis. This approach may be a helpful guide prior to ablation procedures.