Natural Language Processing to Identify Pulmonary Nodules and Extract Nodule Characteristics From Radiology Reports.

BACKGROUND: There is an urgent need for population-based studies on managing patients with pulmonary nodules. RESEARCH QUESTION: Is it possible to identify pulmonary nodules and associated characteristics using an automated method? STUDY DESIGN AND METHODS: We revised and refined an existing natural language processing (NLP) algorithm to identify radiology transcripts with pulmonary nodules and greatly expanded its functionality to identify the characteristics of the largest nodule, when present, including size, lobe, laterality, attenuation, calcification, and edge. We compared NLP results with a reference standard of manual transcript review in a random test sample of 200 radiology transcripts. We applied the final automated method to a larger cohort of patients who underwent chest CT scan in an integrated health care system from 2006 to 2016, and described their demographic and clinical characteristics. RESULTS: In the test sample, the NLP algorithm had very high sensitivity (98.6%; 95% CI, 95.0%-99.8%) and specificity (100%; 95% CI, 93.9%-100%) for identifying pulmonary nodules. For attenuation, edge, and calcification, the NLP algorithm achieved similar accuracies, and it correctly identified the diameter of the largest nodule in 135 of 141 cases (95.7%; 95% CI, 91.0%-98.4%). In the larger cohort, the NLP found 217,771 reports with nodules among 717,304 chest CT reports (30.4%). From 2006 to 2016, the number of reports with nodules increased by 150%, and the mean size of the largest nodule gradually decreased from 11 to 8.9 mm. Radiologists documented the laterality and lobe (90%-95%) more often than the attenuation, calcification, and edge characteristics (11%-14%). INTERPRETATION: The NLP algorithm identified pulmonary nodules and associated characteristics with high accuracy. In our community practice settings, the documentation of nodule characteristics is incomplete. Our results call for better documentation of nodule findings. The NLP algorithm can be used in population-based studies to identify pulmonary nodules, avoiding labor-intensive chart review.

Sestamibi Single-Positron Emission Computed Tomography/Diagnostic-quality Computed Tomography for the localization of abnormal parathyroid glands in patients with primary hyperparathyroidism: What clinicopathologic factors affect its accuracy?

PURPOSE: Sestamibi Single-Positron Emission Computed Tomography/Diagnostic-quality Computed Tomography (MIBI-SPECT/CT) is a common technology used for primary hyperparathyroidism (PHPT) localization in clinical practice. However, the clinicopathologic factors affecting the accuracy of MIBI-SPECT/CT and the potential limitations remain unclear. METHODS: Retrospectively enrolled PHPT patients (n = 280) were analyzed from August 2017 to December 2019. RESULTS: Of 96 patients with PHPT (mean age, 54 years; 63 females), 17 had discordance between MIBI-SPECT/CT and intraoperative findings. Among the 17 patients with discordance, 58.8% had major discordance, which occurred in most patients with multigland disease (MGD). Compared with concordant patients, discordant patients exhibited increased frequencies of autoimmune thyroid disease (29.4% vs 10.1%, p = 0.035), MDG (41.2% vs 3.8%, p = 0.035), higher PTH (296 pg/mL vs 146 pg/mL; p = 0.012),and lower phosphorus levels (0.77 mmol/L vs 0.90 mmol/L; p = 0.024). MDG (odds ratio [OR], 16.95; 95% CI 2.10-142.86), parathyroid lesion size of 12 mm or less (OR, 6.93; 95% CI 1.41-34.10), and a PTH level higher than 192.5 pg/mL (OR, 12.66; 95% CI 2.17-71.43) were independently associated with discordant MIBI-SPECT/CT results. CONCLUSION: MGD was most strongly associated with discordance between MIBI-SPECT/CT and intraoperative findings followed by a PTH level higher than 192.5 pg/mL and parathyroid lesion size of 12 mm or less. Surgeons should recognize these potential limitations, which may improve the preoperative procedure by encouraging further localization imaging and promptly facilitate intraoperative troubleshooting.

High-resolution, real-time, and nonfluoroscopic 3-dimensional cardiac imaging and catheter navigation in humans using a novel dielectric-based system.

BACKGROUND: Catheter navigation and 3-dimensional (3D) cardiac mapping are essential components of minimally invasive electrophysiological procedures. OBJECTIVE: The purpose of this study was to develop a novel 3D mapping system (KODEX - EPD, EPD Solutions, Best, The Netherlands) that measures changing electric field gradients induced on intracardiac electrodes to enable catheter localization and real-time 3D cardiac mapping. METHODS: We first validated the accuracy of the system's measurement and localization capabilities by comparing known and KODEX - EPD-measured distances and locations at 12 anatomical landmarks in both the atria and ventricles of 4 swine. Next, in vivo images of 3D porcine cardiac anatomy generated by KODEX - EPD and widely used CARTO 3 system (Biosense Webster, Inc., Diamond Bar, CA) were compared with gold standard computed tomography images acquired from the same animals. Finally, 3D maps of atrial anatomy were created for 22 patients with paroxysmal atrial fibrillation (Dielectric Unravelling of Radiofrequency ABLation Effectiveness trial). RESULTS: First, the mean error between known and measured distances was 1.08 ± 0.11 mm (P < .01) and the overall standard deviation between known and measured locations in 12 areas of the porcine heart was 0.35 mm (P < .01). Second, an expert comparison of 3D image quality revealed that KODEX - EPD is noninferior to CARTO 3. Third, the system enabled 3D imaging of atrial anatomy in humans, provided real-time images of atrioventricular valves, and detected important anatomical variations in a subset of patients. CONCLUSION: The KODEX - EPD system is a novel 3D mapping system that accurately detects catheter location and can generate high-resolution images without the need for preacquired imaging, specialty catheters, or a point-by-point mapping procedure.

A novel pacing maneuver to verify the postpacing interval minus the tachycardia cycle length while adjusting for decremental conduction: Using "dual-chamber entrainment" for improved supraventricular tachycardia discrimination.

BACKGROUND: The postpacing interval (PPI) minus the tachycardia cycle length (TCL) is frequently used to investigate tachycardias. However, a variety of issues (eg, failure to entrain, decremental conduction, and oscillating TCLs) can make interpretation of the PPI-TCL challenging. OBJECTIVE: The purpose of this study was to investigate a novel maneuver to confirm the PPI-TCL value without using either the ventricular PPI or the TCL interval and to assess the ability of this maneuver to identify decremental conduction and differentiate supraventricular tachycardias. METHODS: We analyzed 77 intracardiac recordings from patients (age 25 ± 20 years; 40 female) who underwent catheter ablation of atrioventricular nodal reentrant tachycardia (AVNRT) or orthodromic reciprocating tachycardia (ORT) with a concealed pathway. We calculated the PPI-TCL, the AH-corrected PPI-TCL, and estimated the PPI-TCL using "dual-chamber entrainment" calculated as [PPIV - TCL = Stim(A→V) + Stim(V→A) - PPIA]. RESULTS: The PPI-TCL calculated by dual-chamber entrainment highly correlated with the observed and AH-corrected PPI-TCL (R2 = 0.79 and 0.96, respectively; P <.001]. A dual-chamber entrainment PPI-TCL value of 80 ms correctly differentiated all AVNRT from septal ORT cases, whereas the standard PPI-TCL and AH-corrected PPI-TCL methods were incorrect in 14% and 6% of cases, respectively. Dual-chamber entrainment identified 3 ± 10 ms of additional decremental conduction beyond AH prolongation, including 4 pathways with significant (>10 ms) decrement. CONCLUSION: Dual-chamber entrainment estimates the PPI-TCL value without using either the ventricular PPI or the TCL interval. This maneuver adjusts for all decremental conduction, including within concealed pathways, where a dual-chamber entrainment PPI-TCL value >80 ms favors AVNRT over ORT. This maneuver can be used to verify the observed PPI-TCL value in challenging cases.

Sonographic diagnosis of colorectal polyps in children: Diagnostic accuracy and multi-factor combination evaluation.

This study was established to evaluate the diagnostic value of ultrasonography in screening colorectal polyps in children and to discuss the necessity of colonic preparation before an ultrasonic examination.In this study, 288 children with colorectal polyps managed at our hospital between January 2007 and December 2016 were retrospectively reviewed. All patients were examined before and after basic colon preparation. The colorectal polyps were confirmed by colonoscopy/laparotomy and histopathology. Among all 288 patients, solitary polyps were identified in 278 patients (96.52%), and multiple polyps were identified in 10 patients (43 polyps) (3.48%) by colonoscopy/laparotomy and histopathology.By ultrasonic examination, 264 cases (264/278) were detected as solitary polyp and 9 cases (9/10) as multiple polyps (31 polyps). In 278 solitary polyps, 180 (64.74%) were detected by ultrasonic examination without a colon preparation. Following glycerine enema (10-20 mL) treatment, 264 (94.96%) cases were detected by ultrasonic examination. The sensitivity and specificity of ultrasonography with glycerine enema for the detection of colorectal polyps were 94.96% and 100%, respectively. Colon preparation significantly increased the proportion of polyps identified by ultrasonography (P < .0001), as well as the diagnostic rate of polyps in rectum, sigmoid colon and descending colon (P < .05).Ultrasonography can be the primary diagnostic method for screening colorectal polyps in children on the strength of its safety, validity, and accuracy. Basic colon preparation with glycerine enema is recommended for children, which enable the detection of intraluminal lesions before ultrasonic examination.

Evaluation of an activity monitor for use in pregnancy to help reduce excessive gestational weight gain.

BACKGROUND: Excessive weight gain during pregnancy increases the risk for negative effects on mother and child during pregnancy, delivery, and also postnatally. Excessive weight gain can be partially compensated by being sufficiently physically active, which can be measured using activity trackers. Modern activity trackers often use accelerometer data as well as heart rate data to estimate energy expenditure. Because pregnancy affects the metabolism and cardiac output, it is not evident that activity trackers that are calibrated to the general population can be reliably used during pregnancy. We evaluated whether an activity monitor designed for the general population is sufficiently accurate for estimating energy expenditure in pregnant women. METHODS: Forty pregnant women (age: 30.8 ± 4.7 years, BMI: 25.0 ± 4.0) from all three trimesters performed a 1-h protocol including paced and self-paced exercise activities as well as household activities. We tracked reference energy expenditure using indirect calorimetry and used equivalence testing to determine whether the estimated energy expenditure from the activity monitor was within the limits of equivalence. RESULTS: Overall we found an averaged underestimation of 10 kcal (estimated energy expenditure was 97% of the reference measurement). The 90% CI for the cumulative total energy expenditure was 94-100%. The activities of self-paced cycling, household activities, stair-walking, and yoga had one of their equivalence boundaries outside a 80-125% range of equivalence; for exercise on a cross-trainer, for self-paced and fixed-pace walking, fixed-paced cycling, and resting, the estimations were within the limits of equivalence. CONCLUSIONS: We conclude that the activity monitor is sufficiently accurate for every-day use during pregnancy. The observed deviations can be accounted for and are acceptable from a statistical and an applied perspective because the positive and negative deviations that we observed cancel out to an accurate average energy expenditure over a day, and estimations during exercise are sufficiently accurate to enable coaching on physical activity. The positive and negative deviations themselves were relatively small. Therefore, the activity monitor can be used to help in preventing excessive weight gain during pregnancy by accurately tracking physical activity.

Establishment of Comprehensive Indicators in TCM Pectoral-qi Case Report Based on Experts Diagnosis and Self-test Technology.

RATIONALE: To establish TCM Pectoral-qi comprehensive indicators and highlight the inner structure among different variables in an objective way, the article uses Partial Least Square Second-order Latent Variable Model (PLS-SLVM) and accomplishes 3 different comprehensive indicators based on both experts diagnosis and self-test data. SLVM includes a measurement model that defines the relationship between observed variables and latent variables and a structure model that imputes relationships between latent variables. The article focuses on PLS as the estimation method. Without normal distribution and independence assumptions, PLS uses objective weighting methods based on the data. Bootstrap method (B = 200) is used to calculate the mean value and standard errors of the PLS estimates. The article chooses the percentile interval to obtain the confidence interval of PLS parameters. PATIENT CONCERNS: The patients were diagnosed by the means of experts diagnosis and self-test technology. On the one hand, the patients want to know the effect of self-test by wearing a kind of instrument. On the other hand, we want to establish TCM Pectoral-qi comprehensive indicators and highlight the inner structure among different variables in an objective way. DIAGNOSES: The group of 59 subjects are the same no matter whether they were diagnosed through TCM Pectoral-qi Assessment Questionnaire of self-test technology. INTERVENTIONS: The same group of 59 subjects keep wearing the instrument for hours and get the self-test data consequently. OUTCOMES: As one of comprehensive indicator establishing methods, PLS-SLVM highlights the structure state among variables and improves the evaluation efficiency. Furthermore, it provides a new tool and method in TCM diseases prevention and health security. LESSONS: As expected, PLS-SLVM is a useful tool due to its nonassumption of normal distribution and independence with consideration of correlation among different variables. Thus PLS-SLVM can be applied in ordinal data from assessment questionnaire and continuous data about physicochemical indexes for the same group of people. It displays that PLS-SLVM builds a connection between TCM experts diagnosis and the self-testing technology.

Uso do emprego da reflexão estruturada como ferramenta para aumentar a acurácia diagnóstica de casos dermatológicos em alunos de Medicina / Structured reflection as a tool to increase diagnostic accuracy of dermatological clinical vignettes among medical students

Introdução: O uso da reflexão estruturada para aumentar a acurácia diagnóstica vem ganhando destaque como estratégia de ensino e já foi avaliada em diferentes cenários na graduação médica. Esta estratégia, entretanto, ainda não foi avaliada em relação a casos dermatológicos. Objetivos: Avaliar e estudar o impacto da utilização da reflexão estruturada na acurácia diagnóstica de casos dermatológicos na graduação. Métodos: O estudo foi realizado em duas fases (fase treinamento e fase avaliação) com alunos do 4º ano do curso de medicina da UNIFENAS-BH. Os alunos foram divididos em dois grupos (controle (GC) e reflexão (GR)). Na fase treinamento, os dois grupos resolveram os mesmos 12 casos clínicos dermatológicos, mas o GC foi solicitado a apontar o diagnóstico mais provável e posteriormente fazer uma atividade distratora, enquanto o GR apontou o diagnóstico e realizou uma atividade reflexiva. Na fase avaliação, realizada após 7 dias, ambos os grupos foram solicitados a darem livremente o diagnóstico a outros 12 casos clínicos. A acurácia diagnóstica na fase avaliação foi comparada entre os dois grupos e, dentro de um mesmo grupo, foi comparada a acurácia entre a primeira e segunda fases em diferentes tipos de lesões. Resultados: Foram incluídos 41 alunos, sendo alocados 19 para o GR e 22 para o GC. Os grupos foram semelhantes em relação à idade, sexo e desempenho no módulo de dermatologia. Ambos os grupos (GC e GR) apresentaram melhora estatisticamente significativa da acurácia na fase avaliação em relação à fase de treinamento (p < 0,001), mas não houve diferença de desempenho entre os grupos (p=0,495). A análise estratificada por síndrome dermatológica mostrou que os alunos do grupo reflexão estruturada apresentaram ganho na acurácia diagnóstica para lesões do tipo pápulas e placas e uma piora na acurácia para lesões pigmentadas, diferentemente do padrão observado no grupo controle. A estratificação por dificuldade dos casos mostrou que houve uma melhora significativa na acurácia dos casos difíceis (p=0,005), comparando a fase de treinamento com a fase de avaliação, mas sem impacto do uso da reflexão estruturada (p=0,19). Conclusão: A acurácia diagnóstica global na fase de avaliação foi semelhante entre o grupo reflexão e o grupo controle. Entretanto, observou-se que o grupo que usou a reflexão estruturada apresentou uma melhora na acurácia das lesões do tipo pápulas e placas que não foi observada no grupo controle. Novos estudos são necessários para avaliar se diferentes tipos de lesões requerem diferentes estratégias de ensino

Introduction: The teaching of dermatology faces difficulties due to the short available time for teaching the specialty and it is of great importance due to the crescent demand of dermatological cases in primary care. The use of structured reflection to increase diagnostic accuracy has gained prominence as a teaching strategy and has already been evaluated in different scenarios in medical graduation. This strategy, however, has not yet been evaluated in relation to dermatological cases. Goals: The present study evaluated the impact of structured reflection on the diagnostic accuracy of dermatological cases at undergraduate level. Methods: The study was carried out in two phases (training phase and evaluation phase) with students of the 4th year of the UNIFENAS medical course. The students were divided into two groups (control (GC) and reflection (GR)). In the training phase, the two groups resolved the same 12 dermatological clinical cases, but the CG was asked to point out the most likely diagnosis and then to do a distracting activity, while the GR pointed out the diagnosis and then performed a reflexive activity on the case. In the evaluation phase, performed after 7 days, both groups were asked to freely give the diagnosis to another 12 clinical cases. The diagnostic accuracy in the evaluation phase was compared between the two groups and, within a same group, the accuracy between the first and second phases in different types of lesions was compared. Results: Thirty-one students were included, 19 for GR and 22 for GC. The groups were similar in relation to age, gender and performance in the dermatology module. Both groups (CG and GR) showed a statistically significant improvement in accuracy in the evaluation phase compared to the training phase (p <0.001), but there was no difference in performance between the groups (p = 0.495). Stratified analysis showed that students from the structured reflection group improved their diagnostic accuracy of lesions classified as "papules and plaques" and worsened their accuracy for those classified as "pigmented lesions", showing a different pattern of performance from the control group. When stratified by case difficulty, both groups showed improvement in their performance comparing the training phase with the evaluation phase but no statistically significant difference was observed between the two groups. Conclusion: Overall diagnostic accuracy in the evaluation phase was similar between the reflection group and the control group. However, students who used structured reflection showed an improvement in accuracy for papule/plaque-type lesions that was not observed in the control group. New studies are needed to better evaluate the potential of using structured reflection in the teaching of dermatology, particularly in defining if different type of lesions require different teaching strategies

Daily modulation of the speed-accuracy trade-off.

Goal-oriented arm movements are characterized by a balance between speed and accuracy. The relation between speed and accuracy has been formalized by Fitts' law and predicts a linear increase in movement duration with task constraints. Up to now this relation has been investigated on a short-time scale only, that is during a single experimental session, although chronobiological studies report that the motor system is shaped by circadian rhythms. Here, we examine whether the speed-accuracy trade-off could vary during the day. Healthy adults carried out arm-pointing movements as accurately and fast as possible toward targets of different sizes at various hours of the day, and variations in Fitts' law parameters were scrutinized. To investigate whether the potential modulation of the speed-accuracy trade-off has peripheral and/or central origins, a motor imagery paradigm was used as well. Results indicated a daily (circadian-like) variation for the durations of both executed and mentally simulated movements, in strictly controlled accuracy conditions. While Fitts' law was held for the whole sessions of the day, the slope of the relation between movement duration and task difficulty expressed a clear modulation, with the lowest values in the afternoon. This variation of the speed-accuracy trade-off in executed and mental movements suggests that, beyond execution parameters, motor planning mechanisms are modulated during the day. Daily update of forward models is discussed as a potential mechanism.

Evaluation of a novel high-resolution mapping technology for ablation of recurrent scar-related atrial tachycardias.

BACKGROUND: Rhythmia is a new technology capable of rapid and high-resolution mapping. However, its potential advantage over existing technologies in mapping complex scar-related atrial tachycardias (ATs) has not yet been evaluated. OBJECTIVE: The purpose of this study was to examine the utility of Rhythmia for mapping scar-related ATs in patients who had failed previous ablation procedure(s). METHODS: This multicenter study included 20 patients with recurrent ATs within 2 years after a previous ablation procedure (1.8 ± 0.7 per patient). In all cases, the ATs could not be adequately mapped during the index procedure because of scar with fractionated electrograms, precluding accurate time annotation, frequent change in the tachycardia in response to pacing, and/or degeneration into atrial fibrillation. These patients underwent repeat mapping and ablation procedure with Rhythmia. RESULTS: From a total of 28 inducible ATs, 24 were successfully mapped. Eighteen ATs (75%) terminated during radiofrequency ablation and 4 (16.6%) with catheter pressure or entrainment from the site of origin or isthmus. Two ATs that were mapped to the interatrial septum slowed but did not terminate with ablation. In 21 of 24 ATs the mechanism was macroreentry, while in 3 of 24 the mechanism was focal. Interestingly, in 5 patients with previously failed ablation of an allegedly "focal" tachycardia, high-resolution mapping demonstrated macroreentrant arrhythmia. The mean mapping time was 28.6 ± 17 minutes, and the mean radiofrequency ablation time to arrhythmia termination was 3.2 ± 2.6 minutes. During a mean follow-up of 7.5 ± 3.1 months, 15 of 20 patients (75%) were free of AT recurrences. CONCLUSION: The Rhythmia mapping system may be advantageous for mapping complex scar-related ATs.

[The analysis of acoustic activity unsynchronized with the stimulus with the use of TEOAE]. / Analiz akusticheskoi aktivnosti, ne sinkhronizirovannoi so stimulom, pri registratsii zaderzhannoi vyzvannoi otoakusticheskoi emissii.

The presence of ambient noise or the troubled child's behavior during the registration of transiently induced optoacoustic emission (TEOAE) can lead to false positive results at the first stage of hearing screening. The aim of this study is to evaluate the effectiveness of the noise reduction method based on weighted averaging of the data in the frequency and time slot, to check TEOAE, and to improve the effectiveness of universal hearing screening. Particular attention is paid to the analysis of the origin of noise recorded during the UAE. PATIENTS AND METHODS: We have developed a method of noise reduction, based on weighted averaging of the data in the frequency and time cells. In this study, 20 people were examined (9 adults and 11 children). TEOAE was performed using the probe of the ILO 288 instrument manufactured by Otodinamics Ltd. that was connected to the E-MU 0204 sound card. The probe microphone was connected through the preamplifier to one input channel of the sound card, and the second channel was used to receive a signal from the ECG and the respiration recorder. Thereafter, the data thus obtained were processed by several methods, including the method of averaging in the frequency and time slot designed to average a set of implementations that contain a noisy signal. The comparison of the results of the use of noise suppression method based on weighted averaging of the data in the frequency and time cells showed that it increases the accuracy of TEOAE. MAIN RESULTS: Our work suggests that the use of the noise suppression method based on weighted averaging of the data in the frequency and time cells, increases the accuracy of TEOAE. Similar results were obtained by the weighted averaging method.

Injection of cold saline for diagnosis of intramural ventricular arrhythmias.

BACKGROUND: The failure to identify a successful target site for catheter ablation despite extensive endocardial and epicardial mapping is a common feature for an intramural site of origin of a ventricular arrhythmia. OBJECTIVE: The purpose of this study was to assess whether transient suppression of premature ventricular complexes (PVCs) by injection of cold saline into the distal coronary venous system can identify an intramural focus. METHODS: Cold saline (room temperature) was injected through an irrigated-tip catheter into the distal coronary venous system in a consecutive series of 26 patients with frequent PVCs referred for catheter ablation. RESULTS: PVCs were temporarily suppressed in 11 of 26 patients during injection of cold saline. Extensive mapping suggested the presence of an intramural site of origin in 9 of 11 patients with PVC suppression by cold saline but in only 1 of 15 patients in whom PVCs were not suppressed. The suppression of PVCs by cold saline was associated with the presence of an intramural PVC focus with an accuracy of 88% (sensitivity 90%, specificity 88%, positive predictive value 82%, negative predictive value 93%, P = .0002). CONCLUSION: Temporary suppression of PVCs by cold saline infused into the distal coronary venous system and the perforator veins strongly suggests the presence of an intramural septal focus of the PVCs.

Differentiating the origin of outflow tract ventricular arrhythmia using a simple, novel approach.

BACKGROUND: Numerous electrocardiographic (ECG) criteria have been proposed to identify localization of outflow tract ventricular arrhythmias (OT-VAs); however, in some cases, it is difficult to accurately localize the origin of OT-VA using the surface ECG. OBJECTIVE: The purpose of this study was to assess a simple criterion for localization of OT-VAs during electrophysiology study. METHODS: We measured the interval from the onset of the earliest QRS complex of premature ventricular contractions (PVCs) to the distal right ventricular apical signal (the QRS-RVA interval) in 66 patients (31 men aged 53.3 ± 14.0 years; right ventricular outflow tract [RVOT] origin in 37) referred for ablation of symptomatic outflow tract PVCs. We prospectively validated this criterion in 39 patients (22 men aged 52 ± 15 years; RVOT origin in 19). RESULTS: Compared with patients with RVOT PVCs, the QRS-RVA interval was significantly longer in patients with left ventricular outflow tract (LVOT) PVCs (70 ± 14 vs 33.4±10 ms, P < .001). Receiver operating characteristic analysis showed that a QRS-RVA interval ≥49 ms had sensitivity, specificity, and positive and negative predictive values of 100%, 94.6%, 93.5%, and 100%, respectively, for prediction of an LVOT origin. The same analysis in the validation cohort showed sensitivity, specificity, and positive and negative predictive values of 94.7%, 95%, 95%, and 94.7%, respectively. When these data were combined, a QRS-RVA interval ≥49 ms had sensitivity, specificity, and positive and negative predictive values of 98%, 94.6%, 94.1%, and 98.1%, respectively, for prediction of an LVOT origin. CONCLUSION: A QRS-RVA interval ≥49 ms suggests an LVOT origin. The QRS-RVA interval is a simple and accurate criterion for differentiating the origin of outflow tract arrhythmia during electrophysiology study; however, the accuracy of this criterion in identifying OT-VA from the right coronary cusp is limited.

Subcutaneous nerve activity is more accurate than heart rate variability in estimating cardiac sympathetic tone in ambulatory dogs with myocardial infarction.

BACKGROUND: We recently reported that subcutaneous nerve activity (SCNA) can be used to estimate sympathetic tone. OBJECTIVE: The purpose of this study was to test the hypothesis that left thoracic SCNA is more accurate than heart rate variability (HRV) in estimating cardiac sympathetic tone in ambulatory dogs with myocardial infarction (MI). METHODS: We used an implanted radiotransmitter to study left stellate ganglion nerve activity (SGNA), vagal nerve activity (VNA), and thoracic SCNA in 9 dogs at baseline and up to 8 weeks after MI. HRV was determined based on time-domain, frequency-domain, and nonlinear analyses. RESULTS: The correlation coefficients between integrated SGNA and SCNA averaged 0.74 (95% confidence interval [CI] 0.41-1.06) at baseline and 0.82 (95% CI, 0.63-1.01) after MI (P <.05 for both). The absolute values of the correlation coefficients were significantly larger than that between SGNA and HRV analysis based on time-domain, frequency-domain, and nonlinear analyses, respectively, at baseline (P <.05 for all) and after MI (P <.05 for all). There was a clear increment of SGNA and SCNA at 2, 4, 6, and 8 weeks after MI, whereas HRV parameters showed no significant changes. Significant circadian variations were noted in SCNA, SGNA, and all HRV parameters at baseline and after MI, respectively. Atrial tachycardia (AT) episodes were invariably preceded by SCNA and SGNA, which were progressively increased from 120th, 90th, 60th, to 30th seconds before AT onset. No such changes of HRV parameters were observed before AT onset. CONCLUSION: SCNA is more accurate than HRV in estimating cardiac sympathetic tone in ambulatory dogs with MI.

Pupillometry: the eyes shed fresh light on the mind.

Recent studies provide promising methodological advances in the use of pupillometry as on-line measurement of cognitive processes and show that visual attention allocation, mind-wandering, mental imagery, and even rhyme expectations can influence the size of the human pupil.

Face perception is whole or none: disentangling the role of spatial contiguity and interfeature distances in the composite face illusion.

Compelling evidence that faces are perceived holistically or configurally comes from the composite face illusion: identical top halves of a face are perceived as being different if they are aligned with different bottom halves. The visual illusion disappears when the top and bottom face halves are spatially misaligned. Whether this is because the two halves no longer form a whole face (ie they form two segmented parts), or because of an increase in interfeatures distance in the misaligned condition (eg eyes-mouth distance) remains unclear. Here, thirty-four participants performed a delayed matching composite task in which the amount of spatial misalignment between face halves varied parametrically (from 8.33% of face width to 100%). The difference in performance between aligned and misaligned faces (ie the composite face effect) was already of full magnitude at the smallest level of misalignment. These results imply that a small spatial misalignment is sufficient to measure the composite face effect. From a theoretical standpoint, they indicate that it is the breaking of a whole configuration rather than the increase in relative distance between the face parts that explains the presence or absence of the composite face effect, clarifying an outstanding issue concerning the nature of holistic face perception.