Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 158
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Heart Rhythm ; 2020 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-32454219

RESUMO

BACKGROUND: 12-lead electrocardiogram (ECG) criteria have been developed to identify idiopathic ventricular arrhythmias (VAs) from the left ventricular (LV) papillary muscles (PAPs), but accurate localization remains a challenge. OBJECTIVE: To develop ECG criteria for accurate localization of LV PAP VAs utilizing lead V1 exclusively. METHODS: Consecutive patients undergoing mapping and ablation of VAs from the LV PAPs guided by intracardiac echocardiography from 2007-2018 were reviewed (study group). The QRS morphology in V1 was compared to patients with VAs with a "RBBB" morphology from other LV locations (reference group). Patients with structural heart disease were excluded. RESULTS: 111 patients with LV PAP VAs (age 54±16, male 59%) including 64 (55%) from the posteromedial PAP and 47 (42%) from the anterolateral PAP. The reference group included patients with VAs from the following LV locations: fascicles (n=21), outflow tract (n=36), ostium (n=37), inferobasal segment (n=12), and apex (5). PAP VAs showed 3 distinct QRS morphologies in V1 93% of the time: Rr (53%), R with a slurred downslope (29%), and RR (11%). Sensitivity, specificity, and positive and negative predictive values for the 3 morphologies combined are 93%, 98%, 98%, and 93%, respectively. The intrinsicoid deflection of the PAP VAs in V1 were shorter than the reference group (63±13 ms versus 79±24 ms; p<0.001). An intrinsicoid deflection time less than 74 ms best differentiated the two groups (sensitivity, 79%; specificity, 87%). CONCLUSION: VAs originating from the LV PAPs manifest unique QRS morphologies in lead V1, which can aid in rapid and accurate localization.

4.
Artigo em Inglês | MEDLINE | ID: mdl-32298038

RESUMO

INTRODUCTION: In patients with nonischemic cardiomyopathy (NICM) little is known about the clinical impact of catheter ablation (CA) of septal ventricular tachycardia (VT) resulting in the collateral injury of the conduction system (CICS). METHODS AND RESULTS: Ninety-five consecutive patients with NICM underwent CA of septal VT. Outcomes in patients with no baseline conduction abnormalities who developed CICS (group 1, n = 28 [29%]) were compared to patients with no CICS (group 2, n = 17 [18%]) and to patients with preexisting conduction abnormalities or biventricular pacing (group 3, n = 50 [53%]). Group-1 patients were younger, had a higher left ventricular ejection fraction and a lower prevalence of New York Heart Association III/IV class compared to group 3 while no significant differences were observed with group 2. After a median follow-up of 15 months, VT recurred in 14% of patients in group 1, 12% in group 2 (P = .94) and 32% in group 3 (P = .08) while death/transplant occurred in 14% of patients in group 1, 18% in group 2 (P = .69) and 28% in group 3 (P = .15). A worsening of left ventricular ejection fraction (LVEF) (median LVEF variation, -5%) was observed in group 1 compared to group 2 (median LVEF variation, 0%; P < .01) but not group-3 patients (median LVEF variation, -4%; P = .08) with a consequent higher need for new biventricular pacing in group 1 (43%) compared to group 2 (12%; P = .03) and group 3 (16%; P < .01). CONCLUSIONS: In patients with NICM and septal substrate, sparing the abnormal substrate harboring the conduction system provides acceptable VT control while preventing a worsening of the systolic function.

6.
Curr Biol ; 30(8): 1537-1546.e3, 2020 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-32243854

RESUMO

In healthy adult organs, robust feedback mechanisms control cell turnover to enforce homeostatic equilibrium between cell division and death [1, 2]. Nascent tumors must subvert these mechanisms to achieve cancerous overgrowth [3-7]. Elucidating the nature of this subversion can reveal how cancers become established and may suggest strategies to prevent tumor progression. In adult Drosophila intestine, a well-studied model of homeostatic cell turnover, the linchpin of cell equilibrium is feedback control of the epidermal growth factor (EGF) protease Rhomboid (Rho). Expression of Rho in apoptotic cells enables them to secrete EGFs, which stimulate nearby stem cells to undergo replacement divisions [8]. As in mammals, loss of adenomatous polyposis coli (APC) causes Drosophila intestinal stem cells to form adenomas [9]. Here, we demonstrate that Drosophila APC-/- tumors trigger widespread Rho expression in non-apoptotic cells, resulting in chronic EGF signaling. Initially, nascent APC-/- tumors induce rho in neighboring wild-type cells via acute, non-autonomous activation of Jun N-terminal kinase (JNK). During later growth and multilayering, APC-/- tumors induce rho in tumor cells by autonomous downregulation of E-cadherin (E-cad) and consequent activity of p120-catenin. This sequential dysregulation of tumor non-autonomous and -autonomous EGF signaling converts tissue-level feedback into feed-forward activation that drives cancerous overgrowth. Because Rho, EGF receptor (EGFR), and E-cad are associated with colorectal cancer in humans [10-17], our findings may shed light on how human colorectal tumors progress.

7.
Cereb Cortex ; 30(5): 2721-2739, 2020 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-32118259

RESUMO

Certain transformations must occur within the brain to allow rapid processing of familiar experiences. Complex objects are thought to become unitized, whereby multifeature conjunctions are retrieved as rapidly as a single feature. Behavioral studies strongly support unitization theory, but a compelling neural mechanism is lacking. Here, we examined how unitization transforms conjunctive representations to become more "feature-like" by recruiting posterior regions of the ventral visual stream (VVS) whose architecture is specialized for processing single features. We used functional magnetic resonance imaging to scan humans before and after visual training with novel objects. We implemented a novel multivoxel pattern analysis to measure a conjunctive code, which represented a conjunction of object features above and beyond the sum of the parts. Importantly, a multivoxel searchlight showed that the strength of conjunctive coding in posterior VVS increased posttraining. Furthermore, multidimensional scaling revealed representational separation at the level of individual features in parallel to the changes at the level of feature conjunctions. Finally, functional connectivity between anterior and posterior VVS was higher for novel objects than for trained objects, consistent with early involvement of anterior VVS in unitizing feature conjunctions in response to novelty. These data demonstrate that the brain implements unitization as a mechanism to refine complex object representations over the course of multiple learning experiences.

9.
JACC Clin Electrophysiol ; 6(3): 272-281, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32192677

RESUMO

OBJECTIVES: This study describes the technique and outcomes of atrial fibrillation (AF) ablation via a superior approach in patients with interrupted or absent inferior vena cavas (IVCs). BACKGROUND: In patients with interrupted or absent IVCs, transseptal access cannot be obtained via standard femoral venous access. In these patients, alternative strategies are necessary to permit catheter ablation in the left atrium (LA). This study reports on the outcomes of AF ablation from a superior venous access with a radiofrequency (RF)-assisted transseptal puncture (TSP) technique. METHODS: This study identified patients with interrupted or absent IVCs who underwent AF ablation via a superior approach at 2 ablation centers from 2010 to 2019. RESULTS: Fifteen patients (mean age: 50.8 ± 11.2 years; 10 men; 10 with paroxysmal AF) with interrupted or absent IVCs underwent AF ablation with transseptal access via a superior approach. Successful TSP was performed either with a manually bent RF transseptal needle (early cases: n = 4) or using a RF wire (late cases: n = 11); this approach permitted LA mapping and ablation in all patients. Mean time required to perform single (n = 8) or double (n = 7) TSP was 16.1 ± 4.8 min, and mean total procedure time was 227.9 ± 120.7 min (fluoroscopy time: 57.0 ± 28.5 min). LA mapping and ablation were successfully performed in all patients. CONCLUSIONS: In patients with AF undergoing catheter ablation and who had a standard transseptal approach via femoral venous approach is impossible due to anatomic constraints, RF-assisted transseptal access via a superior approach can be an effective alternative strategy to permit LA mapping and ablation.

10.
Heart Rhythm ; 2020 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-32112873

RESUMO

BACKGROUND: Postoperative bradycardia can complicate orthotopic heart transplantation (OHT). Previous studies suggested donor age and surgical technique as possible risk factors. However, risk factors in the era of bicaval anastomosis have not been elucidated. OBJECTIVE: We sought to examine the association between donor/recipient characteristics with need for chronotropic support and permanent pacemaker (PPM) implantation in patients with OHT. METHODS: All patients treated with OHT between January 2003 and January 2018 at the Hospital of the University of Pennsylvania were retrospectively evaluated until June 2018. Chronotropic support was given upon postoperative inability to increase the heart rate to patient's demands and included disproportionate bradycardia and junctional rhythm. RESULTS: A total of 820 patients (mean age 51.3 ± 12.6 years; 74% men) underwent 826 OHT procedures (95.3% bicaval anastomosis). Patients who were exposed to amiodarone (odds ratio [OR] 2.30; 95% confidence interval [CI] 1.58-3.34; P < .001) and have older donor (OR 1.02; 95% CI 1.01-1.04; P = .001) were more likely to develop need for chronotropic support. In multivariable analysis, recipient age (OR 1.03; 95% CI 1.00-1.06; P = .04) and biatrial anastomosis (OR 6.12; 95% CI 2.48-15.09) were significantly associated with PPM implantation within 6 months of OHT. No association was found between pre-OHT amiodarone use and PPM implantation. No risk factors assessed were associated with PPM implantation 6 months after OHT. CONCLUSION: Surgical technique and donor age were the main risk factors for the need for chronotropic support post-OHT, whereas surgical technique and recipient age were risk factors for early PPM implantation.

11.
JACC Clin Electrophysiol ; 6(2): 221-230, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32081227

RESUMO

OBJECTIVES: This study sought to examine clinical characteristics of procedural and long-term outcomes in patients undergoing catheter ablation (CA) of outflow tract ventricular arrhythmias (OT-VAs) over 16 years. BACKGROUND: CA is an effective treatment strategy for OT-VAs. METHODS: Patients undergoing CA for OT-VAs from 1999 to 2015 were divided into 3 periods: 1999 to 2004 (early), 2005 to 2010 (middle), and 2011 to 2015 (recent). Successful ablation site (right ventricular OT, aortic cusps/left ventricular OT, or coronary venous system/epicardium), VA morphology (right bundle branch block or left bundle branch block), and acute and clinical success rates were assessed. RESULTS: Six hundred eighty-two patients (336 female) were included (early: n = 97; middle: n = 204; recent: n = 381). Over time there was increase in use of irrigated ablation catheters and electroanatomic mapping, and more VAs were ablated from the aortic cusp/left ventricular OT or coronary venous system/epicardium (14% vs. 45% vs. 56%; p < 0.0001). Acute procedural success was achieved in 585 patients (86%) and was similar between groups (82% vs. 84% vs. 88%; p = 0.27). Clinical success was also similar between groups (86% vs. 87% vs. 88%; p = 0.94), but more patients in earlier periods required repeat ablation (18% vs. 17% vs. 9%; p = 0.02). Overall complication rate was 2% (similar between groups). CONCLUSIONS: Over a 16-year period there was an increase in patients undergoing CA for OT-VTs, with more ablations performed at non-right ventricular outflow tract locations using electroanatomic mapping and irrigated-tip catheters. Over time, single procedure success has improved and complications have remained limited.

12.
JACC Clin Electrophysiol ; 6(2): 231-240, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32081228

RESUMO

OBJECTIVES: This study sought to evaluate the prevalence, mapping features, and ablation outcomes of non-scar-related ventricular tachycardia (NonScar-VT) and Purkinje-related VT (Purkinje-VT) in patients with structural heart disease. BACKGROUND: VT in structural heart disease is typically associated with scar-related myocardial re-entry. NonScar-VTs arising from areas of normal myocardium or Purkinje-VTs originating from the conduction system are less common. METHODS: We retrospectively analyzed 690 patients with structural heart disease who underwent VT ablation between 2013 and 2017. RESULTS: A total of 37 (5.4%) patients (16 [43%] with ischemic cardiomyopathy, 16 [43%] with nonischemic dilated cardiomyopathy, and 5 [14%] others) demonstrated NonScar/Purkinje-VTs, which represented the clinical VT in 76% of cases. Among the 37 VTs, 31 (84%) were Purkinje-VTs (28 bundle branch re-entrant VT). The remaining 6 (16%) VTs were NonScar-VTs and included 4 idiopathic outflow tract VTs. A total of 16 patients had prior history of VT ablations: empirical scar substrate modification was performed in 6 (38%) patients and residual inducibility of VT had not been assessed in 7 (44%). In all 37 patients, the NonScar/Purkinje-VT was successfully ablated. After a median follow-up of 18 months, the targeted NonScar/Purkinje-VT did not recur in any patients, and 28 (76%) of patients were free from any recurrent VT episodes. CONCLUSIONS: NonScar/Purkinje-VTs can be identified in 5.4% of patients undergoing VT ablation in the setting of structural heart disease. Careful effort to induce, characterize, and map these VTs is important because substrate-based ablation strategies would fail to eliminate these types of VT.

13.
Circ Arrhythm Electrophysiol ; 13(1): e007611, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31922914

RESUMO

BACKGROUND: Data characterizing structural changes of arrhythmogenic right ventricular (RV) cardiomyopathy are limited. METHODS: Patients presenting with left bundle branch block ventricular tachycardia in the setting of arrhythmogenic RV cardiomyopathy with procedures separated by at least 9 months were included. RESULTS: Nineteen consecutive patients (84% males; mean age 39±15 years [range, 20-76 years]) were included. All 19 patients underwent 2 detailed sinus rhythm electroanatomic endocardial voltage maps (average 385±177 points per map; range, 93-847 points). Time interval between the initial and repeat ablation procedures was mean 50±37 months (range, 9-162). No significant progression of voltage was observed (bipolar: 38 cm2 [interquartile range (IQR), 25-54] versus 53 cm2 [IQR, 25-65], P=0.09; unipolar: 116 cm2 [IQR, 61-209] versus 159 cm2 [IQR, 73-204], P=0.36) for the entire study group. There was a significant increase in RV volumes (percentage increase, 28%; 206 mL [IQR, 170-253] versus 263 mL [IQR, 204-294], P<0.001) for the entire study population. Larger scars at baseline but not changes over time were associated with a significant increase in RV volume (bipolar: Spearman ρ, 0.6965, P=0.006; unipolar: Spearman ρ, 0.5743, P=0.03). Most patients with progressive RV dilatation (8/14, 57%) had moderate (2 patients) or severe (6 patients) tricuspid regurgitation recorded at either initial or repeat ablation procedure. CONCLUSIONS: In patients with arrhythmogenic RV cardiomyopathy presenting with recurrent ventricular tachycardia, >10% increase in RV endocardial surface area of bipolar voltage consistent with scar is uncommon during the intermediate term. Most recurrent ventricular tachycardias are localized to regions of prior defined scar. Voltage indexed scar area at baseline but not changes in scar over time is associated with progressive increase in RV size and is consistent with adverse remodeling but not scar progression. Marked tricuspid regurgitation is frequently present in patients with arrhythmogenic RV cardiomyopathy who have progressive RV dilation.

14.
JACC Clin Electrophysiol ; 6(1): 21-30, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31971902

RESUMO

OBJECTIVE: This study sought to investigate incidence of left atrial appendage (LAA) triggers of atrial fibrillation (AF) and/or organized atrial tachycardias (OAT) in patients undergoing AF ablation and to evaluate outcomes after ablation. BACKGROUND: Although LAA isolation is being increasingly performed during AF ablation, the true incidence of LAA triggers for AF remains unclear. METHODS: All patients with LAA triggers of AF and/or OAT during AF ablation from 2001 to 2017 were included. LAA triggers were defined as atrial premature depolarizations from the LAA, which initiated sustained AF and/or OAT. RESULTS: Out of 7,129 patients undergoing AF ablation over 16 years, LAA triggers were observed in 21 (0.3%) subjects (age 60 ± 9 years; 57% males; 52% persistent AF). Twenty (95%) patients were undergoing repeat ablation. The LAA was the only nonpulmonary vein trigger in 3 patients; the remaining 18 patients had both LAA and other nonpulmonary vein triggers. LAA triggers were eliminated in all patients (focal ablation in 19 patients; LAA isolation in 2 patients). Twelve months after ablation, 47.6% remained free from recurrent arrhythmia. After overall follow-up of 5.0 ± 3.6 years (median: 3.7 years; interquartile range: 1.4 to 8.9 years), 38.1% were arrhythmia-free. All 3 patients with triggers limited to the LAA remained free of AF recurrence. One patient undergoing LAA isolation developed LAA thrombus during follow-up. CONCLUSIONS: The incidence of true LAA triggers is very low (0.3%). Most patients with LAA triggers have additional nonpulmonary vein triggers, and despite elimination of LAA triggers, long-term arrhythmia recurrence rates remain high. Potential risks of empiric LAA isolation during AF ablation (especially first-time AF ablation) may outweigh benefits.

15.
J Cardiovasc Electrophysiol ; 31(1): 293-299, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31778268

RESUMO

The standard technique for percutaneous catheter ablation of atrial fibrillation (AF) involves obtaining left atrial access and catheter manipulation from an inferior transfemoral venous access. However, in patients with inferior vena cava interruption, a standard transfemoral venous approach is not possible. In these cases, a percutaneous approach from a superior central vein, such as the internal jugular vein or the axillary/subclavian vein can be considered. In this article, we describe the details of our technique to obtain left atrial catheterization and perform catheter ablation of AF from a superior approach. Our technique involves the use of steerable sheaths, dedicated radiofrequency wires, and intracardiac echocardiography guidance.

16.
J Cardiol ; 75(4): 368-373, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31522792

RESUMO

BACKGROUND: The safety and efficacy of superior vena cava (SVC) isolation (SVCI) using second-generation cryoballoon (CB) ablation remains unknown. METHODS: Electrical isolation of SVC was attempted using the second-generation CB ablation catheter in 14 canines. Ablation duration was randomized to either 90 s (7 canines) or 120 s (7 canines). SVC venography was performed to identify the SVC-right atrium (RA) junction. The 28-mm CB was positioned above SVC-RA junction. Repeat electrophysiological assessment in the live animals was conducted 40-60 days post-ablation, after which animals were euthanized for histological examination. RESULTS: Acute SVCI was successfully performed in all canines. No significant differences in numbers of freezes (1.7 ±â€¯0.8 vs. 1.5 ±â€¯0.5, p = 0.658), time to isolation (TTI) (24.3 ±â€¯8.1s vs. 22.7 ±â€¯9.0s, p = 0.297), temperature at isolation (-23.4 ±â€¯12.5 °C vs. -21.5 ±â€¯11.1 °C, p = 0.370), and nadir temperature (-51.2 ±â€¯6.2 °C vs. -53.3 ±â€¯7.0 °C, p = 0.195) were observed between the 90-s and 120-s groups. There were no procedural complications except one transient sinus bradycardia in the 120-s group. After ablation, animals survived for 51 ±â€¯5 days. Chronic SVCI was achieved in 6 of 7 (85.7%) SVCs in the 90-s group and 7 of 7 SVCs (100%) in the 120-s group (p = 0.299). Histological analysis revealed that a circumferential transmural lesion was achieved in all isolated SVCs. No sinus node (SN) and phrenic nerve injuries were observed. The minimum distance between ablation lesion and SN was 5.1 ±â€¯3.0 mm. CONCLUSIONS: The second-generation CB ablation catheter is both safe and effective in achieving SVC isolation in a canine model. Effective SVCI was found in the 90-s dosing strategy.

17.
Clin Cancer Res ; 26(3): 657-668, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31611282

RESUMO

PURPOSE: Emerging data suggest immune checkpoint inhibitors have reduced efficacy in heavily pretreated triple-negative breast cancers (TNBC), but underlying mechanisms are poorly understood. To better understand the phenotypic evolution of TNBCs, we studied the genomic and transcriptomic profiles of paired tumors from patients with TNBC. EXPERIMENTAL DESIGN: We collected paired primary and metastatic TNBC specimens from 43 patients and performed targeted exome sequencing and whole-transcriptome sequencing. From these efforts, we ascertained somatic mutation profiles, tumor mutational burden (TMB), TNBC molecular subtypes, and immune-related gene expression patterns. Stromal tumor-infiltrating lymphocytes (stromal TIL), recurrence-free survival, and overall survival were also analyzed. RESULTS: We observed a typical TNBC mutational landscape with minimal shifts in copy number or TMB over time. However, there were notable TNBC molecular subtype shifts, including increases in the Lehmann/Pietenpol-defined basal-like 1 (BL1, 11.4%-22.6%) and mesenchymal (M, 11.4%-22.6%) phenotypes, and a decrease in the immunomodulatory phenotype (IM, 31.4%-3.2%). The Burstein-defined basal-like immune-activated phenotype was also decreased (BLIA, 42.2%-17.2%). Among downregulated genes from metastases, we saw enrichment of immune-related Kyoto Encyclopedia of Genes and Genomes pathways and gene ontology (GO) terms, and decreased expression of immunomodulatory gene signatures (P < 0.03) and percent stromal TILs (P = 0.03). There was no clear association between stromal TILs and survival. CONCLUSIONS: We observed few mutational shifts, but largely consistent transcriptomic shifts in longitudinally paired TNBCs. Transcriptomic and IHC analyses revealed significantly reduced immune-activating gene expression signatures and TILs in recurrent TNBCs. These data may explain the observed lack of efficacy of immunotherapeutic agents in heavily pretreated TNBCs. Further studies are ongoing to better understand these initial observations.See related commentary by Savas and Loi, p. 526.

18.
JACC Clin Electrophysiol ; 5(12): 1363-1383, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31857035

RESUMO

Although implantable cardioverter-defibrillators positively affect survival in patients at increased risk for arrhythmic sudden cardiac death, quality of life can be negatively affected by recurrent therapies. Ventricular tachycardia (VT) ablation targets clinical arrhythmias to prevent recurrence. Although treatment of VT initially required open heart surgery, it has since been replaced by percutaneous ablation, a safe and effective catheter-based therapy to ablate myocardium from either the endocardial or the epicardial surface. Four basic mapping techniques are used to guide VT ablation: activation, entrainment, and pace and substrate mapping. Current recommendations for VT ablation, especially in the setting of structural heart disease, mostly reserve this treatment for patients for whom antiarrhythmic therapy has failed or is not tolerated or desired. These recommendations derive from multiple observational reports and several randomized prospective studies in patients with VT in the setting of ischemic cardiac disease. Patients are usually referred late in their clinical course for VT ablation, limiting enrollment in clinical trials and resulting in limited prospective randomized data on long-term outcomes with ablative therapy. Future research efforts should address unmet needs, including more rigorous assessment of survival benefit from VT ablation, outcomes data of VT ablation in patients with nonischemic cardiomyopathy, and assessment of strategies to improve intramural substrate ablation. Emerging technologies with disruptive potential include the use of lower ionic strength irrigants, energy delivery guided by impedance modulation, simultaneous unipolar and bipolar ablation, and novel ablation catheters, including the retractable needle-tip electrode catheter. Promising alternatives to radiofrequency ablation include alcohol ablation from the coronary arterial or venous system, direct current or pulsed field electroporation, and stereotactic body radiotherapy guided by noninvasive substrate mapping. Future studies are needed to demonstrate the safety and efficacy of these novel technologies compared with standard radiofrequency catheter ablation.

19.
J Exp Psychol Gen ; 2019 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-31580102

RESUMO

Subjective similarity holds a prominent place in many psychological theories, influencing diverse cognitive processes ranging from attention and categorization to memory and problem solving. Despite the known importance of subjective similarity, there are few resources available to experimenters interested in manipulating the visual similarity of shape, one common type of subjective similarity. Here, across seven validation iterations, we incrementally developed a stimulus space consisting of 360 shapes using a novel image-processing method in conjunction with collected similarity judgments. The result is the Validated Circular Shape space, the first Validated Circular Shape space comparable to the commonly used "color wheel", whereby angular distance along a 2D circle is a proxy for visual similarity. This extensively validated resource is freely available to experimenters wishing to precisely manipulate the visual similarity of shape. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

20.
Artigo em Inglês | MEDLINE | ID: mdl-31440875

RESUMO

PURPOSE: In arrhythmogenic right ventricular cardiomyopathy (ARVC), abnormal electroanatomic mapping (EAM) areas are proportional to extent of T-wave inversion on 12-lead ECG. We aimed to evaluate local repolarization changes and their relationship to EAM substrate in ARVC. METHODS: Using unipolar recordings, we analyzed the proportion of negative T waves ≥ 1 mV in depth (NegT), NegT area, Q-Tpeak (QTP), Tpeak-Tend (TPE) intervals and their relationship to bipolar (< 1.5 mV ENDO, < 1.0 mV EPI) and unipolar (< 5.5 mV) endocardial (ENDO) and epicardial (EPI) low-voltage area (LVA) in 21 pts. (15 men, mean age 39 ± 14) with ARVC. Control group included 5 pts. with normal hearts and idiopathic PVCs. RESULTS: On ENDO, the % of NegT (7 ± 5% vs 30 ± 20%, p = 0.004) and the NegT area (12.9 ± 9.7 c m2 vs 61.4 ± 30.0 cm2, p = 0.001) were smaller in ARVC compared to controls. On EPI, the % of NegT was similar (5 ± 7% vs 3 ± 4%, p = 0.323) and the NegT area, larger (11.0 ± 8.4 cm2 vs 2.7 ± 0.9 cm2, p = 0.027) in ARVC group. In ARVC group, the % of NegT area inside LVA was larger on EPI compared to ENDO for both bipolar (81 ± 27% vs 31 ± 33%, p < 0.001) and unipolar (90 ± 19% vs 73 ± 28%, p = 0.036) recordings. Compared to normal voltage regions, QTP inside ENDO abnormal LVA was on average 58 ± 26 ms shorter and TPE, 25 ± 56 ms longer (97 ± 26 ms and 56 ± 86 ms on EPI, respectively). CONCLUSIONS: In ARVC, NegT areas are more closely associated with abnormal depolarization LVA on the EPI and QTP is shorter and TPE longer inside ENDO and EPI abnormal LVA compared to normal voltage regions. The results add to our understanding of ARVC arrhythmia substrate.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA