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PURPOSE: The second-generation multi-electrode catheter, PVAC Gold, was designed to improve the safe delivery of phased radiofrequency energy using a "single shot" approach for pulmonary vein isolation (PVI), while retaining efficacy. This large registry presents long-term performance in a daily practice setting. METHODS: A total of 1011 patients undergoing first time ablation for atrial fibrillation (AF) using PVAC Gold were included, 639 patients with PVI for paroxysmal AF (PAF PVI) and 372 patients with persistent or long-standing persistent AF, divided into 175 patients receiving PVI only (PersAF PVI) and 197 patients receiving PVI with additional substrate ablation (PersAF PVI +). RESULTS: At 24-month follow-up, single procedure freedom from atrial tachyarrhythmia (ATA) was 58% (368/639) in the PAF PVI group, 44% (77/175) in the PersAF PVI group, and 29% (57/197) in the PersAF PVI + group. Allowing one repeat procedure in 33% of patients, 76%, 65%, and 54% were free from ATA at 24 months, respectively. Pulmonary vein reconnection was observed in 98% of patients with recurrent arrhythmia after PVI. CONCLUSIONS: Although phased RF ablation with PVAC Gold is quick and safe, the efficacy outcomes are modest compared to current mainstream ablation strategies.
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Fibrilação Atrial , Ablação por Cateter , Veias Pulmonares , Humanos , Fibrilação Atrial/cirurgia , Ouro , Seguimentos , Resultado do Tratamento , Ablação por Cateter/métodos , Veias Pulmonares/cirurgia , Catéteres , RecidivaRESUMO
INTRODUCTION: The AcQMap High Resolution Imaging and Mapping System was recently introduced. This system provides 3D maps of electrical activation across an ultrasound-acquired atrial surface. METHODS: We evaluated the feasibility and the acute and short-term efficacy and safety of this novel system for ablation of persistent atrial fibrillation (AF) and atypical atrial flutter. RESULTS: A total of 21 consecutive patients (age (mean⯱ standard deviation) 62⯱ 8 years, 23% female) underwent catheter ablation with the use of the AcQMap System. Fourteen patients (67%) were treated for persistent AF and 7 patients (33%) for atypical atrial flutter. Eighteen patients (86%) had undergone at least one prior ablation procedure. Acute success, defined as sinus rhythm without the ability to provoke the clinical arrhythmia, was achieved in 17 patients (81%). At 12 months, 4 patients treated for persistent AF (29%) and 4 patients treated for atypical flutter (57%) remained in sinus rhythm. Complications included hemiparesis, for which intra-arterial thrombolysis was given with subsequent good clinical outcome (nâ¯= 1), and complete atrioventricular block, for which a permanent pacemaker was implanted (nâ¯= 2). No major complications attributable to the mapping system occurred. CONCLUSION: The AcQMap System is able to provide fast, high-resolution activation maps of persistent AF and atypical atrial flutter. Despite a high acute success rate, the recurrence rate of persistent AF was relatively high. This may be due to the selection of the patients with therapy-resistant arrhythmias and limited experience in the optimal use of this mapping system that is still under development.
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PURPOSE: Ablation of atypical atrial flutter (AAFL) can be challenging. High-density (HD) mapping of ablation targets may potentially increase procedural success and freedom from recurrent AAFL. The objective of the present study was to explore whether employing HD mapping leads to a more favorable outcome in ablation of AAFL. METHODS: We compared baseline and procedural characteristics, procedural success, safety and outcome of mapping and ablation of atypical flutter in three groups. (1) HD Grid catheter + the high-density electroanatomical mapping (EAM) system EnSite Precision; (2) standard 10-pole circular mapping catheter (CMC) + EnSite Precision; (3) CMC + the low-density EnSite Velocity EAM. Voltage and propagation maps were constructed. RESULTS: Mapping of 142 AAFL in 82 patients was performed. Acute ablation success was 78%, 68%, and 51% in groups 1, 2, and 3 (p = 0.037 between group 1 and 3, non-significant between groups otherwise). Moreover, 8%, 27%, and 36% of flutters were unmappable in groups 1, 2, and 3, respectively (p < 0.05 between group 1 and both groups 2 and 3). AAFL recurrence at 1-year FU was 26%, 36%, and 62% in groups 1, 2, and 3 (p = 0.007 between groups 1 and 3, p = 0.05 between groups 2 and 3). AAFL-free survival was significantly higher in patients mapped with Precision than with Velocity (p = 0.011). No strokes or mortality occurred within 30 days. CONCLUSIONS: Acute procedural success of ablation of atypical atrial flutter is higher and the number of unmappable flutters is lower using the HD Grid mapping catheter in combination with the high-density EnSite Precision system, as compared to a decapolar circular mapping catheter and the low-density EnSite Velocity EAM system. This may lead to increased freedom from recurrent AAFL at 1 year. HD mapping is safe.
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Flutter Atrial , Ablação por Cateter , Arritmias Cardíacas , Flutter Atrial/diagnóstico por imagem , Flutter Atrial/cirurgia , Humanos , Fatores de Tempo , Resultado do TratamentoRESUMO
PURPOSE: The second-generation multi-electrode catheter, pulmonary vein ablation catheter (PVAC) GOLD, was designed to improve the delivery of phased radiofrequency energy and reduce procedure times using a 'single-shot' approach for pulmonary vein isolation (PVI), while retaining efficacy and safety. This large registry presents acute success rates and safety outcomes in a daily practice setting. METHODS: A total of 1017 patients undergoing first-time ablation for atrial fibrillation (AF) using PVAC GOLD were included, 644 patients with paroxysmal AF and 373 patients with non-paroxysmal AF, divided into 175 patients receiving PVI only and 198 patients receiving PVI with additional substrate modification. RESULTS: High and comparable percentages of successful PVI could be achieved in all groups (98%, 95% and 99%; p = 0.108). The median total procedure time for all groups was 90 min [70-100]. As expected, the total procedure, ablation and fluoroscopy time were significantly longer in the PVI + substrate modification group compared with the PVI-only cases (all p < 0.001), but not between the PVI-only groups (p = 0.306, p = 0.088, p = 0.233, respectively). A total of 44 complications were observed in 43 patients (4.2%). Major complications were seen in 19 patients (1.87%) and non-major procedure-related complications were seen in 25 patients (2.46%). Complications leaving permanent sequelae were rare and occurred in only four patients (0.39%). Complications did not differ between groups (p = 0.199, p = 0.438, p = 0.240 and p = 0.465 respectively). CONCLUSION: PVAC GOLD performs successful PVI, while reducing procedure times and retaining safety for paroxysmal, persistent and long-standing persistent AF. Safety was unaffected by additional substrate modification.
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Fibrilação Atrial , Ablação por Cateter , Veias Pulmonares , Fibrilação Atrial/cirurgia , Catéteres , Humanos , Veias Pulmonares/diagnóstico por imagem , Veias Pulmonares/cirurgia , Resultado do TratamentoRESUMO
This study aimed to evaluate rib fracture rate as well as rib fracture characteristics after thoracic trauma in patients with normal versus diminished bone mineral density (BMD). A retrospective cohort study of persons aged 50 years or older presenting to the Emergency Department after sustaining blunt thoracic trauma between July 1, 2014, and December 31, 2017, was performed. Patient and trauma characteristics and DXA scan results were collected. Rib fracture rate and characteristics were evaluated on a radiograph and/or CT scan of the thorax. In total, 119 patients were included for analysis. Fifty-eight of them (49%) had a diminished BMD. In the remaining 61, the BMD was normal. The diminished BMD group experienced rib fractures more often than the normal BMD group (n = 43 (74%) versus n = 31 (51%); p = 0.014). Patients with diminished BMD suffered low-energy trauma more frequently than the normal BMD group (21 (36%) versus 11 patients (15%), respectively (p = 0.011)). Rib fracture characteristics such as the median number of rib fractures, concomitant intrathoracic injury rate, and rib fracture type distribution were not different between the groups. The rate of rib fractures after blunt thoracic trauma was significantly higher in patients with diminished BMD than in patients with a normal BMD. Differences in number and location of rib fractures between groups could not be proven. When assessing patients aged 50 years or older presenting to the hospital after substantial blunt thoracic trauma, the presence of diminished BMD should be taken into account and the presence of rib fractures should be investigated with appropriate diagnostic procedures. Diminished bone mineral density (i.e., osteopenia or osteoporosis) is associated with increased fracture risk. This study evaluated if diminished BMD increases the rib fracture risk. Patients with diminished BMD have a higher risk of sustaining rib fractures after substantial blunt thoracic trauma, which implicates a lower threshold for CT imaging of the chest.
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Densidade Óssea , Fraturas das Costelas , Traumatismos Torácicos , Ferimentos não Penetrantes , Feminino , Humanos , Pessoa de Meia-Idade , Estudos Retrospectivos , Fraturas das Costelas/diagnóstico por imagem , Fraturas das Costelas/epidemiologia , Fraturas das Costelas/etiologia , Traumatismos Torácicos/complicações , Traumatismos Torácicos/diagnóstico por imagem , Traumatismos Torácicos/epidemiologia , Ferimentos não Penetrantes/complicações , Ferimentos não Penetrantes/diagnóstico por imagem , Ferimentos não Penetrantes/epidemiologiaRESUMO
BACKGROUND: Current guidelines recommend non-vitaminK oral anticoagulants (NOACs) as the first-choice therapy for stroke prevention in patients with atrial fibrillation (AF). The use of drugs in a clinical trial setting differs from that in real-world populations. Real-world data are important to accrue more heterogeneous patient populations with respect to co-morbidities and co-medication use. The aim of this study was to evaluate the use of NOACs in daily practice in a large tertiary hospital in the Netherlands. METHODS: A single-centre prospective study was conducted among all patients with AF using a NOAC in the St. Antonius Hospital between 2013 and June 2017. The outcomes were the rates of any bleeding, stroke/transient ischaemic attack, mortality, discontinuation rate and adverse drug reactions. RESULTS: In total, 799 patients were enrolled with a mean follow-up of 1.7 years. Mean age was 69.8 (SD⯱ 11) and 61.2% were male. Mean CHA2DS2-VASc score was 2.8 (SD⯱ 1.6) and mean HAS-BLED score was 1.4 (SD⯱ 0.9). Bleeding occurred in 6.0, major bleeding in 1.8, stroke in 1.2 patients per 100 patient-years, and 87 patients (10.9%) died during the follow-up period. Adverse drug reactions were reported by 59 patients (7.4%). Finally, 249 patients (31.2%) reported a temporary interruption and 132 (16.5%) permanent discontinuation of NOAC treatment, of whom 33 (25%) patients switched to a vitaminK antagonist. CONCLUSIONS: We observed low rates of bleeding and adverse drug reactions. However, rates of mortality and discontinuation were relatively high. These results could possibly be explained by the real-world nature of the data including higher-risk patients.
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The aim of this study was to determine the rate of carpal tunnel syndrome (CTS) in patients with a volar plated distal radius fracture (DRF), with or without prophylactic carpal tunnel release (CTR). The PubMed database was searched for studies reporting on CTS in patients with a DRF fixed by a volar plate. Selected patients were those who underwent prophylactic CTR versus patients who did not. Pooled rates of CTS were calculated using inverse - variance weighting assuming a random effects model. Tests for heterogeneity were applied. In this study, 172 patients in the CTR group and 1839 patients in the non-CTR group were included. The pooled rate for CTS in the CTR group was 28.1% (95% CI: 11.8% to 48.2%) while it was 4.4% (95% CI: 3.1% to 6.0%) in the non-CTR group. CTR is of no prophylactic value for postoperative CTS in volar plated DRF patients.
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Síndrome do Túnel Carpal/etiologia , Fixação Interna de Fraturas , Complicações Pós-Operatórias , Fraturas do Rádio/cirurgia , Placas Ósseas , Descompressão Cirúrgica , HumanosRESUMO
This study evaluated the value of computed tomography scans for the diagnosis of distal radioulnar joint instability. A total of 46 patients, conservatively treated for a unilateral distal radius fracture, were evaluated. Clinical instability was tested using the stress test and clunk test. A computed tomography scan of both wrists was performed in pronation and supination. Two independent observers reviewed the computed tomography scans using: the radioulnar line, subluxation ratio, epicentre and radioulnar ratio methods. Radiological distal radioulnar joint instability was assessed by comparing the measurements of the injured wrist with those of the contralateral uninjured wrists. A total of 22 patients had clinical instability of whom 12 suffered from pain in the injured wrist. Distal radioulnar joint instability was diagnosed on computed tomography in 29 patients. Reliability analysis between clinical and radiological evaluations showed at best moderate, but generally poor agreement. The diagnostic ability of computed tomography for identifying distal radioulnar joint instability seems limited. LEVEL OF EVIDENCE: IV.
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Instabilidade Articular/diagnóstico por imagem , Fraturas do Rádio/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Traumatismos do Punho/diagnóstico por imagem , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Instabilidade Articular/etiologia , Instabilidade Articular/terapia , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Fraturas do Rádio/complicações , Fraturas do Rádio/terapia , Reprodutibilidade dos Testes , Estudos Retrospectivos , Traumatismos do Punho/complicações , Traumatismos do Punho/terapia , Adulto JovemRESUMO
OBJECTIVE: The presence of distal radioulnar joint (DRUJ) instability remains often unnoticed initially, but may worsen functional outcome of distal radius fractures (DRF). The aim of this study was to evaluate the influence of concurring clinical DRUJ instability on the outcome of conservatively treated DRF. METHODS: In a retrospective cohort study, all unilateral, conservatively treated DRF patients were invited for physical examination, CT scan of both wrists and filling out questionnaires. Static and dynamic DRUJ instability were clinically tested. RESULTS: Forty-nine DRF patients with a mean follow-up of 4.2 years (SD 0.5) were assessed. Seventeen patients tested positive for DRUJ instability. No differences were found in baseline characteristics between the DRUJ stable and unstable group. Apart from wrist flexion, no statistical significant differences in outcome was found between patients with and without DRUJ instability. CONCLUSION: The presence of clinical DRUJ instability does not seem to affect functional outcome of conservatively treated distal radius fractures at long-term follow-up.
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Instabilidade Articular/diagnóstico por imagem , Fraturas do Rádio/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Articulação do Punho/fisiopatologia , Feminino , Humanos , Instabilidade Articular/fisiopatologia , Instabilidade Articular/terapia , Masculino , Pessoa de Meia-Idade , Exame Físico , Fraturas do Rádio/fisiopatologia , Amplitude de Movimento Articular , Estudos Retrospectivos , Resultado do TratamentoRESUMO
PURPOSE: There is no consensus on the relation between ulnar styloid process nonunion and outcome in patients with distal radius fractures. The aim of this study was to analyze whether patient-reported outcome is influenced by the nonunion of the accompanying ulnar styloid fracture in distal radius fracture patients. METHODS: A meta-analysis of published studies comparing outcomes after distal radius fractures with a united versus a non-united ulnar styloid process was performed. In addition, if provided by the authors, the raw data of these studies were pooled and analysed as one study. The outcome measures of the analyses included patient-reported outcome, functional outcome, grip-strength, pain, and distal radioulnar joint (DRUJ) instability. RESULTS: Data from six comparative studies were included, concerning 365 patients with a distal radius fracture. One hundred and thirty-five patients with an ulnar styloid union were compared with 230 patients with a nonunion of the ulnar styloid. No significant differences were found between groups regarding any outcome measure. CONCLUSION: Based on this meta-analysis, there is no relation between the nonunion of the ulnar styloid process and function in patients with a distal radius fracture.
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Fixação Interna de Fraturas , Fraturas Mal-Unidas/cirurgia , Instabilidade Articular/patologia , Fraturas do Rádio/cirurgia , Fraturas da Ulna/cirurgia , Articulação do Punho/fisiopatologia , Ensaios Clínicos como Assunto , Consolidação da Fratura , Fraturas Mal-Unidas/fisiopatologia , Humanos , Medição da Dor , Fraturas do Rádio/fisiopatologia , Amplitude de Movimento Articular , Recuperação de Função Fisiológica , Resultado do Tratamento , Fraturas da Ulna/fisiopatologiaRESUMO
INTRODUCTION: The pulmonary vein ablation catheter (PVAC) is designed for pulmonary vein isolation (PVI). Electrical reconnection of pulmonary veins is believed to result in AF recurrence. The purpose of this study was to establish the location and extent of PV reconnection after PVI with the PVAC catheter. METHODS AND RESULTS: Eighty-two patients (79 % male, age 60 ± 9 years) that underwent a redo procedure for recurrent AF after PVAC ablation were assessed for prevalence and location of reconnection. The number of reconnected PV's was 0, 1, 2, 3, or 4 in 2 (2.4 %), 14 (17 %), 23 (28 %), 28 (34 %), and 15 (18 %) patients, respectively. Reconnection of left superior, left inferior, left common, right superior, and right inferior PV's was found in 66, 63, 83, 57, and 67 %, respectively (p = 0.48). In the left PV's, reconnection was located significantly more anterior than posterior; LSPV anterior 32/70 vs posterior 13/70 (p < 0.01), LIPV anterior 26/70 vs posterior 9/70 (p < 0.01). In the right PV's reconnection was distributed equally in all quadrants. Different modes of RF delivery during PVAC ablation (bipolar/unipolar 2:1 [n = 35] vs. 4:1 [n = 47]) yielded comparable rates of PV reconnection. During follow-up (median 296 days) no AF/AT was documented in 57 patients (70 %). CONCLUSION: Almost all patients (98 %) with AF after PVAC ablation show reconnection of at least one PV. All PV's are equally likely to show reconnection. In the left PV's, reconnection was found more often anteriorly than posteriorly. During pulmonary vein isolation with the PVAC catheter, prevalent sites of reconnection deserve close attention to increase success.
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Fibrilação Atrial/diagnóstico , Fibrilação Atrial/cirurgia , Ablação por Cateter/instrumentação , Ablação por Cateter/métodos , Eletrodos , Sistema de Condução Cardíaco/cirurgia , Veias Pulmonares/cirurgia , Desenho de Equipamento , Análise de Falha de Equipamento , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Recuperação de Função Fisiológica , Recidiva , Reoperação/instrumentação , Reoperação/métodosRESUMO
PURPOSE: The effect of an ulnar styloid fracture (USF) on the stability of nonoperatively treated distal radius fractures (DRF) is unknown. The aim of this study was to evaluate the influence of USFs on the dislocation of DRFs treated by closed reduction. METHODS: Standardized radiographs of 100 nonoperatively treated DRFs were evaluated. DRFs with a USF were compared to DRFs without a USF with respect to dorsal tilt, radial inclination, and ulnar variance. RESULTS: We evaluated the radiographs of 100 DRFs in 99 consecutive patients, of whom 84 were women. An accompanying USF was present in 58 wrists, of which 49 were displaced. On the trauma radiograph, the USF group showed significantly more overall dislocation. After closed reduction, fracture position improved, and no significant differences in dislocation were observed between groups. After a mean of 42 days, radial inclination significantly decreased if a USF was present. When USF displacement was taken into account, significantly more ulnar variance occurred in the displaced USF group on the trauma and follow-up radiograph compared to the nondisplaced USF group and no-USF group. CONCLUSIONS: The results of this study show that presence of a dislocated USF in patients with a DRF is associated with a worse position directly after trauma, and with recurrence of radial shortening after adequate reduction. These results warrant early radiologic follow-up in patients with reduced combined DRFs and USFs in order to evaluate the redislocation of the distal radius. Early detection of redislocation in these combined fractures may induce early surgical intervention.
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AIMS: In this study, we evaluated the effects of atrial shock delivered via diagnostic electrophysiology catheters. METHODS AND RESULTS: In 11 anaesthetized goats, decapolar catheters were positioned in the right atrial appendage (RAA) and coronary sinus (CS). Three different catheters and two cardioversion protocols were evaluated. In four goats, 50 J shocks were delivered using catheters with 1 mm electrodes (surface area 70 mm(2)). In 6 goats, catheters with 2 mm electrodes (area 140 mm(2)) were used. In three of the six goats, 50 J shocks were given while in the other 3, 10 J shocks were delivered. In 1 goat 50 J shocks were delivered via 5 mm electrode catheters (area 310 mm(2)). No persisting adverse effects occurred. However, the electrogram amplitude at the RAA and CS decreased by >50-98% (P > 0.01). The amount of amplitude decrease was most pronounced at the CS site and for 50 J shocks. Goats were sacrificed after 9 +/- 1 days. Macroscopy revealed endocardial lesions at the electrode locations. Microscopy showed endocardial thrombosis, and necrosis with formation of granulation tissue. Changes were most marked with diagnostic catheters and 50 J shocks. CONCLUSIONS: Atrial shock delivery via diagnostic catheters causes local ablation lesions. The amount of amplitude decrease, macroscopic and microscopic damages were related to the energy applied and electrode surface area.
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Artefatos , Função Atrial/efeitos da radiação , Cateterismo Cardíaco/métodos , Cardioversão Elétrica/métodos , Eletrocardiografia/métodos , Técnicas Eletrofisiológicas Cardíacas/métodos , Sistema de Condução Cardíaco/fisiologia , Animais , Feminino , Cabras , Átrios do Coração/anatomia & histologia , Sistema de Condução Cardíaco/anatomia & histologia , Sistema de Condução Cardíaco/efeitos da radiaçãoRESUMO
Atriofascicular accessory bundles with AV-node like conduction properties can sustain atrioventricular (AV) re-entrant tachycardia (Mahaim tachycardia). During early embryogenesis, the AV canal is situated above the primitive left ventricle (LV), and a right AV connection has not been achieved yet. We studied the formation of the right ventricular (RV) inflow tract in relation to the developing cardiac conduction system and hypothesized a morphological explanation for functional atriofascicular bypass tracts. Analysis of lacZ-expression during sequential stages of cardiogenesis was performed in CCS-lacZ transgenic mice (E9.5 to 15.5). Embryos were stained for beta-galactosidase activity and the myocardial marker HHF35. At early stages CCS-lacZ expression was observed in a ring surrounding the AV canal, which connected at the inner curvature to the primary fold. The first sign of formation of the (CCS-lacZ negative) RV inlet component was a groove in the CCS-lacZ positive tissue of the primary fold. Outgrowth of the RV inlet tract resulted in division of the primary fold in a septal part, the trabecula septomarginalis and a lateral part, the moderator band, which extended laterally up to the right AV ring. Electrophysiological measurements in embryonic hearts (E15.5) in which the right atrium (RA) and RV were isolated from the left atrium (LA) and LV supported the functionality of this AV-connection via the moderator band, by demonstrating sequential atrial and ventricular activation in both RA/RV and LA/LV preparations. In conclusion, our observations may provide a possible morphological and functional explanation for atriofascicular accessory pathways via the moderator band, underlying Mahaim tachycardia.
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Sistema de Condução Cardíaco/embriologia , Taquicardia por Reentrada no Nó Atrioventricular/etiologia , Animais , Feminino , Sistema de Condução Cardíaco/fisiologia , Camundongos , Camundongos Transgênicos , Gravidez , Taquicardia por Reentrada no Nó Atrioventricular/patologia , Taquicardia por Reentrada no Nó Atrioventricular/fisiopatologiaRESUMO
We have studied 105 patients with 107 acute, primary, dislocations of the glenohumeral joint seen between January 1, 1991 and July 1, 1994. The mean time of follow-up was 71 months (46 to 91). In 34% the injury occurred during a sports activity and in 28% at home. The bias toward sport was even greater in patients less than 40 years of age, and in men. In patients older than 40 years of age, and in women, the dislocation occurred more often at home. The overall probability of recurrence within four years was 26%. Age was the most significant prognostic factor in recurrence which took place in 64% of patients less than 20 years of age and in 6% of those older than 40 years. Statistically, there was no difference between the rates of recurrence in patients who were active in sport and those who were not. The mean Rowe score for the whole group was 87 (15 to 100). Associated fractures were found in 20 patients (19%) and nerve injuries in 22 (21%). None of those in whom a fracture of the greater tuberosity was seen subsequently suffered a recurrent dislocation. At follow-up we found that 36 patients (34%) had not returned to their former employment but in only 2% was this owing to the injured shoulder.
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Acidentes Domésticos/estatística & dados numéricos , Traumatismos em Atletas/epidemiologia , Luxação do Ombro/epidemiologia , Adolescente , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Criança , Humanos , Incidência , Pessoa de Meia-Idade , Países Baixos/epidemiologia , Prognóstico , Recidiva , Estudos Retrospectivos , Fatores de Risco , Fatores Sexuais , Fraturas do Ombro/epidemiologiaRESUMO
BACKGROUND: Recently, the temporal excitable gap during atrial fibrillation (AF) has been identified as a vulnerable parameter for cardioversion of AF. In this study, we evaluated 5 methods to measure the refractory period (RP(AF)) and the excitable period (EP(AF)) during persistent AF. METHODS AND RESULTS: In 11 goats instrumented with 83 epicardial atrial electrodes, persistent AF (43+/-34 days) was induced with a median AF cycle length (CL) of 98+/-14 ms. To measure RP(AF), premature stimuli were applied to the center of the electrode array on the right or left atrium. The RP(AF) measured by mapping of premature stimuli was 70+/-12 ms ("gold standard"). The RP(AF) determined during entrainment of AF was 77+/-17 ms (R(2)=0.88, P<0.01). Statistical analysis of the effects of synchronized stimuli (each coupling interval x100) on the AFCL histogram yielded an RP(AF) of 70+/-13 ms (R(2)=0.94, P<0.01). A further simplification was to apply slow fixed-rate pacing (1 Hz) during AF. For each stimulus (n=250 to 500), the paced AFCL was plotted against its coupling interval, and capture was determined by statistical shortening of the AFCL (RP(AF) 71+/-17 ms, R(2)=0.84, P<0.01). The 5th percentile of the AFCL histogram as an index of RP(AF) was 77+/-12 ms (R(2)=0.90, P<0.01). CONCLUSIONS: During persistent AF with an AFCL of 98+/-14 ms, the RP(AF) determined by mapping of synchronized premature stimuli (gold standard) was 70+/-12 ms, with an excitable period of 28+/-8 ms. Although the indirect methods to measure RP(AF) all correlated well with the gold standard, slow fixed-rate pacing seems to be the most attractive technique because of the ease of acquiring the data and the clear graphic result.