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Artigo em Inglês | MEDLINE | ID: mdl-32462550


PURPOSE: The prospective, multicenter SMART SF trial demonstrated the acute safety and effectiveness of the 56-hole porous tip irrigated contact force (CF) catheter for drug-refractory paroxysmal atrial fibrillation (PAF) ablation with a low primary adverse event rate (2.5%), leading to FDA approval of the catheter. Here, we are reporting the long-term effectiveness and safety results that have not yet been reported. METHODS: Ablations were performed using the 56-hole porous tip irrigated CF catheter guided by the 3D mapping system stability module. The primary effectiveness endpoint was freedom from atrial tachyarrhythmia (including atrial fibrillation, atrial tachycardia, and/or atrial flutter), based on electrocardiographic data at 12 months. Atrial tachyarrhythmia recurrence occurring 3 months post procedure, acute procedural failures such as lack of entrance block confirmation of all PVs, and undergoing repeat procedure for atrial fibrillation in the evaluation period (91 to 365 days post the initial ablation procedure) were considered to be effectiveness failures. RESULTS: Seventy-eight patients (age 64.8 ± 9.7 years; male 52.6%; Caucasian 96.2%) participated in the 12-month effectiveness evaluation. Mean follow-up time was 373.5 ± 45.4 days. The Kaplan-Meier estimate of freedom from 12-month atrial tachyarrhythmia was 74.9%. Two procedure-related pericardial effusion events were reported at 92 and 180 days post procedure. There were no pulmonary vein stenosis complications or deaths reported through the 12-month follow-up period. CONCLUSIONS: The SMART SF 12-month follow-up evaluation corroborates the early safety and effectiveness success previously reported for PAF ablation with STSF.

Heart Rhythm ; 7(9): 1346-55, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20659587


BACKGROUND: Recent economic trends influenced by healthcare reform, an aging population, changes in physician reimbursement, and increasing competition will have a significant impact on the electrophysiology workforce. Therefore, there is an important need to obtain information about the EP workforce to assess training of arrhythmic healthcare providers in order the meet the requisite societal need. This report summarizes the data collected by the HRS Workforce Study Task Force in relation to physician workforce issues. OBJECTIVE: The HRS Workforce Study Task Force was charged with conducting a comprehensive study to assess changes in the field of electrophysiology since the last workforce study conducted in 2001 and to identify the population and distribution of professionals who treat patients with heart rhythm disorders. METHODS: A series of comprehensive questionnaires were designed by the HRS Workforce Study Task Force to conduct online surveys with physicians, basic science researchers, and allied professionals. Data collected in the physician survey included: personal demographics and professional profile characteristics such as primary work setting and areas of affiliation; workload characteristics such as hours worked, time spent by activity, workload relative to capacity, competition for patients, volume by specific procedure, sources of referrals, income levels, personal mobility, and anticipated future changes in the respondent's practice. Survey responses were collated and analyzed by the Workforce Study Task Force. RESULTS: Work capacity is expected to increase to offset some of the economic drivers; however, recruitment of new EPs could be challenging and uncertain. Specifically, geographic mobility (>50 miles) appears to be minimal at present overall and unlikely to significantly change for the majority of physicians once they have established themselves in a given community following the completion of their training. Practice time is predominantly spent performing device implantations, device follow-ups and ablations. These activities are being tasked upon younger physicians, thereby suggesting a need for trained allied professionals to assume a greater role in device management. The perception of competition varied by respondent age and geographic location but, in general, was felt to be at least moderate by most respondents. Furthermore, there are concerns that increasing competition may dilute operator experience and potentially lower high quality outcomes if increasing competition leads to lower procedural volumes. CONCLUSION: Based on findings from this study, the task force identified specific workforce (supply) trends and the key drivers of current and future challenges. Although specific areas will require further analysis, overall, the current EP workforce is stable, with the exception of geographic dispersion. However, the workforce must adapt to the key economic drivers (demand) and address future recruitment challenges.

Eletrofisiologia , Pesquisas sobre Serviços de Saúde , Necessidades e Demandas de Serviços de Saúde/tendências , Mão de Obra em Saúde/tendências , Admissão e Escalonamento de Pessoal/tendências , Médicos/provisão & distribução , Sociedades Médicas , Adulto , Idoso , Canadá , Humanos , Pessoa de Meia-Idade , Estados Unidos , Carga de Trabalho
FASEB J ; 18(7): 857-9, 2004 May.
Artigo em Inglês | MEDLINE | ID: mdl-15033930


Recent studies suggest that RhoA and Rac1 mediate hypertrophic signals in cardiac myocyte hypertrophy. However, effects on cardiac function caused by inhibition of their activity in the heart have yet to be evaluated. Cardiac-specific inhibition of Rho family protein activities was achieved by expressing Rho GDIalpha, an endogenous specific GDP dissociation inhibitor for Rho family proteins, using the alpha-myosin heavy-chain promoter. Increased expression of Rho GDIalpha led to atrial arrhythmias and mild ventricular hypertrophy in adult mice (4-7 months). However, left ventricular systolic and diastolic function was largely preserved before and after the development of cardiac hypertrophy, indicating that Rho GTPases are not required to maintain ventricular contractile function under basal physiological condition. Electrocardiography and intracardiac electrophysiological studies revealed first-degree atrioventricular (AV) block in the transgenic heart at 1 week of age, which further progressed into second-degree AV block at 4 weeks of age before the development of cardiac hypertrophy. Expression of connexin 40 dramatically decreased from 1 week to 4 weeks of age in the transgenic heart, which may contribute in part to the conduction defects in the transgenic mice. This study provides novel evidence for an important role of Rho GTPases in regulating AV conduction.

Nó Atrioventricular/fisiopatologia , Cardiomiopatia Hipertrófica/enzimologia , Inibidores de Dissociação do Nucleotídeo Guanina/fisiologia , Bloqueio Cardíaco/etiologia , Miócitos Cardíacos/metabolismo , Transdução de Sinais/fisiologia , Função Ventricular Esquerda , Adaptação Fisiológica , Animais , Cardiomiopatia Hipertrófica/fisiopatologia , Bovinos , Conexina 43/biossíntese , Conexina 43/genética , Conexinas/biossíntese , Conexinas/genética , Progressão da Doença , Regulação da Expressão Gênica , Inibidores de Dissociação do Nucleotídeo Guanina/genética , Átrios do Coração/anormalidades , Bloqueio Cardíaco/fisiopatologia , Heterozigoto , Camundongos , Camundongos Transgênicos , Cadeias Pesadas de Miosina/genética , Regiões Promotoras Genéticas , Transgenes , Proteínas rho de Ligação ao GTP/antagonistas & inibidores , Proteínas rho de Ligação ao GTP/fisiologia , Inibidor alfa de Dissociação do Nucleotídeo Guanina rho , Inibidores da Dissociação do Nucleotídeo Guanina rho-Específico
FASEB J ; 17(1): 59-60, 2003 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-12528713


Adult transgenic mice with muscle-specific overexpression of insulin-like growth factor (IGF)-I have enlarged skeletal muscles. In this study, we; 1) characterized the development of muscle hypertrophy with respect to fiber type, age, and sex; 2) determined the primary anabolic process responsible for development of hypertrophy; and 3) identified secondary effects of muscle hypertrophy on body composition. Transgene expression increased with age and was present only in fibers expressing type IIB fast myosin heavy chain. Muscle masses were greater by 5 wk of age, and by 10 wk of age the differences were maximal despite continued transgene expression. Total DNA and RNA contents of the gastrocnemius muscle were greater for transgenic mice than for nontransgenic littermates. The differences were maximal by 5 wk of age and preceded the increase in protein mass. The accelerated protein deposition ceased when the protein/DNA ratio attained the same value as in nontransgenic controls. Despite localization of IGF-I expression to muscle without changes in plasma IGF-I concentrations, genotype also modified the normal age and sex effects on fat deposition and organ growth. Thus, enhanced DNA accretion by IGF-I was primarily responsible for stimulating muscle growth. In turn, secondary effects on body composition were incurred that likely reflect the impact of muscle mass on whole body metabolism.

DNA/metabolismo , Fator de Crescimento Insulin-Like I/genética , Músculo Esquelético/crescimento & desenvolvimento , Animais , Divisão Celular , DNA/análise , Feminino , Humanos , Fator de Crescimento Insulin-Like I/metabolismo , Cinética , Masculino , Camundongos , Camundongos Transgênicos , Modelos Biológicos , Proteínas Musculares/análise , Músculo Esquelético/química , Músculo Esquelético/metabolismo , RNA/análise , Ganho de Peso