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BACKGROUND: A scarcity of organs has driven the transplant community to broaden selection criteria for both living and deceased donors. Living donor transplants offer better patient and allograft survival when compared with deceased donor transplants. Many transplant centers now allow complex living donors such as those with nephrolithiasis to undergo nephrectomy. METHODS: We conducted a survey of medical and surgical directors of kidney transplant programs in the United States to shed light on current practices pertaining to medical evaluation of living kidney donors with nephrolithiasis. 353 surveys were e-mailed to medical directors and surgical directors of transplant programs after contacts were obtained from UNOS. RESULTS: 49 completed surveys were returned (13.9%). 77.7% (38/49) of survey participants said their centers will consider living kidney donor candidates with a history of symptomatic kidney stones, 69.4% (34/49) said their centers will consider candidates who are incidentally found to have kidney stones and 10.2% (5/49) said their centers decline all potential donors with nephrolithiasis. CONCLUSIONS: Several programs are still reluctant to allow potential donors with nephrolithiasis to donate. There is an unmet need to develop evidence-based guidelines to optimize outcomes in this population of kidney donors with nephrolithiasis and their recipients.
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Trasplante de Riñón/normas , Donadores Vivos , Nefrolitiasis , Humanos , Trasplante de Riñón/estadística & datos numéricos , Programas Médicos Regionales/estadística & datos numéricos , Encuestas y CuestionariosRESUMEN
BACKGROUND: Little is known about the predictive value of single items from the work ability index (WAI) on the risk of sickness absence over several years, and whether such risk varies across age groups. AIMS: The aim of the study was to investigate whether poor self-perceived physical and mental work ability among employees in the public sector are associated with long-term sickness absence over a 10-year period. METHODS: The study was based on a prospective cohort of employees within the public sector in Sweden reporting 'good health for working'. Baseline information was collected with questionnaires from 2000 to 2003. Poor physical and mental work ability in relation to work demands were assessed with two items from the WAI. The outcome was the number of years of long-term sickness absence between 2003 and 2012. Long-term sickness absence was defined as ≥28 days of sickness and this information was retrieved from Swedish National Registers. Crude and adjusted incidence rate ratios were calculated with analyses stratified by age. RESULTS: Compared with those reporting very good physical work ability, employees reporting any lower grade of physical work ability had a higher risk of long-term sickness absence across all age strata, with higher risk estimates in the highest age groups and 6-fold increased risk in the oldest age group. Similar results were found for mental work ability with an almost 4-fold increased risk in the highest age group. CONCLUSIONS: Self-reported physical and mental poor work ability are associated with long-term sickness absence during the subsequent 10 years. The risk increases with age.
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Estado de Salud , Ausencia por Enfermedad/estadística & datos numéricos , Evaluación de Capacidad de Trabajo , Adulto , Factores de Edad , Estudios de Cohortes , Femenino , Humanos , Estudios Longitudinales , Masculino , Salud Mental/estadística & datos numéricos , Persona de Mediana Edad , Estudios Prospectivos , Sector Público , Autoinforme , Encuestas y Cuestionarios , SueciaRESUMEN
The legal concept of first person authorization (FPA) is based on the principle that a decision by a person with decision-making capacity should be respected even after he or she dies. Although the transplant community largely supports this concept, its implementation has not been universal. We conducted a web-based survey of all 58 Organ Procurement Organization (OPO)executive directors in the United States to assess OPOs' procurement policies and practices in the context of family objections. All 58 respondents(100%) responded to our survey. All OPOs except one have an online donor registration website. Most OPOs(89%) (51 of 57 respondents) estimated that the frequency of family objecting to organ donation in cases of registered donors was <10%. No OPOs reported the frequency to be higher than 25%. Only 50% (27 of 54) of the OPOs have a written policy on handling family objections. Approximately 80% of the OPOs reported honoring FPA. However, in the past 5 years, 20 OPOs (35%) have not yet participated in organ procurement from a registered deceased donor over family objection. Further research to identify the barriers and possible solutions to implementing FPA is warranted.
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Familia , Donantes de Tejidos/legislación & jurisprudencia , Obtención de Tejidos y Órganos/legislación & jurisprudencia , Recolección de Datos , Humanos , Estados UnidosRESUMEN
OBJECTIVES: This study presents an investigation of first-time decisions regarding work injury annuity due to occupational disease. Focus is a number of potential underlying factors behind the gender gap, where women are disadvantaged, in the granting of work injury annuity. METHODS: All 99 subjects (80 men and 19 women) who met the conditions of long-lasting reduction of work ability due to occupational disease (not occupational accident) in the Swedish Work Injury Insurance Act and were granted work injury annuity in 2010, together with a random sample of 118 subjects (55 men and 63 women) who were denied annuity in the same year, were selected for analysis. Each subject's case file from the Social Insurance Agency was examined with regards to cause of disease, diagnosis and the Social Insurance Agency's management and decision making of claims. The data were analysed by logistic regression analysis. RESULTS: Men had a higher probability of being granted work injury annuity than women for musculoskeletal disorders (OR 4.16), mental disorders (OR 7.93) and diseases in other diagnostic chapters (OR 3.65). After adjustment for age, country of birth, diagnosis, work exposure factors and decision support factors, the higher probability for men of being granted work injury annuity remained (full model: OR 2.67, 95% CI 1.20 to 5.94). CONCLUSIONS: Actions are necessary in order to establish equitable and gender-neutral treatment of work injury insurance claims. There is a need for more detailed knowledge of exposures in female-dominated jobs and the relationship between these exposures and occupational disease.
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Enfermedades Profesionales/economía , Factores Sexuales , Indemnización para Trabajadores/estadística & datos numéricos , Adulto , Femenino , Humanos , Modelos Logísticos , Masculino , SueciaRESUMEN
BACKGROUND: There is increasing global evidence that today's work environment results in higher risk of adverse health among nursing staff than among other professions. AIM: To investigate self-reported general and mental health among Iranian nursing staff, and associations with organizational, physical and psychosocial working conditions and family situation. METHODS: 520 nursing personnel from 10 university hospitals in Tehran participated in this cross-sectional study. Data were collected using a validated questionnaire in the Persian language, containing the Copenhagen Psychosocial Questionnaire, physical items from the Nurse Early eXit Study and two scales relating to general health and mental health from the Short Form-36. The Chi-square test with P<0.05 and logistic regression were used to analyse data. RESULTS: Three out of four nursing staff reported overtime work. The self-reported general and mental health rates of participants were poor/fair (38%, 41%), good (44%, 39%) and very good/excellent (18%, 20%), respectively. Family demands were associated with general health but were not associated with mental health. Adverse physical and psychosocial work conditions gave an elevated odds ratio for poor health. CONCLUSION: Poor general and mental health was associated with adverse working conditions and family demands. Physical and psychosocial working conditions of nursing personnel should be improved. Social facilities such as daycare for children and care for the elderly should be available during work shifts to help Iranian nurses play their family roles.
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Familia , Estado de Salud , Salud Mental , Personal de Enfermería en Hospital , Autoinforme , Adulto , Femenino , Hospitales Universitarios , Humanos , Irán , Estilo de Vida , Masculino , Persona de Mediana Edad , Factores Socioeconómicos , Encuestas y Cuestionarios , Carga de Trabajo , Adulto JovenRESUMEN
AIM: Self-reported assessments of sickness absence are often performed in epidemiological studies. The objective of this study was to compare the number of sick-leave days according to self-reported data over 12 months with data from the employer's register for the same period. An additional aim was to ascertain whether the self-reported information and the recorded data would show equivalent associations with self-reported general health. METHODS: The study was based on a cohort of 4869 municipal employees in Sweden, about 80% women, who answered a questionnaire in 2001-2. The responses provided by the employees included information on number of sick-leave days and self-rated health. Data on sick-leave days, occupation and age were derived from the employers' computerised registers. The questionnaire information on sick-leave days was compared with the corresponding information retrieved from the employer register by means of calculating sensitivity and specificity, using the employers' data as the "gold standard". RESULTS: The annual number of sick-leave days was lower according to the self-reported information than to the register data. For women the agreement between the two sickness absence measures for no sick-leave days, 1-7 days and >/=28 days were 74%, 72% and 67%, respectively. The sensitivity of questionnaire versus register information regarding any self-reported sick-leave day was 91% and the specificity was 74%. Sensitivity and specificity for sickness absence >/=28 days were 67% and 98%, respectively. The results for men were similar to those for women. Self-reported and recorded sickness absence were both associated with self-rated health. The odds ratios were 7.27 and 8.25, for subjects with >/=28 recorded and self-reported number of sick-leave days respectively, compared to subjects with no sickness absence. CONCLUSIONS: Good agreement was found between self-reported and register information on sickness absence. Self-reported data on sickness absence may be useful in common epidemiological applications.
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Absentismo , Sector Público/estadística & datos numéricos , Sistema de Registros , Encuestas y Cuestionarios , Femenino , Estado de Salud , Humanos , Modelos Logísticos , Masculino , Sensibilidad y Especificidad , Ausencia por Enfermedad , SueciaRESUMEN
The pattern of retrograde His-Purkinje conduction was evaluated in 28 patients using ventricular extrastimuli. In each patient progressive prolongations of His-Purkinje conduction (S2H2) which appeared as ventricular extrastimuli were induced at closer coupling intervals (S1S2). There was an inverse linear relationship of S2H2 to S1S2 which was cycle length-dependent: i.e., at any S1S2 interval the resultant S2H2 was less at shorter drive cycle lengths. The degree of S2H2 delay varied widely (from 30 to 340 ms) and was unrelated to the presence of bundle branch block, H-V intervals, or capability of ventriculoatrial conduction. Prolongation of S2H2 was independent of intraventricular (muscle) conduction delay; such delay was usually absent at most, and occasionally all, S1S2 coupling intervals during which S2H2 was lengthening. Furthermore, in two patients both left and right ventricles were activated before the timed depolarization of the His bundle occurred, demonstrating that under the stress of extrastimuli, the impulse conducts through ventricular muscle with less delay than through the His-Purkinje system. We conclude that the His-Purkinje system typically displays slow conduction response to ventricular stress. The site of this conduction delay is probably at the distal "gate".
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Arritmias Cardíacas/fisiopatología , Sistema de Conducción Cardíaco/fisiopatología , Pruebas de Función Cardíaca , Ensayos Clínicos como Asunto , Estimulación Eléctrica , Humanos , Estrés Fisiológico/fisiopatologíaAsunto(s)
Mapeo Encefálico/instrumentación , Diagnóstico por Imagen/instrumentación , Magnetismo , Técnicas Estereotáxicas/instrumentación , Animales , Electrocardiografía , Corazón/anatomía & histología , Corazón/fisiología , Humanos , Procesamiento de Imagen Asistido por Computador , Porcinos , Tomógrafos Computarizados por Rayos XRESUMEN
AIM: Health has been described as a continuum between the two poles of excellent health and ill health. Research has so far focused on the negative pole, leaving knowledge about the positive pole vague. With a main focus on working life, the authors aim was to identify determinants promoting excellent work ability and determinants preventing poor work ability. METHODS: 5638 (73% answering rate) employees in the public sector in Sweden answered a questionnaire both at baseline and at follow up 18 months later. The employees were divided into three groups based on sick leave at follow up: excellent work ability (13%), poor work ability (15%), and a middle group (72%). Self reported sociodemographic data, lifestyle data, and working life exposures at baseline were fitted into logistic regression models to determine which factors, if any, promoted excellent work ability or protected against poor work ability. RESULTS: Some determinants were mutual, but more than half of the determinants in the final model were associated solely with promoting excellent work ability or preventing poor work ability, thus creating different patterns of associations. Promotion of excellent work ability seemed more dependent on physical factors, clear work tasks, and positive feedback, while prevention of poor work ability seemed more dependent on job security and psychosocial factors. CONCLUSIONS: This explorative longitudinal study showed slightly different patterns of determinants promoting excellent work ability and preventing poor work ability. As most of the identified determinants are amenable to influence, our results open up the possibility of interventions for promoting excellent work ability and preventing poor work ability.
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Salud Laboral/estadística & datos numéricos , Ausencia por Enfermedad/estadística & datos numéricos , Adulto , Anciano , Métodos Epidemiológicos , Femenino , Promoción de la Salud/métodos , Estado de Salud , Humanos , Satisfacción en el Trabajo , Estilo de Vida , Masculino , Persona de Mediana Edad , Ocupaciones , Sector Público/estadística & datos numéricos , Suecia/epidemiologíaRESUMEN
OBJECTIVES: Despite extensive research on turnover among nursing personnel very little is known about the impact of physical workload and health on leaving. The aim of this study was to find predictors for leaving nursing care with special reference to physical working conditions and musculoskeletal problems. METHODS: This study is based on longitudinal data from a survey of nursing personnel who were employed at various county hospitals in Sweden from 1992-95. A self administrated follow up questionnaire was used to identify their present position in the labour market. The response rate was 73% (n = 1095). RESULTS: The results showed that nursing personnel reporting musculoskeletal problems of the neck/shoulder or knees and those who had limited use of transfer devices were more likely to leave nursing care. CONCLUSIONS: The study highlights the importance of taking musculoskeletal problems and use of transfer devices into consideration in order to retain nursing personnel.
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Enfermedades Musculoesqueléticas/epidemiología , Enfermeras y Enfermeros/estadística & datos numéricos , Reorganización del Personal/estadística & datos numéricos , Carga de Trabajo/estadística & datos numéricos , Adulto , Anciano , Femenino , Hospitales de Condado , Humanos , Satisfacción en el Trabajo , Modelos Logísticos , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Enfermeras y Enfermeros/psicología , Suecia/epidemiología , Recursos Humanos , Carga de Trabajo/psicologíaRESUMEN
1. Cytochrome c oxidase (ferrocytochrome c:oxygen oxidoreductase, EC 1.9.3.1) was purified from the mycelial fungus Botryodiplodia theobromae by sodium cholate and ammonium sulfate solubilization, ammonium sulfate fractionation, and DEAE-cellulose chromatography. The purified enzyme contained 6--7 nmol heme a/mg of protein. The specific activity of the purified enzyme was 2.1--2.3 . 10(3) k (min-1) per mg of protein with 15 mumol ferrocytochrome c and at pH 5.9 and optimal phosphate and Tween 80 concentrations (65 mM and 0.1%, respectively). The Km for ferrocytochrome c was determined to be 1.2--1.3 . 10(-5) M, while at infinite substrate concentration the enzyme catalyzed the oxidation of about 60 mumole of ferrocytochrome c/min per mg of protein. Sedimentation behavior and kinetic evidence suggest that the purified enzyme exists as aggregates of the single molecule. The purified B. theobromae cytochrome c oxidase with its 428 nm Soret absorption maximum may be similar if not identical to oxygenated forms of the enzyme from other fungal species. 2. The purified enzyme was shown by sodium dodecyl sulfate polyacrylamide gel electrophoresis to consist of seven polypeptides with the following respective molecular weights: I, 41 000; II, 28 000; III, 19 000; IV, 14 800; V, 12 800; VI, 11 500; and VII, 9300. Biosynthesis studies showed that the three highest molecular weight polypeptides of the enzyme were synthesized on mitochondrial ribosomes, and the four smaller polypeptides were products of cytoplasmic ribosomes.
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Complejo IV de Transporte de Electrones/metabolismo , Hongos Mitospóricos/enzimología , Grupo Citocromo c/metabolismo , Citoplasma/metabolismo , Complejo IV de Transporte de Electrones/análisis , Cinética , Mitocondrias/metabolismo , Peso Molecular , Polisorbatos , Ribosomas/metabolismo , Análisis Espectral , Esporas Fúngicas/metabolismoRESUMEN
[14C]Arachidonic acid conversion in lung homogenates of 28-day fetuses from control and alloxan-diabetic rabbits was studied. The major metabolites were 12-L-hydroxy-5,8,10,14-eicosatetraenoic acid and prostaglandin E2. Small amounts of 6-ketoprostaglandin F1 alpha, prostaglandin F2 alpha, and thromboxane B2 were also observed. Lung homogenates from fetuses of alloxan-diabetic rabbits convert significantly less [14C]arachidonic acid to prostaglandin E2, whereas all other metabolites were present in similar quantities compared to fetuses of non-diabetic rabbits. These studies suggest that the decreased arachidonic acid conversion to prostaglandin E2 could be partially responsible for the functional delay of lung maturation in offspring of alloxan-diabetic rabbits.
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Diabetes Mellitus Experimental/metabolismo , Feto/metabolismo , Pulmón/metabolismo , Prostaglandinas/metabolismo , Animales , Ácido Araquidónico , Ácidos Araquidónicos/metabolismo , Glucemia/análisis , Femenino , Embarazo , Conejos , Factores de TiempoRESUMEN
The effects of maternal diabetes upon fetal lung surfactant phospholipid metabolism were studied using 19-day gestational age fetal rats from mothers with streptozotocin-induced diabetes mellitus. In this experimental animal model, maternal glucose intolerance significantly impaired fetal body and lung development. However, incorporation of [14C]palmitate and [3H]choline into lung total and disaturated phosphatidylcholine was unimpaired in offspring of diabetic mothers. Dexamethasone, which is known to promote fetal lung maturation in normal pregnancies, was administered to diabetic and control mothers during late gestation. Prenatal dexamethasone inhibited lung growth in both diabetic and control pregnancies. While this agent slightly stimulated [14C]palmitate incorporation into total phosphatidylcholine and markedly enhanced [3H]choline incorporation into both disaturated and total phosphatidylcholine in control pregnancies, it failed to stimulate incorporation of either precursor into fetal lung from diabetic pregnancies.
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Dexametasona/farmacología , Diabetes Mellitus Experimental/complicaciones , Pulmón/metabolismo , Fosfatidilcolinas/biosíntesis , Embarazo en Diabéticas/tratamiento farmacológico , Animales , Glucemia/metabolismo , Diabetes Mellitus Experimental/metabolismo , Femenino , Feto/efectos de los fármacos , Feto/metabolismo , Humanos , Recién Nacido , Pulmón/efectos de los fármacos , Embarazo , Embarazo en Diabéticas/metabolismo , Ratas , Síndrome de Dificultad Respiratoria del Recién Nacido/prevención & controlRESUMEN
BACKGROUND: Resetting has been used to characterize reentrant circuits causing clinical tachycardias. METHODS AND RESULTS: To determine the mechanisms of resetting, sustained ventricular tachycardia was induced in dogs with 4-day-old myocardial infarctions by programmed stimulation. Premature stimulation was accomplished from multiple regions within reentrant circuits; resetting curves were constructed and compared with activation maps. Monotonically increasing responses, or a "mixed" response (increasing portion preceded by a flat portion), occurred. All reentrant circuits had a fully excitable gap. Interval-dependent conduction delay and concealed retrograde penetration led to increased resetting response curves. CONCLUSIONS: Multiple mechanisms revealed by mapping cause resetting of reentrant circuits.
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Taquicardia Ventricular/fisiopatología , Animales , Modelos Animales de Enfermedad , Perros , Electrofisiología , Sistema de Conducción CardíacoRESUMEN
BACKGROUND: A variety of mapping criteria have been proposed to localize critical sites at which radiofrequency (RF) can predictably terminate reentrant ventricular tachycardia (VT) caused by coronary artery disease. The purpose of this study was to determine the accuracy of using a combination of 3 mapping criteria in predicting termination of VT by a single RF lesion. METHODS AND RESULTS: Fifteen consecutive patients with coronary artery disease and recurrent sustained VT underwent an attempted RF ablation of 20 monomorphic VTs. Successful termination of VT by a single RF lesion was predicted if all the following mapping criteria were met: (1) an exact QRS match in the 12-lead ECG during entrainment; (2) a return cycle length =10 ms of the VT cycle length; (3) presystolic potentials (<70% of VT cycle length) with an activation time to the QRS within 10 ms of the stimulus to QRS. Inability to meet these 3 criteria was considered to predict failure of VT termination by RF energy at that site. RF ablation was applied to 44 left ventricular sites in 20 VTs at which at least 1 of the mapping criteria was met. VT was terminated with a single RF lesion in 19 of 19 sites meeting all criteria; RF failed to terminate VT at 24 of 25 sites at which all 3 criteria were not met (P<0.0005). CONCLUSIONS: To maximize success and minimize the number of RF lesions in patients with infarct-related VT, all the above 3 mapping criteria should be met before the application of RF energy.
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Ablación por Catéter , Enfermedad Coronaria/complicaciones , Taquicardia Ventricular/cirugía , Adulto , Anciano , Electrocardiografía , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana EdadRESUMEN
BACKGROUND: Dual-chamber pacing (DDD) has been proposed as a treatment alternative to surgery for severely symptomatic patients with obstructive hypertrophic cardiomyopathy (HCM), based largely on uncontrolled studies. METHODS AND RESULTS: This prospective, multicenter trial assessed pacing in 48 symptomatic HCM patients with >/=50 mm Hg basal gradient, refractory to drug therapy. Patients were randomized to 3 months each of DDD pacing and pacing backup (AAI-30) in a double-blind, crossover study design, followed by an uncontrolled and unblinded 6-month pacing trial. With randomization, no significant differences were evident between pacing and no pacing for subjective or objective measures of symptoms or exercise capacity, including NYHA functional class, quality of life score, treadmill exercise time or peak oxygen consumption. After 6 additional months of unblinded pacing, functional class and quality of life score were improved compared with baseline (P<0.01), but peak oxygen consumption was unchanged. Outflow gradient decreased 40%, 82+/-32 mm Hg to 48+/-32 mm Hg (P<0. 001), and was reduced in 57% of patients but showed no change or an increase in 43%. At 12 months, 6 individual patients (12%) showed improved functional capacity; each was 65 to 75 years of age. Left ventricular wall thicknesses in the overall study group showed no remodeling between baseline (22+/-5 mm) and 12 months (21+/-5 mm; P=NS). CONCLUSIONS: (1) Pacing cannot be regarded as a primary treatment for obstructive HCM; (2) with randomization, perceived symptomatic improvement was most consistent with a substantial placebo effect; (3) longer, uncontrolled pacing periods were associated with some subjective benefit but unaccompanied by objective improvement in cardiovascular performance and should be interpreted cautiously; (4) modest reduction in outflow gradient was achieved in most patients; and (5) a small subset (12%) >/= 65 years of age showed a clinical response, suggesting that DDD pacing could be a therapeutic option for some elderly patients.
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Estimulación Cardíaca Artificial/métodos , Cardiomiopatía Hipertrófica/terapia , Adulto , Anciano , Anciano de 80 o más Años , Velocidad del Flujo Sanguíneo/fisiología , Estimulación Cardíaca Artificial/efectos adversos , Cardiomiopatía Hipertrófica/tratamiento farmacológico , Cardiomiopatía Hipertrófica/fisiopatología , Circulación Coronaria/fisiología , Estudios Cruzados , Método Doble Ciego , Resistencia a Medicamentos , Ecocardiografía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Función Ventricular Izquierda/fisiologíaRESUMEN
BACKGROUND: An abnormal signal-averaged ECG (SAECG) is a noninvasive marker of the substrate of sustained ventricular tachycardia after myocardial infarction. We assessed its prognostic ability in patients with asymptomatic unsustained ventricular tachycardia, coronary artery disease, and left ventricular dysfunction. METHODS AND RESULTS: A blinded core laboratory analyzed SAECG tracings from 1925 patients in a multicenter trial. Cox proportional hazards modeling was used to examine individual and joint relations between SAECG variables and arrhythmic death or cardiac arrest (primary end point), cardiac death, and total mortality. We also assessed the prognostic utility of SAECG at different levels of ejection fraction (EF). A filtered QRS duration >114 ms (abnormal SAECG) independently predicted the primary end point and cardiac death, independent of clinical variables, cardioverter-defibrillator implantation, and antiarrhythmic drug therapy. With an abnormal SAECG, the 5-year rates of the primary end point (28% versus 17%, P=0.0001), cardiac death (37% versus 25%, P=0.0001), and total mortality (43% versus 35%, P=0.0001) were significantly higher. The combination of EF <30% and abnormal SAECG identified a particularly high-risk subset that constituted 21% of the total population. Thirty-six percent and 44% of patients with this combination succumbed to arrhythmic and cardiac death, respectively. CONCLUSIONS: SAECG is a powerful predictor of poor outcomes in this population. The noninvasive combination of an abnormal SAECG and reduced EF may have utility in selecting high-risk patients for intervention.
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Enfermedad Coronaria/fisiopatología , Electrocardiografía/métodos , Taquicardia Ventricular/fisiopatología , Disfunción Ventricular Izquierda/fisiopatología , Enfermedad Coronaria/diagnóstico , Enfermedad Coronaria/mortalidad , Pronóstico , Análisis de Supervivencia , Tasa de Supervivencia , Taquicardia Ventricular/diagnóstico , Taquicardia Ventricular/mortalidad , Factores de Tiempo , Disfunción Ventricular Izquierda/diagnóstico , Disfunción Ventricular Izquierda/mortalidadRESUMEN
BACKGROUND: The terms counterclockwise (CC) and clockwise (C) atrial flutter (Afl) are used to describe right atrial activation around the tricuspid valve in the left anterior oblique view. The manner in which the left atrium is activated, as reflected by coronary sinus (CS) recordings, has not been systematically evaluated. METHODS AND RESULTS: Nine patients with both CC and C Afl underwent electrophysiological study with CS recordings during both rhythms with the use of a decapolar catheter with the tip placed in the distal CS. Patterns of CS activation during each type of Afl as well as during during sinus rhythm were categorized into 1 of 3 patterns: sequential proximal-to-distal, sequential distal-to-proximal, and fused, indicating activation from different directions. In 7 of 9 patients, the pattern of CS activation in CC Afl and C Afl differed, with a proximal-to-distal pattern in CC Afl and a fused pattern in C Afl. In 2 patients, pacing the high right atrial septum near the presumed site of Bachmann's bundle in sinus rhythm showed a similar fused pattern of CS activation. CONCLUSIONS: These results demonstrate different patterns of CS activation in CC Afl and C Afl in the majority of patients and are consistent with a model in which the left atrium is activated predominantly over Bachmann's bundle during C Afl and over the CS os in CC Afl. These findings may have implications for maintenance of Afl, interpretation of flutter wave morphology on surface ECG, and left atrial mechanical function in Afl.
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Aleteo Atrial/fisiopatología , Atrios Cardíacos/fisiopatología , Sistema de Conducción Cardíaco/fisiopatología , Anciano , Anciano de 80 o más Años , Estimulación Cardíaca Artificial , Electrocardiografía , Técnicas Electrofisiológicas Cardíacas , Femenino , Tabiques Cardíacos/fisiopatología , Humanos , Masculino , Persona de Mediana EdadRESUMEN
Automaticity in the Kent anomalous atrioventricular bundle has been postulated to occur on the basis of electrocardiographic recordings. This hypothesis was confirmed using intracardiac recordings and programmed stimulation in a patient with pre-excitation. It was supported, in part, by demonstrating the presence of phase 3 and phase 4 block in the Kent bundle during decremental atrial pacing. The existence of automaticity in the Kent bundle may explain the manifestation of intermittent pre-excitation in certain patients. Furthermore, the presence of phase 3 and phase 4 block makes the likelihood of rapid antidromic conduction over the Kent bundle pathway unlikely within this subgroup.
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Nodo Atrioventricular/anomalías , Bloqueo Cardíaco/fisiopatología , Sistema de Conducción Cardíaco/anomalías , Fibrilación Atrial/fisiopatología , Nodo Atrioventricular/fisiopatología , Electrofisiología , Humanos , Masculino , Persona de Mediana Edad , Nodo Sinoatrial/fisiopatología , Taquicardia/fisiopatología , Factores de TiempoRESUMEN
Forty patients with sustained tachycardia occurring 3 to 65 days after myocardial infarction underwent programmed ventricular stimulation within 3 months of the infarction. Patients were characterized clinically by a complicated initial 48 hours of hospitalization for their acute infarction (85% of study group). The development of bundle branch block in association with infarction occurred with an unusually high frequency (32%). Ventricular tachycardia similar in configuration to spontaneous arrhythmia was induced with programmed ventricular stimulation in 33 (83%) of the 40 patients. In 15 (45%) of these 33 patients, additional morphologically distinct ventricular tachycardia not seen clinically was initiated. The induction of ventricular tachycardia was not significantly related to the time after myocardial infarction at which spontaneous ventricular tachycardia was initially observed. Only 20 of the 40 patients are alive after a mean follow-up period of 20 +/- 15 months. Twelve of the 20 deaths were sudden cardiac deaths. Sixteen of the 33 patients with inducible ventricular tachycardia died; 8 of the 16 deaths were sudden. By comparison, four of the seven patients with no inducible ventricular tachycardia died (probability [p] = not significant), all suddenly. The mode of therapy did not influence subsequent survival. It appears that in patients with sustained ventricular tachycardia occurring more than 48 hours after a recent myocardial infarction, ventricular tachycardia similar to that clinically observed can usually be induced by programmed stimulation. In addition, multiple morphologically distinct ventricular tachycardias, some of which have not been previously observed, are frequently induced. Finally, the prognosis for survival is poor, regardless of inducibility or mode of therapy, and may in part be related to a changing arrhythmia substrate.