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1.
N Engl J Med ; 388(1): 22-32, 2023 01 05.
Artículo en Inglés | MEDLINE | ID: mdl-36342109

RESUMEN

BACKGROUND: Patients with acute heart failure are frequently or systematically hospitalized, often because the risk of adverse events is uncertain and the options for rapid follow-up are inadequate. Whether the use of a strategy to support clinicians in making decisions about discharging or admitting patients, coupled with rapid follow-up in an outpatient clinic, would affect outcomes remains uncertain. METHODS: In a stepped-wedge, cluster-randomized trial conducted in Ontario, Canada, we randomly assigned 10 hospitals to staggered start dates for one-way crossover from the control phase (usual care) to the intervention phase, which involved the use of a point-of-care algorithm to stratify patients with acute heart failure according to the risk of death. During the intervention phase, low-risk patients were discharged early (in ≤3 days) and received standardized outpatient care, and high-risk patients were admitted to the hospital. The coprimary outcomes were a composite of death from any cause or hospitalization for cardiovascular causes within 30 days after presentation and the composite outcome within 20 months. RESULTS: A total of 5452 patients were enrolled in the trial (2972 during the control phase and 2480 during the intervention phase). Within 30 days, death from any cause or hospitalization for cardiovascular causes occurred in 301 patients (12.1%) who were enrolled during the intervention phase and in 430 patients (14.5%) who were enrolled during the control phase (adjusted hazard ratio, 0.88; 95% confidence interval [CI], 0.78 to 0.99; P = 0.04). Within 20 months, the cumulative incidence of primary-outcome events was 54.4% (95% CI, 48.6 to 59.9) among patients who were enrolled during the intervention phase and 56.2% (95% CI, 54.2 to 58.1) among patients who were enrolled during the control phase (adjusted hazard ratio, 0.95; 95% CI, 0.92 to 0.99). Fewer than six deaths or hospitalizations for any cause occurred in low- or intermediate-risk patients before the first outpatient visit within 30 days after discharge. CONCLUSIONS: Among patients with acute heart failure who were seeking emergency care, the use of a hospital-based strategy to support clinical decision making and rapid follow-up led to a lower risk of the composite of death from any cause or hospitalization for cardiovascular causes within 30 days than usual care. (Funded by the Ontario SPOR Support Unit and others; COACH ClinicalTrials.gov number, NCT02674438.).


Asunto(s)
Insuficiencia Cardíaca , Humanos , Insuficiencia Cardíaca/terapia , Hospitalización , Ontario , Alta del Paciente , Enfermedad Aguda , Resultado del Tratamiento , Toma de Decisiones Clínicas , Canadá , Sistemas de Atención de Punto , Algoritmos
2.
JAMA ; 321(8): 753-761, 2019 02 26.
Artículo en Inglés | MEDLINE | ID: mdl-30806695

RESUMEN

Importance: Health care services that support the hospital-to-home transition can improve outcomes in patients with heart failure (HF). Objective: To test the effectiveness of the Patient-Centered Care Transitions in HF transitional care model in patients hospitalized for HF. Design, Setting, and Participants: Stepped-wedge cluster randomized trial of 2494 adults hospitalized for HF across 10 hospitals in Ontario, Canada, from February 2015 to March 2016, with follow-up until November 2016. Interventions: Hospitals were randomized to receive the intervention (n = 1104 patients), in which nurse-led self-care education, a structured hospital discharge summary, a family physician follow-up appointment less than 1 week after discharge, and, for high-risk patients, structured nurse homevisits and heart function clinic care were provided to patients, or usual care (n = 1390 patients), in which transitional care was left to the discretion of clinicians. Main Outcomes and Measures: Primary outcomes were hierarchically ordered as composite all-cause readmission, emergency department (ED) visit, or death at 3 months; and composite all-cause readmission or ED visit at 30 days. Secondary outcomes were B-PREPARED score for discharge preparedness (range: 0 [most prepared] to 22 [least prepared]); the 3-Item Care Transitions Measure (CTM-3) for quality of transition (range: 0 [worst transition] to 100 [best transition]); the 5-level EQ-5D version (EQ-5D-5L) for quality of life (range: 0 [dead] to 1 [full health]); and quality-adjusted life-years (QALY; range: 0 [dead] to 0.5 [full health at 6 months]). Results: Among eligible patients, all 2494 (mean age, 77.7 years; 1258 [50.4%] women) completed the trial. There was no significant difference between the intervention and usual care groups in the first primary composite outcome (545 [49.4%] vs 698 [50.2%] events, respectively; hazard ratio [HR], 0.99 [95% CI, 0.83-1.19]) or in the second primary composite outcome (304 [27.5%] vs 408 [29.3%] events, respectively; HR, 0.93 [95% CI, 0.73-1.18]). There were significant differences between the intervention and usual care groups in the secondary outcomes of mean B-PREPARED score at 6 weeks (16.6 vs 13.9; difference, 2.65 [95% CI, 1.37-3.92]; P < .001); mean CTM-3 score at 6 weeks (76.5 vs 70.3; difference, 6.16 [95% CI, 0.90-11.43]; P = .02); and mean EQ-5D-5L score at 6 weeks (0.7 vs 0.7; difference, 0.06 [95% CI, 0.01 to 0.11]; P = .02) and 6 months (0.7 vs 0.6; difference, 0.06 [95% CI, 0.01-0.12]; P = .02). There was no significant difference in mean QALY between groups at 6 months (0.3 vs 0.3; difference, 0.00 [95% CI, -0.02 to 0.02]; P = .98). Conclusions and Relevance: Among patients with HF in Ontario, Canada, implementation of a patient-centered transitional care model compared with usual care did not improve a composite of clinical outcomes. Whether this type of intervention could be effective in other health care systems or locations would require further research. Trial Registration: ClinicalTrials.gov Identifier: NCT02112227.


Asunto(s)
Servicio de Urgencia en Hospital/estadística & datos numéricos , Insuficiencia Cardíaca/terapia , Aceptación de la Atención de Salud/estadística & datos numéricos , Readmisión del Paciente/estadística & datos numéricos , Atención Dirigida al Paciente , Cuidado de Transición , Anciano , Femenino , Insuficiencia Cardíaca/mortalidad , Hospitalización , Humanos , Masculino , Ontario , Años de Vida Ajustados por Calidad de Vida , Resultado del Tratamiento
3.
Am Heart J ; 199: 75-82, 2018 05.
Artículo en Inglés | MEDLINE | ID: mdl-29754670

RESUMEN

INTRODUCTION: Heart Failure (HF) is a common cause of hospitalization in older adults. The transition from hospital to home is high-risk, and gaps in transitional care can increase the risk of re-hospitalization and death. Combining health care services supported by meta-analyses, we designed the PACT-HF transitional care model. METHODS: Adopting an integrated Knowledge Translation (iKT) approach in which decision-makers and clinicians are partners in research, we implement and test the effectiveness of PACT-HF among patients hospitalized for HF. We use a pragmatic stepped wedge cluster randomized trial design to introduce the complex health service intervention to 10 large hospitals in a randomized sequence until all hospitals initiate the intervention. The goal is for all patients hospitalized with HF to receive self-care education, multidisciplinary care, and early follow-up with their health care providers; and in addition, for high-risk patients to receive post-discharge nurse-led home visits and outpatient care in Heart Function clinics. This requires integration of care across hospitals, home care agencies, and outpatient clinics in our publicly funded health care system. While hospitals are the unit of recruitment and analysis, patients (estimated sample size of 3200) are the unit of analysis. Primary outcomes are hierarchically ordered as time to composite all-cause readmissions / emergency department (ED) visits / death at 3 months and time to composite all-cause readmissions / ED visits at 30 days. In a nested study of 8 hospitals, we measure the patient-centered outcomes of Discharge Preparedness, Care Transitions Quality, and Quality Adjusted Life Years (QALY); and the 6-month health care resource use and costs. We obtain all clinical and cost outcomes via linkages to provincial administrative databases. CONCLUSIONS: This protocol describes the implementation and testing of a transitional care model comprising health care services informed by high-level evidence. The study adopts an iKT and pragmatic approach, uses a robust study design, links clinical trial data with outcomes held in administrative databases, and includes patient-reported outcomes. Findings will have implications on clinical practice, health care policy, and Knowledge Translation (KT) research methodology.


Asunto(s)
Servicio de Urgencia en Hospital , Insuficiencia Cardíaca/terapia , Transferencia de Pacientes/organización & administración , Atención Dirigida al Paciente/métodos , Ensayos Clínicos Controlados Aleatorios como Asunto/métodos , Humanos
4.
J Card Fail ; 21(1): 68-75, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25451706

RESUMEN

BACKGROUND: Chronic heart rate (HR) reduction in the treatment of heart failure (HF) with systolic dysfunction is beneficial, but the immediate mechanical advantages or disadvantages of altering HR are incompletely understood. We examined the effects of increasing HR on early and late diastole in humans with and without HF. METHODS AND RESULTS: We studied force-interval relationships of the left ventricle (LV) in 11 HF patients and 14 control subjects. HR was controlled by right atrial pacing, and LV pressure was recorded by a micromanometer-tipped catheter. The time constant of isovolumic relaxation (tau) was calculated, and simultaneous sonographic images were analyzed for LV volumes. The end-diastolic pressure-volume relationship (EDPVR) was analyzed with the use of a single-beat method. Tau was shortened in response to increasing HR in both groups; the slope of this relationship was steeper in HF than in control subjects. The predicted volume at a theoretic pressure of 0 mm Hg (V30) increased at higher HRs compared with baseline, shifting the predicted EDPVR compliance curve to the right in HF patients but not in control subjects. CONCLUSIONS: In HF, changes in HR affect early relaxation and diastolic compliance to a greater extent than in control subjects. Our study reinforces current recommendations for HR-lowering drug treatment in HF.


Asunto(s)
Insuficiencia Cardíaca/diagnóstico , Insuficiencia Cardíaca/fisiopatología , Frecuencia Cardíaca/fisiología , Contracción Miocárdica/fisiología , Función Ventricular Izquierda/fisiología , Adulto , Anciano , Cateterismo Cardíaco/métodos , Estimulación Cardíaca Artificial/métodos , Diástole/fisiología , Femenino , Insuficiencia Cardíaca/terapia , Humanos , Masculino , Persona de Mediana Edad
5.
Curr Opin Cardiol ; 27(2): 148-53, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-22314299

RESUMEN

PURPOSE OF REVIEW: This article will review the noninvasive modalities currently available for imaging the right ventricle, including two-dimensional echocardiography, cardiac magnetic resonance (CMR), multidetector computed tomography (MDCT), radionuclide ventriculography (RNV) and PET. RECENT FINDINGS: Improvements in established imaging techniques, as well as development of newer imaging modalities, have shed light on the right ventricle's adaptation to pressure and volume overload states and have allowed better prognostication in patients with right ventricular failure (RVF). SUMMARY: As therapies are developed to alter the natural history of RVF, a better understanding of the imaging modalities for the assessment of right ventricular morphology and function is needed. This review will provide an approach to investigating the patient with suspected RVF and highlight the strengths and weakness of each imaging modality.


Asunto(s)
Ecocardiografía/métodos , Insuficiencia Cardíaca/diagnóstico , Ventrículos Cardíacos , Imagen por Resonancia Cinemagnética/métodos , Tomografía Computarizada Multidetector/métodos , Disfunción Ventricular Derecha/diagnóstico , Ventrículos Cardíacos/diagnóstico por imagen , Ventrículos Cardíacos/patología , Humanos , Pronóstico , Reproducibilidad de los Resultados
6.
Rehabil Nurs ; 45(5): 245-251, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32858709

RESUMEN

This study investigated the dynamics of patient-provider communication in the cardiac rehabilitation (CR) referral process, to identify which aspects lead to CR participation. Semi-structured individual interviews were conducted with 31 patients eligible for CR. Questions probed the content and perception of the discussion that patients had with healthcare providers (HCP) regarding CR attendance. The interviews were audiotaped, transcribed, and imported into N6 software for grounded analyses. Key emerging themes were identified: illness perceptions; HCP encouragement; timing of discussion; and ease of referral. CR attenders were apt to self-advocate to ensure their enrollment in CR, whereas nonattenders were more likely to minimize the seriousness of their disease, and less likely to persevere to overcome obstacles in enrolling in a CR program. Surprisingly, the strength of the HCP referral did not influence the decision to attend CR as strongly when compared to the HCP's ability to facilitate enrollment in a CR program.


Asunto(s)
Rehabilitación Cardiaca/métodos , Comunicación , Relaciones Profesional-Paciente , Derivación y Consulta/normas , Anciano , Femenino , Humanos , Entrevistas como Asunto/métodos , Masculino , Persona de Mediana Edad , Investigación Cualitativa , Derivación y Consulta/estadística & datos numéricos , Estadísticas no Paramétricas
7.
Am Heart J ; 154(3): 575-80, 2007 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-17719309

RESUMEN

BACKGROUND: Women with systolic heart failure (HF) demonstrate better survival than men. Whether sex differences occur in hemodynamics or measures of left ventricular (LV) function is not well understood. METHODS: We retrospectively analyzed a cohort who underwent evaluation by right heart catheterization +/- micromanometer-tipped catheterization of the LV. Two groups, defined at the time of catheterization, were studied: normal LV (NLV) function or HF (LV ejection fraction <35%, New York Heart Association II-III symptoms). For each female, we identified 2 male controls matched for age and LV ejection fraction in the HF group. RESULTS: In the NLV group, we matched 73 men (56 +/- 10 years) to 39 women (56 +/- 10 years). In the HF group, we matched 71 men (57 +/- 10 years) to 36 women (57 +/- 10 years). In the NLV group, women had higher heart rate and lower right atrial pressure, mean pulmonary artery pressure, and pulmonary capillary wedge pressure. Left ventricular peak systolic pressure was higher, and LV end-diastolic pressure was lower in women. In the HF group, no sex differences were observed in any hemodynamic measurement. In both groups, no sex differences were observed in isovolumic contractility or relaxation. CONCLUSIONS: Sex differences in hemodynamics are observed in patients with NLV function but not with HF. The intrinsic or extrinsic factors responsible for sex differences observed in patients with NLV function may be eclipsed by the HF disease state or its treatment.


Asunto(s)
Insuficiencia Cardíaca/fisiopatología , Función Ventricular Izquierda , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Caracteres Sexuales
8.
Rehabil Nurs ; 30(4): 140-6, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-15999858

RESUMEN

This study investigated the dynamics of patient-provider communication in the cardiac rehabilitation (CR) referral process, to identify which aspects lead to CR participation. Semi-structured individual interviews were conducted with 31 patients eligible for CR. Questions probed the content and perception of the discussion that patients had with healthcare providers (HCP) regarding CR attendance. The interviews were audiotaped, transcribed, and imported into N6 software for grounded analyses. Key emerging themes were identified: illness perceptions; HCP encouragement; timing of discussion; and ease of referral. CR attenders were apt to self-advocate to ensure their enrollment in CR, whereas nonattenders were more likely to minimize the seriousness of their disease, and less likely to persevere to overcome obstacles in enrolling in a CR program. Surprisingly, the strength of the HCP referral did not influence the decision to attend CR as strongly when compared to the HCP's ability to facilitate enrollment in a CR program.


Asunto(s)
Comunicación , Enfermedad Coronaria , Pacientes Internos/psicología , Aceptación de la Atención de Salud/psicología , Relaciones Profesional-Paciente , Derivación y Consulta/estadística & datos numéricos , Anciano , Actitud del Personal de Salud , Causalidad , Enfermedad Coronaria/psicología , Enfermedad Coronaria/rehabilitación , Toma de Decisiones , Negación en Psicología , Femenino , Conocimientos, Actitudes y Práctica en Salud , Hospitales de Enseñanza , Hospitales Urbanos , Humanos , Pacientes Internos/educación , Control Interno-Externo , Tiempo de Internación/estadística & datos numéricos , Masculino , Persona de Mediana Edad , Investigación Metodológica en Enfermería , Ontario , Educación del Paciente como Asunto/normas , Investigación Cualitativa , Índice de Severidad de la Enfermedad , Encuestas y Cuestionarios , Factores de Tiempo
9.
Ann Thorac Surg ; 73(6): 1822-9; discussion 1829, 2002 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-12078776

RESUMEN

BACKGROUND: Although small valve size and patient-prosthesis mismatch are both considered to decrease long-term survival, little direct evidence exists to support this hypothesis. METHODS: To assess the prevalence of patient-prosthesis mismatch and the influence of small valve size on survival, we prospectively studied 1,129 consecutive patients undergoing aortic valve replacement between 1990 and 2000. Mean and peak gradients and indexed effective orifice area were measured by transthoracic echocardiography postoperatively (3 months to 10 years). Abnormal postoperative gradients were defined as those patients with mean or peak gradient above the 90th percentile (mean gradient > or = 21 or peak gradient > or = 38 mm Hg). Patient-prosthesis mismatch was defined as those patients with indexed effective orifice area below the 10th percentile (< 0.60 cm2/m2). RESULTS: A multivariable analysis identified internal diameter of the implanted valve as the only independent predictor of abnormal gradients postoperatively. However, there was no significant difference in actuarial survival between normal and abnormal gradient groups (7 years: 91.2% +/- 1.5% versus 95.0% +/- 2.2%; p = 0.48). Freedom from New York Heart Association class III or IV (7 years: 74.5% +/- 3.1% versus 74.6% +/- 6.2%; p = 0.66) and left ventricular mass index were not different between normal and abnormal gradient groups. Patients with and without patient-prosthesis mismatch were similar with respect to postoperative left ventricular mass index, 7-year survival (95.1% +/- 1.3% versus 94.7% +/- 3.0%; p = 0.54), and 7-year freedom from New York Heart Association class III or IV (79.3% +/- 6.6% versus 74.5% +/- 2.5%; p = 0.40). In patients with patient-prosthesis mismatch and abnormal gradients, the majority had prosthesis dysfunction owing to degeneration. CONCLUSIONS: Severe patient-prosthesis mismatch is rare after aortic valve replacement. Patient-prosthesis mismatch, abnormal gradient, and the size of valve implanted do not influence left ventricular mass index or intermediate-term survival.


Asunto(s)
Válvula Aórtica , Implantación de Prótesis de Válvulas Cardíacas/métodos , Prótesis Valvulares Cardíacas , Complicaciones Posoperatorias/etiología , Adulto , Anciano , Antropometría , Femenino , Estudios de Seguimiento , Implantación de Prótesis de Válvulas Cardíacas/estadística & datos numéricos , Humanos , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias/epidemiología , Prevalencia , Estudios Prospectivos , Diseño de Prótesis , Tasa de Supervivencia
10.
Can J Cardiol ; 29(9): 1138.e7-8, 2013 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23474137

RESUMEN

A young woman thought to have seronegative rheumatoid arthritis developed Stevens-Johnson syndrome after treatment with sulfasalazine; this resolved with prednisone. Later she was found to be HLA-B27-positive in keeping with a spondyloarthropathy. Soon afterward, she developed clinical myopericarditis and cardiogenic shock that responded initially to methylprednisolone and intravenous immunoglobulin, but recurred. An endomyocardial biopsy demonstrated active myocarditis with a mixed cell composition including rare giant cells, but not enough to classify it as giant cell myocarditis. Heart failure symptoms returned and she eventually required a heart transplant; the explanted heart showed giant cell myocarditis.


Asunto(s)
Antirreumáticos/efectos adversos , Hipersensibilidad a las Drogas/etiología , Miocarditis/etiología , Espondiloartropatías/etiología , Síndrome de Stevens-Johnson/inducido químicamente , Sulfasalazina/efectos adversos , Adulto , Artritis Reumatoide/tratamiento farmacológico , Biopsia , Hipersensibilidad a las Drogas/inmunología , Ecocardiografía , Femenino , Células Gigantes/patología , Antígeno HLA-B27/inmunología , Trasplante de Corazón , Humanos , Miocarditis/cirugía , Espondiloartropatías/tratamiento farmacológico , Síndrome de Stevens-Johnson/tratamiento farmacológico
12.
Heart ; 97(5): 382-7, 2011 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-20876737

RESUMEN

BACKGROUND: Clinical outcomes for cardiovascular syndromes such as heart failure differ between men and women. OBJECTIVE: To seek phenotypic evidence for sex-differences in cardiac-specific sympathetic nervous system activation, as abnormal sympathetic nervous system activation is a key pathophysiological mechanism in heart failure (HF). METHODS: Patients who underwent evaluation of cardiac norepinephrine spillover (CNESP) using radiotracer methodology were identified retrospectively, and included in the analysis if they met criteria for either a normal left ventricular (NLV) function group, or systolic HF group, defined as an LV ejection fraction <40% and NYHA class II-III symptoms. Within each group a matched cohort analysis, identifying two control men for each woman, was performed. RESULTS: 166 subjects were identified, 48 within the NLV function group and 118 within the HF group. In the NLV function group, 12 women were matched for age to 24 men. Women had significantly higher NE concentrations in coronary sinus plasma. When normalised to total body NE spillover (CNESP:TBNESP), women had significantly higher values than men (CNESP:TBNESP, 6±3% in women vs 3±3% in men, p<0.05). In the HF group, 20 women were matched for age, date of study and presence of coronary disease to 39 men. There were no differences in comorbidities, drugs or haemodynamic measurements. Both CNESP and CNESP:TBNESP were significantly higher in women with HF than in men (CNESP 264±191 in women vs 182±110 in men, CNESP:TBNESP 9±6% in women vs 4±2% in men, p<0.05 for both). CONCLUSION: In patients with and without HF, women exhibit increased cardiac-specific sympathetic activation. Sexual dimorphism in cardiac autonomic physiology and its relationship to disease merits further investigation.


Asunto(s)
Enfermedades del Sistema Nervioso Autónomo/complicaciones , Insuficiencia Cardíaca/etiología , Factores Sexuales , Anciano , Enfermedades del Sistema Nervioso Autónomo/fisiopatología , Femenino , Insuficiencia Cardíaca/fisiopatología , Hemodinámica/fisiología , Humanos , Masculino , Persona de Mediana Edad , Miocardio/metabolismo , Norepinefrina/metabolismo , Estudios Retrospectivos , Disfunción Ventricular Izquierda/etiología , Disfunción Ventricular Izquierda/fisiopatología
13.
J Card Surg ; 19(6): 552-8, 2004.
Artículo en Inglés | MEDLINE | ID: mdl-15548192

RESUMEN

The purpose of this study is to present a comprehensive profile of the trends in aortic valve replacement at a single institution over the past decade. Prospectively collected data concerning 873 patients undergoing aortic valve replacement (AVR), with and without coronary artery bypass grafting (CABG), were analysed. The patients were divided into three time periods: period I, (1990 to 1993); period II, (1994 to 1996); and period III, (1997 to 2000). Actuarial survival of AVR patients with and without CABG at 7 years was 82.9 +/- 2.4% and 79.1 +/- 3.3% (p = 0.17), respectively. Actuarial survival at 7 years for stentless, mechanical, and stented valve patients were 89.5 +/- 2.7%, 85.5 +/- 2.8%, and 76.0 +/- 3.2%, respectively. There was a significant difference in survival between the stentless and stented valve groups (p = 0.014). Age (63.8 +/- 12.9 yrs, 66.2 +/- 11.0 yrs, 67.9 +/- 10.3 yrs; p = 0.01), the incidence of peripheral vascular disease (5.1%, 10.8%, 16.6%; p = 0.001), and the extent of coronary artery disease necessitating CABG (34.0%, 38.8%, 41.0%; p = 0.05) have increased significantly in the later time period. However, operative mortality has remained constant (4.7%, 4.8%, 4.5%; p = 0.9). Moreover, perioperative complications have decreased significantly (27.4%, 18.0, 16.0%; p = 0.001). Multivariate analysis identified more recent time period as independent protective factor for early mortality and morbidity (period I, RR 1.00; period II, RR 0.47; period III, RR 0.40).


Asunto(s)
Válvula Aórtica/cirugía , Implantación de Prótesis de Válvulas Cardíacas , Anciano , Anciano de 80 o más Años , Implantación de Prótesis Vascular , Canadá/epidemiología , Puente de Arteria Coronaria , Femenino , Estudios de Seguimiento , Enfermedades de las Válvulas Cardíacas/cirugía , Implantación de Prótesis de Válvulas Cardíacas/efectos adversos , Implantación de Prótesis de Válvulas Cardíacas/métodos , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Análisis Multivariante , Valor Predictivo de las Pruebas , Estudios Prospectivos , Factores de Riesgo , Stents , Análisis de Supervivencia , Factores de Tiempo , Resultado del Tratamiento
14.
Pacing Clin Electrophysiol ; 27(10): 1415-23, 2004 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-15511252

RESUMEN

Sudden intense physical activity is a trigger for ventricular arrhythmias in long QT syndrome (LQTS), and beta-blockers (B) reduce the risk of ventricular arrhythmias in LQTS. We compared the effect of graded (gradual intensity) versus burst (sudden intensity) exercise on QT-rate adaptation and T wave complexity in LQTS + B (n = 21), LQTS - B (n = 5), and normal controls (n = 20). Graded exercise consisted of symptom-limited bicycle ergometry (30 W, increment 20 W/min). Burst exercise involved a fixed 200 W load for 1.0 minute. ECGs were digitally recorded every 10 seconds during exercise and a 10 minute recovery period. QT-rate adaptation was quantified using the slope of the QT cycle length relationship fit to a quadratic function. Principle component analysis (PCA) was used to quantify T wave complexity. The QT-rate slope was two-fold greater with burst exercise than graded exercise for LQTS + B (-82E +/- 40E vs -36E +/- 40E, P = 0.0016), LQTS - B (-85E +/- 60E vs -30E +/- 50E, P = 0.011) and controls (-100E +/- 60E vs -48E +/- 100E, P = 0.0011) (E = x10(-5)). For each exercise protocol, there was no difference in QT-rate slope between the three groups. In contrast, the QT-rate slope during the 10 minute recovery period was similar between the burst and graded protocol for LQTS + B (25E +/- 40E vs 30E +/- 50E), LQTS - B (81E +/- 80E vs 85E +/- 70E) and controls (90E +/- 80E vs 82E +/- 80E). The coefficient of variability of PCA (T wave complexity variability) during burst exercise was greater than that during graded exercise for LQTS + B (41 +/- 15 vs 30 +/- 10, P = 0.017), LQTS - B (47 +/- 25 vs 26 +/- 4, P = 0.016), and control (46 +/- 14 vs 33 +/- 19, P = 0.012). For each exercise protocol, no difference in T wave complexity variability was seen between the three groups. In conclusion, QT heart rate slope and T wave complexity variability are greater during sudden intense exercise than graded exercise in LQTS patients (on and off beta-blockers) and normal subjects, with similar findings among the three groups of patients.


Asunto(s)
Electrocardiografía , Prueba de Esfuerzo/métodos , Síndrome de QT Prolongado/fisiopatología , Adaptación Fisiológica , Adulto , Femenino , Humanos , Masculino
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