Measuring impedance in congestive heart failure: Current options and clinical applications

Tang, W.H. Wilson; Tong, Wilson

doi:10.1016/j.ahj.2008.10.016

Cited by 110 publications

(90 citation statements)

References 71 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…An OptiVol alert (at this threshold) thus may not be very specific for the detection of fluid overload and imminent cardiac decompensation. 11 Although changes in intrathoracic impedance overall are associated with an increased risk, questions remain regarding its clinical use (especially early after device implantation) 23 ; in particular, the value of an audible alert in this setting is unclear. A number of studies examining the value of monitoring intrathoracic impedance are currently ongoing and will clarify the place of this technology in the management of patients with heart failure.…”

Section: (66)mentioning

confidence: 99%

“…to improving prognosis, they offer diagnostic features that allow monitoring of several variables, including intrathoracic impedance used to measure changes in thoracic fluid content, 10,11 intracardiac pressures, 12 heart rate variability, 13 patients' physical activity level, and arrhythmias. It is unknown whether interventions based on these parameters may improve outcome.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Intrathoracic Impedance Monitoring, Audible Patient Alerts, and Outcome in Patients With Heart Failure

et al. 2011

View full text Add to dashboard Cite

Background-Heart failure is associated with frequent hospitalizations, often resulting from volume overload. Measurement of intrathoracic impedance with an implanted device with an audible patient alert may detect increases in pulmonary fluid retention early. We hypothesized that early intervention could prevent hospitalizations and affect outcome. Methods and Results-We studied 335 patients with chronic heart failure who had undergone implantation of an implantable cardioverter-defibrillator alone (18%) or with cardiac resynchronization therapy (82%). All devices featured a monitoring tool to track changes in intrathoracic impedance (OptiVol) and other diagnostic parameters. Patients were randomized to have information available to physicians and patients as an audible alert in case of preset threshold crossings (access arm) or not (control arm). The primary end point was a composite of all-cause mortality and heart failure hospitalizations. During 14.9Ϯ5.4 months, this occurred in 48 patients (29%) in the access arm and in 33 patients (20%) in the control arm (Pϭ0.063; hazard ratio, 1.52; 95% confidence interval, 0.97-2.37). This was due mainly to more heart failure hospitalizations (hazard ratio, 1.79; 95% confidence interval, 1.08 -2.95; Pϭ0.022), whereas the number of deaths was comparable (19 versus 15; Pϭ0.54). The number of outpatient visits was higher in the access arm (250 versus 84; PϽ0.0001), with relatively more signs of heart failure among control patients during outpatient visits. Although the trial was terminated as a result of slow enrollment, a post hoc futility analysis indicated that a positive result would have been unlikely. Conclusion-Use of an implantable diagnostic tool to measure intrathoracic impedance with an audible patient alert did not improve outcome and increased heart failure hospitalizations and outpatient visits in heart failure patients. Clinical Trial Registration-URL: http://www.clinicaltrials.gov. Unique identifier: NCT 00480077.

show abstract

Section: (66)mentioning

confidence: 99%

mentioning

confidence: 99%

Intrathoracic Impedance Monitoring, Audible Patient Alerts, and Outcome in Patients With Heart Failure

et al. 2011

View full text Add to dashboard Cite

show abstract

“…Resistance (R) is a function of the relationship between the applied voltage (V) and the current (I) measured across an electric field. 2 In patients with cardiac implantable electronic devices that can measure impedance, the electric field includes the lung and thoracic tissue that lie between the device and the tip of the pacing electrode. Presumably, a congested chest has higher fluid content and thus a lower resistance (or impedance), as water is a better electric conductor than air.…”

Section: See Article By Zile Et Almentioning

confidence: 99%

Assessing Impedance in Heart Failure

Small

Tang²

2016

Circ: Heart Failure

Self Cite

View full text Add to dashboard Cite

“…Impedance bioelectrical equipment (IBE) has become increasingly available in the clinical setting as a tool for the assessment of volume overload in patients with HF (9). This technology has been used for the subclinical detection and prediction of congestion events, characterized as HF aggravation.…”

Section: Introductionmentioning

confidence: 99%

Cambios en la composición corporal por impedancia bioeléctrica y su asociación con el deterioro de la capacidad funcional en pacientes con insufi ciencia cardiaca crónica estable

et al. 2016

View full text Add to dashboard Cite

ResumenIntroducción: los pacientes con insufi ciencia cardiaca (IC) desarrollan cambios importantes en la composición corporal; sin embargo, pocos estudios han evaluado prospectivamente la asociación entre estos cambios y el empeoramiento de la clase funcional en pacientes con IC crónica estable. Objetivo: el objetivo de este estudio fue evaluar si los cambios en los parámetros de la bioimpedancia estaban relacionados con el deterioro de la clase funcional de la clasifi cación de la New York Heart Association (NYHA) después de 6 meses. Métodos: se incluyeron 275 sujetos con IC crónica estable confi rmada por ecocardiograma. Se les realizaron mediciones de composición corporal por impedancia bioeléctrica de cuerpo completo con un equipo de múltiples frecuencias BodyStat QuadScan 4000 y se determinó la clase funcional por la clasifi cación de la New York Heart Association (NYHA) después de seis meses. Resultados: sesenta y seis (24%) sujetos mostraron deterioro de su clase funcional y 209 la mejoraron o no cambiaron. Se encontró mayor proporción de pacientes que cuya clase funcional se deterioró, en los que aumentó > 5% el agua extracelular y que desarrollaron hipervolemia de acuerdo a su localización en la gráfi ca resistencia/reactancia. La disminución de > 5% de la resistencia/talla se asoció de forma independiente con el deterioro de la clase funcional con un OR = 1.42 (IC 95% 1.01-2.0, p = 0.04). Conclusiones: la evaluación de la composición corporal a través de bioimpedancia eléctrica en pacientes con IC es un marcador de deterioro funcional. AbstractBackground: Heart failure (HF) patients develop important changes in body composition, but only a small number of studies have evaluated the associations between these changes and functional class deterioration in a prospective manner. Objective: The aim of this study was to evaluate whether changes in bioimpedance parameters were associated with NYHA functional class deterioration over six months. Methods: A total of 275 chronic stable HF patients confi rmed by echocardiography were recruited. Body composition measurements were obtained by whole body bioelectrical impedance with multiple frequency equipment (BodyStat QuadScan 4000). We evaluated functional class using the New York Heart Association (NYHA) classifi cation at baseline and after six months. Results: According to our results, 66 (24%) subjects exhibited functional class deterioration, while 209 improved or exhibited no change. A greater proportion of patients exhibited higher extracellular water (> 5%), and these patients developed hypervolemia, according to location on the resistance/reactance graph. A 5% decrease in resistance/height was associated with functional class deterioration with an OR of 1.42 (95% CI 1.01-2.0, p = 0.04). Conclusions: Body composition assessment through bioelectrical impedance exhibited a valuable performance as a marker of functional class deterioration in stable HF patients.

show abstract

Measuring impedance in congestive heart failure: Current options and clinical applications

Cited by 110 publications

References 71 publications

Intrathoracic Impedance Monitoring, Audible Patient Alerts, and Outcome in Patients With Heart Failure

Intrathoracic Impedance Monitoring, Audible Patient Alerts, and Outcome in Patients With Heart Failure

Assessing Impedance in Heart Failure

Cambios en la composición corporal por impedancia bioeléctrica y su asociación con el deterioro de la capacidad funcional en pacientes con insufi ciencia cardiaca crónica estable

Contact Info

Product

Resources

About