Left Ventricular End Diastolic Pressure and Serum Brain Natriuretic Peptide Levels in Patients with Abnormal Impedance Cardiography Parameters

Correlation of impedance cardiography with invasive hemodynamic measurements in patients with advanced heart failure: The BioImpedance CardioGraphy (BIG) substudy of the Evaluation Study of Congestive Heart Failure and Pulmonary Artery Catheterization Effectiveness (ESCAPE) Trial

“…In a study of 63 patients with compensated HF, the combination of a high TFC and low stroke volume index was associated with a higher LV end-diastolic pressure when compared with the combination of a low TFC and high stroke volume index 13. However, that study included subjects both with reduced and preserved ejection fraction.…”

Transthoracic Impedance Accurately Estimates Pulmonary Wedge Pressure in Patients With Decompensated Chronic Heart Failure

“…Since the direct measurement of hemodynamics in these patients is limited by its invasiveness, noninvasive techniques represent attractive options. Among them, biomarkers, echocardiography, and transthoracic impedance cardiography have received attention due to their relationship with invasively measured estimates of filling pressures in several studies 7–10,12–18 . However, evidence challenging the use of these indexes has also been provided 11,19 …”

“…A limitation of the study could have been the selection of “ideal” patients, in whom no confounding problems were present (such as arrhythmias, very large ventricles, prosthetic valves, pleural or pericardial effusions, chronic obstructive pulmonary disease): this selection excluded about one third of potential candidates. In smaller studies carried out in less selected patients with systolic HF, the use of thoracic bioimpedance has provided conflicting results: either TFC was poorly correlated with invasively measured PCWP 18 or the combination of a high TFC and low stroke volume index was associated with a higher LV end‐diastolic pressure when compared with the combination of a low TFC and high stroke volume index 15 . We did not measure LV end‐diastolic or left atrial pressure, and we relied on PCWP as an accepted and validated surrogate.…”

“…11 In the past few years, bedside assessment of brain natriuretic peptide (BNP) levels has been proposed as a screening tool for the severity of the disease in patients with acute HF, due to its reported relationship with PCWP in some studies. [12][13][14][15] Another tool for noninvasive hemodynamic evaluation may be the analysis of thoracic electrical bioimpedance (TEB), [16][17][18] but its reliability is controversial 19 and may depend on the clinical setting in which it is employed (ie, acute vs chronic HF). 20 This study was carried out in patients with worsening advanced chronic HF 21 with a 2-fold purpose.…”

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

“…These results were derived in a post hoc manner in an observational series and should be interpreted with great caution, as addition of the impedance data to the assessment of clinical data was neither clearly additive nor predictive. Associations between high-risk variables from the band-electrode technique have also been associated with higher natriuretic peptide levels and more adverse hemodynamics 47. It should be recognized that these are merely surrogates of adverse outcomes in heart failure, and data demonstrating incremental clinical benefit are still lacking.…”