title: Intrathoracic impedance changes reflect reverse left ventricular remodeling in response to cardiac resynchronization therapy in chronic heart failure patients.
abstract: Intrathoracic impedance monitoring has been reported to be useful for prediction of worsening chronic heart failure (CHF). However, it has not revealed the relation between changes in intrathoracic impedance and improvement of cardiac function in CHF patients with cardiac resynchronization therapy (CRT) implantation. Therefore, we investigated whether intrathoracic impedance change reflects reverse left ventricular (LV) remodeling in response to CRT in patients with CHF. The study subjects consisted of 29 CHF patients (23 males, mean age 64 ± 12 years) with CRT-defibrillator (CRT-D) implantation. The patients were divided into two groups based on whether the Opti-vol Fluid Index® reached over 60 ohms (group A, n = 7) or not (group B, n = 22) within 6 months of observation after CRT-D implantation. Levels of plasma B-type natriuretic peptide (BNP) were measured, and LV end-diastolic volume (LVEDV), LV end-systolic volume (LVESV), and LV ejection fraction (LVEF) were evaluated before and 6 months after CRT-D implantation. In group B, BNP (556 ± 88 pg/mL versus 330 ± 70 pg/mL, P < 0.05), LVEDV (177 ± 18 mL versus 149 ± 14 mL, P < 0.01), and LVESV (128 ± 14 mL versus 100 ± 12 mL, P < 0.01) were significantly decreased 6 months after CRT-D implantation. LVEF (28 ± 2% versus 35 ± 2%, P < 0.01) was significantly increased after CRT-D implantation. On the other hand, no significant changes were detected in any parameters in group A. These data showed intrathoracic impedance changes reflected reverse LV remodeling in response to CRT in patients with CHF. Therefore, the monitoring of changes in intrathoracic impedance is useful for predicting CRT responders in patients with CHF.
authors.affiliation: Department of Cardiology and Hematology, Fukushima Medical University, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Kaneshiro
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Suzuki
authors.forename: Shinya
authors.initials: S
authors.lastname: Yamada
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Kamiyama
authors.forename: Shu-ichi
authors.initials: S
authors.lastname: Saitoh
authors.forename: Yasuchika
authors.initials: Y
authors.lastname: Takeishi
mesh_terms: D000368:Aged; D058406:Cardiac Resynchronization Therapy; D004452:Echocardiography; D017097:Electric Impedance; D005260:Female; D006333:Heart Failure / Q000097:blood / Q000000981:diagnostic imaging / Q000628:therapy*; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain / Q000097:blood; D020257:Ventricular Remodeling
chemical_list: D020097:Natriuretic Peptide, Brain