title: Continuous ambulatory right heart pressure measurements with an implantable hemodynamic monitor: a multicenter, 12-month follow-up study of patients with chronic heart failure.
abstract: BACKGROUND
  We describe the performance of an implantable hemodynamic monitor (IHM) that allows continuous recording of heart rate, patient activity levels, and right ventricular systolic, right ventricular diastolic, and estimated pulmonary artery diastolic pressures. Pressure parameters derived from the implantable monitor were correlated to measurements made with a balloon-tipped catheter to establish accuracy and reproducibility over time in patients with chronic heart failure (CHF).
  
  
  RESULTS
  IHM devices were implanted in 32 patients with CHF (left ventricular ejection fraction, 29% +/- 11%; range, 14%-62%) and were tested with right heart catheterization at implantation and 3, 6, and 12 months later. Hemodynamic variables were digitally recorded simultaneously from the IHM and catheter. Values were recorded during supine rest, peak response of Valsalva maneuver, sitting, peak of a 2-stage (25-50 W) bicycle exercise test, and final rest period. The median of 21 paired beat-to-beat cardiac cycles was analyzed for each intervention. A total of 217 paired data values from all maneuvers were analyzed for 32 patients at implantation and 129 paired data values for 20 patients at 1 year. The IHM and catheter values were not different at baseline or at 1 year (P >.05). Combining all interventions, correlation coefficients were 0.96 and 0.94 for right ventricular systolic pressure, 0.96 and 0.83 for right ventricular diastolic pressure, and 0.87 and 0.87 for estimated pulmonary artery diastolic pressure at implantation and 1 year, respectively.
  
  
  CONCLUSIONS
  The IHM and a standard reference pressure system recorded comparable right heart pressure values in patients with CHF. This implantable pressure transducer is accurate over time and provides a means to precisely monitor the hemodynamic condition of patients with CHF in a continuous fashion.
authors.affiliation: Mid-America Heart Institute, St Luke's Hospital, Kansas City, MO 64111, USA.
authors.forename: Anthony
authors.initials: A
authors.lastname: Magalski
authors.forename: Philip
authors.initials: P
authors.lastname: Adamson
authors.forename: Frederick
authors.initials: F
authors.lastname: Gadler
authors.forename: Michael
authors.initials: M
authors.lastname: Böehm
authors.forename: David
authors.initials: D
authors.lastname: Steinhaus
authors.forename: Dwight
authors.initials: D
authors.lastname: Reynolds
authors.forename: Kathryn
authors.initials: K
authors.lastname: Vlach
authors.forename: Cecilia
authors.initials: C
authors.lastname: Linde
authors.forename: Bodo
authors.initials: B
authors.lastname: Cremers
authors.forename: Brandon
authors.initials: B
authors.lastname: Sparks
authors.forename: Tom
authors.initials: T
authors.lastname: Bennett
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D018670:Monitoring, Ambulatory / Q000295:instrumentation*; D011446:Prospective Studies; D012044:Regression Analysis; D013997:Time Factors; D017725:Ventricular Pressure / Q000502:physiology*