title: Single center experience with intrathoracic impedance monitoring.
abstract: BACKGROUND
  The Medtronic InSync Sentry is the first available cardiac resynchronization therapy defibrillator (CRT-D) which can monitor fluid status by measuring intrathoracic impedance. This study was designed to observe the effectiveness of intrathoracic impedance monitoring on detecting aggravation of heart failure.
  
  
  METHODS
  We retrospectively analyzed the clinical data of 14 consecutive patients. Patients were regularly followed up every 3 - 6 months after the implantation. At each visit, interrogation of the device was done. Patients were instructed to inform the researcher on hearing the device alert, and to take extra 40 milligrams of furosemidum if they had aggravated symptoms later. If the symptoms could not be relieved, they were asked to see a doctor. Data about heart failure hospitalization were collected from the medical record.
  
  
  RESULTS
  During 18 - 48 months follow-up, a total of 7 patients encountered 28 alert events. On one hand, alert events appeared before all deteriorated symptoms and heart failure hospitalizations. On the other hand, there were 23 alerts followed by deterioration of heart failure symptoms, and 2 alerts related to 2 hospitalizations caused by pulmonary infection in one patient. Only 5 patients were hospitalized 10 times for deterioration of cardiac function.
  
  
  CONCLUSIONS
  The function of intrathoracic impedance monitoring is reliable in predicting deterioration of heart failure.
authors.affiliation: Centre of Arrhythmia Diagnosis and Treatment, Fuwai Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100037, China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Qiao
authors.forename: Wei
authors.initials: W
authors.lastname: Hua
authors.forename: Li-gang
authors.initials: LG
authors.lastname: Ding
authors.forename: Ke-ping
authors.initials: KP
authors.lastname: Chen
authors.forename: Jing
authors.initials: J
authors.lastname: Wang
authors.forename: Fang-zheng
authors.initials: FZ
authors.lastname: Wang
authors.forename: Shu
authors.initials: S
authors.lastname: Zhang
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D058406:Cardiac Resynchronization Therapy; D002307:Cardiography, Impedance / Q000379:methods*; D005260:Female; D006333:Heart Failure / Q000473:pathology* / Q000628:therapy; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies