title: Enhancement of cardiac performance by bilevel positive airway pressure ventilation in heart failure.
abstract: BACKGROUND
  Recent studies have reported the clinical usefulness of positive airway pressure ventilation therapy with various kinds of pressure support compared with simple continuous positive airway pressure (CPAP) for heart failure patients. However, the mechanism of the favorable effect of CPAP with pressure support can not be explained simply from the mechanical aspect and remains to be elucidated.
  
  
  RESULTS
  In 18 stable chronic heart failure patients, we performed stepwise CPAP (4, 8, 12 cm H(2)O) while the cardiac output and intracardiac pressures were continuously monitored, and we compared the effects of 4 cm H(2)O CPAP with those of 4 cm H(2)O CPAP plus 5 cm H(2)O pressure support. Stepwise CPAP decreased cardiac index significantly in patients with pulmonary arterial wedge pressure (PAWP) <12 mm Hg (n = 10), but not in those with PAWP ≥12 mm Hg (n = 8). Ventilation with CPAP plus pressure support increased cardiac index slightly but significantly from 2.2 ± 0.7 to 2.3 ± 0.7 L min(-1) m(-2) (P = .001) compared with CPAP alone, regardless of basal filling condition or cardiac index.
  
  
  CONCLUSIONS
  Our results suggest that CPAP plus pressure support is more effective than simple CPAP in heart failure patients and that the enhancement might be induced by neural changes and not simply by alteration of the preload level.
authors.affiliation: Cardiology Division Saiseikai Futsukaichi Hospital, Chikushino, Japan.
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Yoshida
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Kadokami
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Momii
authors.forename: Atsumi
authors.initials: A
authors.lastname: Hayashi
authors.forename: Takahisa
authors.initials: T
authors.lastname: Urashi
authors.forename: Sumito
authors.initials: S
authors.lastname: Narita
authors.forename: Natsumi
authors.initials: N
authors.lastname: Kawamura
authors.forename: Shin-ichi
authors.initials: S
authors.lastname: Ando
mesh_terms: D000368:Aged; D002302:Cardiac Output; D045422:Continuous Positive Airway Pressure; D005260:Female; D006333:Heart Failure / Q000628:therapy*; D006801:Humans; D007385:Intermittent Positive-Pressure Ventilation; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000097:blood; D011669:Pulmonary Wedge Pressure
chemical_list: D010100:Oxygen