title: Acute effects of continuous positive air way pressure on pulse pressure in chronic heart failure.
abstract: BACKGROUND
  Patients with heart failure (HF) have left ventricular dysfunction and reduced mean arterial pressure (MAP). Increased adrenergic drive causes vasoconstriction and vessel resistance maintaining MAP, while increasing peripheral vascular resistance and conduit vessel stiffness. Increased pulse pressure (PP) reflects a complex interaction of the heart with the arterial and venous systems. Increased PP is an important risk marker in patients with chronic HF (CHF). Non-invasive ventilation (NIV) has been used for acute decompensated HF, to improve congestion and ventilation through both respiratory and hemodynamic effects. However, none of these studies have reported the effect of NIV on PP.
  
  
  OBJECTIVE
  The objective of this study was to determine the acute effects of NIV with CPAP on PP in outpatients with CHF.
  
  
  METHODS
  Following a double-blind, randomized, cross-over, and placebo-controlled protocol, twenty three patients with CHF (17 males; 60±11 years; BMI 29±5 kg/cm2, NYHA class II, III) underwent CPAP via nasal mask for 30 min in a recumbent position. Mask pressure was 6 cmH2O, whereas placebo was fixed at 0-1 cmH2O. PP and other non invasive hemodynamics variables were assessed before, during and after placebo and CPAP mode.
  
  
  RESULTS
  CPAP decreased resting heart rate (Pre: 72±9; vs. Post 5 min: 67±10 bpm; p<0.01) and MAP (CPAP: 87±11; vs. control 96±11 mmHg; p<0.05 post 5 min). CPAP decreased PP (CPAP: 47±20 pre to 38±19 mmHg post; vs. control: 42±12 mmHg, pre to 41±18 post p<0.05 post 5 min).
  
  
  CONCLUSIONS
  NIV with CPAP decreased pulse pressure in patients with stable CHF. Future clinical trials should investigate whether this effect is associated with improved clinical outcome.
authors.affiliation: Universidade Federal Fluminense, RJ, Brasil.
authors.forename: Mônica
authors.initials: M
authors.lastname: Quintão
authors.affiliation: Universidade Federal Fluminense, RJ, Brasil.
authors.forename: Sérgio
authors.initials: S
authors.lastname: Chermont
authors.affiliation: Universidade Federal Fluminense, RJ, Brasil.
authors.forename: Luana
authors.initials: L
authors.lastname: Marchese
authors.affiliation: Clinica de Insuficiencia Cardiaca, Centro Universitario Serra dos Orgaos, Teresopolis, RJ, Brasil.
authors.forename: Lúcia
authors.initials: L
authors.lastname: Brandão
authors.affiliation: Universidade Federal Fluminense, RJ, Brasil.
authors.forename: Sabrina Pereira
authors.initials: SP
authors.lastname: Bernardez
authors.affiliation: Universidade Federal Fluminense, RJ, Brasil.
authors.forename: Evandro Tinoco
authors.initials: ET
authors.lastname: Mesquita
authors.affiliation: Universidade Federal Fluminense, RJ, Brasil.
authors.forename: Nazareth de
authors.initials: Nd
authors.lastname: Novaes Rocha
authors.affiliation: Universidade Federal Fluminense, RJ, Brasil.
authors.forename: Antônio Claudio L
authors.initials: AC
authors.lastname: Nóbrega
mesh_terms: D000368:Aged; D000704:Analysis of Variance; D001794:Blood Pressure / Q000502:physiology*; D015992:Body Mass Index; D002908:Chronic Disease; D045422:Continuous Positive Airway Pressure / Q000379:methods*; D018592:Cross-Over Studies; D004311:Double-Blind Method; D005260:Female; D006333:Heart Failure / Q000503:physiopathology* / Q000628:therapy*; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D063087:Noninvasive Ventilation / Q000379:methods*; D015203:Reproducibility of Results; D018709:Statistics, Nonparametric; D013997:Time Factors; D016896:Treatment Outcome; D018487:Ventricular Dysfunction, Left / Q000503:physiopathology