title: Left ventricular pacing improves haemodynamic variables in patients with heart failure with a normal QRS duration.
abstract: OBJECTIVE
  To assess whether patients with congestive heart failure (CHF) and a normal QRS duration can benefit from left ventricular (VDD-LV) pacing.
  
  
  METHODS
  Cardiac resynchronisation is reserved for patients with a broad QRS duration on the premise that systolic resynchronisation is the mechanism of benefit, yet improvement from pacing correlates poorly with QRS duration. In CHF patients with a broad QRS duration, those with a high resting pulmonary capillary wedge pressure (PCWP) > 15 mm Hg benefit. In this acute haemodynamic VDD-LV pacing study, patients with CHF with a normal QRS duration were divided into two groups--patients with a resting PCWP > 15 mm Hg and patients with a resting PCWP < 15 mm Hg--to determine whether benefit is predicted by a high resting PCWP.
  
  
  METHODS
  20 patients with CHF, New York Heart Association functional class IIb-IV, all with a normal QRS duration (< or = 120 ms).
  
  
  METHODS
  Temporary pacing wires were positioned to enable VDD-LV pacing and a pulmonary artery catheter was inserted for measurement of PCWP, right atrial pressure, and cardiac output.
  
  
  RESULTS
  In patients with a PCWP > 15 mm Hg (n = 10), cardiac output increased from 3.9 (1.5) to 4.5 (1.65) l/min (p < 0.01), despite a fall in PCWP from 24.7 (7.1) to 21.0 (6.2) mm Hg (p < 0.001). In patients with a PCWP < 15 mm Hg there was no change in PCWP or cardiac output. Combined data showed that PCWP decreased from 17.0 (9.1) to 15.3 (7.7) mm Hg during VDD-LV pacing (p < 0.014) and cardiac output increased non-significantly from 4.7 (1.5) to 4.9 (1.5) (p = 0.125).
  
  
  CONCLUSIONS
  Patients with CHF with a normal QRS duration and PCWP > 15 mm Hg derive acute haemodynamic benefit from VDD-LV pacing.
authors.affiliation: Department of Cardiology, Wales Heart Research Institute, University of Wales College of Medicine, Heath Park, Cardiff, UK.
authors.forename: M S
authors.initials: MS
authors.lastname: Turner
authors.forename: R A
authors.initials: RA
authors.lastname: Bleasdale
authors.forename: C E
authors.initials: CE
authors.lastname: Mumford
authors.forename: M P
authors.initials: MP
authors.lastname: Frenneaux
authors.forename: J A
authors.initials: JA
authors.lastname: Morris-Thurgood
mesh_terms: D002302:Cardiac Output / Q000502:physiology; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D005260:Female; D006333:Heart Failure / Q000503:physiopathology / Q000628:therapy*; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D008297:Male; D011669:Pulmonary Wedge Pressure / Q000502:physiology; D018487:Ventricular Dysfunction, Left / Q000503:physiopathology / Q000628:therapy