title: Cardiac resynchronization therapy acutely improves ventricular-arterial coupling by reducing the arterial load: assessment by pressure-volume loops.
abstract: BACKGROUND
  Cardiac resynchronization therapy (CRT) has been demonstrated to improve ventricular-arterial coupling by reducing effective arterial elastance (Ea) on long-term follow-up. Detailed invasive studies showing possible acute peripheral effects of CRT are not available. We evaluated the hemodynamic effects of CRT in patients with systolic dysfunction, in order to investigate the impact on ventricular-arterial coupling and, in particular, on Ea immediately after the initiation of pacing.
  
  
  METHODS
  We studied 37 heart failure patients undergoing CRT implantation based on conventional criteria. On implantation, left ventricular (LV) pressure and volume data were determined via a conductance catheter. Twelve patients with a standard indication for electrophysiologic study and preserved LV function served as a control group.
  
  
  RESULTS
  In comparison with the control group, heart failure patients showed reduced systolic and diastolic function. LV end-systolic elastance (Ees: end-systolic pressure/volume) was impaired (0.79 ± 0.33 mm Hg/mL vs 1.84 ± 0.89 mm Hg/mL, P = 0.012) and Ees/Ea reduced (0.36 ± 0.17 vs 1.19 ± 1.81, P = 0.022). In heart failure patients, CRT immediately improved systolic function, increasing stroke work from 3.9 ± 1.8 L*mm Hg to 6.9 ± 3.3 L*mm Hg (P < 0.001) and Ees to 1.02 ± 0.62 mm Hg/mL (P = 0.001). Ea decreased from 2.59 ± 1.35 mm Hg/mL to 1.68 ± 0.91 mm Hg/mL (P < 0.001), leading to an increase in Ees/Ea to 0.70 ± 0.38 (P < 0.001).
  
  
  CONCLUSIONS
  Our data indicate that switching CRT on induces an immediate reduction in arterial load, conceivably as a consequence of restored autonomic balance.
authors: University of Florence, Florence, Italy.
authors: Paolo
authors: P
authors: Pieragnoli
authors: Giovanni Battista
authors: GB
authors: Perego
authors: Giuseppe
authors: G
authors: Ricciardi
authors: Stefania
authors: S
authors: Sacchi
authors: Margherita
authors: M
authors: Padeletti
authors: Antonio
authors: A
authors: Michelucci
authors: Sergio
authors: S
authors: Valsecchi
authors: Luigi
authors: L
authors: Padeletti
mesh_terms: D000368:Aged; D062186:Arterial Pressure; D058406:Cardiac Resynchronization Therapy / Q000379:methods*; D006333:Heart Failure / Q000503:physiopathology* / Q000517:prevention & control*; D006801:Humans; D008297:Male; D016896:Treatment Outcome; D014655:Vascular Resistance; D018487:Ventricular Dysfunction, Left / Q000503:physiopathology* / Q000517:prevention & control*
keywords: arterial load; cardiac resynchronization; heart failure; heart-arterial coupling; pressure-volume loop