title: Extrasystolic stimulation with bi-ventricular pacing: an acute haemodynamic evaluation.
abstract: OBJECTIVE
  Cardiac resynchronization therapy (CRT) by means of biventricular pacing (BiVP) is well established as a treatment for patients with heart failure (HF). Post-extrasystolic potentiation, (PESP) which involves a transient increase in myocardial contractility following a ventricular extrasystole, can be achieved using extrasystolic stimulation (ESS). On this basis, ESS has been proposed as a therapeutic. We assessed acute haemodynamic effects of ESS in the context of BiVP.
  
  
  RESULTS
  Patients (n = 15, left ventricular ejection fraction < 40%, QRS ≥ 125 ms) with HF, received BiVP in combination with right ventricular (RV) ESS (single stimulus or pulse train). Left ventricular (LV) and peripheral arterial pressures were recorded and dP/dt was monitored. Addition of RV ESS to BiVP pacing led to a 21% increase in maximum (max) dP/dt (P < 0.001) and an 8.5 mm Hg increase in a systolic arterial pressure (P < 0.001). The modest fall in end-diastolic pressure (3.3 mmHg, P < 0.001) observed during ESS and BiVP was prevented by maintaining baseline sinus rate. Varying ESS modes or pacing outputs was not associated with differences in haemodynamic parameters.
  
  
  CONCLUSIONS
  Biventricular pacing in combination with ESS, with maintenance of sinus rate, improves myocardial contractility in patients undergoing CRT.
authors.affiliation: Bakken Research Center, GW Maastricht, The Netherlands.
authors.forename: Berthold
authors.initials: B
authors.lastname: Stegemann
authors.forename: Attila
authors.initials: A
authors.lastname: Mihalcz
authors.forename: Csaba
authors.initials: C
authors.lastname: Földesi
authors.forename: Radu
authors.initials: R
authors.lastname: Vatasescu
authors.forename: Attila
authors.initials: A
authors.lastname: Kardos
authors.forename: Zsolt
authors.initials: Z
authors.lastname: Török
authors.forename: Vince
authors.initials: V
authors.lastname: Splett
authors.forename: Richard
authors.initials: R
authors.lastname: Cornelussen
authors.forename: Laszlo
authors.initials: L
authors.lastname: Rudas
authors.forename: Tamas
authors.initials: T
authors.lastname: Szili-Török
mesh_terms: D000368:Aged; D001794:Blood Pressure / Q000502:physiology*; D058406:Cardiac Resynchronization Therapy / Q000379:methods*; D003971:Diastole / Q000502:physiology; D004558:Electric Stimulation; D005260:Female; D006333:Heart Failure / Q000503:physiopathology / Q000628:therapy*; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction / Q000502:physiology*; D012189:Retrospective Studies; D012849:Sinoatrial Node / Q000502:physiology; D013599:Systole / Q000502:physiology; D016896:Treatment Outcome; D016277:Ventricular Function, Left / Q000502:physiology; D018879:Ventricular Premature Complexes / Q000503:physiopathology*