title: Haemodynamic effects of different basic heart rates in ambulatory heart failure patients treated with cardiac resynchronization therapy.
abstract: OBJECTIVE
  The impact of different basic paced heart rates (pHRs) in patients receiving cardiac resynchronization therapy (CRT) remains largely unknown. The aim of the present study was to investigate the haemodynamic effects of different pHRs (60 or 80 b.p.m.), using an implanted haemodynamic monitor (IHM), during a 2-week period in ambulatory CRT patients.
  
  
  RESULTS
  Ten CRT patients received an IHM (Chronicle(®), Medtronic Inc.) to continuously record right ventricular systolic (RVSP) and diastolic (RVDP) pressure, as well as estimated pulmonary artery diastolic pressure (ePAD) during a 2-week period at two basic pHR programming (60 and 80 b.p.m.). Cardiac output (CO) was calculated using a validated IHM algorithm. At the end of each period, 6 min walk test (6MWT), quality of life (QoL), and plasma levels of brain natriuretic peptide (BNP) were also assessed. Pacing at 80 b.p.m. significantly reduced the 2-week average of ePAD compared with 60 b.p.m. (23.4 ± 6.2 vs. 25.1 ± 6.5 mmHg, P = 0.03), whereas CO was increased (4.5 ± 1.3 vs. 4.2 ± 1.4 L/min; P = 0.01). Similarly ePAD, RVSP, and RVDP were significantly lower with a pHR of 80 b.p.m. (P < 0.05). The 6MWT, QoL score, and BNP were not affected by the pHR.
  
  
  CONCLUSIONS
  In CRT patients, a basic pHR of 80 b.p.m. compared with 60 b.p.m. reduces filling pressures and increases CO during a 2-week period of ambulatory living. This suggests that increasing the basic pHR may be considered to achieve short-term haemodynamic improvement. The long-term effects of differential pHR programming remain to be established.
authors.affiliation: Department of Cardiology, Karolinska Institutet, Karolinska University Hospital, S-17176 Stockholm, Sweden. marcus.stahlberg@ki.se
authors.forename: Marcus
authors.initials: M
authors.lastname: Ståhlberg
authors.forename: Kathryn
authors.initials: K
authors.lastname: Hilpisch
authors.forename: Pascalle
authors.initials: P
authors.lastname: Reiters
authors.forename: Cecilia
authors.initials: C
authors.lastname: Linde
authors.forename: Frieder
authors.initials: F
authors.lastname: Braunschweig
mesh_terms: D000368:Aged; D001794:Blood Pressure; D002302:Cardiac Output; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D058409:Cardiac Resynchronization Therapy Devices; D005260:Female; D006333:Heart Failure / Q000175:diagnosis / Q000503:physiopathology* / Q000517:prevention & control*; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D016037:Single-Blind Method; D016896:Treatment Outcome
keywords: Cardiac output; Cardiac resynchronization therapy; Haemodynamics; Heart failure; Heart rate