title: Impact of haemodynamic SonR sensor on monitoring of left ventricular function in patients undergoing cardiac resynchronization therapy.
abstract: OBJECTIVE
  The haemodynamic SonR sensor is able to measure myocardial contractility. The isometric effort is useful in quantifying left ventricular (LV) performance. We investigated the amplitude changes in SonR signal over time and during static exercise according to the recovery of the left ventricle.
  
  
  RESULTS
  Twenty five patients [18 male, 70 ± 8 years, LV ejection fraction (LVEF) 29 ± 5%, in sinus rhythm] underwent biventricular SonR implantable cardioverter defibrillator implant. After procedure and at 6 months, each patient underwent detection of SonR signal and continuous measurement of blood pressure, at rest and during isometric effort. During evaluation at baseline device was programmed in VVI at 40 bpm while in DDD at 60 bpm at follow-up. At 6 months, LV reverse remodelling was investigated. Cardiac resynchronization therapy patients were considered responders when an absolute improvement in LV ejection fraction ≥ 5% occurred. At 6 months, 14 (56%) patients were responders and 11 (44%) non-responders (mean LVEF 40 ± 10% vs. 27 ± 6%, respectively). In responders, SonR value did not significantly change at follow-up compared to baseline (P = 0.894). At follow-up, SonR value was not significantly different between two groups (P = 0.651). SonR signal significantly increased during isometric effort in responders (P = 0.002) while it slightly decreased in non-responders at follow-up (P = 0.572). No differences were observed in response to isometric effort between two groups at baseline (P = 0.182, P = 0.069, respectively).
  
  
  CONCLUSIONS
  The absolute SonR amplitude provides limited information on the status of LV performance. The variation in SonR signal during static exercise is more likely to identify responders at follow-up.
authors.affiliation: Department of Internal Medicine and Cardiology, Institute of Internal Medicine and Cardiology, University of Florence, Florence, Italy.|International Centre for Circulatory Health, National Heart and Lung Institute, Imperial College, London, UK.
authors.forename: Stefania
authors.initials: S
authors.lastname: Sacchi
authors.affiliation: Department of Internal Medicine and Cardiology, Institute of Internal Medicine and Cardiology, University of Florence, Florence, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Pieragnoli
authors.affiliation: Department of Internal Medicine and Cardiology, Institute of Internal Medicine and Cardiology, University of Florence, Florence, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Ricciardi
authors.affiliation: Department of Internal Medicine and Cardiology, Institute of Internal Medicine and Cardiology, University of Florence, Florence, Italy.
authors.forename: Gino
authors.initials: G
authors.lastname: Grifoni
authors.affiliation: Department of Internal Medicine and Cardiology, Institute of Internal Medicine and Cardiology, University of Florence, Florence, Italy.|Department of Cardiology, IRCCS, Multimedica, Sesto San Giovanni, Milan, Italy.
authors.forename: Luigi
authors.initials: L
authors.lastname: Padeletti
mesh_terms: D000368:Aged; D001794:Blood Pressure; D058406:Cardiac Resynchronization Therapy; D058409:Cardiac Resynchronization Therapy Devices; D017147:Defibrillators, Implantable; D004554:Electric Countershock / Q000295:instrumentation*; D004867:Equipment Design; D005080:Exercise Test; D005260:Female; D006333:Heart Failure / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D006334:Heart Function Tests / Q000295:instrumentation*; D006339:Heart Rate; D006439:Hemodynamics; D006801:Humans; D007537:Isometric Contraction; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction; D011237:Predictive Value of Tests; D011446:Prospective Studies; D020127:Recovery of Function; D012815:Signal Processing, Computer-Assisted; D013318:Stroke Volume; D013686:Telemetry / Q000295:instrumentation*; D013997:Time Factors; D014159:Transducers; D016896:Treatment Outcome; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D016277:Ventricular Function, Left; D020257:Ventricular Remodeling
keywords: Cardiac resynchronization therapy; Haemodynamic sensor; Heart failure monitoring; SonR sensor