title: Endocardial acceleration (sonR) vs. ultrasound-derived time intervals in recipients of cardiac resynchronization therapy systems.
abstract: OBJECTIVE
  Optimization of cardiac resynchronization therapy (CRT) requires the gathering of cardiac functional information. An accurate timing of the phases of the cardiac cycle is key in the optimization process.
  
  
  RESULTS
  We compared Doppler echocardiography to an automated system, based on the recording of sonR (formerly endocardial acceleration), in the detection of mitral and aortic valves closures and measurements of the duration of systole and diastole. We prospectively studied, under various conditions of cardiac stimulation, 75 recipients of CRT systems (69% men), whose mean age was 72 ± 9.2 years, left ventricular ejection fraction 35 ± 11%, baseline QRS duration 154 ± 29 ms, and New York Heart Association functional class 3.0 ± 0.7. We simultaneously recorded (i) sonR, detected by a non-invasive piezoelectric micro-accelerometer sensor clipped onto an electrode located in the parasternal region, (b) electrocardiogram, and (c) Doppler audio signals, using a multichannel data acquisition and analysis system. The correlation between timing of mitral and aortic valve closure by sonR vs. Doppler signals was examined by linear regression analysis. Correlation coefficients and the average absolute error were calculated. A concordance in the timing of the mitral (r = 0.86, error = 9.7 ms) and aortic (r = 0.93, error = 9.7 ms) valves closure was observed between the two methods in 94% of patients. Similarly, sonR and the Doppler-derived measurements of systolic (r = 0.85, error = 13.4 ms) and diastolic (r = 0.99, error = 12 ms) interval durations were concordant in 80% of patients.
  
  
  CONCLUSIONS
  A high concordance was found between sonR and the cardiac ultrasound in the timings of aortic and mitral valve closures and in the estimation of systolic and diastolic intervals durations. These observations suggest that sonR could be used to monitor cardiac function and adaptively optimize CRT systems.
authors.affiliation: Cardiology Department, CHU Rennes, Rennes, France. erwan.donal@chu-rennes.fr
authors.forename: Erwan
authors.initials: E
authors.lastname: Donal
authors.forename: Lionel
authors.initials: L
authors.lastname: Giorgis
authors.forename: Serge
authors.initials: S
authors.lastname: Cazeau
authors.forename: Christophe
authors.initials: C
authors.lastname: Leclercq
authors.forename: Lotfi
authors.initials: L
authors.lastname: Senhadji
authors.forename: Amel
authors.initials: A
authors.lastname: Amblard
authors.forename: Gael
authors.initials: G
authors.lastname: Jauvert
authors.forename: Marc
authors.initials: M
authors.lastname: Burban
authors.forename: Alfredo
authors.initials: A
authors.lastname: Hernández
authors.forename: Philippe
authors.initials: P
authors.lastname: Mabo
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001021:Aortic Valve / Q000000981:diagnostic imaging / Q000502:physiology; D058409:Cardiac Resynchronization Therapy Devices; D003971:Diastole / Q000502:physiology; D015150:Echocardiography, Doppler; D005260:Female; D006321:Heart / Q000502:physiology*; D006333:Heart Failure / Q000503:physiopathology* / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000000981:diagnostic imaging / Q000502:physiology; D011446:Prospective Studies; D013018:Sound Spectrography; D013318:Stroke Volume / Q000502:physiology; D013599:Systole / Q000502:physiology; D013997:Time Factors