title: A novel system for continuous, real-time monitoring of heart motion signals.
abstract: BACKGROUND
  Understanding cardiac mechanics is important for developing cardiac therapies. Current modalities for assessing cardiac mechanics sample patient's heart at specific heart rate, contractility, preload, and afterload. The objective of this study was to test the feasibility of a novel system composed of intra-cardiac leads equipped with an inertial module chip (3D accelerometers and 3D gyroscopes) in monitoring continuous heart motion.
  
  
  METHODS
  In this descriptive study, four healthy pigs were anesthetized and instrumented with motion-sensitive intra-cardiac leads; the temporal correlation between signals from motion sensors and tissue Doppler from the chest wall were studied; changes in real-time heart accelerations (ACC) and angular velocity (ANGV) were reported as percentages of change from baseline.
  
  
  RESULTS
  Heart motion signals were sensed continuously from the right ventricular apex (RVa) and coronary sinus (CS). Volume expansion did not produce significant changes in the ACC and ANGV signals. Increasing heart rate increased the peak systolic ACC signal recorded from RVa and CS by 94 and 76%, respectively, and increased both peak systolic (61% RVa and 27% CS) and diastolic ANGV (200% CS vs. 31% RVa). Epinephrine administration increased peak systolic ACC signals at both sites (246% RVa; 331% CS). Peak systolic and diastolic ANGV increased in response to epinephrine (systolic: 198% RVa and 175% CS; diastolic: 723% CS and 89% RVa) (p = 0.125 for all changes expressed in percent). Temporal correlation between the ANGV signal and tissue Doppler signal was detected throughout all interventions.
  
  
  CONCLUSIONS
  A novel system for continuously monitoring heart motion signals from within the heart was presented. Heart motion signals in response to physiologic manipulations were characterized.
authors.affiliation: Department of Internal Medicine E, HaEmek Medical Center, Rabin Blvd, 18101, Afula, Israel. guydo@clalit.org.il.|Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel. guydo@clalit.org.il.|DHS Medical Ltd., Nazareth Industrial Area, POB 1252, 17111, Nazareth Elit, Israel. guydo@clalit.org.il.
authors.forename: Guy
authors.initials: G
authors.lastname: Dori
authors.affiliation: Department of Cardiovascular Medicine, Lady Davis Carmel Medical Center, Haifa, Israel.|DHS Medical Ltd., Nazareth Industrial Area, POB 1252, 17111, Nazareth Elit, Israel.
authors.forename: Jorge E
authors.initials: JE
authors.lastname: Schliamser
authors.affiliation: Faculty of Biomedical Engineering, Technion-Israel Institute of Technology, Haifa, Israel.|DHS Medical Ltd., Nazareth Industrial Area, POB 1252, 17111, Nazareth Elit, Israel.
authors.forename: Oscar
authors.initials: O
authors.lastname: Lichtenstein
authors.affiliation: DHS Medical Ltd., Nazareth Industrial Area, POB 1252, 17111, Nazareth Elit, Israel.
authors.forename: Ilia
authors.initials: I
authors.lastname: Anshelevich
authors.affiliation: Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel.|Department of Cardiovascular Medicine, Lady Davis Carmel Medical Center, Haifa, Israel.
authors.forename: Moshe Y
authors.initials: MY
authors.lastname: Flugelman
mesh_terms: D000818:Animals; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006352:Heart Ventricles / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008991:Monitoring, Physiologic / Q000295:instrumentation*; D009038:Motion; D013552:Swine
keywords: Cardiac motion; Cardiac rotation; Cardiac twist; Resynchronization therapy