Abstract: A phase analysis technique provides for quantification of regional wall motion asynchrony from endocardial border contours generated from two-dimensional echocardiographic ventricular images. The technique produces results including a degree of radial ventricular asynchrony in heart failure patients with ventricular conduction delay to predict a magnitude of contractile function improvement with pacing therapy. Quantification of change in ventricular regional wall motion asynchrony in response to a therapy provides for a means to identify candidates to receive the therapy and quantitatively predict the benefit of the therapy. Quantification of changes in ventricular regional wall motion asynchrony in response to a sequence of therapies provides for a means to determine an approximately optimal therapy for an intended patient response.

Abstract: A phase analysis technique provides for quantification of regional wall motion asynchrony from endocardial border contours generated from two-dimensional echocardiographic ventricular images. The technique produces results including a degree of radial ventricular asynchrony in heart failure patients with ventricular conduction delay to predict a magnitude of contractile function improvement with pacing therapy. Quantification of change in ventricular regional wall motion asynchrony in response to a therapy provides for a means to identify candidates to receive the therapy and quantitatively predict the benefit of the therapy. Quantification of changes in ventricular regional wall motion asynchrony in response to a sequence of therapies provides for a means to determine an approximately optimal therapy for an intended patient response.

Abstract: A phase analysis technique provides for quantification of regional wall motion asynchrony from endocardial border contours generated from two-dimensional echocardiographic ventricular images. The technique produces results including a degree of radial ventricular asynchrony in heart failure patients with ventricular conduction delay to predict a magnitude of contractile function improvement with pacing therapy. Quantification of change in ventricular regional wall motion asynchrony in response to a therapy provides for a means to identify candidates to receive the therapy and quantitatively predict the benefit of the therapy. Quantification of changes in ventricular regional wall motion asynchrony in response to a sequence of therapies provides for a means to determine an approximately optimal therapy for an intended patient response.

Abstract: An intracardiac impedance-derived parameter, Half Cycle Activity (HCA) is used in sensing and controlling cardiac activities in implantable cardiac devices such as bradycardia pacemakers and cardioverter defibrillators. This impedance-derived parameter correlates closely with physical workload and at the same time provides hemodynamic feedback information. Thus, it allows a pacemaker system to implement accurately an increase in hemodynamically driven pacing rate, as well as to limit an inappropriate decrease of driven pacing rate advised by another sensor such as an accelerometer. In addition, it determines the maximum pacing rate for the pacemaker so as to prevent hemodynamic compromise. Therefore, the HCA parameter may be used to determine a Hemodynamic Upper Rate Limit and a Hemodynamic Lower Rate Limit, and thus define a Hemodynamic Pacing Range that is compatible with the range of physiological rate. This allows a closed-loop control of the pacing rate.

Abstract: A phase analysis technique provides for quantification of regional wall motion asynchrony from endocardial border contours generated from two-dimensional echocardiographic ventricular images. The technique produces results including a degree of radial ventricular asynchrony in heart failure patients with ventricular conduction delay to predict a magnitude of contractile function improvement with pacing therapy. Quantification of change in ventricular regional wall motion asynchrony in response to a therapy provides for a means to identify candidates to receive the therapy and quantitatively predict the benefit of the therapy. Quantification of changes in ventricular regional wall motion asynchrony in response to a sequence of therapies provides for a means to determine an approximately optimal therapy for an intended patient response.

Abstract: A phase analysis technique provides for quantification of regional wall motion asynchrony from endocardial border contours generated from two-dimensional echocardiographic ventricular images. The technique produces results including a degree of radial ventricular asynchrony in heart failure patients with ventricular conduction delay to predict a magnitude of contractile function improvement with pacing therapy. Quantification of change in ventricular regional wall motion asynchrony in response to a therapy provides for a means to identify candidates to receive the therapy and quantitatively predict the benefit of the therapy. Quantification of changes in ventricular regional wall motion asynchrony in response to a sequence of therapies provides for a means to determine an approximately optimal therapy for an intended patient response.

Abstract: A phase analysis technique provides for quantification of regional wall motion asynchrony from endocardial border contours generated from two-dimensional echocardiographic ventricular images. The technique produces results including a degree of radial ventricular asynchrony in heart failure patients with ventricular conduction delay to predict a magnitude of contractile function improvement with pacing therapy. Quantification of change in ventricular regional wall motion asynchrony in response to a therapy provides for a means to identify candidates to receive the therapy and quantitatively predict the benefit of the therapy. Quantification of changes in ventricular regional wall motion asynchrony in response to a sequence of therapies provides for a means to determine an approximately optimal therapy for an intended patient response.

Abstract: An intracardiac impedance-derived parameter, Half Cycle Activity (HCA) is used in sensing and controlling cardiac activities in implantable cardiac devices such as bradycardia pacemakers and cardioverter defibrillators. This impedance-derived parameter correlates closely with physical workload and at the same time provides hemodynamic feedback information. Thus, it allows a pacemaker system to implement accurately an increase in hemodynamically driven pacing rate, as well as to limit an inappropriate decrease of driven pacing rate advised by another sensor such as an accelerometer. In addition, it determines the maximum pacing rate for the pacemaker so as to prevent hemodynamic compromise. Therefore, the HCA parameter may be used to determine a Hemodynamic Upper Rate Limit and a Hemodynamic Lower Rate Limit, and thus define a Hemodynamic Pacing Range that is compatible with the range of physiological rate. This allows a closed-loop control of the pacing rate.

Abstract: An intracardiac impedance-derived parameter, Half Cycle Activity (HCA) is used in sensing and controlling cardiac activities in implantable cardiac devices such as bradycardia pacemakers and cardioverter defibrillators. This impedance-derived parameter correlates closely with physical workload and at the same time provides hemodynamic feedback information. Thus, it allows a pacemaker system to implement accurately an increase in hemodynamically driven pacing rate, as well as to limit an inappropriate decrease of driven pacing rate advised by another sensor such as an accelerometer. In addition, it determines the maximum pacing rate for the pacemaker so as to prevent hemodynamic compromise. Therefore, the HCA parameter may be used to determine a Hemodynamic Upper Rate Limit and a Hemodynamic Lower Rate Limit, and thus define a Hemodynamic Pacing Range that is compatible with the range of physiological rate. This allows a closed-loop control of the pacing rate.