Abstract: A cardiac rhythm management device in which an accelerometer is used to detect diaphragmatic or other skeletal muscle contraction associated with the output of a pacing pulse. Upon detection of diaphragmatic contraction, the device may be configured to automatically adjust the pacing pulse energy and/or pacing configuration.

Abstract: A cardiac pacemaker is configured to estimate the intrinsic atrial conduction time from sensed signals detected by an atrial sensing channel. Atrial conduction delays have been found to be associated with the onset of atrial tachyarrhythmias. Upon detection of an atrial conduction time above a specified limit value, the pacemaker is programmed to switch from a normal pacing mode to an atrial pacing preference mode.

Abstract: An apparatus and method for assessing the status of well-being of patients being treated for CHF using cardiac pacing as a therapy. By sampling the output from an activity sensor or the like, and by noting the frequency with which the averaged rectified sensor output exceeds a preset threshold following changes in the pacing mode, the efficacy of the new mode compared to the previous one can be evaluated.

Abstract: Based upon patient studies indices a high degree of correlation was found between HRV and VO2max, i.e., the patient's exercise capacity. Based on this finding, a pacing therapy optimization protocol for treating patients with CHF has been devised. The protocol involves first pacing the patient's heart with a pacemaker programmed to operate in a first mode for a predetermined time period and then collecting electrogram data from which a HRV index is derived. The mode is then changed and the steps repeated until all possible modes have been utilized. At that time, a determination is made as to which of the modes is associated with the largest HRV index and the pacemaker is then programmed to function in that mode. Alternatively, the method of the present invention can be applied to changes in drug therapy instead of or in combination with pacing therapy. By the plotting the HRV index computed in the manner described, the efficacy of a change in therapy on patient exercise capacity can be assessed.

Abstract: A cardiac rhythm management system detects edema. In response to an episode of detected edema, it initiates or adjusts a cardiac resynchronization therapy and/or a cardiac contractility modulation (CCM) therapy.

Abstract: A method and apparatus for treating or preventing neurocardiogenic syncope is disclosed. Upon detection of bradycardia or a drop in blood pressure indicating the onset of syncope, electrostimulation pulses are delivered during the heart's refractory period. The pulses are non-excitatory but increase myocardial contractility and thereby increase cardiac output.

Abstract: A method and system for operating a cardiac pacemaker which employs pacing therapy to regularize the ventricular rhythm together with biventricular sensing. Biventricular sensing allows the ventricular rate regularization to be accomplished with greater hemodynamic stability.

Abstract: A cardiac rhythm management system selects one of multiple electrodes associated with a particular heart chamber based on a relative timing between detection of a depolarization fiducial point at the multiple electrodes, or based on a delay between detection of a depolarization fiducial point at the multiple electrodes and detection of a reference depolarization fiducial point at another electrode associated with the same or a different heart chamber. Subsequent contraction-evoking stimulation therapy is delivered from the selected electrode.

Abstract: A method and device for preventing plaque build-up in a coronary artery includes providing an electrical field generating device, and generating an electrical field in the coronary artery to prevent plaque build-up in the coronary artery. The method further includes sensing the heart rhythm and generating the electrical field after a depolarization wave in the heart. The electrical field is generated by circuitry, in one embodiment implanted circuitry, connected to leads which are epicardially or intracardially positioned on the heart.

Abstract: An apparatus and method for reversing ventricular remodeling with electro-stimulatory therapy. A ventricle is paced by delivering one or more stimulatory pulses in a manner such that a stressed region of the myocardium is pre-excited relative to other regions in order to subject the stressed region to a lessened preload and afterload during systole. The unloading of the stressed myocardium over time effects reversal of undesirable ventricular remodeling.

Abstract: A method of accurately determining if ectopic beats are occurring in the heart by detecting the time interval, T, between a point Q* defined is the onset of the QRS complex and the peak value of R (T=Q*R) during a heart beat cycle and comparing that time with a running mean value calculated from normal heartbeats. A beat is identified as an ectopic beat if the Q*R time interval for a current beat is at least four standard deviations from the mean Q*R time interval of normal preceding beats. The electrodes for detecting the ectopic beats may be inside the patient's heart or on the patient's skin. If more than one electrode is used for monitoring the depolarization of the heart, then by combining the Q*R intervals (e.g. using a triangulation method) calculated from different electrodes, the location of the ectopic excitation can be determined and identified.

Abstract: A cardiac rhythm management system that provides an indication of patient well-being based on the autonomic balance between the sympathetic and parasympathetic/vagal components of the autonomic nervous system, using time-domain processing of frequency components of a heart rate interval signal.

Abstract: A device and method in which spectral analysis of heart rate variability is performed in order to assess autonomic balance. When a threshold level is reached, a diagnostic mode is triggered in which the device performs computationally intensive data analysis to assess the probability of a pathological event such as an arrhythmia occurring.

Abstract: A system and method for measuring the capture threshold of a bipolar lead in order to determine an appropriate value for the stimulus pulse energy to be used with the lead by a cardiac rhythm management device. An appropriate bipolar stimulating configuration can also be determined. The method is particularly useful in testing bipolar leads used to excite the left ventricle such as when delivering cardiac resynchronization therapy.

Abstract: A cardiac rhythm management system for coordination therapy includes a pulse generator to generate pacing and discharging of recharge pulses. A pulse delivery controller coupled to the pulse generator, times the delivery of the pacing and discharging of recharge pulses in a desired sequence. A therapy circuit coupled to the pulse delivery controller, receives the timed pulses from the pulse delivery controller and delivers the timed pulses to one or more electrodes disposed in or around a heart to communicate the timed pacing and discharging of recharge pulses to different sites of a heart, to avoid any interactions resulting from the electric fields surrounding the electrodes during a multiple site pacing required by the coordination therapy.

Abstract: A method and system for operating a cardiac pacemaker which employs pacing therapy to regularize the ventricular rhythm together with biventricular sensing. Biventricular sensing allows the ventricular rate regularization to be accomplished with greater hemodynamic stability.

Abstract: A method and apparatus for selection of one or more ventricular chambers to stimulate for ventricular resynchronization therapy. Intrinsic intracardia electrograms that include QRS complexes, are recorded from a left and right ventricle. A timing relationship between the intrinsic intracardia electrograms recorded from the left and right ventricle is then determined. In one embodiment, the timing relationship is determined using a delay between a left ventricular and a right ventricular sensed intrinsic ventricular depolarizations and a duration interval of one or more QRS complexes. In one embodiment, the duration of QRS complexes is determined from either intracardiac electrograms or from surface ECG recordings. One or more ventricular chambers in which to provide pacing pulses are then selected based on the timing relationship between intrinsic intracardia electrograms recorded from the right and left ventricle, and the duration of one or more QRS complexes.

Abstract: A cardiac rhythm management system for coordination therapy includes a pulse generator to generate pacing and discharging of recharge pulses. A pulse delivery controller coupled to the pulse generator, times the delivery of the pacing and discharging of recharge pulses in a desired sequence. A therapy circuit coupled to the pulse delivery controller, receives the timed pulses from the pulse delivery controller and delivers the timed pulses to one or more electrodes disposed in or around a heart to communicate the timed pacing and discharging of recharge pulses to different sites of a heart, to avoid any interactions resulting from the electric fields surrounding the electrodes during a multiple site pacing required by the coordination therapy.

Abstract: Based upon patient studies indices a high degree of correlation was found between HRV and VO2max, i.e., the patient's exercise capacity. Based on this finding, a pacing therapy optimization protocol for treating patients with CHF has been devised. The protocol involves first pacing the patient's heart with a pacemaker programmed to operate in a first mode for a predetermined time period and then collecting electrogram data from which a HRV index is derived. The mode is then changed and the steps repeated until all possible modes have been utilized. At that time, a determination is made as to which of the modes is associated with the largest HRV index and the pacemaker is then programmed to function in that mode. Alternatively, the method of the present invention can be applied to changes in drug therapy instead of or in combination with pacing therapy. By the plotting the HRV index computed in the manner described, the efficacy of a change in therapy on patient exercise capacity can be assessed.

Abstract: Based upon patient studies indices a high degree of correlation was found between HRV and VO2max, i.e., the patient's exercise capacity. Based on this finding, a pacing therapy optimization protocol for treating patients with CHF has been devised. The protocol involves first pacing the patient's heart with a pacemaker programmed to operate in a first mode for a predetermined time period and then collecting electrogram data from which a HRV index is derived. The mode is then changed and the steps repeated until all possible modes have been utilized. At that time, a determination is made as to which of the modes is associated with the largest HRV index and the pacemaker is then programmed to function in that mode. Alternatively, the method of the present invention can be applied to changes in drug therapy instead of or in combination with pacing therapy. By the plotting the HRV index computed in the manner described, the efficacy of a change in therapy on patient exercise capacity can be assessed.