摘要:
An implantable anti-tachyarrhythmia device which delivers atrial cardioversion or defibrillation pulses heart in response to detection of atrial tachyarrhythmias. The pulses are synchronized to atrial and ventricular events in such a fashion as to assure they occur outside of the vulnerable periods associated with both chambers. The device is provided with a pulse synchronizer which defines a first synchronization interval initiated following a sensed atrial event and a second synchronization interval initiated responsive to a sensed ventricular event and a pulse triggerer which triggers delivery of a cardioversion or defibrillation pulse responsive to the first and second synchronization intervals simultaneously being underway. In particular, the pulse triggerer may be responsive to initiation of the first synchronization interval during the second synchronization interval. In addition, the synchronizer may also define minimum time intervals following ventricular events and the triggerer may additionally be responsive to expiration of a defined minimum time interval following a ventricular event preceding the sensed ventricular event which initiated the second synchronization interval currently underway.
摘要:
In an implantable pacemaker/cardioverter/defibrillator, a system for correlating the delivery of a cardioversion therapy to an optimum point or phase of the respiratory cycle of the patient to effect delivery of the therapy when the impedance between the cardioversion electrodes is minimized. In a first application for use with cardioversion electrodes located substantially in contact with the heart chamber, the optimum point or phase is at the end of inspiration. In a second application for use with at least one cardioversion electrode located remotely from the heart chamber, the optimum point or phase is at end expiration or beginning of inspiration. The cardioversion therapy is delivered in synchrony with a ventricular sense event, if present. If the optimum point or phase of the respiratory cycle cannot be determined during a therapy time, a pre-shock may be delivered to elicit a respiration cycle through a stimulated contraction of the diaphragm.
摘要:
A method an apparatus for treating fibrillation, particularly atrial fibrillation. In response to detection of fibrillation, a high frequency, low energy pulse burst is delivered via pacing electrodes, accompanied by a high energy pulse delivered via defibrillation electrodes. The low energy pulse burst is preferably delivered to an area of the heart which exhibits relatively lower current density during delivery of the high energy pulse.
摘要:
A method and apparatus for treating fibrillation, particularly atrial fibrillation. In response to detection of fibrillation, a series of low energy pulse bursts is delivered, separated by defined inter-burst intervals, and including bursts unsynchronized to heart depolarizations. Detection of termination of fibrillation during inter-burst intervals results in cancellation of further pulse bursts to prevent reinduction of fibrillation.
摘要:
An implantable anti-tachyarrhythmia device which delivers atrial cardioversion or defibrillation pulses heart in response to detection of atrial tachyarrhythmias. The pulses are synchronized to atrial and ventricular events in such a fashion as to assure they occur outside of the vulnerable periods associated with both chambers.
摘要:
A cardiac pacemaker and a method of its use. The pacemaker paces a patient's heart in a tachyarrhythmia prevention pacing mode for an extended time period, defines a metric of success of the tachyarrhythmia prevention pacing mode, monitors the metric over the extended time period and, responsive to the monitored metric, adjusts the tachyarrhythmia prevention pacing mode. Adjustment of the tachyarrhythmia prevention pacing mode may take the form of pacing the patient's heart with a different set of electrodes, pacing the patient's heart with a different tachyarrhythmia prevention pacing mode and/or terminating operation of the tachyarrhythmia prevention pacing mode.
摘要:
A method and apparatus for treating atrial tachyarrhythmias, particularly atrial fibrillation. High energy pulses are delivered between electrodes located in the right atrium/SVC, the right ventricle and the coronary sinus/great vein, with the right ventricular and coronary sinus/great vein electrodes connected in common. Optionally a subcutaneous electrode, preferably located in the left pectoral area may also be employed, coupled in common to the right atrial/SVC electrode.
摘要:
In an implantable pacemaker.backslash.cardioverter.backslash.defibrillator, a system for correlating the delivery of an atrial cardioversion therapy to an optimum blood pressure to effect delivery of the therapy when the volume of the atrium is minimized. In a first embodiment, the blood pressure in the atrium or ventricle is monitored and delivery is timed to a low blood pressure occurring as blood is emptying from the atrium. In a variation ventricular pacing may be provided to ensure that the ventricles are contracting forcefully and at a rate which optimizes atrial emptying. In a second embodiment, the delivery of the cardioversion therapy is also timed to an optimum point or phase of the respiratory cycle. The optimum point or phase of the respiration cycle depends in part on the chamber to be cardioverted and the location of the cardioversion electrodes with respect to the chamber.
摘要:
A system includes a data retrieval module and a determination module. The data retrieval module receives a command from a user, the command indicating a first implantable medical device (IMD) and a second IMD. The data retrieval module also retrieves a first set of data from the first IMD in response to the command and retrieves a second set of data from a datastore. The second set of data includes data retrieved from the first IMD and stored in the datastore prior to receiving the command. The determination module determines a third set of data based on the first and second sets of data and transfers the third set of data to the second IMD.
摘要:
Methods and devices for determining optimal Atrial to Ventricular (AV) pacing intervals and Ventricular to Ventricular (VV) delay intervals in order to optimize cardiac output. Impedance, preferably sub-threshold impedance, is measured across the heart at selected cardiac cycle times as a measure of chamber expansion or contraction. One embodiment measures impedance over a long AV interval to obtain the minimum impedance, indicative of maximum ventricular expansion, in order to set the AV interval. Another embodiment measures impedance change over a cycle and varies the AV pace interval in a binary search to converge on the AV interval causing maximum impedance change indicative of maximum ventricular output. Another method varies the right ventricle to left ventricle (VV) interval to converge on an impedance maximum indicative of minimum cardiac volume at end systole. Another embodiment varies the VV interval to maximize impedance change.