Medtronic, Inc.

Michael R Hill

Rahul Mehra

Luc Roland Mongeon

Xiaoyi Min

David K Peterson

Paul J DeGroot

Ren Zhou

Eduardo N Warman

Li Ping Wang

Walter H Olson

Michael F Hess

Kenneth M Anderson

Kenneth R Jonkman

Thomas L Jirak

John T Meador

Kathleen A Prieve

R Hardwin Mead

Mehra Rahul

An endocardial pacing and/or cardioversion/defibrillation lead having a plurality of electrodes and a mechanism for adjusting the exposed surface area of one or more electrode and/or the position and/or angular orientation of an electrode along a lead body. A fixed exposed, flexible, elongated commutator surface is provided extending along the lead body intermediate the proximal and distal lead body ends coupled by an electrical lead conductor extending to the proximal end of the lead body. A movable electrode assembly is provided that fits over and slides along the lead body, including the fixed commutator surface, that supports an exposed movable electrode on it. The movable electrode assembly includes at least one flexible, elongated, movable commutator surface within it that is electrically connected with the movable electrode. Electrical contact is established between the movable electrode and the lead connector end through contact of the fixed and movable commutator surfaces in a contact segment of contact area that varies with the relative movement of the movable contact surface with respect to the fixed contact surface. The position and exposed surface area of the movable electrode may be adjusted even further by use of a further electrode adjustable area outer insulating sheath positioned over the movable electrode assembly.

Mechanism for adjusting the exposed surface area and position of an

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.

Apparatus for treating atrial tachyarrhythmias with synchronized shocks

An electro-stimulation device includes a pair of electrodes for connection to at least one location in the body that affects or regulates the heartbeat. The electro-stimulation device both electrically arrests the heartbeat and stimulates the heartbeat. A pair of electrodes are provided for connection to at least one location in the body that affects or regulates the heartbeat. The pair of electrodes may be connected to an intravenous catheter for transvenous stimulation of the appropriate nerve. A first switch is connected between a power supply and the electrodes for selectively supplying current from the power supply to the electrodes to augment any natural stimuli to the heart and thereby stop the heart from beating. A second switch is connected between the power supply and the electrodes for selectively supplying current from the power supply to the electrodes to provide an artificial stimulus to initiate heartbeating. In another aspect, the invention is directed to a method for arresting the beat of a heart in a living body comprising the steps of connecting the pair of electrodes to at least one location in the body that affects or regulates the heartbeat and supplying an electrical current to the electrodes of sufficient amplitude and duration to arrest the heartbeat. The device may also serve to still the lungs by input to a respirator or by stimulation of the phrenic nerve during surgical procedures.

Method and device for electronically controlling the beating of a heart

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.

Cardioversion energy reduction system

A pacemaker provided with a mode switching feature adapted to stabilize ventricular heart rate during atrial fibrillation. In a preferred embodiment of the invention, the device nominally operates in an atrial synchronized pacing mode such as DDD, DDDR, VDD or VDDR. In response to detection of atrial rhythm characteristics consistent with atrial fibrillation, the device switches into a non-atrial synchronized, ventricular rate stabilization pacing mode with the base ventricular pacing rate modulated on a beat by beat basis based upon preceding intrinsic or paced ventricular heartbeat intervals to adjust the pacing interval towards a desired preset rate stabilization target pacing interval which is typically less than the programmed base pacing interval of the device. While the ventricular rate stabilization mode is in effect, the current pacing interval is set equal to the preceding intrinsic or paced interval, with an increment if the preceding interval is less than the desired or target pacing interval, as typically will be the case, or with a decrement if the preceding interval is greater than the desired pacing interval. In a preferred embodiment of the invention, the device paces both the atria and ventricles in a DDI rate stabilization pacing mode with the ventricular pacing interval being modulated.

Method and apparatus for diagnosis and treatment of arrhythmias

An implantable pacemaker employing an arrhythmia prevention pacing modality particularly optimized for inclusion in dual chamber pacemakers and anti-arrhythmia devices which include dual chamber pacemakers. When the pacing mode is in effect, the device alters timing of scheduled atrial and/or ventricular pacing pulses in response to depolarizations sensed during the refractory periods and to ventricular depolarizations sensed outside of the pacemaker's A-V escape intervals. The arrhythmia prevention pacing mode is activated and deactivated in conjunction with the operation of arrhythmia detection features which may also be employed by the device to trigger delivery of anti-arrhythmia therapies.

Apparatus for diagnosis and treatment of arrhythmias

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.

A cardiac pacemaker with a rate stabilization pacing mode. The pacemaker varies the increment following a cycle ending in a sensed depolarization as a function of the underlying heart rate and may additionally vary the increment as a function of the prematurity of the most recently sensed depolarization relative to the preceding depolarization. A greater increment is generally provided if the underlying cycle length is greater, while the increment may be lessened following relatively more premature depolarizations. Prematurity may be determined by comparing the cycle (CLnew) ending in the most recently sensed depolarization with the previous cycle length (CLold), for example by calculating CLnew/CLold or CLold-CLnew. The mechanism for determining the duration of the increment provides for a more rapid return to a lower underlying heart rate, while still avoiding the short-long interval pattern sometimes associated with the onset of tachycardia.

Rate stabilization pacemaker

New pacing algorithm defines faster than indicated pacing rate during detection of PAC's/PVC's and reduces rate after awhile to a safety rate unless natural depolarizations are detected.

Arrhythmia and fibrillation prevention pacemaker using ratchet up and

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.

Defibrillation threshold reduction system

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.

Method and apparatus for treatment of atrial fibrillation

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.

Atrial defibrillator and method of use

A device for controlling the duration of A-V conduction intervals ia a patient's heart. Stimulation of the AV nodal fat pad is employed to maintain the durations of the A-V conduction intervals within a desired interval range, which may vary as a function of sensed heart rate or other physiologic parameter. AV nodal fat pad stimulation may also be triggered in response to defined heart rhythms such as a rapid rate or the occurrence of PVC's, to terminate or prevent induction of arrhythmias.

Method and apparatus for control of A-V interval

A device for controlling the duration of A-V conduction intervals in a patient's heart. Stimulation of the AV nodal fat pad is employed to maintain the durations of the A-V conduction intervals within a desired interval range, which may vary as a function of sensed heart rate or other physiologic parameter. AV nodal fat pad stimulation may also be triggered in response to defined heart rhythms such as a rapid rate or the occurrence of PVC's, to terminate or prevent induction of arrhythmias.

A method and apparatus for pacing the atrium to reduce the incidence of dangerous arrhythmias. Electrodes are located at least two locations within the atrium, preferably in the triangle of Koch and/or an area of prolonged effective refractory period elsewhere within the atrium. Additional or alternative electrode locations may also be employed. The apparatus defines a variable interval following atrial depolarizations, based on the detected rate of the depolarizations. In response to a sensed depolarization at one of the locations, outside the variable interval, pacing pulses are delivered at least to the electrodes located at the other locations. Demand atrial pacing using some or all electrodes is also provided.

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Minneapolis, MN, United States of America

Michael R Hill