Surgery: light – thermal – and electrical application – Light – thermal – and electrical application – Electrical therapeutic systems
Reexamination Certificate
1999-09-07
2001-07-24
Layno, Carl (Department: 3762)
Surgery: light, thermal, and electrical application
Light, thermal, and electrical application
Electrical therapeutic systems
C607S014000, C607S004000
Reexamination Certificate
active
06266563
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to methods and an implantable apparatus for treating cardiac arrhythmia, particularly ventricular fibrillation.
BACKGROUND OF THE INVENTION
One object in developing implantable defibrillation apparatus has been to lower the shock strength produced by that apparatus so that the size of the shock capacitor, and hence the size of the implantable apparatus itself, can be reduced. Several approaches to achieving this goal have been taken. U.S. Pat. No. 4,780,145 to Tacker et al. discusses the problem with single-pulse defibrillation systems in that the current density between the electrodes is not uniform throughout the ventricles. Tacker describes a sequential-pulse, multiple current pathway defibrillation method in which two defibrillation pulses are delivered along different current pathways.
U.S. Pat. No. 5,536,764 to Adams et al. and U.S. Pat. No. 5,344,430 to Berg et al. both describe implantable defibrillation systems employing two or more successive pulses, but again all pulses are defibrillation pulses. Similarly, U.S. Pat. No. 5,324,309 to Kallok describes successive defibrillation pulses that overlap in time. Adams et al. point out that, after four separate defibrillation attempts, therapy is terminated because conversion thresholds increase with time in a fibrillation episode, and that patients are likely to suffer brain damage after prolonged fibrillation. Hence, it is extremely desirable to increase the likelihood of successful defibrillation on an early attempt: a goal not always consonant with that of decreasing shock strength.
Other implantable defibrillators employ pacing, or pretreatment, pulses. U.S. Pat. No. 5,366,485 to Kroll et al. and U.S. Pat. No. 4,559,946 to Mower et al. both describe defibrillation apparatus in which pacing or pretreatment pulses are delivered through the same electrodes as the defibrillation pulse. U.S. Pat. No. 4,693,253 to Adams and U.S. Pat. No. 5,431,682 to Hedberg both describe defibrillation apparatus in which pacing pulses are delivered after defibrillation. U.S. Pat. No. 5,282,836 to Kreyenhagen et al. describes an a trial defibrillator wherein pacing pulses are delivered through a pacing electrode prior to defibrillation pulses being delivered through a separate set of defibrillation electrodes.
U.S. Pat. No. 5,489,293 to Pless et al. describes an apparatus for treating cardiac tachyarrhythmia which uses a lower voltage defibrillation apparatus by providing a rapid sequence of defibrillation shocks synchronized with sensed sequential cardiac or electrogram events or features during an arrhythmia.
U.S. Pat. No. 5,464,429 to Hedberg et al. describes an apparatus in which a stimulation pulse is delivered through an electrode that ordinarily serves as a pacing electrode, with the stimulation pulse being delivered prior to a defibrillation pulse (the latter being delivered through separate defibrillation electrodes). The stimulation pulse is of a magnitude greater than that of a pacing pulse, but less than that of a defibrillation pulse, and is said to produce a refractory area around the stimulation electrode. However, the stimulation pulse is delivered via an electrode that also serves as a pacing electrode, rather than an electrode specifically positioned in a weak field area of the defibrillation electrodes. The use of a stimulation pulse of a reverse polarity to the first phase of a biphasic defibrillation pulse is not disclosed.
U.S. Pat. No. 5,282,837 to Adams et al. (InControl, Inc.)(see also Divisional application 5,282,837) describes, in FIG.
1
and accompanying text, an atrial defibrillator and method in which a lead
36
is inserted into the coronary sinus so that a first tip electrode
42
is within the coronary sinus adjacent the left ventricle, a second ring electrode
44
is within the coronary sinus beneath the left atrium, and the third electrode
46
within the right atrium or superior vena cava. The first electrode serves as a sensing electrode, the second electrode (still in the coronary sinus) serves as both a sensing and defibrillating electrode, and the third electrode serves as a sensing and defibrillating electrode (see Col. 5 line 57 to Col. 6 line 12).
U.S. Pat. No. 5,433,729 to Adams et al. (corresponds to PCT WO92/18198) is a CIP of Adams '837. Adams '729 describes, in FIG.
9
and accompanying text, a lead system
250
configured in accordance with that described above. A first (right ventricle) lead
252
includes an elongate large surface area electrode
256
, a distal or tip sense electrode
258
, and a ring or proximal sense electrode
260
. Sense electrodes
258
,
260
are positioned in and in contact with the wall of the right ventricle, and elongate electrode
256
is in the right atrium. A second (coronary sinus) lead
254
includes a tip, or distal sense electrode
264
, a ring or proximal sense electrode
266
, and a second elongate, large surface area electrode
262
. Distal and proximal sense electrodes
264
,
266
are both adjacent the left ventricle within the great vein, and elongate electrode
262
is within the coronary sinus beneath the left atrium. The right ventricle sense electrodes
258
,
260
are coupled to inputs
50
a
,
50
b
of first sense amplifier
50
; the great vein sense electrodes
264
,
266
are coupled to inputs
52
a
,
52
b
of second sense amplifer
52
. This is to provide sensing of the right ventricle and the left ventricle, and the non-coincident sensing of the depolarization activation waves. for synchronizing delivery of energy to the atria (see column 15 line 34 to column 16 line 54; column 5 lines 62-64).
U.S. Pat. No. 5,014,696 to Mehra (Medtronic Inc.) describes an endocardial defibrillation electrode system in which a coronary sinus electrode extending from an area adjacent the opening of the coronary sinus and terminating in the great vein is used in combination with subcutaneous plate electrodes and with right ventricular electrodes. The coronary sinus electrode
78
encircles the left ventricle cavity
86
(Col. 5 lines 50-51; FIG.
5
B). It is stated “it is important not to extend the electrode
78
downward through the great vein
80
toward the apex
79
of the heart” (col. 5 lines 28-30). U.S. Pat. No. 5,165,403 to Mehra (Medtronic, Inc.) describes an atrial defibrillation electrode
112
that is located “within the coronary sinus and the great cardiac vein.”
U.S. Pat. No. 5,099,838 to Bardy (filed Dec. 15, 1988; Medtronic, Inc.) describes a defibrillation electrode in the great vein that is used in combination with subcutaneous plate electrodes and with right ventricular electrodes (col. 1 line 65 to col. 2 line 2). With respect to the great vein electrode, it is stated at column 5, lines 20-33 therein: “When so mounted, the elongate defibrillation electrode
78
extends from a point adjacent the opening of the coronary sinus
74
and into the great vein
80
. This provides a large surface area defibrillation electrode which is generally well spaced from the ventricular defibrillation electrode
74
and provides good current distribution in the area of the left ventricle
77
. It is desireable to extend the electrode
78
around the heart as far as possible. However, it is important not to extend the electrode
78
downward through the great vein
80
toward the apex
79
of the heart, as this will bring the coronary sinus and right ventricular electrodes into close proximity to one another, interfering with proper current distribution. U.S. Pat. No. 5,193,535 to Bardy (filed Aug. 27, 1991) also describes a great vein electrode. At column 7, lines 31-35, it is stated: “The coronary sinus lead is provided with an elongated electrode located in the coronary sinus and great vein region at
112
, extending around the heart until approximately the point at which the great vein turns downward toward the apex of the heart.”
U.S. Pat. No. 5,431,683 to Bowald et al. (Siemens) describes a ventricular defibrillation electrode system in which on electrode is placed through the coronary sinus
Booker, III Robert S.
Hahn Stephen J.
Ideker Raymond E.
KenKnight Bruce H.
Layno Carl
Myers Bigel & Sibley & Sajovec
UAB Research Foundation
LandOfFree
Method and apparatus for treating cardiac arrhythmia does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and apparatus for treating cardiac arrhythmia, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for treating cardiac arrhythmia will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2560464