Connect public, paid and private patent data with Google Patents Public Datasets

Atrial defibrillator and method for providing synchronized delayed cardioversion

Info

Publication number
CA2107147C
CA2107147C CA 2107147 CA2107147A CA2107147C CA 2107147 C CA2107147 C CA 2107147C CA 2107147 CA2107147 CA 2107147 CA 2107147 A CA2107147 A CA 2107147A CA 2107147 C CA2107147 C CA 2107147C
Authority
CA
Grant status
Grant
Patent type
Prior art keywords
heart
atrial
th
atria
ventricular
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
CA 2107147
Other languages
French (fr)
Other versions
CA2107147A1 (en )
Inventor
John M. Adams
Clifton A. Alferness
Kenneth Ross Infinger
Yixuan Jin
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Cardiac Pacemakers Inc
Original Assignee
InControl Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Grant date
Family has litigation

Links

Classifications

    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61NELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
    • A61N1/00Electrotherapy; Circuits therefor
    • A61N1/18Applying electric currents by contact electrodes
    • A61N1/32Applying electric currents by contact electrodes alternating or intermittent currents
    • A61N1/38Applying electric currents by contact electrodes alternating or intermittent currents for producing shock effects
    • A61N1/39Heart defibrillators
    • A61N1/3956Implantable devices for applying electric shocks to the heart, e.g. for cardioversion
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61NELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
    • A61N1/00Electrotherapy; Circuits therefor
    • A61N1/18Applying electric currents by contact electrodes
    • A61N1/32Applying electric currents by contact electrodes alternating or intermittent currents
    • A61N1/38Applying electric currents by contact electrodes alternating or intermittent currents for producing shock effects
    • A61N1/39Heart defibrillators
    • A61N1/395Heart defibrillators for treating atrial fibrillation
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61NELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
    • A61N1/00Electrotherapy; Circuits therefor
    • A61N1/18Applying electric currents by contact electrodes
    • A61N1/32Applying electric currents by contact electrodes alternating or intermittent currents
    • A61N1/38Applying electric currents by contact electrodes alternating or intermittent currents for producing shock effects
    • A61N1/39Heart defibrillators
    • A61N1/3987Heart defibrillators characterised by the timing or triggering of the shock

Abstract

An implantable atrial defibrillator provides cardioverting electrical energy to the atria of a human heart in need of cardioversion. The atrial defibrillator includes a first detector for detecting ventricular activations of the heart, a second detector for detecting atrial activity of the heart, and an atrial fibrillation detector responsive to the second detector for determining when the atria of the heart are in need of cardioversion. The atrial defibrillator further includes a cardioverter for applying the cardioverting electrical energy to the atria of the heart when the atria of the heart are in need of cardioversion, and a timer delay stage responsive to the first detector for causing the cardioverter to apply the cardioverting electrical energy to the atria of the heart a predetermined delay time after the first detector detects one of the ventricular activations and before the T wave of the heart immediately following the one of the ventricular activations.

Description

2~71 ~7 PATENT
~4407-120 ~p~AT-9~0~ L~ FOR P~uv 8r~Rn D~T-~YRn CA~DIO~8ION
8~ ~v O~ ~8 ~ ON
The present invention generally relates to an atrial defibrillator and method for applying cardioverting electrical energy to the atria of a human heart in need of cardioversion. The present invention is more particularly directed to a fully automatic implantable atrial defibrillator which exhibits i~vv~d safety by reducing the potential risk of in~ e~
ventricular fibrillation which may result fro~ the mistimed deli~ery of cardioverting electrical energy to the atria. More spPcifically, the atrial defibrillator and method of th~ prQsent invention guards ~ga ~ ~ct applying cardioverting electrical energy to the atria under conditions believed to contribute to. 1~ ,o~
ventricle fibrillation.
Atrial fibrillation is~probably the mo~t co~on cardiac arrhythmia. Although it is ~ot usually a li~8 threatening arrhythmia, it i~ a~sociated with ~trokes thought to be caused by blood clots forming in ar~a~ o~ :
stagnant bloo~ flow a3 a result of prolonged atrial fibrillation. In add~tion, pati~nts a~flictQd with atrial fibrillation gonerally exp~rience palpitation~ of ., .

:

:

7 1 ~ 7 the heart and may even experience dizzines~ or even 1088 of consciousnes~.
Atrial fibrillation occurs su~enly and ~an~ -times can only b~ corrected by a discharge of electricial energy to the heart through the skin of the patiQnt by way of an external defibrillator o~ the type ~ell known in the art. This treatmsnt i~ c~ ~nly referred to a~
synchronized cardiovQrsion and, as its na~a impli~s~
involves applying electrical defibrillating ener~y to tha heart in syn~hronism with a d~tected ventricular electrical activia~ion (R wave) of the heart. The tr~atment is very painful and, unfortunately, most o~ten only results i~ temporary relie~ ~or patients, lastlng but a f ew weeks.
Drugs are available for reducing the ~na~
of atrial fibrillation. ~ v~r, these drugs hav~ ~any side effect~ and many patient~ are re~i~te~t to th2m which greatly re~u~s their therapeutic e~fect.
Implantable atrial defibrillators hav~ b~n proposed to provide patientC suffering from o~ l.c~
o~ atrial fibrillation with relief. Unfortunately, to the detriment of such patients, none of thes atrial de~ibrillators hav~ becom~ a co~erclal reality.~ .
Implantabl~ atrial defibrillator~ o~ in the past:have exhibited a number of disadvantiage3 which ~.
: probably has precluded these defibrillators from beco~ing ':
.

~ 071 ~7 a com~ercial reality~ Two such proposed defibrillators, although represented as being implantable, were not *ully automatic, requiring human in~eraction ~or cardioverting or de~ibrillatinq the heart. Both of these proposed de~ibrillators re~uire the patient to recognize the ~ympto~s of atrial ~ibrillation with one defibrillator requiring a visit to a physician to activate the defibrillator and the other defibrillator re~uiring the patient to activate ths defibrillator from external to the patient's skin with a magnet.

Improved atrial de~ibrillators and lead sys~ems which ~h;~it ~oth automatic operation and ~ , o~ed ~a~e~y are fully described in cop~n~ing U.S. Applications, Serial h~ . 07/685,130, ~iled April 12, 1~1, in ~h~ name~ o$ ~ohn M. Adams and Cli~ton A. ~lfernes8 for IMPROVED ATRIAL DEFT~TT-T~ToR AND ..~n~ and Serial Numb2r 07f856,514 ~iled March 24, l~g2, in ~he nam~ o~ John M~ Adams, Cli~ton A. Alferness, and Paul E. Krey~n~g~n for ~ kv~u ~TRTAT
DEFT~RTT~T~OR, LEAD ~Y~ , A~D HET~OD wh~ch applications are assigned to the assigne~ o~ the pre~ent inven~ion. A~ di~closed in tne aforementioned re~erenced appllcations, ~ynchronizing t~e delivery of the de~ibrlllating or cardioverting electrical energy to the atria with a ventri~ular electrical ~¢tivation ~ wav~) of the heart ~as been con~id~red important to avoi~

:,, . , ,, ,, , ,,, . " , . . . . ~ . .. ... . . . .. . .

.: ' ' . '.:, . '."':'' ~ '' ''.' ' ' ' ' ; ' . ~ , '', ' ' .'' ' . ., ,. : . ' ,, .'; ' ": ' ' '; ~', , '' ~. ' .. ' ', ',.' , . ~. : .. .

' ' ' ' '' , ' ' . ' ":', ' ' '' . ' . ' ', ' ' ' ': " ' ' ' : , l ' :

cardioverting the heart during the heart's vulnerabl~
period or T wave to thus prevent induced ventricular fibrillation. Ventricular fibrillation i~ a ~atal arrhythmia which can be cau~ed by electrical energy beln~-deli~ered to the heart at the wrong ti~e in the cardiaccycle, such as during the T wav~ of the cycl~. Th~
atrial defibrillators of the aforementionQd re~5~n~Q~
applications exhibit improved safety from tn~tt~in~
ventricular fibrillation by sansing ventricular lQ activation~ of the heart in a manner which avoids detecting noise as ventricular elactrical activations for generating reliable ~yll~hLo~ization signals. HenGQ~
these implantable atrial defibrillator~, by pro~ldi~g~ -such noise i ~ty in R wavQ detection assur~ r~l~Ahl~
synchronization.
Another mea ure for reducing the ri~k of inducing ventricular fibrillation during the deli~xy of cardioverting electric~1 en~rgy to the atria of the haart employed by the deflbrillator~ of the af~- ~ Lt~d referenced applications i5 the reduc~ion of th~ amount o~
the electrical energy which i~ pa~s~ through thQ
ventricles during cardioversion of the atria. Thi~
achieved by locating the cardioverting electrode~ in or near the heart to provide a cardio~erting energy path :25 which con~in~s substantially all of the cardiov~rting electrical energy to the atria of ths heart.

4 -:~

~ ~7~ f~7 It has also been obser~ed that during epi~e~
of atrial fibrillation, the cardiac rate increases to a high rate and/or becomes extremely variable. At high cardiac rates, the R wave of each cardlac cycl~ b~co~s~
closely spaced from the T wav~ o~ the imm~diat~ly preced1n~ cardiac cycle. This create3 a condition known in the art as an "R on T" con~ition which is beli~v~d to contribute to induced ventricular fibrillation i~ th~
atria are cardioverted in synchronism with thQ R wav~
close to the prece~i n~ T wave. For highly variabl~
cardiac rates, a long cardiac cy~le can be followed by a relatively short cardiac cycle. Thi~ condition i~
believed to cause disper~ion o~ r~ractoriness and al~o can result in a vulnerable R on T condition~ For a more complete understanding of the aforementioned highly variable cardiac rate and the conseql~e~c~R ther20f, rPference may be had to an article entitled El-Sheri~ ~t al., Reentrant Vsntricu1~r Arrhyth~ias in the ~ts Myocardia1 Infarction Period: N~chanism by ~h~ah a Short-Long-Short Cardlac Sequence F~cilitat~s th~
Inductlon o~ Reentry, Circulation, g3(1):26~ 8 (1991).
It ha3 been further ob~er~ed t~at a~
ventricular activation~ propagate through th~ heart~ th~
riqht ventricle apex activates slightly prior to the superior left ventricle. Hence, if the atria ar~
cardioverted in synchronis~ with an activation of th~

; 5 .

?:~ ~71 /~

right ventricular apex, the activation of th~ ~uperior left ventricle may not be completed. Recent studie3 have shown that cardioverting the atria when the ventricular activation is not fully completed may contr~buts t~
induced ventricular fibrillation.
The atrial defibrillator and method Or th~
present invention greatly re~ he ri~k o~ ~ n~ n~
ventricular fibrillation during atrial cardiov~r3ion or defibrillation by assuring that the card~overting electrical ener~y is not applied to the atria during both an R on T condition and a not yet completed ventri~ular activation. As will be seen hereinafter, this is acc~mplished by d~laying the application o~ ~h~ : .
cardioverting or defibrillating Ql~ckrical en~r~y ~ntil a predeter~ined delay time has elapsed after detecting a ventricular aativation. The delay tim¢ is chosen to b~
o~ suf f icient duration to a~sure thzt the ventricul~r activation has fully complet~d and of insu~icient duration to avoid applying the cardioverting el~ctrlc~l energy to the atria during the T wave i~med~ately following the detected ven~ricular activation. A~ a result, a reduced risk of i.n~ e~ ventricu~ar ~ibrillation is assured be~aus~ the cardiovor~ing electrical energy will not be applied to fhe atria during an R on T condition, during an llnr , leted ve~ $cl~
activa~ion, or during a vulnerabla period of the he~r~.

:

~ ~ ~ i7 ~ ~ 7 S~A~ OF ~ NV~ ON
The pr~sent invention therefore provide~ atrial defibrillator for providing cardioverting elsctrical energy to the atria of a human heart. The atrial defibrillator includes detecting means for dQtecting ventricular activations of the heart, cardioverting m~n3 for applying the cardioverting electrical en~rgy to the atria of the heart, and d~lay m~an~ L~o~,~iva to th~
detecting means ~or causing the cardioverting ~e~n~ to apply the cardioverting electrical energy to the atria o~
the h2art a predetermined delay time a~ter the ~irst detecting mean~ detects one ~f the ventricular activations and before khe T wave of thQ heart ; le~iately followlng one of the ventricular act~vation~.
The present invention also provides an implantable atrial defibrillator for providing cardioverting electrical energy to the atria of a hu~a~
heart in need o~ cardiover~ion. The atrial defibrillator include~ first detecting ~ean~ ~or dQtecting ventricular ZO activations of the heart and second detecting mean~ ~or d~ecting atrial activity of the heart. ~he ~tri l de~ibrillator further includes atrial defibrillation detecting mean~ respons ve to the second detecting mean~
~or deteL i~i~g when the atria of the heart are in nee~
of cardioversion and cardiovert1ng mean~ for applying the cardioverting ~lectrical en~xgy to the atria o~ the heart .

.. , . . ~ , ., ~ . . ~ . . . . . .. .

~ ~7~ ~7 when the atria of the heart are in need of cardioversion.
The atrial defibrillator further includes delay me2ns responsive to the fir~t det~cting means for causiD~ th~
cardioverting means to apply the cardioverting electric~L
energy to the atria of the heart a predetermined d~lay tim~ after the first detecting mean~ detects one of th~, ventricular activations and before ths T wava o~ th~
heart ~ tely following the one o~ the ventri~ula~:
activations~ :
The present invPntion further provide~ a m~thod of applying cardioverting electrical energy to th~ atria of a human heart in need of cardiover~ion. Ths ~thod include~ the steps o~ detectin~ ventricular activ~t~Q~
o~ the heart, detecting atrial activity of the heart, and determining, responsive to the detected atrial acti~ity of the heart, when ths atria of the heart are in ne~d 9 cardioversion. The method further include~ the st~p o~
applying the cardioverting electrical energy to thQ atria of the heart when the atria of the heart are in nQ~d 0~
cardioversion and a predQtermined delay tim~ a~t~r detecting one of the ventricular activation~ and b~or~-~
the T wav~ of the heart i ~di~ely following the ona og :~
th~ ventricular activations.
' -..,' :

, .

9~E~ DE~Ca~PT~ON OF ~H~ D~INa8 The features of the present invention which ara believed to be novel are set forth with particularity in the appended claims. The invention, togethQr ~ith further objects and advantages thereof, may b~st b~
understood by maklng reference to the following-description tak~n in con-Junction witb the accompanying~
drawing, in the sole fiqure of which like r~f~a~c~
numerals identify identlcal elements, and wherein the sole Figure is a schematic block diagram of a ~ully implantable atrial dePibrillator e~bodying ths ~
invention for applying defibrillating electrical ~n~ ~y to the atria of a human heart and which i3 shown in association with a human heark in need oP atrial fibrillation monitoring and potential cardiovers~on of the atria.

DETAI~D DB8CRIP~ION O~ ~B PR~E~R~D ~M~ODI~E~.
Prior to re~erring to the sole Figur~, a ~eneral description of a typical or normal cardiac cycla m~y be helpful in underst~n~ing th~ operation and varlou~
aspQcts of the present invention. The beginni n~ 0~ a Gardiac cycle is ini~iated by a P wave which is nor~ally a snall positive wave. The P wave in~ucps depolarization of the a~ria of the heart. Following the P wav~ th-r~ i~
a cardiac cycle portio~ which is substantially con~tant : ~ g ~ n7~ 7 have a time duration on the order of, for exampl~, 120 milliseconds.
The QRS complex of the cardiac cycla then normally occurs after the substantially c~nstant portion.
The ~ ting feature of th~ QRS complex i~ tha R wav~
which is a rapid positive or negative de~lection. Thc R wave ge~erally ha~ an amplitude gr~ater than any other wave of the cardiac cycle and will have a spik~d qh~pe o~
relatively short duration with a ~harp rise, a peak amplitude, and a sharp decline. The R wave i3 the : :
depolarization o~ the ventricle~ and hence, as us~d herein, the term "ventricl~ activation~l' denote~ R Wa~B
o~ the heart cardiac cycle. As previously m~ntion~d, a~
ventricular activations propagate through the he~rt, th~
right ventricle ap~x is generally depolartzed 81ig~1y prior to the depolarization of the supsrior le~t ve~tricle. :
Following the QRS complex, the cardiac cyaln i~
completed with the T wave whic~ eparated from th~ QR~
complex by about 250 milli~econ~. The T ~av~ is relatively long in duration o~, for example, on the order oP 150 ~ conA~0 It i~ during thQ T wav~ that the heart i5 most vulnerable to in~c~ ventricular fibrillation should the heart be cardiovert~d during th~s ~eriod. The next ~ardiac cycle begins with th~ n~xt ' "- 2.~ 7 P wave. The duration of a cardiac cycle may be on thei order of 800 milliseconds.
As will be appreciated hy those skilled in the art, thei characteristics of a cardiac cyclG of a h~a~t experiencing atrial fibrillation will be di~tinctly differ~nt than described above for a normal cardiac cycle~ During atrial fibrillation, there gsnerally are no discernable P waves because the atria are in a~
unstable or fibrillating condition. Also, the cardiac rate may be extremely high and highly variable which result~ in the previously referred to R on T condition where the ventricular acti~ation (R wave) of one cardiac cycle i5 closiely adjacent in time to the T wave o~ th~
i -~iately preceding cardia~ cycle.
Referring now to the sole Figure, it illustrates a fully implantable atrial deflbrillator 30 embod~ing the present invention shown in association wit~
a schematically illustrated human heart 10 in neQd o~
atrial fibrillation monitoring and potential cardioversion of the atria. The portion~ of the heart 10 illustrated in Figure 1 are the right ventricle 12, the le~t ~entricle 14, the right atrium 16, the left atrium 18, the superior vena cava 20, the ccronary sinus ~h~n~l 21 which, as used herein, deno es the coronary sinu$ 22 and the great cardiac vein 23, th~ coronary sinus ost~um 11 - ' ~ .

. J1 7 or opening 24, the left ventricular free wall 26 and th~
inferior vena cava 27.
The atrial defibrillator 30 gensrally incl~des an enclosure 32 for hermetically sealing the inter~al circuit elaments of the atrial defibrillator to bo described her~inaft~r, an endocardial first lead 34, and an intravascular seco~ lead 36. The enclosur~ 32 and.
first and second leads 34 and 3C are arranged to be implanted beneath the skin of a pati~nt so as to L~n'~
the atrial defibrillator 30 fully i~plantable.
The en~oc~rdial first lead 34 pre~rably comprise~ a endocardial bi-polar lead having ele~trod~
38 and 40 arranged for establj~h~n~ electrical cont~t with the right ventricle 12 o~ th~ heart 10. Th~
electrodes 38 and 40 permit bi-polar sen~ing o~
ventricular activation in the right ventricl~. A~
illustrated, th~ lead 34 is fed ~hrough the ~uperior vQna cava 20, into the right atrium 16, and then in~o th~ : :
right ventricle 12.
The second lead 36 generally include~ a ~ir~t or tip electrode 44 and a second or proximal ele~ 0~2 46. As illustrated, the s~cond lead 36 is ~ ;hl~ and arranged to be passed down the superior vena ca~a 20, into the right atrium 15, into the coronary sinus ostium 24, and advanced into th~ coronary sinu~ ~h~nn~l 21 of the heart near the le~ side thereof ~o that the ~lr~t or .

tip electrode 44 i~ within the coronary sinus ch~el 21 either within the coronary sinus 22 adjacent the left ventricle 14 and beneath the l~t atrium 18 or mo~t preferably within the yreat cardiac vein 23 adjacent t~
left ~entricle 14 and beneath the left atrium 18. Th~
electrodes 44 and 46 are paced apart such that when thQ
first electrode 44 is positioned a~ described abovQ~ the second electrode 46 is in the right atriu~ 16. Tha fir~t electrode 44 together with the second electxod~ 4Ç
provide bi-polar sensing o~ heart activity in tha a~ria 16 and 18. The first electrode 44 and the RecQ~
electrode 46 further provide ~or khe deliv~y of defibrillating electrical energy to the atria. B~a~l~~~
the first el2ctrode 44 i~ locat~d beneath the l~t ~trium 18 near the left ventricle 14 and the ~econd ~le~L~o~e 46 is within the right atrium 16, the electrical ~ y applied between these electrodes will be substantially con~ined to the atr~a 16 and 18 o~ the heart 10. A~ a re~ult, the electrical energy applied to the rig~t ventricle 12 and left ventricle 14 when the atria are cardioverted or de~ibrillated will be minimized. This greatly re~uce~ the potential for ventricular fibrillation of the he~rt to be in~uce~ as a reeu~ o~ -the application o~ defibrillating ~lectrical en~r~y o~
the atria of the heart~

: ~ ~3 Within ~he enclosure 32, the atrial defibrillator 30 includes a first sense amplifier 50, an R wave detector 52, and a second ~ense amplifier 54~ The first sen~e amplifier 50 and the R wave de~ector 52 ~or~
a first detecting ~eans which toge her with ele~L~.7~F 38 and 40 of the ~irst lead 34 to which sense ampli~i~r 50-is coupled, sense~ ventricular activations o~ the right ventricle 12. The second sense ampliSier 5~ ~orms ~
~econd detecting means which, together with th~ ~irst electrode 44 and second electrode 46 of th~ secn~ lead ~ -36 to which it is coupled detects atrial activity o~ th~
heart.
The output of the ~irst sense amplifier 50 18 coupled to the R wave detector 52. ~he R wave dets~tor 52 is ~f the type well known in the art which provide3 an output pulse upon the oc~ ence of an R wav~ bQing sensed during a cardiac cycle of the heart. Th~ ~u~y~
of the second ~ense amplifier 54 i~ coupled to an ~log ~ -to digital convQrter 60 which converts the analog ~i~n~
representative of the atrial activi~y of th~ heart being detected to digita1 samples ~or ~urther proce~3ing in a manner to be dascribed hereinafter. .:.
ThQ enclosure 32 of the atrial de:fibrillator 39 further include~ ~ mioLe~oc2ssor 62. The mi~Lo~ o~e~o~
62 is preferably imple~ented in a manner a~ disclos~d ln : the aforementioned copending U.S~ Applications, S~Eial :.
~: , : ~ 14 Numbers 07/685,130 and U7/856,514 and ~urther a~
dascribed hereinafter. The implementation of th~
microprocessor 62 in accordance with this ~ ho~;r~t o~
the present invention results in a plurality o~
functional stages. The stage~ include a synchronization detector 64, a delay timer stage 66, a comparator ~tage 68, a time delay set stage 70, an atrial arrhythmia detector in the form of an atrial fibrillation dQtQctor 72, and a charge delivery and energy control stage 74.
The microproc~or 62 is arranged to operats in conjunction with a memory (not shown) which may bQ
coupled to the microprocessor 62 by a ml~ltiple-bit addres bu~ (not shown) and a bi-directional mult~p~e bit databus (not shown). This permits the mi~ opioces~r 62 to address desired memory locations within the me~ory ~or executing write or read operations. During a write operation, the mi~ o~,oce~or ~tores data, such a~ tim~
intervals or operating parameter~ in the memory at th~
addresse~ defined by multiple-bit addresse~ co.lYeye~ over the addres~ bu~ and co~eya the data to the - ~ 92 ov~r the multiple-bit data bus. During a read operation, the microprocessor 62 obtains data ~ro~ the memory a~ th~
storage locations identified by the multipl~-~it addresses provided over the addres~ bus and receive~ th~
~5 data from the ~ over the b~-directional data bu~.

'~

~ ~97~ ~

For entering operating parameters into the miGroproCesSOr 62, as for example the time delay re~erred to hereinafter into time delay set stage 70, th~
microprocessor 62 receive~ programmable ~ ing parameters f rom an external controller 100 wh~ch ~
external to the skin of the patient. The ext~rnal cor.L,oller 100 i5 arranqed to communicat~ w1th a receiver/transmitter 102 within enclosura 32 which ~
coupled to the microproc~ssor 62 ov~r a bi-directional bus 104. The receiver/transmitter 102 may b~ o~ th~ typ~
well known in the art for conveying various inform~tion which it obtains from the micropro~essor 62 to the external controller 100 or for receiving progra~lng parameters from the external col,~Loller 100 whioh the receiver/transmitter 102 then conveys to thQ
mi~u~ocsssor 62 for ~torage in internal memory, ~uch a~
in time delay set stage 70, or in the a~oreman~i~ne~
external me~ory within enclosure 32.
The receiver/transmitter 102 include~ a transmitting coil 106 so that the receiver/tr~itt~r 102 and coil 106 form a communication means. Such communication means are well known in the art and may be utilized a3 noted above for receivin~ ro~
external to the implantable enclosuxe 32 and ~or transmi~ing data to the external con~oller ~00 ~ro~ the 1~

7 1 ~ 7 implanted enclosure 32. One such c lication sy~t~m i~
disclosed, for example, in U.S. Patent No. 4,586,508.
To complete the identification of the variou~
structural elements within the enclosure 32, the atr~l de~ibrillator 30 further includQ~ a charger and ~tosag2-capacitor circuit 76 o~ the type well known in th~ art which charge~ a storage capacitor to a predet~x~in~d voltage lev~l and a dischargQ circu.~t 78 for ~t~eh~r~ing.
the storage capacitor wi hin circuit 76 by a predetermined amount to provide a c~ .olled ~ q~
out~u~ of electrical energy when required to the atri~ o~
the heart. To that end, the ~ h~rge circuit 7~ i~
coupled to the first electrodQ ~4 and th~ ~o~S-~A"
el~ctrode 46 of the ~acond lead 36 for applying the cardioverting or defibril~ating electrical energy to th~
atria. Lastly, the defibrillator 30 include~ a depletable power source 80, such a lithium batte~y, ~or providing power to the electrical components o~ th~
atrial def~brillator 30.
The sense ampli~ier 50 and the R wave d~t~ctor 52 continuously detect ~he oc~ ence o~ ventr~c~
activations of the right ventricle 12. As ~isa~o~ed in the a~ore~entioned cop~n~ing U.S. Applicatlon~ S~r~al Numbers 07/685,1~0 and 07/856,514, her~in incorporat~d ~y.
25 : ref~rence, when the tim~ intervals between i~media~ely ~ sucoessive R waves indicate the probability o~ an epi~ode :: 17 7 1 ~ 7 of atrial fibrillation, the microprocessor 62 enable3 the atrial fibrillation detector 72, sense ampli~ier 54, and the analog to digital converter 60. If the atrial ~ibrill~tion detector 72 determines that the atria 16 and ~8 are in fibrillation and thus in need of cardiover~lon, the charge delivery control 74 cause the charg~r and storage capacitor circuit 76 to charge the ~tor~g~
capacitor within c~rcuit 76. The atrial de~lbrillator 30 is then ready to apply cardioverting electrical el~e~y~ to the atria 16 and 18 at the a~r~ iate time in a manner described hereinafter.
The synchronization detector 64, tha del~y timer 66, the comparator 68, and t~e time d~lay ~et ~tago ::
70 ~orm a delay mean~ 82 for delaying th~ application o~
the cardioverting electrical enerqy to t~e atria 16 and 18 of the heart 10 until after a predetermined delay ti~e ~ollowing ~he de~ection of a ventricular activation by the sensa amplifier 50 and the R wave detectox 52. The predetermined delay time is prevlously entered into th~
time delay set stage 70 ~rom the external contrcll~r 100 and through the transmitter/receiver 102 a~ pr~iou31y described. Also, he delay timer is reset wh~n the storage capacitor in circuit 76 reA~h~C full char~
The synchronization detector 64 pro~idQ a 25: pulse to the delay ti~er in re~po~ to ths pulse fro~
the R wave detector upon the detection of a ventricul~r :
~ 18 ' 7 1 ~ 7 activation. Prior to starting the delay timer h~
and in accordance with the a~or~mentioned cro~s referenced cop~in~ application~, Serial NumDers 07/68s,~30 and 07/856,514, ~ynchronization pulse counting may be employed wherein the synchronization dete~tor 64 first counts a predetermined numb~r, such as ~iVQ, consecutive R wave datect pulses from R wa~e det~ctor 52 to assure that therQ is still reliable detection o~ th~
ventricular activations.
lo Upon the gixth pulse from R wave det~ctor 52 (if such pulse counting is employed) or upon th~ ~irst pulse from R wave detector 52 (if such pulse counting i~
not employed), th~ ~ynchronization counter 64 provide~
its pulse to delay timer 66 to start the delay ti~r~
The comparator 68 then contlnuously compares th~ tl~e kept by the delay timer 66 to tha predeteL 1 n~ d~lay time stored in the timQ delay set ~tag~ 70. When the time kept by the delay timer 66 equals the stored delay time, the comparator 68 causes the charge delivery control 74 to provide a control signal t~ the di~charge circuit 78 for ~s~h~rging the cardiovertinq electrical energy stored in circuit 76 ~etween ele~o~es 46 and 44.
This applies the ~ardioverting electrical energy to tha ~ atria 16 and 18 of the heart.
: 25 As a result o~ the foregoing, ~he ~ardiovertin~ . .

electrical energy is applied to the atria when the atria . .
.:

are in need of cardiovers.ion and a predetermined~d~lay time after one of the ventricular activation~
detected. The delay time i~ selected to be long t-,~ Jh to assure that the ventricular activation, whic~
ultimately ~tarts delay timer 66, is completed and ~hort enough so as to avoid cardioverting the atria during-th~
T wave which i ~l1~tely follows the v~lL~
activation in abo~t 250 millisecon~. A3 an exampl~, an~-without li~itations, the delay time m~y be in th~ rang~
of five to eighty mill1~eaQn~. Th~ rang~ of suit~blQ
delay times, o~ course, will dep~nd upon the par~qn heart physiology of a particular patient.
In co~trolling tha applica~ion or d~liv0xy o~
the cardio~erting electrical enerqy in the ~L~e~n~
r-nn~r~ it will be assured that th~ atria ~ not cardioverted during a partially completed ventricular activation, an R on T condition, or the vulnerabls p~r~od T wave of the heart. The present invention h~n~e-provide~ an improved atrial defibrillator and ~t~od wh$ch exhibits increased saPety in reducing the ri~k o~
inducing ventricular fibrillation wh~n cardioverting:th~
atria o~ the heart.
While a particular embodiment of th~ p~ t invention has been shown and described, modificatlon~ ~y be made. For examplb~ th~ delayed cardiov~rsion o~ th~
presen~ invention may be utilized to advanta~e in an 2~

7 ~ ~ 7 external atrial defibrillator wherein an ele~L.od~ or electrodes adhered to the sur~ace of th~ ski~ o~ a patient are e~ployed along with an R wav~ detector for detecting ventricular activations and sur~ac~ ~a~:
electrodes are utilized for applying th~ cardlovorting-i electrical energy to the atria of the heart. Such~
surface detecting and pad electrod~s are well known in~
the art. Hence, it i.~ therefore int~n~ed in the ~e-r~
claim~ to cover all su~h change~ and modification~ whi~h fall within the true spirit and ~cope o~ thQ inv~ntlon.

.

Claims (11)

1. An implantable atrial defibrillator for providing cardioverting electrical energy to the atria of a human heart in need of cardioversion, said atrial defibrillator comprising:
first detecting means for detecting ventricular activations of the heart;
second detecting means for detecting atrial activity of the heart;
atrial fibrillation detecting means responsive to said second detecting means for determining when the atria of the heart are in need of cardioversion;
cardioverting means for applying said cardioverting electrical energy to the atria of the heart when the atria of the heart are in need of cardioversion; and delay means responsive to said first detecting means for causing said cardioverting means to apply said cardioverting electrical energy to the atria of the heart a predetermined delay time after said first detecting means detects one of said ventricular activations and before the T wave of the heart immediately following said one of said ventricular activations.
2. An atrial defibrillator as defined in claim 1 wherein said predetermined delay time is of sufficient duration for the completion of said one of said ventricular activations.
3. An atrial defibrillator as defined in claim 1 wherein said predetermined delay time is between five and eighty milliseconds.
4. An atrial defibrillator as defined in claim 1 wherein said delay means includes timing means responsive to said first detecting means for timing said predetermined delay time.
5. An atrial defibrillator as defined in claim 4 wherein said delay means further includes a synchronizing detector for starting said timing means responsive to said first detecting means detecting said one of said ventricular activations.
6. An atrial defibrillator as defined in claim 5 wherein said delay means further includes comparing means for comparing the time of said timing means to said predetermined delay time and for causing said cardioverting means to apply said cardioverting electrical energy to the atria of the heart when the time of said timing means equals said predetermined delay time.
7. A method of applying cardioverting electrical energy to the atria of a human heart in need of cardioversion, said method including the steps of:
detecting ventricular activations of the heart;
detecting atrial activity of the heart;
determining, responsive to said detected atrial activity of the heart, when the atria of the heart are in need of cardioversion; and applying said cardioverting electrical energy to the atria of the heart when the atria of the heart are in need of cardioversion and a predetermined delay time after detecting one of said ventricular activations and before the T ware of the heart immediately following said one of said ventricle activations.
8. A method as defined in claim 7 wherein said predetermined delay time is of sufficient duration for the completion of said one of said ventricular activations.
9. A method as defined in claim 7 wherein said predetermined delay time is between five and eighty millisecond.
10. A method a defined in claim 1 including the further step of timing said predetermined delay time upon detecting said one of said ventricular activations.
11. An atrial defibrillator for providing cardioverting electrical energy to the atria of a human heart, said atrial defibrillator comprising:
detecting means for detecting ventricular activations of the heart;
cardioverting means for applying said cardioverting electrical energy to the atria of the heart; and delay means responsive to said detecting means for causing: said cardioverting means to apply said cardioverting electrical energy to the atria of the heart a predetermined delay time after said detecting means detects one of said ventricular activations and before the T wave of the heart immediately following said one of said ventricular activations.
CA 2107147 1992-10-23 1993-09-28 Atrial defibrillator and method for providing synchronized delayed cardioversion Expired - Fee Related CA2107147C (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
US07965168 US5269298A (en) 1992-10-23 1992-10-23 Atrial defibrillator and method for providing synchronized delayed cardioversion
US07/96,168 1992-10-23

Publications (2)

Publication Number Publication Date
CA2107147A1 true CA2107147A1 (en) 1994-04-24
CA2107147C true CA2107147C (en) 1998-01-27

Family

ID=25509558

Family Applications (1)

Application Number Title Priority Date Filing Date
CA 2107147 Expired - Fee Related CA2107147C (en) 1992-10-23 1993-09-28 Atrial defibrillator and method for providing synchronized delayed cardioversion

Country Status (4)

Country Link
US (1) US5269298A (en)
CA (1) CA2107147C (en)
DE (2) DE69322592T2 (en)
EP (1) EP0594271B1 (en)

Families Citing this family (87)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5350402A (en) * 1993-05-26 1994-09-27 Incontrol, Inc. Atrial defibrillator and method for providing T wave detection and interval timing prior to cardioversion
US5411524A (en) * 1993-11-02 1995-05-02 Medtronic, Inc. Method and apparatus for synchronization of atrial defibrillation pulses
WO1995028988A1 (en) * 1994-04-21 1995-11-02 Medtronic, Inc. Treatment of atrial fibrillation
US5562708A (en) * 1994-04-21 1996-10-08 Medtronic, Inc. Method and apparatus for treatment of atrial fibrillation
US5527344A (en) * 1994-08-01 1996-06-18 Illinois Institute Of Technology Pharmacologic atrial defibrillator and method
US5549642A (en) * 1994-08-19 1996-08-27 Medtronic, Inc. Atrial defibrillator and method of use
US5630834A (en) * 1995-05-03 1997-05-20 Medtronic, Inc. Atrial defibrillator with means for delivering therapy in response to a determination that the patient is likely asleep
FR2739783B1 (en) * 1995-10-13 1998-01-23 Ela Medical Sa Medical device of the type defibrillator / cardioverter has active implantable defibrillation of the atrium
US5690686A (en) * 1996-04-30 1997-11-25 Medtronic, Inc. Atrial defibrillation method
US5800465A (en) * 1996-06-18 1998-09-01 Medtronic, Inc. System and method for multisite steering of cardiac stimuli
US6006131A (en) * 1996-08-13 1999-12-21 Uab Research Foundation Dual current pathway atrial defibrillation apparatus
US5987354A (en) 1996-08-13 1999-11-16 Uab Research Foundation Dual shock atrial defibrillation apparatus
US5843130A (en) * 1997-03-31 1998-12-01 Masood Akhtar System for delivering atrial defibrillation shocks
US5814081A (en) * 1997-04-07 1998-09-29 Incontrol, Inc. Atrial flutter cardioverter and method
US5855592A (en) * 1997-04-24 1999-01-05 Ep Technologies, Inc. Systems and methods for multi-site cardiac defibrillation using multiple electrode structures
US5836976A (en) * 1997-04-30 1998-11-17 Medtronic, Inc. Cardioversion energy reduction system
FR2765884B1 (en) * 1997-07-09 2001-07-27 Rhodia Chimie Sa Silicone composition for coating substrates made of flexible material, especially textile
US5800497A (en) * 1997-07-17 1998-09-01 Medtronic, Inc. Medical electrical lead with temporarily stiff portion
US5922014A (en) * 1997-09-02 1999-07-13 Medtronic, Inc. Single pass lead and method of use
US5928271A (en) * 1998-02-25 1999-07-27 Medtronic, Inc. Atrial anti-arrhythmia pacemaker and method using high rate atrial and backup ventricular pacing
US6091989A (en) 1998-04-08 2000-07-18 Swerdlow; Charles D. Method and apparatus for reduction of pain from electric shock therapies
US6091988A (en) * 1998-04-30 2000-07-18 Medtronic, Inc. Apparatus for treating atrial tachyarrhythmias with synchronized shocks
US6266555B1 (en) 1998-05-07 2001-07-24 Medtronic, Inc. Single complex electrogram display having a sensing threshold for an implantable medical device
US6058327A (en) * 1998-07-09 2000-05-02 Medtronic, Inc. Implantable device with automatic sensing adjustment
US6249701B1 (en) 1999-02-12 2001-06-19 Medtronic, Inc. Implantable device with automatic sensing adjustment
US6411851B1 (en) 1999-11-04 2002-06-25 Medtronic, Inc. Implantable medical device programming apparatus having an auxiliary component storage compartment
DE19957481A1 (en) * 1999-11-23 2001-05-31 Biotronik Mess & Therapieg implantable defibrillator
US6514195B1 (en) 2000-04-28 2003-02-04 Medtronic, Inc. Ischemic heart disease detection
US6526311B2 (en) 2000-08-11 2003-02-25 Medtronic, Inc. System and method for sensing and detecting far-field R-wave
US6792308B2 (en) 2000-11-17 2004-09-14 Medtronic, Inc. Myocardial performance assessment
US6901291B2 (en) 2000-12-04 2005-05-31 Medtronic, Inc. Distinguishing valid and invalid cardiac senses
US6442430B1 (en) 2000-12-04 2002-08-27 Medtronic, Inc. Implantable medical device programmers having headset video and methods of using same
DE10064597A1 (en) * 2000-12-18 2002-06-27 Biotronik Mess & Therapieg Apparatus for treating fibrillation of at least one chamber of a heart
US6484057B2 (en) 2000-12-21 2002-11-19 Uab Research Foundation Pacing methods and devices for treating cardiac arrhythmias and fibrillation
US6650941B2 (en) 2000-12-22 2003-11-18 Medtronic, Inc. Implantable medical device programming wands having integral input device
US6694189B2 (en) 2001-03-07 2004-02-17 Medtronic, Inc. Rate adaptive pacemaker system with dual sensing component and method of using same
US6609028B2 (en) 2001-04-26 2003-08-19 Medtronic, Inc. PVC response-triggered blanking in a cardiac pacing system
US6889078B2 (en) 2001-04-26 2005-05-03 Medtronic, Inc. Hysteresis activation of accelerated pacing
US6580946B2 (en) 2001-04-26 2003-06-17 Medtronic, Inc. Pressure-modulated rate-responsive cardiac pacing
US7058443B2 (en) 2001-04-26 2006-06-06 Medtronic, Inc. Diagnostic features in biatrial and biventricular pacing systems
US6658293B2 (en) 2001-04-27 2003-12-02 Medtronic, Inc. Method and system for atrial capture detection based on far-field R-wave sensing
US6477420B1 (en) 2001-04-27 2002-11-05 Medtronic, Inc Control of pacing rate in mode switching implantable medical devices
US6636762B2 (en) 2001-04-30 2003-10-21 Medtronic, Inc. Method and system for monitoring heart failure using rate change dynamics
US6873870B2 (en) 2001-04-30 2005-03-29 Medtronic, Inc. Methods for adjusting cardiac detection criteria and implantable medical devices using same
US6654637B2 (en) 2001-04-30 2003-11-25 Medtronic, Inc. Method and system for ventricular fusion prevention
US6595927B2 (en) 2001-07-23 2003-07-22 Medtronic, Inc. Method and system for diagnosing and administering therapy of pulmonary congestion
US7027861B2 (en) 2001-10-09 2006-04-11 Medtronic, Inc. Method and apparatus for affecting atrial defibrillation with bi-atrial pacing
US6695790B2 (en) 2001-10-26 2004-02-24 Medtronic, Inc. Method and system for determining kidney failure
US6671549B2 (en) 2001-11-16 2003-12-30 Medtronic, Inc. Pacemaker utilizing QT dynamics to diagnose heart failure
US6836682B2 (en) 2001-11-16 2004-12-28 Medtronic, Inc. Rate responsive pacing system with QT sensor based on intrinsic QT data
US6721599B2 (en) 2001-11-16 2004-04-13 Medtronic, Inc. Pacemaker with sudden rate drop detection based on QT variations
US6889077B2 (en) * 2002-02-28 2005-05-03 Pacesetter, Inc. Implantable cardiac stimulation device that defibrillates the atria while avoiding the ventricular vulnerable period and method
US7058450B2 (en) * 2002-04-22 2006-06-06 Medtronic, Inc. Organizing data according to cardiac rhythm type
US6934586B2 (en) * 2002-04-22 2005-08-23 Medtronic, Inc. Cardiac resynchronization with adaptive A1-A2 and/or V1-V2 intervals
US7024244B2 (en) * 2002-04-22 2006-04-04 Medtronic, Inc. Estimation of stroke volume cardiac output using an intracardiac pressure sensor
US6882882B2 (en) * 2002-04-22 2005-04-19 Medtronic, Inc. Atrioventricular delay adjustment
US7164948B2 (en) * 2002-04-22 2007-01-16 Medtronic, Inc. Cardiac output measurement using dual oxygen sensors in right and left ventricles
US7386346B2 (en) * 2002-04-22 2008-06-10 Medtronic, Inc. Controlled and modulated high power racing combined with intracardiac pressure monitoring feedback system utilizing the chronicle implantable hemodynamic monitoring (IHM) and calculated EPAD
US7181272B2 (en) 2002-04-22 2007-02-20 Medtronic, Inc. Cardiac restraint with electrode attachment sites
US6996437B2 (en) 2002-04-25 2006-02-07 Medtronic, Inc. Ventricular safety pacing in biventricular pacing
US7037266B2 (en) * 2002-04-25 2006-05-02 Medtronic, Inc. Ultrasound methods and implantable medical devices using same
US7139608B2 (en) * 2002-07-31 2006-11-21 Uab Research Foundation Pacing methods and devices using feedback controlled timing
US20040049118A1 (en) * 2002-09-10 2004-03-11 Ideker Raymond E. Methods, systems and computer program products for treating fibrillation in a patient based on the presence of fibrillation following administration of defibrillation therapy
US7162298B2 (en) * 2002-09-10 2007-01-09 Uab Research Foundation Devices for detecting the presence of cardiac activity following administration of defibrillation therapy
US8560063B2 (en) * 2002-09-10 2013-10-15 Uab Research Foundation Post-defibrillation pacing methods and devices
US7215998B2 (en) * 2003-01-06 2007-05-08 Medtronic, Inc. Synchronous pacemaker with AV interval optimization
US7725172B2 (en) 2003-01-13 2010-05-25 Medtronic, Inc. T-wave alternans train spotter
US7162300B2 (en) * 2003-01-13 2007-01-09 Medtronic, Inc. Synchronized atrial anti-tachy pacing system and method
US7522958B2 (en) 2003-03-13 2009-04-21 Uab Research Foundation Methods and systems for reducing discomfort from cardiac defibrillation shocks
US7363078B2 (en) * 2003-04-24 2008-04-22 Medtronic, Inc. Intracardiac polarization signal stabilization
US20040215238A1 (en) * 2003-04-24 2004-10-28 Van Dam Peter M. Pacemaker with improved capability for detecting onset of tachyarrhythmias and heart failure
US7190245B2 (en) 2003-04-29 2007-03-13 Medtronic, Inc. Multi-stable micro electromechanical switches and methods of fabricating same
US7388459B2 (en) * 2003-10-28 2008-06-17 Medtronic, Inc. MEMs switching circuit and method for an implantable medical device
US7734344B2 (en) * 2003-12-02 2010-06-08 Uab Research Foundation Methods, systems and computer program products to inhibit ventricular fibrillation during cardiopulmonary resuscitation
US7577480B2 (en) * 2005-03-31 2009-08-18 Medtronic, Inc. System for waveform stimulation compensating electrode polarization
US20070239037A1 (en) * 2005-10-05 2007-10-11 Stefano Ghio Interventricular delay as a prognostic marker for reverse remodeling outcome from cardiac resynchronization therapy
US20070282210A1 (en) 2006-05-04 2007-12-06 Stern David R Implantable wireless sensor for in vivo pressure measurement and continuous output determination
WO2009108502A1 (en) * 2008-02-27 2009-09-03 Avi Livnat Atrial defibrillation using an implantable defibrillation system
US8620425B2 (en) 2010-04-29 2013-12-31 Medtronic, Inc. Nerve signal differentiation in cardiac therapy
US8423134B2 (en) 2010-04-29 2013-04-16 Medtronic, Inc. Therapy using perturbation and effect of physiological systems
US8639327B2 (en) 2010-04-29 2014-01-28 Medtronic, Inc. Nerve signal differentiation in cardiac therapy
US8781583B2 (en) 2011-01-19 2014-07-15 Medtronic, Inc. Vagal stimulation
US8718763B2 (en) 2011-01-19 2014-05-06 Medtronic, Inc. Vagal stimulation
US8706223B2 (en) 2011-01-19 2014-04-22 Medtronic, Inc. Preventative vagal stimulation
US8725259B2 (en) 2011-01-19 2014-05-13 Medtronic, Inc. Vagal stimulation
US8781582B2 (en) 2011-01-19 2014-07-15 Medtronic, Inc. Vagal stimulation
JP6099358B2 (en) * 2012-10-30 2017-03-22 オリンパス株式会社 Fibrillation detector and defibrillator

Family Cites Families (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3236239A (en) * 1962-07-17 1966-02-22 American Optical Corp Defibrillator
US3738370A (en) * 1971-01-18 1973-06-12 B Charms Method of defibrillating a malfunctioning heart by means of electrodes located within the atrium
US3952750A (en) * 1974-04-25 1976-04-27 Mieczyslaw Mirowski Command atrial cardioverting device
US4094310A (en) * 1976-10-04 1978-06-13 American Optical Corporation Apparatus for enhanced display of physiological waveforms and for defibrillation
US4300567A (en) * 1980-02-11 1981-11-17 Mieczyslaw Mirowski Method and apparatus for effecting automatic ventricular defibrillation and/or demand cardioversion through the means of an implanted automatic defibrillator
US4384585A (en) * 1981-03-06 1983-05-24 Medtronic, Inc. Synchronous intracardiac cardioverter
DE3232478C1 (en) * 1982-09-01 1984-03-01 Werner Prof Dr-Ing Irnich Synced pacemaker
US5007422A (en) * 1989-06-06 1991-04-16 Ventritex, Inc. Method for combiner cardiac pacing and defibrillation
US5074301A (en) * 1990-07-16 1991-12-24 Telectronics Pacing Systems, Inc. Apparatus and method for atrial pace before ventricular shock in dual chamber arrhythmia control system
US5105809A (en) * 1990-08-23 1992-04-21 Cardiac Pacemakers, Inc. System and method for evaluating lead defibrillation requirements of an implanted device without repeated fibrillation induction
US5129392A (en) * 1990-12-20 1992-07-14 Medtronic, Inc. Apparatus for automatically inducing fibrillation
US5165403A (en) * 1991-02-26 1992-11-24 Medtronic, Inc. Difibrillation lead system and method of use
US5433729A (en) * 1991-04-12 1995-07-18 Incontrol, Inc. Atrial defibrillator, lead systems, and method

Also Published As

Publication number Publication date Type
DE69322592D1 (en) 1999-01-28 grant
EP0594271A2 (en) 1994-04-27 application
US5269298A (en) 1993-12-14 grant
EP0594271B1 (en) 1998-12-16 grant
DE69322592T2 (en) 1999-05-06 grant
EP0594271A3 (en) 1994-12-07 application
CA2107147A1 (en) 1994-04-24 application

Similar Documents

Publication Publication Date Title
US5133350A (en) Mode switching pacemaker
US6873870B2 (en) Methods for adjusting cardiac detection criteria and implantable medical devices using same
US5558098A (en) Method and apparatus for detecting lead sensing artifacts in cardiac electrograms
US6873875B1 (en) Implantable pulse generator and method having adjustable signal blanking
US5314430A (en) Atrial defibrillator employing transvenous and subcutaneous electrodes and method of use
US6574505B1 (en) Atrial and ventricular implantable cardioverter-defibrillator and lead system
US5129394A (en) Method and apparatus for controlling heart rate in proportion to left ventricular pressure
US5928271A (en) Atrial anti-arrhythmia pacemaker and method using high rate atrial and backup ventricular pacing
US4830006A (en) Implantable cardiac stimulator for detection and treatment of ventricular arrhythmias
US6516231B1 (en) Endocardial electrode lead with multiple branches
US5630834A (en) Atrial defibrillator with means for delivering therapy in response to a determination that the patient is likely asleep
US6169918B1 (en) Cardiac rhythm management system with cross-chamber soft blanking
US5827197A (en) System for detecting atrial fibrillation notwithstanding high and variable ventricular rates
US5531768A (en) Implantable atrial defibrillator having ischemia coordinated intervention therapy and method
US6128529A (en) Device and method providing pacing and anti-tachyarrhythmia therapies
US7167747B2 (en) Identification of oversensing using sinus R-wave template
US5464433A (en) Atrial defibrillator and method providing dual reset of an interval timer
US6892094B2 (en) Combined anti-tachycardia pacing (ATP) and high voltage therapy for treating ventricular arrhythmias
US7266409B2 (en) Method and apparatus for determining oversensing in a medical device
US7386342B1 (en) Subcutaneous cardiac stimulation device providing anti-tachycardia pacing therapy and method
US4960123A (en) Differentiating between arrhythmia and noise in an arrhythmia control system
US5749901A (en) Method and apparatus for delivering defibrillation shocks with improved effectiveness
US6148230A (en) Method for the monitoring and treatment of spontaneous cardiac arrhythmias
US6249701B1 (en) Implantable device with automatic sensing adjustment
US5486199A (en) System and method for reducing false positives in atrial fibrillation detection

Legal Events

Date Code Title Description
EEER Examination request
MKLA Lapsed