Surgery: light – thermal – and electrical application – Light – thermal – and electrical application – Electrical therapeutic systems
Reexamination Certificate
2000-10-11
2001-11-13
Evanisko, George R. (Department: 3762)
Surgery: light, thermal, and electrical application
Light, thermal, and electrical application
Electrical therapeutic systems
Reexamination Certificate
active
06317632
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates generally to implantable pulse generators and in particular to implantable cardioverter-defibrillators for treating ventricular tachyarrhythmias.
BACKGROUND OF THE INVENTION
Implantable cardioverter-defibrillators (ICDs) have evolved significantly since their clinical introduction by Miroski in 1980. Initial ICDs were designed to recognize ventricular fibrillation and to deliver high-energy shocks in an attempt to treat the arrhythmia. However, clinical electrophysiology research indicated that an ICD capable of recognizing and treating ventricular tachycardias as well as ventricular fibrillation was useful for prevention of arrhythmic death.
Subsequent ICD development lead to devices that were able to treat ventricular tachycardias with antitachycardia pacing and low-energy cardioversion shocks in conjunction with back-up defibrillation therapy. These ICDs monitored the heart rate and the onset of the ventricular arrhythmia from ventricular endocardial signals to determine when the heart was in need either of cardioversion to treat a ventricular tachycardia or of defibrillation to treat ventricular fibrillation. While it was successful in detecting ventricular arrhythmias, the ICDs were unable to reliably discriminate sinus tachycardia and atrial arrhythmias, particularly paroxysmal atrial fibrillation, from malignant ventricular rhythms because of the sole reliance on ventricular cardiac signals to determine the cardiac state. As a result, the ICD might deliver inappropriate therapy based on aberrant ventricular signals that have their origins in an undetected supraventricular tachyarrhythmia, leading to an uncomfortable cardioversion shock being delivered to the patient.
In an attempt to correct this problem ICDs have been designed with dual chamber sensing capabilities to detect and analyze both ventricular and atrial endocardial signals. This increase in cardiac signal input to the ICD has provided an opportunity to determine the origin and the nature of the ventricular tachyarrhythmia, and to reduce the frequency of inappropriate therapy being delivered to an implant patient. However, while the combination of antitachycardia pacing with low and high energy shock delivery as well as backup bradycardia pacing in ICDs has expanded the number of clinical situations in which the device may appropriately be employed, means of coordinating ventricular and atrial rate information in a way that results in a system that effectively and efficiently treats an implant patient is still desired.
SUMMARY OF THE INVENTION
The present invention includes a system and a method for reducing unnecessary treatment of a rapid ventricular rate caused by a conducted atrial fibrillation. The system and method treat ventricular tachycardia by first sensing and analyzing cardiac signals from both the atrial and ventricular chambers. Pathological heart rhythms are detected by determining the patient's heart rate, the atrial/ventricular relationship of the rhythm, the suddenness of onset rate of the arrhythmia, the rate stability of the rhythm, the sustained rate duration of the arrhythmia, and whether the atria are in a state of fibrillation. This information is then used to assess the origin of a rapid ventricular rate and to determine when and what type of ventricular therapy is to be delivered to the heart. By analyzing the origin of the rapid ventricular rate prior to delivering ventricular tachycardia therapy, true ventricular tachycardia can be treated quickly and when ventricular tachycardia is of atrial origin, treatment can be delayed to determine if will convert naturally.
According to one embodiment of the present invention there is provided a system including (1) electronic control circuitry within an implantable housing coupled to implantable ventricular and atrial catheters for identifying and analyzing cardiac signals in the manner described above and for providing electrical energy to the heart to affect sinus rhythm of the heart in the manner described above in response to a signal from the electronic control circuitry indicating the occurrence of an atrial arrhythmia.
The system allows the user to partition therapy into a maximum of three programmable tachycardia therapy zones. The system provides tachycardia therapy to the patient in the form of anti-tachycardia pacing pulses, low energy cardioversion shocks, or high voltage defibrillation shocks. Anti-tachycardia pacing pulses may be adapted to the individual chamber (atrium or ventricle) depolarization rates. A variety of conversion schemes including, fixed or adaptive burst, ramp, scan, and ramp/scan, may be selected. To convert rapid ventricular tachycardia (VT) and ventricular fibrillation (VF), the system provides both monophasic and biphasic, synchronous, defibrillation shocks to the patient.
REFERENCES:
patent: 4208008 (1980-06-01), Smith
patent: 4432360 (1984-02-01), Mumford et al.
patent: 5107850 (1992-04-01), Olive
patent: 5360437 (1994-11-01), Thompson
patent: 5379776 (1995-01-01), Murphy et al.
patent: 5523942 (1996-06-01), Tyler et al.
patent: 5549654 (1996-08-01), Powell
patent: 5607460 (1997-03-01), Kroll et al.
patent: 5620471 (1997-04-01), Duncan
patent: 5716382 (1998-02-01), Snell
patent: 5716384 (1998-02-01), Snell
patent: 5724985 (1998-03-01), Snell et al.
patent: 5725559 (1998-03-01), Alt et al.
patent: 5755736 (1998-05-01), Gillberg et al.
patent: 5978707 (1999-11-01), Krig et al.
patent: 6088618 (2000-07-01), Kerver
patent: 6151524 (2000-11-01), Krig et al.
patent: 0360412 (1990-03-01), None
patent: 0401962 (1990-12-01), None
patent: 0597459 (1994-05-01), None
patent: 0617980 (1994-10-01), None
patent: 0748638 (1996-12-01), None
patent: WO93/02746 (1993-02-01), None
Dreher Robert D.
Gilkerson James O.
Krig David B.
Linder William J.
Wald Jan D.
Cardiac Pacemakers Inc.
Evanisko George R.
Schwegman Lundberg Woessner & Kluth P.A.
LandOfFree
Apparatus and method for treating ventricular tachyarrhythmias does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Apparatus and method for treating ventricular tachyarrhythmias, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Apparatus and method for treating ventricular tachyarrhythmias will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2578835