# US 2007/0191889 A1 · Atrial defibrillator > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2007/0191889 A1 - Document ID: US20070191889A1 - Status: Published application - Kind: A1 - Application number: 11/354,713 - Filed: 2006-02-15 - Published: 2007-08-16 - Earliest claimed: 2006-02-15 - Assignees: Biotronik CRM Patent AG - Inventors: Volker Lang - Web page: https://patentgrep.com/patent/US20070191889A1 ## CPC - A61N 1/056: {Transvascular endocardial electrode systems} - A61N 1/0563: {specially adapted for defibrillation or cardioversion} - A61N 1/39622: {Pacing therapy} - A61N 1/3987: {characterised by the timing or triggering of the shock} - A61N 1/395: {for treating atrial fibrillation} - A61N: ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY (measurement of bioelectric currents A61B; surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body A61B18/00; anaesthetic apparatus in general A61M; incandescent lamps H01K; infrared radiators for heating H05B) ## Abstract An atrial defibrillator has a stimulation pulse generator to generate pacing pulses, a sensing stage for sensing intrinsic ventricular events, (an R-wave having an amplitude). It also includes a defibrillation shock generator to generate an atrial defibrillation shock, an atrial fibrillation detector adapted to detect an atrial fibrillation, and a control unit connected to the stimulation pulse generator. The sensing stage, the atrial fibrillation detector, the defibrillation shock generator, and control unit are adapted to trigger an atrial defibrillation shock after detection of an atrial fibrillation and synchronous with a sensed or a paced ventricular event. The control unit is adapted to compare a sensed R-wave amplitude with a reference R-wave amplitude and synchronize an atrial defibrillation shock with a paced ventricular event or a sensed ventricular event if the sensed ventricular event is an R-wave having an amplitude of at least 60% of the magnitude of the reference amplitude. ## Claims ### Claim 1 An atrial defibrillator comprising: at least one stimulation pulse generator to generate pacing pulses for at least a ventricle of a heart; at least one sensing stage for sensing of intrinsic ventricular events, respectively, said intrinsic ventricular event being an R-wave having an amplitude; a defibrillation shock generator to generate an atrial defibrillation shock; an atrial fibrillation detector adapted to detect an atrial fibrillation; a control unit connected to the stimulation pulse generator, the sensing stage, the atrial fibrillation detector and the defibrillation shock generator, said control unit being adapted to trigger an atrial defibrillation shock after detection of an atrial fibrillation and synchronous with a sensed or a paced ventricular event; wherein the control unit is adapted to compare a sensed R-wave amplitude with a reference R-wave amplitude and synchronize an atrial defibrillation shock with either a paced ventricular event or a sensed ventricular event if said sensed ventricular event is an R-wave having an amplitude of at least 60% of the magnitude of the reference amplitude. ### Claim 2 (depends on 1) The atrial defibrillator according to claim 1, additionally comprising a sensing stage adapted to sense atrial events and being connected to the atrial fibrillation detector. ### Claim 3 (depends on 1) The atrial defibrillator according to claim 1, wherein the sensing stage for sensing of intrinsic ventricular events comprises a band pass filter having a pass band between 15 Hz and 80 Hz. ### Claim 4 (depends on 3) The atrial defibrillator according to claim 3, wherein the ventricular sensing stage comprises a second filter having a lower cut-off frequency of 22 to 26 Hz for filtering the ventricular signal in order to suppress T-wave sensing. ### Claim 5 (depends on 4) The atrial defibrillator according to claim 4, wherein the control unit is adapted to synchronize an atrial defibrillation shock with a ventricular event sensed within the ventricular signal having passed the second filter. ### Claim 6 (depends on 5) The atrial defibrillator according to claim 5, wherein the control unit is adapted to trigger an atrial defibrillation shock within 30-100 ms after detection of an R-wave having an amplitude with a magnitude of at least 60% of the magnitude of the reference amplitude. ### Claim 7 (depends on 1) The atrial defibrillator according to claim 1, additionally comprising a memory for storing R-wave amplitudes sensed during episodes of sinus rate. ### Claim 8 (depends on 7) The atrial defibrillator according to claim 7, wherein the control unit is connected to the memory and is adapted to generate a mean amplitude value from R-wave amplitude values stored in said memory and to set said mean value as a reference amplitude. ### Claim 9 (depends on 8) The atrial defibrillator according to claim 8, wherein the memory for storing R-wave amplitudes is operationally connected to the second filter for filtering the R-wave amplitude to be stored in said memory. ### Claim 10 (depends on 1) The atrial defibrillator according to claim 1, additionally comprising an impedance sensor connected to an impedance evaluation unit adapted to detect ventricular contractions by evaluating an intracardiac impedance signal. ### Claim 11 (depends on 10) The atrial defibrillator according to claim 10, wherein the control unit is connected to the impedance evaluation unit and is adapted to evaluate an actual intracardiac impedance signal by comparing said actual intracardiac impedance signal with a stored reference intracardiac impedance signal. ### Claim 12 (depends on 11) The atrial defibrillator according to claim 11, wherein the control unit is adapted to form a difference area between an actual impedance signal and a stored reference impedance signal and to compare the difference area to a stored reference area, said stored reference area representing the area defined by the reference impedance signal. ### Claim 13 (depends on 12) The atrial defibrillator according to claim 12, wherein the control unit is adapted to evaluate an intracardiac impedance signal in a time window starting with a sensed ventricular event (R-wave) and ending after 30 to 50 ms and to suppress delivery of an atrial defibrillation shock when the difference area is larger than 10 to 20% of the reference area. ### Claim 14 (depends on 13) The atrial defibrillator according to claim 13, wherein the control unit is adapted to suppress delivery of an atrial defibrillation shock when the difference area is larger than 15% of the reference area. ### Claim 15 (depends on 2) The atrial defibrillator according to claim 2, wherein the sensing stage for sensing of intrinsic ventricular events comprises a band pass filter having a pass band between 15 Hz and 80 Hz. ### Claim 16 (depends on 15) The atrial defibrillator according to claim 15, wherein the ventricular sensing stage comprises a second filter having a lower cut-off frequency of 22 to 26 Hz for filtering the ventricular signal in order to suppress T-wave sensing. ### Claim 17 (depends on 16) The atrial defibrillator according to claim 16, wherein the control unit is adapted to synchronize an atrial defibrillation shock with a ventricular event sensed within the ventricular signal having passed the second filter. ### Claim 18 (depends on 1) The atrial defibrillator according to claim 1, wherein the control unit is adapted to trigger an atrial defibrillation shock within 30-100 ms after detection of an R-wave having an amplitude with a magnitude of at least 60% of the magnitude of the reference amplitude. ### Claim 19 (depends on 18) The atrial defibrillator according to claim 18, additionally comprising a memory for storing R-wave amplitudes sensed during episodes of sinus rate. ### Claim 20 (depends on 6) The atrial defibrillator according to claim 6, additionally comprising a memory for storing R-wave amplitudes sensed during episodes of sinus rate.