Abstract: Electrodes can generate electrical stimulation pulses at least one first intensity level and at least one second intensity level. The first and second intensity levels are above and below a given stimulation threshold, respectively. The synchronous or asynchronous delivery of second-level pulses enables the conduction of the atrioventricular node to be modulated by electrotonic effect, for example, to reduce ventricular frequency in the event of atrial fibrillation.

Abstract: An implantable dual-chamber pacemaker system has a means for automatic beat-to-beat adjustment of the maximum allowable variation (MAV) of the sensed atrial rate (AR) as a function of the sympatho-vagal balance, switching from an atrial tracking mode of operation (e.g., DDD or DDD(R)) to a non atrial tracking mode (e.g., VDI or VDI(R)) when either an arrhythmic tachycardic rate, exceeding the MAV, or a sinus tachycardic rate, exceeding the maximum tracking atrial rate (MTAR), is detected. The pacemaker provides logic means for continuously determining the atrial rate variation (&Dgr;AR) and the MAV. The MAV defines the upper limit for the &Dgr;AR above which tracking is not allowed, discriminating between physiological rate variations and arrhythmic variations. The pacemaker system can return to an atrial tracking mode of operation if the AR remains under a defined rate for a defined number of cycles.

Abstract: An implantable dual-chamber pacemaker system has a means for automatic beat-to-beat adjustment of the maximum allowable variation (MAV) of the sensed atrial rate (AR) as a function of the sympatho-vagal balance, switching from an atrial tracking mode of operation (e.g., DDD or DDD(R)) to a non atrial tracking mode (e.g., VDI or VDI(R)) when either an arrhythmic tachycardic rate, exceeding the MAV, or a sinus tachycardic rate, exceeding the maximum tracking atrial rate (MTAR), is detected. The pacemaker provides logic means for continuously determining the atrial rate variation (&Dgr;AR) and the MAV. The MAV defines the upper limit for the &Dgr;AR above which tracking is not allowed, discriminating between physiological rate variations and arrhythmic variations. The pacemaker system can return to an atrial tracking mode of operation if the AR remains under a defined rate for a defined number of cycles.

Abstract: An implantable defibrillator apparatus having a plurality of defibrillation electrodes which can be applied to the heart muscle in order to apply electric defibrillation shocks thereto, and a defibrillation-controller for selectively applying respective electric defibrillation shocks to the electrodes preferably sequentially in time and in synchronism with the QRS.

Abstract: An active implantable device having a sensor capable of detecting signals indicative of the conditions of the wearer of the device; a processor capable of selectively identifying, from signals detected by the sensor, particular conditions of the wearer of the device such as to require urgent assistance, an actuator capable of inducing the performance of therapeutic actions on the body of the wearer upon the occurrence of the particular conditions of the wearer of the device and a telemetry system capable of signaling from the body of the wearer of the device the occurrence of the particular conditions of the wearer of the device.

Abstract: An implantable heart-stimulation apparatus having a plurality of stimulation electrodes which can be applied to the heart muscle in one or more chambers of the heart in order to apply electrical stimulation signals thereto, and stimulation-control means for applying stimulation signals to the electrodes in accordance with a time plan determined individually and separately for each of the plurality of electrodes.

Abstract: A device for locating an electrode used in endocardial treatment comprises further electrode means to be positioned inside the heart together with the electrode, the further electrode means being able to adopt a geometrical arrangement defining a system of spatial coordinates. Polarization means are provided for applying respective electrical signals to at least one of the electrode and the further electrode means, as well as detector means connected to the electrode and to the further electrode means for detecting the potential established between the electrode and the further electrode means as a result of the application of the electrical signals. Measuring means sensitive to the potential are capable of determining, on the basis of the potential, the position of the electrode relative to the system of spatial coordinates defined by the further electrode means.

Abstract: The anchorage element (3) includes a body made of shape memory material which, on reaching a transition temperature, passes from a generally retracted position with respect to the associated implant device (1) to an expanded position in which the element (3) anchors the device (1) to the implant site.

Abstract: Electrodes can generate electrical stimulation pulses at least one first intensity level and at least one second intensity level. The first and second intensity levels are above and below a given stimulation threshold, respectively. The synchronous or asynchronous delivery of second-level pulses enables the conduction of the atrioventricular node to be modulated by electrotonic effect, for example, to reduce ventricular frequency in the event of atrial fibrillation.

Abstract: An implantable defibrillator apparatus having a plurality of defibrillation electrodes which can be applied to the heart muscle in order to apply electric defibrillation shocks thereto, and defibrillation-control means for selectively applying respective electric defibrillation shocks to the electrodes preferably sequentially in time and in synchronism with the QRS.

Abstract: Electrodes can generate electrical stimulation pulses at least one first intensity level and at least one second intensity level. The first and second intensity levels are above and below a given stimulation threshold, respectively. The synchronous or asynchronous delivery of second-level pulses enables the conduction of the atrioventricular node to be modulated by electrotonic effect, for example, to reduce ventricular frequency in the event of atrial fibrillation.

Abstract: An implantable defibrillator apparatus having a plurality of defibrillation electrodes which can be applied to the heart muscle in order to apply electric defibrillation shocks thereto, and defibrillation-control means for selectively applying respective electric defibrillation shocks to the electrodes preferably sequentially in time and in synchronism with the QRS.

Abstract: The device senses Natural Heart Acceleration (NHA), isolating at least one segment (t) thereof corresponding to an isovolumetric phase, such as isovolumetric contraction (P1, P2) and/or isovolumetric relaxation (P3, P4). Preferentially, the action of isolation of the aforesaid segment is made starting from the electrocardiogram (ECG) signal. Among other things, the device may be used to carry out pacing functions (pacemaker, defibrillator, pacer cardioverter defibrillator) and/or to pick up, possibly by telemetry, data on the myocardial function and/or also to control a system of drug administration.