69 results about "Cardiac resynchronization" patented technology

Methods for evaluating motion of a tissue, such as of a cardiac location, e.g., heart wall, via continuous field tomography are provided. In the subject methods, a continuous field (e.g., an electrical, mechanical, electromechanical, or other field) sensing element is stably associated with the tissue location. A property of the applied continuous field is detected with the sensing element to evaluate movement of the tissue location. Also provided are systems, devices and related compositions for practicing the subject methods. The subject methods and devices find use in a variety of different applications, including cardiac resynchronization therapy.

The present invention is related to implantable cardiac devices such as pacemakers and defibrillators that deliver cardiac resynchronization therapy (CRT), and to a method of optimizing acquisition of impedance signals between electrodes present on implanted lead systems. This system then automatically determines which electrodes or electrode combinations acquire impedance waveforms that have the best signal to noise ratio (highest fidelity) and characterize data most representative of dysynchronous electromechanical events. Using closed loop algorithms which provide electrograms and a variety of impedance data reflective of the patient's clinical status, the system autonomously modifies interval timing within the CRT device.

One embodiment of the present invention provides a system for automatically optimizing CRT procedures using a multi-electrode pacing lead. During operation, the system performs a first set of iterations to select one or more satellites on one or more pacing leads inserted in a patient. A pacing lead includes a plurality of pacing satellites, and a pacing satellite includes a plurality of electrodes that can be individually addressed and used for transmitting or detecting electric signals. The system then performs a second set of iterations to select one or more electrodes on the selected satellites. The system further performs a third set of iterations to select one or more timing configurations for pacing signals transmitted through one or more of the selected electrodes.

The present disclosure is a device and method associated with the delivery of medical devices in the pericardial space using a minimally invasive approach with direct visualization. More specifically, the device can be used to deliver permanent pacing, defibrillation and cardiac resynchronization leads, as well as leadless pacemakers for cardiac rhythm management to the epicardial surface of the heart. A subxiphoid procedure is proposed as a minimally invasive alternative to thoracotomy, while the delivery tool incorporates a camera for direct visualization of the procedure. The tool also incorporates a steerable catheter to provide selective control of the placement and orientation of the medical device in the pericardial space.

A system and method for automatically selecting among a plurality of pacing modes based upon capture detection. Patients suffering from heart failure may be optimally treated with different resynchronization pacing modes or configurations. By detecting whether capture is being achieved by a particular configuration or mode, a device is able to automatically switch to one that is both optimal in treating the patient and is successful in capturing the heart with pacing pulses.

An implantable cardiac therapy device and methods of using a device including an implantable stimulation pulse generator, one or more implantable leads defining sensing and stimulation circuits adapted to sense and deliver therapy in at least one right side heart chamber, and an implantable controller in communication with the stimulation pulse generator and the one or more patient leads so as to receive sensed signals indicative of a patient's physiologic activity and deliver indicated therapy. The controller is adapted to monitor at least one indicator of cardiac dysynchrony and to compare the at least one indicator to a determined dysynchrony threshold. The threshold is determined for indications that the patient be further evaluated for cardiac resynchronization therapy. The controller is further adapted to set an alert when the at least one indicator exceeds the threshold to indicate to a clinician that evaluation for bi-ventricular pacing might be indicated.

Cardiac resynchronization therapy is delivered to a heart using an extended bipolar electrode configuration in accordance with programmed pacing parameters including a non-zero intraventricular delay. The extended bipolar electrode configuration comprises a left ventricular electrode defining a cathode of the extended bipolar electrode configuration and a right ventricular electrode defining an anode of the extended bipolar electrode configuration. A pace pulse is delivered to the left ventricular electrode and anodal stimulation of the right ventricle is detected based on the sensed response to the pace pulse.

A medical device for characterizing the cardiac status of a patient equipped with a bi-ventricular pacing active implant device. The implant collects an endocardiac acceleration signal and searches for an optimal pacing configuration. This latter tests a plurality of different pacing configurations and delivers for each tested configuration parameters derived from the endocardiac acceleration peak (PEA). The device derives a patient clinical status from those parameters, the indication being representative of the patient's response to the cardiac resynchronization therapy. Those parameters include: the possibility to automatically get or not a valid optimal AV Delay among all the biventricular pacing configurations; a factor indicating the character sigmoid of the PEA / AVD characteristic; the average value of the PEA for the various configurations; and the PEA signal / noise ratio. The active implantable medical device includes control software and processes for executing the characterizing functionality described.

Techniques are presented for providing adjustable cardiac resynchronization with an implanted medical device such as a pacemaker. For example, cardiac resynchronization may be provided during some time periods but not during other time periods, or cardiac resynchronization may be provided in response to selected sensed events. Adjustable cardiac resynchronization is applicable to therapy such as bi-ventricular pacing, in which both ventricles of the heart are paced in response to sensed atrial events.

In a system that provides bi-atrial and / or bi-ventricular pacing, the system adjusts an interval between paces delivered to the atria, and / or an interval between paces delivered to the ventricles, as a function of heart rate. By adjusting the interval between paces as a function of heart rate, the atria and / or ventricles may be activated in a more synchronous and more hemodynamically efficient fashion.

Cardiac therapy systems include multiple electrodes respectively positionable at multiple left ventricular electrode sites. A pulse generator is coupled to the electrodes and configured to deliver a cardiac resynchronization therapy (CRT). A processor is configured to measure, for each left ventricular electrode site, a timing interval between first and second cardiac signal features associated with left ventricular depolarization. The timing interval is associated with a degree of responsiveness of each left ventricular electrode site to CRT. The processor is configured to determine a pacing output configuration that provides improved patient responsiveness to CRT based on the timing interval measurements and to select at least one left ventricular electrode site from the plurality of left ventricular electrode sites based on the timing interval measurements. The processor may be configured to monitor for a change in hemodynamic status of the patient based on a change in the timing interval.

Systems and methods are provided for evaluating an expected effectiveness of cardiac resynchronization therapy. Electrocardiogram (ECG) data is received as at least one ECG lead from a set of electrodes. A frequency spectrum representing the ECG data is generated via a Fourier transform. At least one predictor value is extracted from the calculated frequency spectrum. A fitness parameter, representing the expected effectiveness of cardiac resynchronization, is determined from at least the extracted predictor value.

Apparatus and methods enable robust, reliable control for implantable medical devices, including cardiac pacemakers, defibrillators and cardiac resynchronization devices. Integrated circuits in the devices have minimized interfaces, can derive power from the interface signals, and have high voltage and latch-up protection. A device lead has a power generation circuit and a switching circuit using cascaded PMOS transistors for operating with a stable voltage despite fluctuations in the supplied voltage. The lead has control electronics that provide a very low impedance between an electrode and a lead conductor during most of the duration of a pacing pulse, but during a brief initial portion of the pacing pulse, provide a very high impedance to permit charging up a power supply that is local to the control electronics. A method of stabilizing the external impedance and a system for fault detection and fault recovery for an implantable device are also provided.

A method for reversing ventricular dyssynchrony uses intracardiac echocardiographic measured parameters to systematically determine an optimal, individualized configuration for a cardiac resynchronization stimulator device. This method is particularly relevant for patients with congestive heart failure. The algorithm evaluates improvement in aortic flow and in left ventricular ejection fraction as atrioventricular and interventricular delay parameters of the patient's resynchronization stimulator device are varied.

The present invention provides a pacing device and method that allows for preferential right atrial, at or near the His bundle, and ventricular pacing, either individually or in combination, including tri-ventricular pacing. The pacing device includes a power source and one or more logic circuits allowing for programmable delivery of pacing to any combination of the right atria, the para-Hisian region, and the right and / or the left ventricles. The pacing device allows the user to select which site(s) to pace as well at the appropriate relative timing of pacing impulse delivery to any of these three previously mentioned sites. The device is constructed and arranged to be combined with an atrial sensing / pacing electrode to allow for atrio-ventricular sequential tri-ventricular pacing or variants of such. Also, a defibrillator lead can be incorporated into the device to allow for protection from ventricular arrhythmias and sudden death.

Apparatus and methods enable robust, reliable control for implantable medical devices, including cardiac pacemakers, defibrillators and cardiac resynchronization devices. Integrated circuits in the devices have minimized interfaces, can derive power from the interface signals, and have high voltage and latch-up protection. A device lead has a power generation circuit and a switching circuit using cascaded PMOS transistors for operating with a stable voltage despite fluctuations in the supplied voltage. The lead has control electronics that provide a very low impedance between an electrode and a lead conductor during most of the duration of a pacing pulse, but during a brief initial portion of the pacing pulse, provide a very high impedance to permit charging up a power supply that is local to the control electronics. A method of stabilizing the external impedance and a system for fault detection and fault recovery for an implantable device are also provided.

The invention is directed to techniques for electrode placement around a heart. A harness having one or more attachment sites may be secured around the heart, and electrodes may be secured at the attachment sites as desired by the physician for the patient. The electrodes may be, for example, pacing and sensing electrodes, defibrillation electrodes, or any combination thereof. The harness holds the electrodes in place and also impedes the progress of ventricular dilation. The electrodes attached to the harness may be used for any of several purposes, such as cardiac resynchronization, selective defibrillation, measurement of impedance, pacing and cardioversion.

The invention is directed to techniques for providing cardiac resynchronization therapy by synchronizing delivery of pacing pulses to the left ventricle with intrinsic right ventricular depolarizations. An implantable medical device measures an interval between an atrial depolarization and an intrinsic ventricular depolarization is measured. In various embodiments, the intrinsic ventricular depolarization may be an intrinsic right or left ventricular depolarization. The implantable medical device delivers pacing pulses to the left ventricle to test a plurality of pacing intervals. The pacing intervals tested may be within a range around the measured interval between the atrial depolarization and the intrinsic ventricular depolarization. One of the pacing intervals is selected based on a measured characteristic of an electrogram that indicates ventricular synchrony. For example, the pacing interval may be selected based on measured QRS complex widths and / or Q-T intervals. The implantable medical device paces the left ventricle based on the selected pacing interval.

In heart failure (HF) patients diagnosed according to the New York Heart Association (NYHA) rating scale as either Class III or Class IV, with QRS duration ≧120 ms, left ventricular (LV) EF≦35% (when in sinus rhythm), cardiac resynchronization therapy (CRT) can predict sustained improvement in at least LV structure and function. The knowledge of aetiology of a subject's HF status and of a few simple echocardiographic characteristics provides useful information as to whether such patients and undergo significant and beneficial reverse remodelling of the LV in particular and, in the long term can be expected to experience an improvement in all-cause mortality, for example such patients can be reasonably expected to survive and enjoy a relatively enhanced quality of life (QOL). A patient who qualifies according to the invention can be termed a reverse remodelling responder (RRR) or the like.

Lead Tracking of Implantable Cardioverter-Defibrillator and Cardiac Resynchronization Therapy Devices improve upon the process of implantation of ICD-CRT devices, placing their leads, and improving the information fed back to the device and / or clinician. Tracking of the placement of the leads during implantation is accomplished along with monitoring the leads once implanted. Benefits include reducing the risk and complication rate, simplifying implantation procedure, and enabling the extraction of vital data not previously available. Leads are tracked to at least minimize the need to use fluoroscopy. Three dimensional tracking (10) is employed to facilitate obtaining of data that allows the surgeon to better visualize lead insertion and placement. Placement of the leads during a procedure requires use of an external tracking component along with means and method for tracking the implantable leads. Transmitting antennas (10, 110) are provided, equal in number to the number of degrees of freedom of tracking required. A link (50) between the sensor (70) and the computation unit (40) can be wired or wireless. Once leads are implanted, heart wall motion must be monitored via the tracking of the leads within a clinical or home environment. Such tracking of the leads may be accomplished in real time.

A system and method for automatically selecting among a plurality of pacing modes based upon capture detection. Patients suffering from heart failure may be optimally treated with different resynchronization pacing modes or configurations. By detecting whether capture is being achieved by a particular configuration or mode, a device is able to automatically switch to one that is both optimal in treating the patient and is successful in capturing the heart with pacing pulses.

The invention relates to a cardiac resynchronization therapy (CRT) method based on self atrioventricular conduction. The method comprises the following steps of implanting a right atrium endocardium electrode and a left ventricle epicardium pace-making electrode in a patient of CRT adaptation diseases; connecting electrodes with a pulse generator; setting parameters of the intelligent pulse generator; executing a scanning search program for collecting real-time electrocardiosignals and left ventricle pace-making commands; performing time fixed point measurement and logic algorithm analysis of scanning search resources by the pulse generator, so as to find an AS / AP-VP interval when the most narrow QRS interval occurs; executing timed CRT by the pulse generator during the AS / AP-VP interval; after the abovementioned process is finished, performing electrocardiosignal collection and pace-making scanning search by the pulse generator, re-finding an AS / AP-VP interval when the most narrow QRS interval occurs; executing timed CRT during the AS / AP-VP interval; and repeating the cycle in such a way. The method is characterized by high intelligent degree, wide application, simple operation and low usage cost.

A pacing system computes optimal cardiac resynchronization pacing parameters using intrinsic conduction intervals. In various embodiments, values for atrio-ventricular delay intervals are each computed as a function of an intrinsic atrio-ventricular interval and a parameter reflective of an interventricular conduction delay. Examples of the parameter reflective of the interventricular conduction delay include QRS width and interval between right and left ventricular senses.

The present direct cardiac compression (DCC) design, termed Cardiac Resynchronization Compression Sac System (CRCSS), combines together the mechanical and electrical characteristics associated with DCC and cardiac resynchronization therapy (CRT), respectively. The CRCSS comprises a shell, at least one opening on the shell, and at least one inflatable balloon, and a pumping system. The shell is custom manufactured to substantially conform to the contour of a portion of a heart, the contour of the heart being obtained by an imaging system. The opening on the shell is designed for passing pericardial fluid so as not to impede the myocardial contraction. The inflatable balloon attaches to at least one predetermined location of the inner surface of the shell. Furthermore, the shell naturally positions in the pericardium space without resorting to any artificial force to prevent it from dislodging from the heart, and when the inflatable balloon inflates at least one ventricular free wall of the heart is compressed.

In bi-ventricular pacing devices (including CRT devices) analysis of myocardial electrogram signals in one ventricle (e.g., a left ventricle, or “LV”) can be used to infer capture or loss-of-capture (LOC) of an earlier stimulus pulse in the same ventricle, on a continuous (every pacing cycle), triggered, aperiodic and / or periodic basis. Rather than using an evoked-response principle as has been the basis of capture detection in prior art and other systems, a principle employed via the present invention uses evidence of inter-ventricular conduction (i.e., from the opposite chamber) and / or atrio-ventricular conduction as evidence of LOC, since a non-capturing pacing stimulus provided to a first chamber will allow the myocardial tissue of the first chamber to remain non-refractory and thus inter-ventricular and atrio-ventricular wavefront propagation and conduction can commence and be detected thereby revealing whether LOC has occurred.

In bi-ventricular pacing devices (including CRT devices) analysis of myocardial electrogram signals in one ventricle (e.g., a left ventricle, or “LV”) can be used to infer capture or loss-of-capture (LOC) of an earlier stimulus pulse in the same ventricle, on a continuous (every pacing cycle), triggered, aperiodic and / or periodic basis. Rather than using an evoked-response principle as has been the basis of capture detection in prior art and other systems, a principle employed via the present invention uses evidence of inter-ventricular conduction (i.e., from the opposite chamber) and / or atrio-ventricular conduction as evidence of LOC, since a non-capturing pacing stimulus provided to a first chamber will allow the myocardial tissue of the first chamber to remain non-refractory and thus inter-ventricular and atrio-ventricular wavefront propagation and conduction can commence and be detected thereby revealing whether LOC has occurred.

The disclosure describes techniques for delivering vagal stimulation to decrease the ventricular rate response during an atrial tachyarrhythmia, such as atrial fibrillation. Decreasing the ventricular rate response during an atrial tachyarrhythmia may facilitate increased ventricular pacing for cardiac resynchronization therapy (CRT), and may also reduce the likelihood of inappropriately detecting a ventricular tachyarrhythmia during the atrial tachyarrhythmia. Furthermore, the vagal stimulation may augment vagal tone, which may facilitate long term left ventricular reverse remodeling and decrease atrial and ventricular arrhythmic burden in heart failure patients. An example system that delivers CRT comprises a processor that detects an atrial tachyarrhythmia in one or more atria of the heart, and monitors at least one of a ventricular rate or degree of ventricular pacing subsequent to the detected atrial arrhythmia. The processor controls a stimulation generator to deliver vagal stimulation based on the least one of a ventricular rate or degree of ventricular pacing.

Methods and devices are disclosed for employing mechanical measurements to synchronize contractions of ventricular wall locations. Accelerometers that may be placed within electrode leads are positioned at ventricular wall locations, such as the left ventricle free wall, right ventricle free wall, and the anterior wall / septum wall. The accelerometers produce signals in response to the motion of the ventricular wall locations. A processor may then compare the signals to determine a difference in the synchronization of the ventricular wall location contractions. The difference in synchronization can be determined in various ways such as computing a phase difference and / or amplitude difference between the accelerometer signals. One or more stimulation pulses may be provided per cardiac cycle to resynchronize the contractions as measured by the accelerometers to thereby constantly and automatically optimize the cardiac resynchronization therapy.