Abstract: Various system embodiments comprise a neural stimulator, a premature ventricular contraction (PVC) event detector, a heart rate detector, an analyzer, and a controller. The neural stimulator is adapted to generate a stimulation signal adapted to stimulate an autonomic neural target. The analyzer is adapted to, in response to a PVC event signal from the PVC event detector, generate an autonomic balance indicator (ABI) as a function of pre-PVC heart rate data and post-PVC heart rate data. Other aspects and embodiments are provided herein.

Abstract: Various techniques for detecting cardiac capture in response to a detected lead related condition are described. One example method described includes delivering a pacing therapy to a heart of a patient, periodically determining whether the pacing therapy captures the heart of the patient, detecting a lead related condition, and, in response to the detected lead related condition, increasing a frequency of determining whether the pacing therapy captures the heart.

Abstract: A leadless pacemaker for pacing a heart of a human includes a hermetic housing and at least two electrodes on or near the hermetic housing. The at least two electrodes are configured to deliver energy to stimulate the heart and to transfer information to or from at least one external device.

Abstract: A system and method for delivering both anti-tachy pacing (ATP) therapy and high-voltage shock therapy in response to detection of abnormal cardiac rhythms is disclosed. The system controls the time between delivering ATP therapy and the charging of high-voltage capacitors in preparation for shock delivery based on a predetermined set of criteria. In one embodiment, the inventive system operates in an ATP During Capacitor Charging (ATP-DCC) mode wherein all, or substantially all, of the ATP therapy is delivered during charging of the high-voltage capacitors. Based on evaluation of the predetermined set of criteria, the system may switch to an additional ATP Before Capacitor Charging (ATP-BCC) mode, wherein substantially all of the ATP therapy is delivered prior to charging of the high-voltage capacitor. According to one aspect of the invention, the predetermined set of criteria is based, at least in part, on the effectiveness of previously-delivered ATP therapy.

Abstract: One aspect of this disclosure relates to an apparatus for providing a selective capacitance. An embodiment of the apparatus includes a first and second capacitor in a stack, and a switching circuit connected between the first and second capacitors. The switching circuit has at least two states, and is adapted to provide a first defibrillation capacitance in a first state and a second defibrillation capacitance in a second state. A switching circuit embodiment includes a field effect transistor (FET) adapted to have a source connected to the first capacitor and a drain connected to the second capacitor, a bipolar junction transistor (BJT) adapted to have an emitter connected to the source of the FET and a collector connected to a gate of the FET, a first current source connected to the collector of the BJT, and a second current source connected to a base of the BJT.

Abstract: A pacing output circuit can be configured to generate a ventricular pacing signal configured to be delivered to an electrode near the His bundle in a right ventricle of a heart to pace the right and left ventricles and improve synchronization of at least one of the ventricles relative to intrinsic activity. In an example, the ventricular pacing signal can include first and second signal components in opposite polarity from each other with respect to a reference component, the first and second signal components having substantially identical duration and magnitude.

Abstract: A defibrillation system for use in treatment of ventricular fibrillation includes at least one sensor to measure heart rhythm; at least one applicator to apply a defibrillation pulse to a patient; and at least one processor in communication with the sensor and the applicator to determine a first value related to the rate of change of a leading edge of a lagged phase space reconstruction of ventricular fibrillation heart rhythm measured over a period of time.

Abstract: A method of automatically determining which type of treatment is most appropriate for (or the physiological state of) a patient. The method comprises transforming one or more time domain measurements from the patient into frequency domain data representative of the frequency content of the time domain measurements; processing the frequency domain data to form a plurality of spectral bands, the content of a spectral band representing the frequency content of the measurements within a frequency band; forming a weighted sum of the content of the spectral bands, with different weighting coefficients applied to at least some of the spectral bands; determining the type of treatment (or physiological state) based on the weighted sum.

Abstract: An automatic external defibrillator including: a sensor for detecting when a rescuer is delivering a CPR chest compression to the patient; electrodes for application to the thorax of the patient for delivering a defibrillation shock to the patient and for detecting an ECG signal; defibrillation circuitry for delivering a defibrillation shock to the electrodes; and a processor and associated memory for executing software that controls operation of the defibrillator. The software provides: ECG analysis for analyzing the ECG signal to determine if the cardiac rhythm is shockable; CPR detection for analyzing the output of the sensor to determine when a CPR chest compression has been delivered, and integration of the ECG analysis and CPR detection so that the determination of whether the cardiac rhythm is shockable is based only on time periods of the ECG signal during which there has not been a CPR chest compression delivered.

Abstract: A constant current pacing apparatus and method for pacing uses, for example, H-bridge circuitry and a constant current source connected to the H-bridge circuitry.

Abstract: A system or method including a device configured to measure at least one pharmacological effect of a drug on a patient. The measured pharmacological effect is compared to an expected pharmacodynamic model. The system can allow for real-time monitoring of positive and side-effects of drugs as well as drug resistance to optimize individual therapy. The system can also enable patient compliance monitoring.

Abstract: Cardiac treatment methods and devices providing templates representative of past tachyarrhythmia events, each template associated with a therapy. A cardiac waveform is detected, and if it corresponds to a particular template associated with a previous therapy that was satisfactory in terminating a past event, the previous therapy is delivered again. If unsatisfactory, the previous therapy is eliminated as an option. If, for example, the previous therapy was an antitachycardia pacing therapy unsatisfactory in terminating the past tachyarrhythmia event, delivery of the antitachycardia pacing therapy is eliminated as an option. Instead of ATP therapy, one or more of a cardioversion, defibrillation, or alternate anti-tachycardia pacing therapy may be associated with the particular template.

Abstract: The present invention relates generally to the use of erythropoietin (EPO) to facilitate resuscitation from cardiac arrest. For a mammalian subject suffering from cardiac arrest, concurrent administration of EPO with resuscitation after the onset of ventricular fibrillation facilitates the resuscitation. Administration of EPO serves to attenuate myocardial abnormalities caused by cardiac arrest and the resuscitation efforts and favor improved resuscitation outcomes.

Abstract: A unitary subcutaneous implantable cardioverter-defibrillator which has a long thin housing in the shape of a patient's rib. The housing contains a source of electrical energy, a capacitor, and operational circuitry that senses the presence of potentially fatal heart rhythms. Provided on the housing are cardioversion/defibrillation electrodes located to deliver electrical cardioversion-defibrillation energy when the operational circuitry senses a potentially fatal heart rhythm. The unitary subcutaneous implantable cardioverter-defibrillator does not have a transvenous, intracardiac, epicardial, or subcutaneous electrode.

Abstract: Various aspects relate to a method. In various embodiments, a therapy of a first therapy type is delivered, and it is identified whether a therapy of a second therapy type is present to affect the therapy of the first therapy type. Delivery of the therapy is controlled based on the presence of the therapy of the second therapy type. Some embodiments deliver the therapy of the first type using one set of parameters in the presence of a therapy of a second type, and deliver the therapy of the first type using another set of parameters when the therapy of the second type is not present. In various embodiments, one of the therapy types includes a cardiac rhythm management therapy, and the other includes a neural stimulation therapy. Other aspects and embodiments are provided herein.

Abstract: An implantable cardioverter/defibrillator (ICD) includes an Anti-Tachycardia Pacing Before Charge (ATP-BC) mode according to which one or more high-voltage capacitors for storing defibrillation energy are charged in preparation of delivering a defibrillation shock only if a ventricular tachycardia (VT) sustains after an ATP delivery. Fast ATP delivery and effect verification methods are applied to avoid significant delay in delivering the defibrillation shock when found necessary to terminate the VT. A switch is provided such that a user decides whether to activate the ATP-BC mode or to deliver the defibrillation shock without delivering the ATP.

Abstract: An intrinsic inter-atrial conduction delay is determined by a pacemaker or implantable cardioverter-defibrillator based, at least in part, on far-field atrial events sensed using ventricular pacing/sensing leads. An atrioventricular pacing delay is then set based on the inter-atrial conduction delay. By detecting atrial events using ventricular leads, rather than using atrial leads, a more useful measurement of the intrinsic inter-atrial conduction delay can be obtained. In this regard, since atrial electrodes detect atrial activity locally around the electrodes, a near-field atrial event sensed using an atrial electrode might not properly represent the actual timing of the atrial event across both the right and left atria. Far-field atrial events sensed using ventricular leads thus allow for a more useful measurement of inter-atrial conduction delays for use in setting atrioventricular pacing delays.

Abstract: Devices, systems, and methods for treating a heart of a patient may make use of structures which limit a size of a chamber of the heart, such as by deploying a tensile member to bring a wall of the heart toward (optionally into contact with) a septum of the heart. The implant may include an electrode or other structure for applying pacing signals to one or both ventricles of the heart, for defibrillating the heart, for sensing beating of the heart or the like. A wireless telemetry and control system may allowing the implant to treat congestive heart failure, monitor the results of the treatment, and apply appropriate electrical stimulation.

Abstract: A method and apparatus for delivering therapy to treat ventricular tachyarrhythmias is described. In one embodiment, neural stimulation, anti-tachycardia pacing, and shock therapy are employed in a progressive sequence upon detection of a ventricular tachycardia.

Abstract: An implantable subcutaneous cardiac device includes at least two subcutaneous electrodes adapted for placement external to a heart beneath the skin of a patient. The device further includes an arrhythmia detector that detects a sustained tachyarrhythmia of the heart and a pulse generator that delivers anti-tachycardia pacing pulses to the subcutaneous electrodes in response to detection of a sustained tachyarrhythmia. The pacing pulses preferably have waveforms devoid of any exponential voltage decay and include rounded or substantially constant portions to minimize pain.

Abstract: According to one aspect, various methods and apparatus are used for treating a condition of a patient's heart, and for monitoring cardiac operation. In one approach consistent therewith, an electrode arrangement is placed in a right ventricle of the heart. The electrode arrangement is used to capture the myocardium for re-synchronization of the left and right ventricles by providing first and second signal components having opposite polarity on respective electrodes. The electrode arrangement is connected to an implantable CRM device that has the capability of pacing/sensing atrium, pacing/sensing ventricles, and deliver defibrillation therapy from the right side of the heart. The CRM device captures ventricular contractions to treat conduction abnormalities in one or more of the ventricles.

Abstract: The presence of a cardiac pulse in a patient is determined by evaluating physiological signals in the patient. In one embodiment, a medical device evaluates two or more different physiological signals, such as phonocardiogram (PCG) signals, electrocardiogram (ECG) signals, patient impedance signals, piezoelectric signals, and accelerometer signals for features indicative of the presence of a cardiac pulse. Using these features, the medical device determines whether a cardiac pulse is present in the patient. The medical device may also be configured to report whether the patient is in a VF, VT, asystole, or PEA condition, in addition to being in a pulseless condition, and prompt different therapies, such as chest compressions, rescue breathing, defibrillation, and PEA-specific electrotherapy, depending on the analysis of the physiological signals. Auto-capture of a cardiac pulse using pacing stimuli is further provided.

Abstract: This invention provides a method to discriminate between ventricular arrhythmia and supraventricular tachycardia by detecting an earliest arriving electrical signal following antitachycardia pacing. Also disclosed is an implantable cardiac defibrillator that is capable of simultaneous atrioventricular anti-tachycardia pacing bursts and detecting an earliest arriving electrical signal. The discrimination capability reduces the incidence of inappropriate shocks from dual-chamber implantable cardiac defibrillators to near zero and provides a method to differentially diagnose supraventricular tachycardia from ventricular tachycardia.

Abstract: An active implantable medical device such as a cardiac prosthesis, including ventricular capture testing by analysis of an endocardial acceleration signal. The device isolates in an endocardial acceleration (“EA”) signal an EA component, extracts from it, n representative indicators (PEA_i, LEA_i), and forms a vector EA (X_i) from these indicators. A classifier allows acquiring reference EA signals at a stimulation energy level sufficient to cause a capture, and in spontaneous rhythm in the absence of ventricular pacing and forms a corresponding plurality of first reference EA vectors. The n-dimensional space of the EA vectors is partitioned into two corresponding subspaces. The presence or absence of a capture is discriminated based on the position of the current EA vector (X_i) in one or other of these two sub-spaces.

Abstract: A system includes an episode classification module and a data retrieval module. The episode classification module receives electrograms (EGMs) from N implantable medical devices (IMDs) and determines whether the EGMs are associated with deliveries of therapy by the N IMDs. The episode classification module analyzes at least some of the EGMs and determines whether the deliveries or non-deliveries of therapy by the IMDs were appropriate. The data retrieval module receives a request from a computing device, via a network, that indicates at least two groups of the N IMDs. The data retrieval module provides to the computing device via the network, in response to the request, data for presentation to a user that indicates for each of the groups, at least one of how many of the one or more deliveries or non-deliveries were appropriate, or how many of the one or more deliveries or non-deliveries were inappropriate.

Abstract: Embodiments of the invention include an implantable medical device having a digital signal processing circuit associated with an implantable medical device function. The digital signal processing circuit can be selectively implementable according to the clinical need of a patient. Embodiments of the invention also include methods of making and using such implantable medical devices.

Abstract: A method of processing a raw acceleration signal, measured by an accelerometer-based compression monitor, to produce an accurate and precise estimated actual depth of chest compressions. The raw acceleration signal is filtered during integration and then a moving average of past starting points estimates the actual current starting point. An estimated actual peak of the compression is then determined in a similar fashion. The estimated actual starting point is subtracted from the estimated actual peak to calculate the estimated actual depth of chest compressions. In addition, one or more reference sensors (such as an ECG noise sensor) may be used to help establish the starting points of compressions. The reference sensors may be used, either alone or in combination with other signal processing techniques, to enhance the accuracy and precision of the estimated actual depth of compressions.

Abstract: A system and method to sense heart sounds with one or more implantable medical devices according to one or more parameters. The system alters one or more of the parameters as a function of one or more triggering events. The system then senses heart sounds with the one or more implantable medical devices according to at least the one or more altered parameters.

Abstract: Electrode arrangement for an electrical stimulation device, having electrode line (10) with electrical connection at proximal end of electrode line and with plurality of conductive surface areas (14, 16) in region of distal end of electrode line for emitting electrical pulses to a heart or for receiving electrical signals from the heart. Electrically conductive surface areas are at least partly electrically connected with the electrical connection at the proximal end of the electrode line. Uses switch or switching means (100), arranged within the electrical connection or within the electrode line, electrically arranged between at least one connection contact of the electrical connection and at least some of the electrically conductive surface areas (14b, 16), and which has an initially electrically conductive or non-conductive component (52), configured via a permanent configuration process by an electrical switching pulse to make permanently electrically non-conductive or conductive.

Abstract: A method and an apparatus for projecting an end of service (EOS) and/or an elective replacement indication (ERI) of a component in an implantable device and for determining an impedance experienced by a lead associated with the implantable device. An active charge depletion of an implantable device is determined. An inactive charge depletion of the implantable device is determined. A time period until an end of service (EOS) and/or elective replacement indication (ERI) of a power supply associated with the IMD based upon the active charge depletion, the inactive charge depletion, and the initial and final (EOS) battery charges, is determined. Furthermore, to determine the impedance described above, a substantially constant current signal is provided through a first terminal and a second terminal of the lead. A voltage across the first and second terminals is measured. An impedance across the first and second terminals is determined based upon the constant current signal and the measured voltage.

Abstract: An implantable medical device is configured so that all of the major components including a housing and attached leads are disposed within the vasculature of a patient. A tether extends from the housing of the device to an implant location where the tether is secured to tissue outside of the vasculature. In this manner, an intravascular medical device may be implanted at a location remote from final placement, delivered via the vasculature and anchored at the initial entry point.

Abstract: The invention relates to a device, a method and a computer program for evaluating images of the heart that have been captured by means of a medical imaging method. According to said method, at least two data records containing functional values, which describe the ventricular wall activity, are produced in a random format, are converted into a uniform format and the data records in the uniform format are compared with one another or calculated.

Abstract: A preferred atrial-based pacing method and apparatus is provided using an intelligent cardiac pacing system to having the ability to continue atrial-based pacing as long as relatively reliable AV conduction is present. In the event that such relatively reliable AV conduction is not present, mode switching to a DDD/R or a DDI/R pacing mode while continually biased to mode switch back to atrial-based pacing. The standard or relatively reliable AV conduction may be changed either automatically or manually. This increases pacing that utilizes natural AV conduction however possible so as to gain all the benefits of cardiac contractile properties resulting therefrom, while tolerating the occasional missed ventricular depolarization (i.e., non-conducted P-wave). In the event where relatively reliable AV conduction is not present, the pacing mode is switched to a DDD/R mode while detecting a return of the relatively reliable AV conduction (and resulting mode switch to preferred atrial based pacing).

Abstract: A method and system for determining undersensing during post-processing of sensing data generated by a medical device that includes transmitting a plurality of stored sensing data generated by the medical device to an access device, the stored sensing data including sensed atrial events and sensed ventricular events. The access device determines, in response to the transmitted data, instances where the medical device identified a cardiac event being detected in response to the sensing data, and determines whether one of a predetermined number of undersensing criteria have been met in response to the transmitted data.

Abstract: A cardiac rhythm management device is configured to discriminate between ventricular and supraventricular tachycardias (referred to as SVT/VT discrimination) by utilizing a morphology criterion in which the morphology of electrogram waveforms during ventricular beats are analyzed to determine if the beats are normally conducted. After the delivery of a cardioversion/defibrillation shock, however, the intraventricular conduction system is left in a modified state which alters the subsequently generated electrogram signal. Use of the morphology criterion for to SVT/VT discrimination is discontinued after delivery of such a shock and resumed after a predetermined minimum number of normally conducted ventricular beats has been detected.

Abstract: A pacing system includes a controller operable to provide control signals indicating desired pacing signals, a pulse generator connected to the controller and operable to receive the control signals and to generate the desired pacing signals based on the control signals, at least one lead electrically connected to the pulse generator and extending into a user's heart and operable to provide the pacing signals to the heart, at least one electrode positioned in the user's heart and electrically connected to the at least one lead, the at least one electrode in contact with the user's heart and operable to stimulate the heart based on the pacing signals; and a transceiver, in communication with the pulse generator and operable to selectively transmit the pacing signals to the electrode wirelessly. The transceiver is controlled by the controller to transmit the pacing signals when pacing signals are not received by the electrode from the at least one lead.

Abstract: Aspects according to the present invention provide a method and implant suitable for implantation inside a human body that includes a power consuming means responsive to a physiological requirement of the human body, a power source and a power storage device. The power source comprises a piezoelectric assembly that is configured to generate an electrical current when flexed by the tissue of the body and communicate the generated current to the power storage device, which is electrically coupled to the power source and to the power consuming means.

Abstract: A method and apparatus for delivering therapy to treat ventricular tachyarrhythmias is described. In one embodiment, neural stimulation, anti-tachycardia pacing, and shock therapy are employed in a progressive sequence upon detection of a ventricular tachycardia.

Abstract: A method and apparatus for monitoring a patient's heart rate sense first cardiac events in a heart chamber using a first cardiac electrode pair and sense second cardiac events in the heart chamber using a second cardiac electrode pair. The method includes estimating a first heart rate using the first cardiac events, comparing the first heart rate to a heart rate threshold and estimating a second heart rate using the second cardiac events in response to the first heart rate exceeding the heart rate threshold, determining whether the second cardiac events are unreliable, and setting the second heart rate equal to the first heart rate in response to the second cardiac events being unreliable.

Abstract: A method and apparatus for monitoring a patient's heart rate sense first cardiac events in a heart chamber using a first cardiac electrode pair and sense second cardiac events in the heart chamber using a second cardiac electrode pair. The method includes estimating a first heart rate using the first cardiac events, comparing the first heart rate to a heart rate threshold and estimating a second heart rate using the second cardiac events in response to the first heart rate exceeding the heart rate threshold.

Abstract: Systems and methods of managing features or functions of an implantable cardiac device involve forming a baseline evoked response template prior to delivery of defibrillation therapy to a patient's heart, and acquiring a post-shock evoked response signal subsequent to defibrillation therapy delivery. The baseline evoked response template is compared to the post-shock evoked response signal. A determination is made whether to enable, disable or adjust a cardiac device feature based on the comparison. The cardiac device feature may be a therapy feature, a monitoring feature, or a diagnostic feature.

Abstract: A system and method for providing pacing pulses after a cardioversion/defibrillation shock, where the pacing pulses have a pacing rate at an initial value. The pacing rate is decreased from the initial value until at least one intrinsic cardiac contraction is detected. In one embodiment, the pacing rate is decreased by a set amount after pacing a set number of cardiac cycles. Providing the set number of pacing pulses and decreasing the pacing rate by the set amount is then repeated until at least one intrinsic cardiac contraction is detected. An intrinsic cardiac rate is then determined from the at least one intrinsic cardiac contraction. The pacing rate is then increased and maintained to be above (i.e., greater than) the intrinsic cardiac rate.

Abstract: Medical devices and methods are used to treat cardiac dysfunction conditions which involve delivery of stimulation pulses in cardiac refractory periods in order to modulate an effective refractory period (ERP). Such devices and methods may be used in conjunction with or in place of other therapies, including increased cardiac contractility (ICC) therapy, post extrasystolic potentiation (PESP) therapy, and other therapies to achieve increased heart contractility, provide a safer and more effective regimen for the corresponding stimulation therapies, and reduce the risk of inducing an arrhythmia.

Abstract: The invention relates to a mobile defibrillator which has a housing. In order to improve the diagnostic reliability, particularly in the case of irregular heart rhythms and myocardial infarctions, provision is additionally made for an imaging ultrasound device to be provided in or on the housing.

Abstract: Various system embodiments comprise a neural stimulator, a premature ventricular contraction (PVC) event detector, a heart rate detector, an analyzer, and a controller. The neural stimulator is adapted to generate a stimulation signal adapted to stimulate an autonomic neural target. The analyzer is adapted to, in response to a PVC event signal from the PVC event detector, generate an autonomic balance indicator (ABI) as a function of pre-PVC heart rate data and post-PVC heart rate data. Other aspects and embodiments are provided herein.

Abstract: The invention is directed to techniques for attempting to restore a patient to a normal sinus rhythm. In a patient experiencing asystole or pulseless electrical activity, defibrillation therapy may be ineffective. The invention is directed to techniques for delivering one or more shocks to induce ventricular fibrillation in the patient, followed by one or more defibrillation shocks to restore normal sinus rhythm. A defibrillator may deliver the fibrillation and defibrillation therapies. The invention may also include techniques for estimating the probability that the patient will respond favorably to the defibrillation therapy, and delivering defibrillation therapy when the therapy has a good probability of success.

Abstract: A cardiac rhythm management device predicts defibrillation thresholds without any need to apply defibrillation shocks or subjecting the patient to fibrillation. Intravascular defibrillation electrodes are implanted in a heart. By applying a small test energy, an electric field near one of the defibrillation electrodes is determined by measuring a voltage at a sensing electrode offset from the defibrillation electrode by a known distance. A desired minimum value of electric field at the heart periphery is established. A distance between a defibrillation electrodes and the heart periphery is measured, either fluoroscopically or by measuring a voltage at an electrode at or near the heart periphery. Using the measured electric field and the measured distance to the periphery of the heart, the defibrillation energy needed to obtain the desired electric field at the heart periphery is estimated. In an example, the device also includes a defibrillation shock circuit and a stimulation circuit.

Abstract: An implantable microstimulator configured for implantation beneath a patient's skin for tissue stimulation to prevent and/or treat various disorders, uses a self-contained power source. Periodic or occasional replenishment of the power source is accomplished, for example, by inductive coupling with an external device. A bidirectional telemetry link allows the microstimulator to provide information regarding the system's status, including the power source's charge level, and stimulation parameter states. Processing circuitry automatically controls the applied stimulation pulses to match a set of programmed stimulation parameters established for a particular patient. The microstimulator preferably has a cylindrical hermetically sealed case having a length no greater than about 27 mm and a diameter no greater than about 3.3 mm. A reference electrode is located on one end of the case and an active electrode is located on the other end.

Abstract: Apparatus and method for detecting and filtering noise artifacts by analysis of a cardiac vectogram is disclosed. An active medical device collects electrical activity signals of a patient's heart over a series of cardiac cycles. At least two distinct temporal components (Vbip, Vuni) are obtained from at least two endocardial electrogram (EGM) signals that are collected concurrently on different respective channels from the same heart cavity.

Abstract: 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.