30 results about "Both ventricles" patented technology

In a method for improving cardiac function, a compressive device is inserted into an intrapericardial space about a lower end portion of a heart. Thereafter the compressive device is operated to compress and close off lower portions of both ventricles of the heart.

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.

An implantable cardiac stimulating device has a pacing circuit connected via an electrode lead system to a first electrode which stimulates and detects activity in the left ventricle, a second electrode to stimulate and detect activity in the right atrium, and to a third electrode to detect activity in the left atrium. Upon the occurrence of a paced or sensed depolarization of the right atrium, a first AV-delay is started. When the subsequent left atrial depolarization is detected, a new AV-interval is started that is optimized for the left side of the heart. Either the left ventricle only, or both ventricles, is paced at the optimized left side AV-interval.

A pacemaker provides multi-chamber pacing with a pacing interval that can be programmed and adapted in response to cardiac output measurements for a given patient. In a typical embodiment, the pacemaker may provide pacing stimuli to both ventricles of a heart. In addition, the invention may include a measurement device that incorporates first and second blood oxygen saturation sensors for deployment in the left and right ventricle. The oxygen saturation sensors provide a differential measurement that can be used to calculate cardiac output in accordance with the Fick method. The oxygen saturation sensors may be carried by a common trans-septal lead that positions one of the sensors proximate the right ventricle and the other sensor proximate the left ventricle. Alternatively, the oxygen saturation sensors may be deployed via separate leads. Whether single or dual leads are used to carry the oxygen saturation sensors, a respective lead may optionally carry electrodes for sensing, pacing, or both.

In a heart treatment equipment provided with a stimulating mechanism for both the ventricles, the both ventricle stimulation is made optimized in order to inhibit the decrease of the cardiac output when a heart rate increase or the vagus nerve stimulation is performed and the equipment comprises a right ventricle pulse generator for stimulation the right ventricle, a left ventricle pulse generator for stimulation the left ventricle, wherein the controller for selecting either one of aforesaid right ventricle pulse generator and left ventricle pulse generator or selecting both of them for the ventricle stimulation is constituted such as to select both of the right ventricle pulse generator and the left ventricle pulse generator in response to the vagus nerve stimulation or the heart rate monitor output.

A pumping system for assisting either or both ventricles of the heart. In one embodiment, separate devices are provided for each ventricle. In another embodiment, one device provides both right and left pumping. The pumping system is small, efficient, atraumatic, and fully implantable. In addition, the pumping system can provide pulsatile flow during systole. The ventricular assist device includes an actuator plate between a pair of serially connected pumping chambers that operate in a two-stroke mode, specifically a power stroke and a transfer stroke. The ventricular assist device also includes an electromagnetic drive system that provides adjustment to the pump pressure according to the current through an electromagnet. For the pumping system, springs provide a “spring force” on the actuator plate that is towards the high-pressure pump chamber. The bias force allows the springs to store and deliver energy from the electromagnetic drive system to provide better utilization of the pump components, and to reduce the pump size and consumption of electricity.

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.

A method of operating a cardiac therapy system to deliver cardiac resynchronization therapy (CRT) pacing that includes pacing both ventricles or pacing only the left ventricle is described. Delivery of the CRT pacing to one or both ventricles is scheduled for a cardiac cycle. If an intrinsic depolarization of a ventricle is detected during a pacing delay of the ventricle, then the scheduled CRT pacing to the ventricle is inhibited for the cycle. The intrinsic interval of the ventricle, such as the intrinsic atrioventricular interval concluded by the intrinsic depolarization, is measured. During a subsequent cardiac cycle, the pacing delay of the ventricle is decreased to be less than or equal to the measured intrinsic interval. Capture of the ventricle is verified after pacing is delivered during the subsequent cardiac cycle.

An anti-reentry apparatus and method for reverting ventricular arrhythmias. Biphasic stimulation is applied at multiple ventricular sites to revert arrhythmias caused by reentry, particularly multiple random reentry. In the preferred embodiment, the first phase of biphasic stimulation is anodal, and is at a maximum subthreshold amplitude. The anodal phase preconditions the myocardium to accept the second phase (cathodal) such that less electrical energy is required to reach the threshold amplitude to produce depolarization. The anodal phase stimulation may have a shape over time that is square wave, ramped, or a series of short square wave pulses. Multiple electrodes located at multiple ventricular sites may be stimulated simultaneously, or they may be sequentially stimulated over time in a manner mimicking the normal progress pattern of cardiac depolarization. The multiple ventricular electrodes may stimulate from internal or external surfaces. One or both ventricles may receive biphasic stimulation from multiple electrodes. The invention also may be practiced with respect to atria.

A pulsatile, positive-displacement mechanical circulatory support pump which can be used for assistance or replacement of one or both ventricles. The pump includes a plurality of contractile elements radiating outward from an apex of a compliance chamber, the elements being incorporated in and/or in contact with at least a portion of an outer surface of the compliance chamber. These contractile elements include an electroactive dielectric elastomer or an ion exchange membrane metallic composite. Application of electric field pulses from an implantable electrical energy source such as a pacemaker will cause the contractile elements to compress and expand the compliance chamber.

Method and apparatus for cyclic ventricular pacing starting at a rate just above the intrinsic atrial firing rate (overdrive pacing), followed by relaxation to a rate just below the intrinsic atrial firing rate (ventricular escape). The method and apparatus can be applied to one or both ventricles, and can utilize one or more electrodes per ventricle. The electrode(s) can be applied to inner or outer ventricular surfaces. Relaxation protocols as a function of time can be linear, curvilinear to include exponential, or mixtures thereof. Furthermore, relaxation protocols can include one or more periods of time during which the pacing rate is held constant. Typically, the average ventricular pacing rate using this invention will be slightly greater than the intrinsic atrial firing rate, though alternate embodiments that encompass average ventricular pacing rates that are equal to or slightly less than the intrinsic atrial firing rate are also envisioned. Application of this method and apparatus to a heart in need thereof will produce a heart with an optimally minimized energy output requirement.

A device and method for improving tachyarrhythmia detection when the ventricles are resynchronized by delivering paces to both ventricles separated by a specified offset interval. Timing of escape intervals and tachyarrhythmia detection is based upon senses from one of the ventricles designated as a rate ventricle. A reversion pacing mode is provided in order to prevent tachyarrhythmia detection from being compromised when the rate ventricle is paced after the other ventricle.

The invention is directed to methods and apparatus for automatically changing from bi-ventricular pacing, in which an implantable medical device (IMD) applies pacing stimuli to both ventricles of a heart during a cardiac cycle, to single-ventricle pacing, in which the IMD paces one ventricle and inhibits pacing of the other. An IMD applying the techniques of the invention automatically changes from bi-ventricular pacing to single-ventricle pacing, or vice versa, as a function of the reliability of left ventricular pacing. Exemplary techniques for determining the reliability of left ventricular pacing include impedance measurement, capture testing, capture threshold testing, or any combination thereof.

The invention belongs to the field of clinical medical treatment, and particularly relates to a ventricular cavity simulation device and a use method and application thereof. The ventricular cavity simulation device comprises a base, a bionic ventricle and a power unit, wherein the bionic ventricle and the power unit are both arranged on the base. The bionic ventricle is internally provided with flexibly sealed double ventricle sacs to simulate a left ventricle and a right ventricle; the power unit is used for providing power for enabling the double ventricular sacs to contract and simulating pulsation of a ventricular cavity; the base is used for connecting the bionic ventricle and the power unit; and a flow channel connected with the power unit and the bionic ventricle is arranged in the base, working liquid is placed in the flow channel, and the working liquid serves as a medium to enable the power unit to push the ventricular sacs to contract. According to the device, rigid reciprocating motion of the linear motor can be converted into flexible contraction motion of the ventricular sac, so that a pressure change curve in a heartbeat cycle can be better fitted, and change curves of outlet pressure and inlet pressure of the ventricular cavity in a pulsation process can be more accurately and truly simulated.