MXPA00011421A - Method allowing cyclic pacing with average rate just above the intrinsic rate - Google Patents

Abstract

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.

Description

METHOD THAT ALLOWS THE CYCLIC CARDIAC RHYTHM WITH AVERAGE SPEED, JUST ABOVE THE INTRINSIC SPEED FIELD OF THE INVENTION The present invention relates generally to pacemakers for controlling heartbeat. In particular, the present invention relates to pacemakers used to cause, on a cyclic basis, ventricular tracing of atrial firing by accelerating the ventricular heart rate at a rate slightly above the intrinsic velocity of the heart (atrium). , followed by the gradual relaxation of the velocity of ventricular pacing at the point of uncoupling from the ventricular beat, from atrial firing, especially in conjunction with ventricular pacing techniques, such as the biventricular heart rate, the biphasic pulse, and / or the ventricular cardiac rhythm of multiple sites.

BACKGROUND OF THE INVENTION Node A-V blockages, frequently encountered in cardiac patients, occur when pulses Ref-125105 electricals that flow from the SA node along the conductors, are delayed when they reach junction A-V / node A-V. In some pathologies, if a delay of node A-V is sufficiently large, the ventricles will beat at their own slower intrinsic velocity. With node A-V blockages in other pathologies, the ventricles may pulsate at an intermittent and / or variable rate, or an ectopic foci may appear, potentially leading to life-threatening ventricular fibrillation.

A variety of strategies have been employed for pacemakers to overcome the adverse physiological effects of node A-V blockade. One such strategy is acceleration or cardiac overrhythm, in which the pacemaker stimulates the ventricles at a rate greater than the atrial beat rate. A problem encountered with such strategies is that the ventricular and atrial beats can not be coordinated for optimal pumping efficiency. Another problem is that such fast velocities of ventricular heart rate strthe heart because physiological and biochemical functioning are not optimized in general. In addition, such additional fatigue only imposes major restrictions on the already limited lifestyle of the typical cardiac patient. Thus, the patient with an already weakened heart can be subjected to unnecessary overstimulation, stress and further weakening as a result of the application of current pacemaker protocols.

The patented technologies that refer to the acceleration of the heart rate with the subsequent relaxation of the heart rate speed, include the patent of US No. 5,626,620 of Kieval, et al., Which publishes a pacing protocol in which the fusion and / or close fusion beats are detected by monitoring changes in the features of the evoked QRS. The protocol is adjusted to allow the selection of an acceptable percentage of fusion beats. When an unacceptable percentage of fusion is measured, the delay of the A-V node is automatically decreased to achieve a higher ventricular rate of the synchronous pacing pace of the pacemaker (ventricular "capture"). Once the ventricular capture is md for a certinterval of time or for a number of cycles without an unacceptable rate of fusion, the range of the AV node is increased in an increased manner to produce a beat rate that goes to the velocity in the that the fusion had happened previously. With repeated knowledge of an unacceptable percentage of fusion, the AV node delay decreases automatically, and the cycle continues to approach the longest interval of the AV node (that is, the slowest ventricular rate), consistent with the evasion of the merger.

U.S. Patent No. 5,527,347 to Shelton, et al., Publishes a pacing pacemaker ventricular pacing protocol in which the AV node delay is slowly increased until the fusion occurs, wherein the AV node delay point is decreases slightly. Then, the cycle repeats itself. Thus, the delay of node A-V rem cyclically within a small range, that corresponding to the fusion, for slightly lower values (ie, a higher ventricular rate).

U.S. Patent No. 5,522,858 to van der Veen, publishes a pacemaker stimulation protocol in which the delays of node A-V are gradually decreased until ventricular tracking of atrial firing occurs. In particular, the ventricles are stimulated after the depolarization impulse of the atrium reaches the ventricles, but they are not stimulated during the refractory ventricular period. The net effect is the decrease of the delay period of the A-V node, and, thus, it increases the velocity of the ventricular beat. In small increments, the delay period of node A-V is further decreased then, until ventricular tracking is observed.

U.S. Patent No. 5,480,413 to Greenhut, et al., Publishes a means for using a pacemaker to correct the velocity of the ventricular beat in the presence of atrial fibrillation / tachycardia. First, the ventricular beat is decoupled by the atrium beat by gradually increasing the ventricular beat rate (dual or multi-chamber pacemakers are switched to a single chamber heart rate mode), by means of appropriately spaced electrical stimulations. Once the velocity of the stabilized beat has been completed, at the highest ventricular beat rate, then the velocity of the ventricular pacing is slowly slowed down to the slowest speed that provides the stability of the ventricular velocity, and is sustained in this speed until the tachycardia / fibrillation disappears. Then, the action of the dual or multiple chamber pacemaker (of the atrium and ventricles) continues.

US Patent No. 5,441,522 to Schüller publishes a dual camera pacing stimulation protocol, in which the interval of the AV node cycles between the values, when the receding conduction of the ventricular pacing is delivered, the atrium is refracted until the stimulation normally timed by the pacemaker. When such a condition is seen, the interval of node A-V is shortened to a value. Once a predetermined time or number of pulses has occurred, or once a spontaneous ventricular reaction is seen within the shortened interval of node A-V, then, the longest interval of node A-V is restored.

US Patent No. 5,340,361 to Sholder, publishes a ventricular pacing protocol in which the AV node range automatically adjusts just to the lower of the intrinsic (and pathological) rate to produce a ventricular trigger that is slightly advanced for the intrinsic ventricular firing time. This invention solves the problem of abnormal retardation of the A-V node, which decreases the cardiac efficiency due to the non-optimal synchronization between the atrium and the ventricle. The atrial and ventricle firing rates are the same in this invention.

US Patent No. 5,334,220 to Sholder, publishes a ventricular pacing protocol in which the AV node interval is automatically adjusted to prevent ventricular pacing in a time that results in fusion (at the crossing point) with ventricular pacing endogenous A final value of the AV node is selected by adjusting the AV node interval incrementally, until the crossing point is reached with respect to the R wave. The final value of the AV node that is established is based on the point of certain crossing, adjusted by a small margin. Thus, this method accelerates the intrinsic velocity to ensure a conveniently short A / V node delay / interval that would otherwise worsen the cardiac pumping efficiency. When this procedure is invoked (automatically) very frequently, it is suspended for a predetermined period.

U.S. Patent No. 5,105,810 to Collins, et al., Publishes a cyclic protocol to produce a minimum voltage for ventricular heart rate., with the purpose of extending the life of the batteries used in pacemakers. The protocol uses a series of heart rate pulses of bradycardia support at a given voltage, and the ventricular pressure measurements are analyzed during the pulse train to determine if the capture has occurred. If the capture has occurred during the pulse train, the heart rate pulses of bradycardia support are sent again, once the stimulation voltage has been decreased by one degree. If the capture is the result, then the graduation of the decreasing voltage and the capture estimate continue until the capture is lost, at which point the voltage increases in an increased manner until the capture occurs.

U.S. Patent No. 4,503,857 to Bourte, et al., Publishes a ventricular cardiac rhythm protocol in which spontaneous bradycardia or tachycardia are altered, first by ventricular capture, followed by gradual increase or decrease, respectively, within the heart rate of the pulse, until a normal programmed heart rate is reached.

As can be seen in the previous inventions, pacemakers use the accelerated ventricular heart rate which adjusts the delay / interval of node A-V in a way that prevents fusion, and which controls ventricular firing solely by the imposed heart rate pulses. However, such protocols have not been optimally designed to minimize the energy consumption of the already compromised heart of the patient. Generally, the above references were designed to change the stimulation rate by adjusting the delay / interval of node A-V to produce a predetermined rate or a physiological standard.

What is needed is a pacemaker with a ventricular trigger protocol that minimizes the energy used by the heart for the contraction / pumping work. In addition, what is needed is a pacemaker with a ventricular triggering protocol in which the fastest accelerated heart rate is only slightly (ie, only a few beats per minute - ideally two or three beats per minute) greater than the Triggering velocity of the atrium at the beginning of the first cycle of the protocol. In addition, what is needed is a pacemaker for ventricular triggering that uses a heart rate protocol that performs resynchronization / fusion, as well as to produce the least amount of stress on a heart that may already be in a condition of weakness. Recently, an improved means for stimulating muscle tissue is also desired, wherein the contraction obtained is enhanced and the damage to the tissue adjacent to the electrode is decreased.

Improved myocardial function is obtained through the biphasic heart rate of the present invention. The combination of the cathode pulses with the anodic pulses of either the stimulation or the conditioning nature preserves the conduction and improved contractility of the anodic heart rate, while eliminating the drawback of increasing the stimulation threshold. The result is a depolarization wave of the increased propagation velocity. This increased rate of spread results in superior cardiac contraction resulting in improved blood flow. Improved stimulation at a lower voltage level also results in reduced power consumption and increased life of the pacemaker batteries.

DISCLOSURE OF THE INVENTION Up to now, an object of the present invention is to provide a pacemaker with a ventricular trigger protocol that minimizes the energy required for the contraction and pumping of the heart of a cardiac patient.

Another objective of the present invention is to provide a pacemaker with a ventricular firing protocol that uses the accelerated ventricular heart rate, only to a minimal degree; that is, it accelerates the heart rate by only a few beats per minute more than the intrinsic atrial firing rate.

A further objective of the present invention is to provide a pacemaker with a ventricular firing protocol with a heart rate relaxation period in which the ventricular heart rate velocity is slowly decreased to a speed only slightly (i.e., only 1 to 2 beats per minute) lower than the intrinsic tripping speed of the atrium before the start of the next cycle.

A further objective of the present invention is to directly adjust the duration of the ventricular heart rate cycle, rather than the delay of the A-V node.

A further objective of the present invention is to provide the modulation of velocity in conjunction with the ventricular cardiac rhythm of multiple sites.

The present invention accomplishes the above objectives by providing a ventricular trigger protocol that is initiated by synchronizing the QRS complex of the electrocardiogram. The time from a QRS complex to the next constitutes a practical definition of the duration of the heartbeat, thereby providing the control circuit with a ready strong reference point, which serves as a timestamp to take the time of the detonator. firing of the first electrical impulse towards the ventricle (s). In theory, a P wave with an appropriate time interval could work. However, the weak P wave could disappear in the presence of conditions such as atrial fibrillation. This is particularly true in the case of pathological hearts. Therefore, the QRS complex, because of its large amplitude, serves as the best reference point available in the electrocardiogram. However, it is understood that the practice of the initial phase of this invention amounts to indirect coordination / time with respect to atrial firing and contraction, as this is required for optimal total heart function.

The ventricular trigger protocol is activated upon the detection of a QRS complex, and an accelerated velocity of only a few beats per minute (ie no more than 3 to 5 beats per minute) is established more than the intrinsic rate of tripping of the atrium. Then, the ventricular firing rate slows down ("relaxes") slowly to a speed of just a few beats per minute (ie, no more than 2 to 3 beats per minute, ideally only 1 to 2 beats per minute) below the atrial intrinsic firing rate, which results in ventricular leakage (ie, atrial contraction and firing are no longer perfectly coordinated with ventricular contraction and firing).

Subsequently, a new cycle begins.

Thus, the present invention uses a stimulation velocity that cycles continuously from a higher velocity that is scarcely above the intrinsic velocity of the atrium state, up to a velocity that is just barely below the intrinsic velocity of the trigger. atrium. Such a stimulation protocol is expected before providing a good approximation to an optimal protocol of minimum energy requirement. Accordingly, the limited energy of the cardiac patient can be used wisely and optimally for the benefit of the already compromised patient. In summary, this technique allows the heart rate at an average speed that is just above the intrinsic velocity of the heart, to maximize the effects of heart and inotropic rhythm at minimum cardiac speeds, and, therefore, conserves the precious energy of the patient's heart.

Additionally, the ventricular firing protocol of the present inversion can be used in conjunction with the biphasic heart rate. The method and apparatus that relate to the biphasic heart rate comprising a first and second phases of stimulation, each with a stimulation phase having a polarity, amplitude, shape and duration. In a preferred embodiment, the first and second phases have different polarities In a first alternative mode, the two phases are of different amplitude In a second alternative mode, the two phases are of different duration. The first phase is bite-shaped In a fourth alternative modality, the amplitude of the first phase is in the form of a ramp In a fifth alternative mode, the first phase is administered over 200 milliseconds after the end of a century of pumping In a preferred alternative modality, the first stimulation phase is an anodic impulse at the maximum threshold amplitude, for a long duration time, and the second stimulation phase is a cathode impulse of short duration and amplitude. The alternative modalities mentioned above can be combined in different ways. It is also noted that these alternative modalities are considered to present by way of example only, and is not limiting.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 shows a cyclic relaxation-stimulation protocol in the form of saw teeth (linear decay) for the ventricular heart rate.

Figure 2 shows a cyclic relaxation-stimulation protocol of exponential decay for the ventricular heart rate.

Figure 3 is a schematic representation of the result of biphasic anodic stimulation.

Figure 4 is a schematic representation of the result of biphasic cathodic stimulation.

Figure 5 is a schematic representation of the result of low-level, long-term anodic stimulation, followed by cathodic stimulation.

Figure 6 is a schematic representation of the result of low-level, long-duration, anodic stimulation, followed by cathode stimulation.

Figure 7 is a schematic representation of the result of low-level, short-term cathode stimulation administered in a series, followed by cathodic stimulation.

Description of the preferred modalities. The bases of the present investment can be understood with reference to figures 1 and 2, which represent two cyclic stimulation-relaxation protocols for the ventricular heart rate, in which the maximum accelerated ventricular heart rate velocity is followed by relaxation to a speed just lower than the intrinsic atrial trigger velocity (corresponding to the ventricular leak). Figure 1 shows a cyclic relaxation-stimulation protocol in the form of saw teeth (linear decay). Figure 2 shows a cyclic relaxation-stimulation protocol of exponential decay.

Referring now to Figure 1, a cyclic relaxation-stimulation protocol in the form of saw teeth, for ventricular heart rate, is represented with points 102, 106 and 108 of time to illustrate the onset of accelerated ventricular heart rate at a speed A maximum of heart rate, followed by linear relaxation / decay of the heart rate speed up to a minimum C heart rate. Each cycle has a total duration of 110. The intrinsic velocity B of atrial firing is shown as a dashed reference line. Speed difference A-B is greater than speed difference B-C in this example. During the course of the linear relaxation of the ventricular heart rate, the crossing point 104 is reached when the ventricular heart rate velocity equals the atrial intrinsic firing speed B, the period between the time point 102 and the crossing point 104 represents period 112 of linear ventricular accelerated heart rate, the period between crossing point 104 and time 106 represents period 114 of linear ventricular escape. It is evident that the period 112 of linear ventricular accelerated cardiac rhythm is a period of time greater than the period 114 of linear ventricular escape. Accordingly, the average ventricular firing rate for this protocol, with the relative parameters cited above, will always be slightly greater than the intrinsic firing rate B of the atrium.

Referring now to Figure 2, the ventricular rhythm stimulation-relaxation exponential decay cardiac rhythm protocol is shown with the accelerated ventricular heart rate up to the maximum heart rate velocity A, being initiated at the 202, 206, 208 time points , followed by the exponential relaxation of the heart rate velocity to the minimum C heart rate. Each cycle has a total duration of time 210. The time course of the heart rate during the relaxation phase will be proportional to the time course of the product obtained by multiplying the maximum heart rate velocity (or the quantity A minus a selected "factor") by the proportionality e 1 / r in, where r is the time constant. The selected "factor" will typically be a value less than C. As in Figure 1, two parameters have been adjusted in Figure 2. First, the relaxation of the heart rate velocity is an exponential function of time, rather than a linear function of time. Second, the minimum velocity C of the ventricular heart rate is closer to the intrinsic atrial trigger rate B.

As Figure 1 the period between time point 202 and junction point 204 represents period 212 of exponential ventricular accelerated heart rate, and the period between junction point 204 and time point 206 represents period 214 of escape exponential ventricular The difference A-B velocity is the same in figure one and two, as are the durations 110 and 210 of the cycle. This combination of parameters produces a protocol in which the exponential ventricular accelerated cardiac rhythm period 212 of FIG. 2 is shorter than the linear ventricular accelerated cardiac rhythm period 112 of FIG. 1.

In the case of a curvilinear relaxation protocol with duration 210 of the cycle, the comparison of the ventricular accelerated heart rate period 212 and the ventricular escape period 214 of FIG. 2 reveals that its magnitudes are effectively controlled by the variations in two parameters : (AB) / (BC), and period 212 of ventricular accelerated heart rate.

Referring again to Figure 1, in the case of a linear relaxation protocol with cycle length 110, the comparison of the period 112 of ventricular accelerated heart rate and the period 114 of linear ventricular escape reveals that its magnitudes are controlled by the variation of a single parameter (AB) / (BC), or any mathematical equivalent, such as (102-104) / (104-106).

It is anticipated that different relaxation protocols will be required for different pathologies different medical situations. In addition, a virtually infinite order of relaxation protocols are possible in theory. Thus, the preferred embodiment of the present invention contemplates any monotonic relaxation protocol, where "monotonic" indicates a unidirectional change in the rate of applied ventricular heart rate. In addition, "unidirectional change" is understood to refer to a change in the rate of ventricular heart rate that is in the direction of the decreasing rate of ventricular heart rate, and that includes the periods of time in which there is no change in the velocity of ventricular heart rate.

Accordingly, the preferred embodiment of the present invention contemplates relaxation protocols beyond the two represented in FIGS. 1 and 2, as long as the relaxation protocol incorporates the unidirectional change in ventricular heart rate velocity as defined. previously. Thus, the forms of relaxation-curves can be, generally, decreasing linearly, curvilinearly decreasing, exponentially decreasing, including one or more periods at a constant heart rate rate, or combinations of these. For example, in reference to Figure 1, one can imagine a protocol in which, between time points 102 and 104, there is a small time segment in which the voltage is constant, followed by linear relaxation in it or different relaxation speed (ie the same or different slope), compared to the initial relaxation rate. In one embodiment, the same or different relaxation velocity following the short constant voltage period is maintained above the time point 106, which marks the end of a cycle and the beginning of the next cycle.

Alternative modalities include relaxation protocols in which ventricular heart rate velocities are not monotonic; that is, while the velocity of the ventricular heart rate is declining in a given cycle, the periods of time in which the ventricular heart rate velocities increase slightly may be included. In addition, alternative modalities may include the use of combinations of • different relaxation rates within a single cycle, for example, within segment 102-106, or 202-206 of time.

Typically, 'the physiological data from one or more sensor electrodes (including the electrodes that perform both, heart rate and sensitization) are used to determine if an "action criterion" has been found, to initiate a cyclic heart rate protocol if the situation demands it. Such sensitization can be aimed at 'detecting such non-limiting physiological parameters as abnormally or unacceptably long AV node delays, if atrial firing enters both left and right ventricles, the length of the QRS complex, the QRS complex magnitude, the velocity cardiac arrest, arterial and / or venous blood pressure, ventricular fibrillation, atrial fibrillation, and density probability function ("PDF"). At the end of such a cyclic heart rate protocol, the detection is performed again to determine if the additional heart rate is required. Alternatively, the detection can be conducted concurrently with a cyclic heart rate protocol.

The ventricular trigger protocol is activated with the detection of a QRS complex, and an accelerated velocity of only a few beats per minute (ie no more than three to five beats per minute) is established more than the intrinsic rate of tripping of the atrium. Then, the ventricular firing rate is slowly ("relaxed") slowed to a speed of only a few beats per minute (ie, no more than 2 to 3 beats per minute, ideally only one to two beats per minute) below the intrinsic tripping velocity of the atrium that results in ventricular leakage (ie, atrial firing and contraction are no longer perfectly coordinated with ventricular firing and contraction). Heart rates can vary from 40 to 120 beats per minute, with these velocities being greatly determined by the intrinsic physiology of the heart. Speeds that vary greatly from this range of 40 to 120 beats per minute may not be beneficial physiologically.

The center of the present invention is that ventricular heart rate velocities advance close to the intrinsic atrial firing rate to minimize the myocardial energy requirements. Generally, the practice of the present invention will result in an average ventricular rate of velocity that is just slightly greater than the intrinsic atrial firing rate. However, it is anticipated that some pathological / medical conditions will minimize cardiac energy requirements with a relaxation protocol that results in an average ventricular heart rate that is equal to, or just slightly less than, the atrial firing rate; and such relaxation protocols are well within the scope of the present invention.

The application of cyclic ventricular cardiac rhythm with any previous range of relaxation protocols, belong not only to a monoventricular heart rhythm, but also to a biventricular heart rhythm, and / or a multiple-site heart rhythm. In the case of biventricular heart rhythm, the left and right ventricles can be cyclically cardiac, either on the same or similar time protocol, or independently of one another. In addition, a heart rate electrode or several heart rate electrodes may be employed by ventricle, and the heart rate electrodes may be applied to the outer surfaces of the ventricles and / or to the internal surfaces. Typically, the internal heart rate electrodes will be applied via the vena cava and the right atrium to the right ventricle only; however, several internal heart rate electrodes are also contemplated for the left ventricle.

Additional modalities include the use of monophasic stimulation, as well as biphasic stimulation. In addition, monophasic stimulation and biphasic stimulation can be applied to either the atrium or the ventricles. Monophasic stimulation can be either cathodic or anodic, and is known to those skilled in the art. Biphasic cardiac stimulation is published in U.S. Patent Application No. 08/699, 552 to Mower, which is hereby incorporated by reference in its entirety.

Typically, the period of relaxation / cyclic heart rate will fall within the range of 3 to 30 seconds; however, longer periods are also contemplated, particularly for patients with more "difficult" pathologies.

Figure 3 represents the biphasic electrical stimulation, wherein a first stimulation phase, comprising the anodic stimuli 302, is administered having an amplitude 304 duration 306. This first stimulation phase is immediately followed by a second stimulation phase comprising a 308 cathodic stimulation of equal intensity and duration.

Figure 4 depicts biphasic electrical stimulation, wherein a first stimulation phase, comprising a sputter 402 having an amplitude 404 and a duration 406, is administered. This first stimulation phase is immediately followed by a second stimulation phase comprising anodic 408 stimulation of equal intensity and duration.

Figure 5 represents a preferred embodiment of biphasic stimulation, wherein a first stimulation phase, comprising a low level, a long-lasting anodic stimulation 502 having an amplitude 504 and a duration 506,. Is administered. This first phase of stimulation is immediately followed by a second stimulation phase comprising the cathodic stimulation 508 of conventional intensity and duration. In different alternative embodiments, the anodic 502 stimulation is: 1) of a maximum threshold amplitude; 2) less than 3 volts; 3) of a duration of approximately 2 to 8 milliseconds; 4) administered for 200 milliseconds after the heartbeat. The maximum threshold amplitude is understood to refer to the maximum amplitude of stimulation that can be administered without causing a contraction. In different alternative modalities, cathodic stimulation 508 is: 1) of short duration; 2) of approximately 0.3 to 1.5 milliseconds; 3) of great amplitude; 4) from within the approximate range of 3 to 20 volts; and / or 5) of a duration less than 0.3 milliseconds and at a voltage greater than 20 volts. In a preferred embodiment, the cathodic stimulation is about 0.8 milliseconds. In the manner published by these modalities, as well as those alterations and modifications that may be obvious upon reading this specification, a maximum membrane potential without activation is carried out in the first phase of stimulation.

Figure 6 represents a preferred alternative modality of biphasic stimulation, wherein a first stimulation phase, comprising anodic stimulation 602, is administered in a period 604 at a level 606 of increasing intensity. The ramp shape of level 606 of increasing intensity can be linear or non-linear, and the slope can vary. This anodic stimulation is immediately followed by a second stimulation phase comprising the cathodic stimulation 608 of conventional intensity and duration. In alternative embodiments, canonical stimulation 602: (1) grows to a maximum threshold amplitude less than three volts; (2) is of a duration of approximately 2 to eight milliseconds; and / or (3) is administered for 200 milliseconds after the heartbeat. Still in other alternative embodiments, the cathodic stimulation 608 is: (1) of short duration; (2) from about 0.3 to 1.5 milliseconds; (3) of a great amplitude; (4) within the approximate range of 3 to 20 volts; and / or (5) of a duration of less than 0.3 millisec and a voltage greater than 20 volts. As published in these modalities, as well as those alterations and modifications that may be obvious on reading this specification, a maximum membrane potential without activation is performed in the first phase of stimulation.

Figure 7 represents the biphasic electrical stimulation, wherein a first stimulation phase, comprising 702 series of anodic pulses, is administered at an amplitude 704. In one embodiment, the rest period 706 is of duration equal to the stimulation period 708, and it is administered at a base amplitude. In an alternative embodiment, the rest period 706 is of a different duration than the stimulation period 708, and is administered at a line basis amplitude. The rest period 706 occurs after each stimulation period 708, with the exception that a second stimulation phase, comprising the cathodic stimulation 710 of conventional intensity and duration, immediately follows the end of the series 702. In alternative modalities: (1) the total charge that is transferred through the 702 series of anodic stimulation is at a maximum threshold level, and / or (2) the first stimulation pulse of the 702 series is administered for 200 milliseconds after the heartbeat . Still in other alternative modalities, cathodic stimulation 710 is: (1) of a short duration; (2) of approximately 0.3 to 1.5 milliseconds, (3) of a large amplitude, (4) within the approximate range of 320 volts, and / or (5 3) of a duration less than 0.3 milliseconds and still per attack greater than 20 volts.

The preferred practice of the present inversion is directed to the ventricular heart rate where the heart rate velocity is marginally above and below the intrinsic heart rate of the atrium, and is timed (though indirectly) relatively to the intrinsic trigger of the heart rate. atrium to carry out the optimal coordinated cardiac function. However, situations can be anticipated in which the ventricular heart rate is affected independently of the atrial intrinsic firing.

In addition, when the rhythmicity of the atrium is pathological, the present invention can be practiced with respect to the rhythmicity of the pacemaker that gives the heart rate to the atrium. In modalities in which the atrium is given by the heart rate by extrinsic pacemakers, the clinician first establishes the rate of cardiac rhythm of the atrium, which can be fixed, or can be variable to allow the appropriate response to changes in the atrium. physical activity or other changes that would require a change in heart rate, for example, an increased heart rate during a fever period. Second, the ventricular triggering protocol is selected according to the principles described and published in this medium. It should be emphasized that the ventricular trigger protocol selection will generally be a decision made independently of the atrial beat pattern, since the atrial beat pattern is intrinsically established extrinsically, for example, by a pacemaker. However, within the approach of the present investment is to apply the teachings in this medium to the cases in which the decisions regarding the extrinsically controlled atrial and ventricular beat protocols are considered in an integrated, united manner.

In addition, test procedures can be applied to bring the optimal parameters for a patient with a particular variety of pathologies. Thus, within the approach of the present invention is to test and vary, the alternative waveforms of the stimulation pulse, for example, the durations, amplitudes, and shapes of the various waveforms required to achieve the optimum physiological parameters for a particular patient at a given time. In addition, several measurable parameters can be used to appreciate that the effects of changes in stimulus waveforms, for example, effects on pulse pressure, QRS complex duration, maximum fusion, and the production of a Minimum intrinsic heart rate, to name a few.

Having thus described the basic concept of the invention, it will be readily apparent to those skilled in the art that the following detailed statement is considered to be presented only by way of example, and is not limiting. Various alterations, improvements and modifications will occur and are considered for those with skill in the art, but are not expressly stated in this medium. These modifications, alterations and improvements are considered to be suggested by this means, and within the scope of the invention. In accordance, the invention is limited only by the following claims in the equivalents thereof.

It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention is that which is clear from the present description of the invention.

Having described the invention as above, it is claimed as property what is contained in the documents.

Claims (56)

Claims

1. A cardiac rhythm method for a heart that has an intrinsic atrial firing rate, characterized in that it comprises: applying a series of heart rate stimuli to at least one ventricle, which has an initial velocity of heart rate, where the Initial velocity of heart rate is slightly higher than the intrinsic velocity of atrial firing; and decreasing the rate of heart rate over the time of the initial heart rate to a minimum heart rate that is slightly less than the intrinsic atrial firing rate.

2. The method for cardiac cardiac rhythm according to claim 1, characterized in that it additionally comprises the physiological detection parameters to determine if the additional cardiac heart rate is needed.

3. The method for cardiac cardiac rhythm according to claim 2, characterized in that the physiological parameters are selected from the group consisting of the interval of the AV node, the entrance of the atrium to the left and right ventricles, the duration of the QRS complex, the magnitude of the QRS complex, arterial blood pressure, blood pressure of the vein, ventricular fibrillation, atrial fibrillation, and density probability function.

4. The method for cardiac cardiac rhythm according to claim 1, characterized in that the application of the heart rate stimulus and the decrease of the heart rate speed is repeated in a cyclic pattern.

5. The method for cardiac cardiac rhythm according to claim 1, characterized in that a protocol for decreasing the rate of heart rate over time is selected from the group consisting of linear, curvilinear, exponential, and combinations of these.

6. The method for cardiac cardiac rhythm according to claim 5, characterized in that the protocol for decreasing the cardiac rhythm speed includes one or more periods of time in which the cardiac rate speed remains constant.

7. The method for cardiac cardiac rhythm according to claim 1, characterized in that a protocol for decreasing the cardiac rhythm speed includes one or more periods of time in which the cardiac rate speed is kept constant.

8. The method for cardiac cardiac rhythm according to claim 1, characterized in that the initial heart rate velocity minus the intrinsic atrial firing rate is greater than the atrial intrinsic firing rate minus the minimum heart rate velocity.

9. The method for cardiac cardiac rhythm according to claim 1, characterized in that the initial heart rate velocity minus the intrinsic atrial firing rate is equal to the atrial intrinsic firing velocity minus the minimum heart rate velocity.

10. The method for cardiac cardiac rhythm according to claim 1, characterized in that the initial heart rate velocity minus the intrinsic atrial firing rate is lower than the intrinsic firing rate of the atrium minus the minimum heart rate velocity.

11. The method for cardiac cardiac rhythm according to claim 1, characterized in that the heart rate stimuli are selected from the group consisting of the monophasic stimulation and the biphasic stimulation.

12. The method for cardiac cardiac rhythm according to claim 11, characterized in that the monophasic stimulation is selected from the group consisting of cathodic stimulation and anodic stimulation.

13. The method for cardiac cardiac rhythm according to claim 11, characterized in that the biphasic stimulation comprises an anodic stimulation phase followed by a cathodic stimulation phase.

14. The method for cardiac cardiac rhythm according to claim 13, characterized in that the phase of anodic stimulation: has a magnitude equal to or less than the maximum threshold amplitude; and has an approximate shape selected from the group consisting of a square wave, an increasing ramp-shaped wave, and short-wave series of square waves.

The method for cardiac heart rate according to claim 1, characterized in that the heart rate stimulus is applied by means of several electrodes to at least one ventricle.

16. A method for cardiac cardiac rhythm for a heart with atrial atrial firing velocity, characterized in that it comprises: applying series of heart rate stimuli to at least one ventricle, where the initial heart rate is slightly greater than the rate of cardiac atrial firing rate; and decreasing the rate of initial ventricular heart rate over time to a minimum heart rate velocity that is slightly less than the rate of atrial atrial firing rate.

17. The method for the. cardiac cardiac rhythm according to claim 16, characterized in that the application of the heart rate stimulus and slowing of the heart rate is repeated in a cyclic pattern.

18. The method for cardiac cardiac rhythm according to claim 16, characterized in that a protocol for decreasing the initial ventricular heart rate is selected from the group consisting of linear, curvilinear, exponential, and combinations of these.

19. The method for cardiac cardiac rhythm according to claim 18, characterized in that the protocol for lowering the initial heart rate includes one or more periods of time in which the heart rate rate remains constant.

20. The method for cardiac cardiac rhythm according to claim 16, characterized in that a protocol for slowing the heart rate includes one or more periods of time in which the heart rate speed is kept constant.

21. The method for cardiac cardiac rhythm according to claim 16, characterized in that the ventricular heart rate velocity minus the cardiac rate velocity of • atrial firing is greater than atrial atrial firing velocity minus minimum ventricular heart rate velocity.

22. The method for cardiac rhythm according to claim 16, characterized in that the ventricular heart rate velocity minus the atrial atrial atrial velocity is equal to the atrial atrial atrial velocity velocity minus the heart rate velocity minimal ventricular

23. The method for cardiac cardiac rhythm according to claim 16, characterized in that the ventricular heart rate velocity minus the atrial atrial atrial velocity velocity is lower than the atrial atrial atrial velocity velocity minus the heart rate velocity minimal ventricular

24. The method for cardiac cardiac rhythm according to claim 16, characterized in that the heart rate stimulus is selected from the group consisting of monophasic stimulation and biphasic stimulation. -

25. The method for cardiac cardiac rhythm according to claim 24, characterized in that the monophasic stimulation is selected from the group consisting of cathodic stimulation and anodic stimulation.

26. The method for cardiac cardiac rhythm according to claim 24, characterized in that the biphasic stimulation comprises an anodal stimulation phase followed by a cathodic stimulation phase.

27. The method for cardiac cardiac rhythm according to claim 26, characterized in that the anodic stimulation phase: has a magnitude equal to or less than the maximum threshold amplitude; and has an approximate shape selected from the group consisting of square wave, wave in the form of increasing ramp, and short wave series of square waves.

28. The method for cardiac cardiac rhythm according to claim 16, characterized in that the heart rate stimuli are applied by means of several electrodes to at least one ventricle. -

29. An implantable cardiac stimulator for performing the heart rate of a heart, the heart has an intrinsic atrial firing rate, the cardiac stimulator characterized in that it comprises: several electrodes adapted to apply the heart rate stimulus to the heart; and the pulse generator circuit connected to the various electrodes and adapted to generate the electrical pulses as the heart rate stimulus; wherein a series of heart rate stimuli are applied to at least one ventricle, having an initial heart rate, the initial heart rate being slightly greater than the intrinsic atrial firing rate, and wherein the velocity of Heart rate decreases over time from the initial heart rate to a minimum heart rate that is slightly less than the intrinsic atrial trigger rate.

30. The cardiac stimulator for performing the cardiac cardiac rhythm according to claim 29, characterized in that it additionally comprises: the sensor of the physiological parameter to determine if the additional cardiac heart rate is needed.

31. The cardiac stimulator for performing cardiac cardiac rhythm according to claim 30, characterized in that the physiological parameters are selected from the group consisting of: the AV node interval, the entrance from the atrium to the left and right ventricles, the duration of the QRS complex, QRS complex magnitude, arterial blood pressure, vein blood pressure, cardiac velocity, ventricular fibrillation, atrial fibrillation, and density probability function.

32. The cardiac stimulator for performing the cardiac cardiac rhythm according to claim 29, characterized in that applying the heart rate stimulus and decreasing the heart rate speed is repeated in a cyclic pattern.

33. The cardiac stimulator for performing cardiac cardiac rhythm according to claim 29, characterized in that a protocol for decreasing the heart rate velocity over time is selected from the group consisting of: linear, curvilinear, exponential, and combinations of these .

34. The cardiac stimulator for performing cardiac cardiac rhythm according to claim 33, characterized in that the protocol for decreasing the heart rate speed includes one or more periods of time in which the cardiac rate speed is kept constant.

35. The cardiac stimulator for performing the cardiac cardiac rhythm according to claim 29, characterized in that a protocol for decreasing the heart rate speed includes one or more periods of time in which the heart rate speed is kept constant.

36. The cardiac stimulator for performing cardiac cardiac rhythm according to claim 29, characterized in that the initial heart rate velocity less than the atrial intrinsic firing rate is greater than the intrinsic firing velocity of the atrium minus the heart rate velocity minimal.

37. The cardiac stimulator for performing cardiac cardiac rhythm according to claim 29, characterized in that the initial heart rate velocity less than the intrinsic atrial trigger velocity is equal to the intrinsic atrial trigger velocity minus the velocity of the atrium. minimal heart rate

38. The cardiac stimulator for performing the cardiac cardiac rhythm according to claim 29, characterized in that the heart rate velocity initil less than the intrinsic atrial firing rate is lower than the atrial intrinsic firing rate minus the minimum heart rate velocity .

39. The cardiac stimulator for performing cardiac cardiac rhythm according to claim 29, characterized in that the heart rate stimuli are selected from the group consisting of: monophasic stimulation and biphasic stimulation.

40. The cardiac stimulator for performing cardiac cardiac rhythm according to claim 39, characterized in that the monophasic stimulation is selected from the group that - consists of: cathodic stimulation and anodic stimulation.

41. The cardiac stimulator for performing cardiac cardiac rhythm according to claim 39, characterized in that the biphasic stimulation comprises an anodic stimulation phase and a cathodic stimulation phase.

42. The cardiac stimulator for performing cardiac cardiac rhythm according to claim 41, characterized in that the anodic stimulation phase has a magnitude equal to or less than the maximum threshold amplitude; and has an approximate shape that is selected from the group consisting of: square wave, wave in the form of an increasing ramp, and series of square waves of short duration.

43. The cardiac stimulator for performing cardiac cardiac rhythm according to claim 29, characterized in that the heart rate stimuli are applied by means of several electrodes to at least one ventricle.

44. An implantable cardiac stimulator for performing the heart rhythm of a heart, the heart has an atrial firing rate of the atrium, the cardiac stimulator characterized in that it comprises: several electrodes adapted to apply the heart rate stimulus to the heart; and the pulse generator circuit connected to the various electrodes and adapted to generate the electrical pulses as the heart rate stimulus; wherein a series of heart rate stimuli are applied to at least one ventricle, having an initial heart rate, the initial heart rate being slightly greater than the intrinsic atrial firing rate, and wherein the velocity of The heart rate decreases over time from the initial heart rate to a minimum heart rate that is slightly less than the intrinsic atrium trigger rate.

45. The cardiac stimulator for performing cardiac cardiac rhythm according to claim 44, characterized in that applying the heart rate stimulus and decreasing the heart rate speed is repeated in a cyclic pattern.

46. The cardiac stimulator for performing cardiac cardiac rhythm according to claim 44, characterized in that a protocol for decreasing the initial ventricular heart rate velocity over time is selected from the group consisting of: linear, curvilinear, exponential, and combinations of these.

47. The cardiac stimulator for performing cardiac cardiac rhythm according to claim 46, characterized in that the protocol for decreasing the initial cardiac rhythm speed includes one or more periods of time in which the cardiac rate speed remains constant.

48. The cardiac stimulator for performing cardiac cardiac rhythm according to claim 44, characterized in that a protocol for decreasing the cardiac rhythm speed includes one or more periods of time in which the cardiac rate speed remains constant.

49. The cardiac stimulator for performing cardiac cardiac rhythm according to claim 44, characterized in that the initial ventricular heart rate velocity minus the atrial atrial atrial rate is greater than the atrial atrial rate of the atrium less the minimum ventricular heart rate velocity.

50. The cardiac stimulator for performing cardiac cardiac rhythm according to claim 44, characterized in that the initial ventricular heart rate velocity minus the atrial atrial atrial velocity is the same as the atrial atrial rate heart rate minus the velocity of minimum ventricular heart rate.

51. The cardiac stimulator for performing cardiac cardiac rhythm according to claim 44, characterized in that the initial ventricular heart rate velocity minus the atrial atrial atrial rate is less than the atrial atrial rate of heart rate minus the velocity of minimum ventricular heart rate.

52. The cardiac stimulator for performing cardiac cardiac rhythm according to claim 44, characterized in that the heart rate stimuli are selected from the group consisting of: monophasic stimulation and biphasic stimulation.

53. The cardiac stimulator for performing cardiac cardiac rhythm according to claim 52, characterized in that the monophasic stimulation is selected from the group consisting of: cathodic stimulation and anodic stimulation.

54. The cardiac stimulator for performing cardiac cardiac rhythm according to claim 52, characterized in that the biphasic stimulation comprises an anodic stimulation phase and a cathodic stimulation phase.

55. The cardiac stimulator for performing cardiac cardiac rhythm according to claim 54, characterized in that the anodic stimulation phase has a magnitude equal to or less than the maximum threshold amplitude; and has an approximate shape that is selected from the group consisting of: square wave, wave in the form of an increasing ramp, and series of square waves of short duration.

56. The cardiac stimulator for performing cardiac cardiac rhythm according to claim 29, characterized in that the heart rate stimuli are applied by means of several electrodes to at least one ventricle. Summary A method and apparatus for the ventricular-cyclic heart rate, starting at a speed just above the intrinsic atrial firing rate (accelerated heart rate), followed by relaxation to a range just below the intrinsic firing rate of the atrium (ventricular leak). The method and apparatus can be applied to one or both ventricles, and you can use one or more electrodes per ventricle. The electrode (s) can be applied to the internal or external ventricular surfaces. Relaxation protocols, as a function of time, can be linear, curvilinear to include exponentials, or mixtures of these. In addition, relaxation protocols may include one or more periods of time during which the heart rate rate remains constant. Typically, the average rate of ventricular heart rate using this invention will be slightly greater than the intrinsic atrial firing rate, through alternative modalities encompassing the average ventricular heart rate speeds that are equal to or slightly less than the intrinsic velocity. of the atrium, are also taken into account. The application of this method and this apparatus to a heart in need of this will produce a heart with an energy output requirement minimized optimally.