MXPA99012000A

MXPA99012000A - Augmentation of electrical conduction and contractility by biphasic cardiac pacing

Info

Publication number: MXPA99012000A
Application number: MXPA/A/1999/012000A
Authority: MX
Inventors: M Mower Morton
Original assignee: M Mower Morton
Filing date: 1999-12-17
Publication date: 2001-12-04

Abstract

La presente invención se refiere al aumento de conducción y contractilidad eléctrica por ritmo cardiaco bifásico. Una primer fase de estimulo se administra al tejido muscular. Estáprimer fase de estimulo tiene predefinidas polaridad, amplitud y duración. Una segunda fase de estimulo luego se administra al tejido muscular. Estásegunda fase también tiene una Polaridad, amplitud y duración predefinidas. Las dos fases se aplican secuencialmente. Contrario al pensamiento actual, el estimulo anódico primero se aplica, seguido por estimulo catódico. De estámanera, la conducción de pulso a través del músculo cardíaco se mejora junto con un incremento en contractilidad. La técnica también puede aplicarse a estimulo de tejido muscular grande diferente a músculo cardíaco.

Description

INCREASE OF CONTRACTILITY AND ELECTRIC DRIVING BY BIPHIC CARDIAC RATE OF THE INVENTION This invention relates in general to a method for stimulating muscle tissue. In particular, this invention relates to a method for cardiac stimulation and rhythm generation with biphasic waveforms, which leads to improved conduction and contractility. BACKGROUND OF INTAINMENT The function of the cardiovascular system is vital for survival. Through the circulation of blood, body tissues obtain the necessary nutrients and oxygen and discard waste substances. In the absence of circulation, cells begin to undergo irreversible changes that lead to death. The muscular contractions of the heart are the driving force behind the circulation. In the heart muscle, the muscle fibers are interconnected in branching networks that disperse in all directions through the heart. When any portion of this network is stimulated, a wave of depolarization passes to all its parts and the entire structure contracts as a unit. Before a muscle fiber can be stimulated for contraction, its membrane must be polarized. A muscle fiber REF: 31467 it generally remains polarized, until it is stimulated by some change in its environment. A membrane can be stimulated in electrical, guímica, mechanical or by temperature change. The minimum stimulation force required to produce a contraction is known as the threshold stimulus. The maximum stimulation amplitude that can be administered without producing a contraction is the maximum sub-threshold amplitude. When the membrane is electrically stimulated, the impulse amplitude required to produce a response depends on a number of factors. First is the duration of current flow. Since the total transferred load is equal to the current amplitude for the duration of the pulse, the increased stimulus duration is associated with a decrease in the threshold current amplitude. Second, the percentage of applied current that currently travels the membrane varies inversely with the size of the electrode. Third, the percentage of applied current that currently travels the membrane varies directly with the proximity of the electrode to the tissue. In fourth, the impulse amplitude required to produce a response depends on the stimulus synchronization within the excitability cycle. Through a large part of the heart are aggregates and filaments of heart muscle tissue .S? I-iai ^^ '^^ B specialized. This tissue comprises the cardiac conduction system and serves to initiate and distribute depolarization waves through the myocardium. Any interference or blogging in conduction of the cardiac impulse, can cause an arrhythmia or marked change in the speed or rhythm of the heart. Sometimes a patient who suffers from a driving disorder can be helped by an artificial pacemaker. This device contains an energized electric stimulator with a battery stick. When the artificial pacemaker is installed, electrodes are usually threaded through veins within the right ventricle or within the right atrium and right ventricle, and the stimulator is planted under the skin on the shoulder or abdomen. The terminals are planted in intimate contact with the heart tissue. The pacemaker then transmits rhythmic electrical impulses to the heart and the myocardium responds by rhythmic contraction. Implantable medical devices for marking the heart rhythm are well known in the art and have been used in humans since about the mid-1960s. Either cathodic or anodic current can be used to stimulate the myocardium. However, the anodic current is not considered clinically useful. The cathodic current comprises electrical pulses of polarity - negative%. This type of current depolarizes the cell membrane when unloading the membrane capacitor and directly reduces the membrane potential towards threshold level. The cathodic current ^ by directly reducing the resting membrane potential towards the threshold has a threshold current of one-half to one-third less at the end of the diastole than the anodic current. The anodic current comprises electrical pulses of positive polarity. The effect of anodic current is to hyper-polarize the membrane at rest. Upon sudden termination of the anodic pulse, the membrane potential returns to resting levels, overstresses the threshold and a propagated response occurs. In general there is opposition to the use of anodic current to stimulate the myocardium, due to higher thresholds of stimulation that lead to the use of an upper current resulting in a battery discharge of an implanted device and a deteriorated longevity. Additionally, the use of anodic current for cardiac stimulation is discouraged, due to the suspicion that the anodic contribution to depolarization can, particularly at higher voltages contribute to arrhythmogenesis. Virtually all artificial pacemaker is performed using stimulus pulses with negative polarity or in the case of bipolar systems, the cathode is closer to the myocardium than the anode. When the use of anodic current is described, it is generally like a charge of magnitude minute or glue used to dissipate residual charge in the electrode. This does not affect or condition the myocardium itself. This use is described in U.S. Pat. No. 4,543,956 granted to Herscovici. The use of a three-phase waveform has been described in US Patents. Nos. 4,903,700 and 4,821,724 granted to higham et al., The patent of the US. No. 4,343,312 granted to Cals et al. Agui, the first and third phases have nothing to do with the myocardium per se, but are only considered to affect the electrode surface itself. In this way, the load applied in these phases is very low amplitude. Finally, the biphasic stimulus is described in the patent of the U.S.A. No. 4,402,322 granted to Duggan. The goal of this description is to produce unnecessary voltage duplication by a large capacitor in the output circuit. The phases of the biphasic stimulus described are of equal magnitude and duration. Improved myocardial function is obtained through the biphasic rhythm production of the present invention. The combination of cathode pulses with anodic pulses either of a nature of stimulation or conditioning, retains improved rhythm conduction and contractility áj ^ ,,. ^^^^^^^^^^^. ^ _,., - niiiMpMitimTtffif - **! ' - Anodic r-fflrifflrrfflimf, while eliminating the disadvantage of an increased stimulus threshold. The result is an increased propagation velocity depolarization wave ^. This increased rate of propagation results in a superior cardiac contraction that leads to improvement in blood flow. Improved stimulus at a lower voltage level also results in reduced power consumption and increased life for the pacemaker batteries. As with the heart muscle, the striated muscle can also be stimulated electrically, mechanically, mechanically or by changing temperature. When the muscle fiber is stimulated by a motor neuron, the neuron transmits an impulse that activates all the muscle fibers within its control, that is, the muscular fibers in its motor unit. Depolarization in one region of the membrane stimulates adjacent regions to depolarize as well and a depolarization wave travels over the membrane in all directions away from the stimulus site. In this way, when a motor neuron transmits an impulse, all the muscle fibers in its motor unit are stimulated for simultaneous contraction. The minimum intensity to produce a contraction is called the threshold stimulus. Once this level of stimulus has been reached, the general belief is that increasing the level will not increase the contraction. Additionally, already *? ~ - ~ * -J £ £ *** £ * ».

Because the muscle fibers within each muscle are organized into motor units and each motor unit is controlled by a single motor neuron, all the muscle fibers in a muscle unit are stimulated at the same time. However, all WF 'muscle is controlled by very different motor units that respond to different stimulus thresholds. In this way, when a given stimulus is applied to a muscle, some motor units can respond while others can not. The combination of cathode and anodic pulses of the present invention also provides improved muscle contraction where electrical muscle stimulation is indicated due to muscle or neural damage. When the nerve fibers have been damaged due to trauma or disease, the muscle fibers in the regions supplied by the damaged nerve fiber tend to atrophy and be wasted. A muscle that you can not exercise can decrease to half your usual size in a few months. When there is no stimulus, not only muscle fibers will decrease in size if they will not fragment and degenerate and will be replaced by connective tissue. Through electrical stimulation, muscle tone can be varied, so that by healing or regenerating nerve fibers, viable muscle tissue remains.

When the tissue has been damaged due to injury or illness, the. Regenprative process can be aided by electrical stimulation. Improved muscle contraction present invention is obtained. Anodic or conditioning, results in contraction of a greater number of motor units at a lower voltage level leading to a higher muscle response. ** X w COMPENDIUM OF THE INVENTIONIt is therefore an object of the present invention to provide an enhanced stimulation of cardiac tissue. Another objective of the present invention is to increase cardiac output or cardiac circulation volume through a superior cardiac contraction that leads to greater volume of expenditure. Another object of the present invention is to increase the impulse propagation velocity. Another objective of the present invention is to extend the life of the pacemaker battery. A further objective of the present invention is to obtain effective cardiac stimulation at a lower voltage level.

A further object of the present invention is to eliminate the need for placing electrical thermics in intimate contact with tissue to obtain tissue stimulation. A further objective of the present invention is to provide an enhanced stimulation of muscle tissue. A further objective of the present invention is to provide contraction of a greater number of muscle motor units at a lower voltage level. A method and apparatus for muscle stimulation according to the present invention include the administration of biphasic stimulation to muscle tissue, wherein both cathodic and anodic impulses are administered. In accordance with one aspect of this invention, the stimulus is administered to the myocardium in order to improve myocardial function. According to a further aspect of this invention, this stimulus is administered to the deposit or accumulation of cardiac blood. This allows cardiac stimulation unnecessarily by placing electrical terminals in intimate contact with the cardiac tissue. According to a still further aspect of this invention, the stimulus is administered to striated muscle tissue to evoke muscular response. The method and apparatus of the present invention comprise a first and a second stimulus phase, with each stimulus phase having a polarity, amplitude, ^ ím? », - * s ** i!? &« Et5 j? > Eli! form and duration. In a preferred embodiment, the first and second phases have different polarities. In an alternate mode, the two phases are of different amplitude. In a second e & jsjmma mode, the two phases are of different duration. In a third alternate mode, the first phase is a discounted waveform. In a fourth alternate mode, the amplitude of the first phase is in ramp. In a second alternate modality, the first phase is administered over 200 milliseconds after the heartbeat; that is, greater than 200 milliseconds after finishing a pumping / heartbeat cycle. In a preferred alternate mode, the first stimulus phase is an anodic pulse at a sub-threshold amplitude maximum for a long duration and the second stimulus phase is a cardiac pulse of short duration and high amplitude. It is noted that the aforementioned alternative modalities can be combined in different ways. It is also noted that these alternative modalities are intended as an example only and are not limiting. The pacemaker electronic components required to practice the method of the present invention are well known to those skilled in the art. The current electronic components are capable of being programmed to supply a variety of pulses including acute pinholes described. * & ** »- - ** Jifl > M * ii «A BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic description of a major biphasic anodic stimulus. Figure 2 is a schematic representation of a main biphasic cathode stimulus. Figure 3 is a schematic representation of a low-level, low-level main anodic stimulus, followed by conventional cathode stimulation. Figure 4 is a skeletal representation of main anodic stimulus of low level in ramp and long duration, followed by conventional cathode stimulation. Figure 5 is a short-term, low-level, main-level, anodic stimulus, which is administered serially followed by conventional cathode stimulation. Figure 6 is a line of conduction velocity transverse to the fiber against resultant rhythm duration per two-phase forward anodic pulse. Figure 7 graphs the conduction velocity parallel to the fiber versus the duration of the rhythm resulting from the anodic biphasic pulse in advance. DETAILED DESCRIPTION The present invention relates to biphasic electrical stimulation of muscle tissue. Figure 1 illustrates biphasic electrical stimulation in which a asas-fisg first phase of stimulus (¿emprende anodic stimulus 102 which has amplitude 104 and duration 106. The first stimulus phase is followed immediately by a second stimulus phase comprising cathodic stress 108 of equal intensity and duration. Figure 2 illustrates biphasic electrical stimulation wherein a first stimulus phase comprises cathodic stimulus 202 which has amplitude 204 and duration 206. This first stimulus phase is immediately followed by a second stimulus phase comprising an anodic stimulus 208 of equal intensity and duration ^ Figure 3 illustrates a preferred embodiment of the present invention, wherein a first stimulus phase is administered comprising a low level, long duration anodic stimulus 302 which has amplitude 304 and duration 306. This first stimulus phase is immediately followed by a second stimulus phase comprising 308 cathodic stimulation of conventional stimuli. intensity and duration. In an alternate embodiment of the invention, the anodic stimulus 302 is at a maximum amplitude-sub-threshold. In yet another alternate embodiment of the invention, the anodic stimulus 302 is less than three volts. In another alternate embodiment of the invention, the anodic stimulus 302 is of a duration of about 2 to 8 milliseconds. In yet another alternative embodiment of the invention, the cathode stimulus 308 is of short duration. In another alternate embodiment of the invention, the cathode stimulus 308 is from about 0.3 to 0.8 milliseconds. Still in another alternate embodiment of the invention, the cathode stimulus 308 is of high amplitude. In another alternate embodiment of the invention, the cathode stimulus 308 is in the approximate range of 3 to 20 volts. In yet another embodiment of the present invention, the cathode stimulus 308 is of a shorter duration than 0.3 millisecond and a greater voltage than 20 volts. In another alternate embodiment, the anodic stimulus 302 is administered over 200 milliseconds after the heartbeat. In the way described by these modalities, as well as alterations and modifications that may be evident upon reading this specification, a maximum membrane potential is achieved without activation in the first stimulus phase. Figure 4 illustrates an alternate preferred embodiment of the present invention, wherein a. First stimulus phase comprises anodic stimulus 402 is administered over period 404 with ascending intensity level 406. Ramp of ascending intensity level 406 may be linear or non-linear, the slope may vary. This anodic stimulus is immediately followed by a second stimulus phase comprising cathodic stimulus 408 of conventional intensity and duration. In an alternate embodiment of the invention, the anodic stimulus 402 amounts to a maximum sub-threshold altitude. In yet another alternate embodiment of the invention, the anodic stimulus 402 amounts to a maximum amplitude which is less than 3 volts. In another alternate embodiment of the invention, the anodic stimulus 402 is a duration of about 2 to 8 mils. In yet another alternative embodiment of the invention, the cathode stimulus 408 is of a short duration. In another alternate embodiment of the invention, the cathode stimulus 408 is approximately .3 to .8 milliseconds. In yet another alternative embodiment of the invention, the cathode stimulus 408 is of high amplitude. In another alternate embodiment of the invention, the cathode stimulus 408 is in the approximate range of 3 to 20 volts. In yet another alternate embodiment of the present invention, the cathode stimulus 408 is of a duration less than 0.3 milliseconds and at a higher voltage than 20 volts. In another alternate embodiment, the anodic stimulus 402 is administered over 200 milliseconds after the heartbeat. In the way described by these modalities, as well as alterations and modifications that may be evident upon reading this specification, a maximum membrane potential without activation is achieved in the first stimulus phase. Figure 5 illustrates biphasic electrical stimulation wherein a first stimulation phase comprising the Sia series 502 of anodic pulses is administered at amplitude 504. In one embodiment, rest period 506 is of equal duration to stimulus period 508 and is administered in baseline amplitude. In an alternate embodiment, the rest period 506 is of a different duration than the stimulus period 508 and is administered to the baseline amplitude. The rest period 506 occurs after each stimulus period 508 except for the second stimulus phase comprising cathodic stimulation 510 of conventional intensity and duration immediately following the completion of the series 502. In an alternate embodiment of the invention, the total charge transferred through the anodic stimulus series 502 is at the maximum sub-threshold level. In yet another alternate embodiment of the invention, the first stimulus pulse of series 502 is administered over 200 milliseconds after the heartbeat. In another alternate embodiment of the invention, the cathodic stimulus 510 is of short duration. In yet another alternate embodiment of the invention, the cathodic stimulus 510 is from about 0.3 to 0.8 rr? Lisys. In another alternate embodiment of the invention, the cathodic stimulus 510 is of high amplitude. In yet another alternate embodiment of the invention, the cathodic stimulus 510 is in the approximate range of 3 to 20 volts. In another alternate embodiment of the invention, the cathodic stimulus 510 is of a ratio less than 0.3 milliseconds and at a higher voltage than 20 volts. EXAMPLE 1 The stimulus and propagation characteristics of the myocardium were studied in isolated hearts, using pulses of different polarities and phases. The experiments were carried out on five isolated Langendorff perfusion rabbit hearts. Driving velocity in the epicardium is measured using a set of bipolar electrodes. Measurements were made between 6 millimeters and 9 millimeters from the stimulus site. The trans-membrane potential is recorded using a floating intracellular micro-electrode. The following protocols were examined: monophasic cathodic pulse, monophasic anodic pulse, forward biphasic cathode pulse and anodic biphasic pulse. Table 1 describes the conduction velocity transverse to the direction of fibers for each stimulus protocol administered, with stimuli of 3, 4 and 5 volts and a pulse duration of two milliseconds.

Transverse Conduction Speed to the Fiber Direction, duration of 2 msec 3 V 4V 5V Single Phase Cathode 18.9 ± 2.5 cm / sec 21.4 + 2.6 cm / sec 23.3 ± 3.0 cm / seg Single Phase Anodic 24.0 ± 2.3 cm / sec 27.5 + 2.1 cra / sec 31.3 + 1.7 cm / sec Cathode Early Biphasic 27.1 + 1.2 cm / sec 28.2 + 2.3 cm / sec 27.5 + 1.8 cm / seg Advanced Anodic Biphasic 26.8 + 2.1 cm / sec 28.5 ± 0.7 cm / sec 29.7 + 1.8 cm / sec Table 2 describes the conduction velocity on fiber direction for each stimulus protocol administered with stimuli of three, four and five volts and pulse duration of two milliseconds. TABLE 2 Conduction Speed Transverse to the Fiber Direction, duration of 2 msec 3 V 4V 5V Single-phase Cathode 45.3 ± 0.9 cm / sec 47.4 + 1.8 cm / sec 49.7 + 1.5 cm / seg Single-phase Anodic 48.1 + 1.2 cm / sec 51.8 ± 0.5 cm / sec 54.9 + 0.7 cm / sec TABLE 2 (Cont.) Conduction Speed Transverse to the Fiber Direction, duration of 2 msec 3 V 4V 5V Cathode Biphasic Advance 50.8 ± 0.9 cm / sec 52.6 + 1.1 cm / sec 52.8 ± 1.7 cm / sec Biphasic Anodic Advanced 52.6 ± 2.5 cm / sec 55.3 + 1.5 cm / sec 54.2 + 2.3 cm / sec The differences in conduction velocities between the cathodic monophasic, monophasic anodic, biphasic cathodic advanced and biphasic advanced anodic were found to be significant (p <0.001). From the transmembrane potential measurements, the maximum upward stroke (dV / dt) max) of the action potentials was found to correlate well with changes in conduction velocity in the longitudinal direction. For a pulse of four volts of duration of two milliseconds, (dV / dt) max was 63.5 ± 2.4 V / sec for cathode pulses and 75.5 + 5.6 V / sec for anodic pulses. EXAMPLE 2 The effects of varying rhythm protocols in cardiac electrophysiology were analyzed using isolated rabbit hearts prepared Langendorff. The stimulus was applied to the heart at a rectangular pulse of ^^^ ss? ¡s ^^ =:? ~ ..S ** ¡& ^,?. Z ^ * Í? constant voltage. The following protocols were examined: monophasic anodic pulse, monophasic cathodic pulse, biphasic anodic pulse forward and biphasic cathodic pulse. The administered voltage was increased in stages of one volt of 1 to 5 volts for both anodic and cathodic stimuli. The duration was increased in stages of two milliseconds from 2 to 10 milliseconds. Epicardial conduction velocities were measured along and transverse to the direction of left ventricular fibers at a distance between three to six millimeters from the free wall of the left ventricle. Figures 6 and 7 illustrate the effects of stimulus pulse duration and the stimulus protocol administered at driving speeds. Figure 6 illustrates the speeds measured between three millimeters and six millimeters transverse to the fiber direction. In this region, the cathodic monophasic stimulus 602 demonstrates the slowest conduction velocity for each pulse duration of stimulus tested. This is followed by anodic monophasic stimulus 604 and forward cathodic biphasic stimulus 606. The higher conduction velocity is demonstrated by the forward anodic biphasic stimulus 608. Figure 7 illustrates the speeds measured between three millimeters and six millimeters parallel to the fiber direction. In this region, the cathodic monophasic stimulus 702 demonstrates the slowest conduction velocity for each pulse duration of stimulus tested. Results of anodic monophasic stimulus velocity 704 and early cathodic biphasic stimulus 706 are similar, with anodic monophasic stimulus showing slightly faster velocities. The fastest conduction velocity is demonstrated by anodic biphasic forward stimulus 708. In one aspect of the invention, electrical stimulation is administered to the heart muscle. The anodic stimulus component of the biphasic electrical stimulus increases cardiac contractility by tissue hyperpolarization before excitation, leading to faster impulse conduction, more intracellular calcium release and the resulting superior cardiac contraction. The cathodic stimulus component eliminates the disadvantages of anodic stimulation, resulting in effective cardiac stimulation at a lower voltage level than would be rewarded with only the anodic stimulus. This in turn extends the life of the pacemaker battery and reduces tissue damage. In a second aspect of the invention, the biphasic electrical stimulus is administered to the cardiac blood reservoir, that is, the blood entering and surrounding the heart. This allows the cardiac stimulation without need for placing electrical terminals in intimate contact with the cardiac tissue. In a third aspect of the invention, the biphasic electrical stimulus is applied to striated muscle tissue. 5 The combination of anodic and cathodic stimulus results in the contraction of a greater number of muscle motor units at a lower voltage level resulting in improved muscle response. Having thus described the concept The basic description of the invention will be readily apparent to those with skill in the art that the following detailed description is intended to be presented by way of example only and not limitation. Various alterations improvements and modifications will occur to you and are pretended to those with skill in the specialty but not expressly established aguí. These modifications, alterations and improvements are intended to be suggested in this way and within the spirit and scope of the invention. In addition, the rhythm pulses described in this The specifications are well within the capabilities of existing electronic pacemaker components with appropriate programming. Accordingly, the invention is limited only by the following claims and their equivalents.

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.

Claims

CLAIMS Having described the invention as above, the content of the following claims is claimed as property: 1. A method for producing biphasic electronic heart rate, characterized by comprising: defining a first stimulus phase with a first phase polarity, a first phase amplitude, a first phase form and a first phase duration to precondition the myocardium to accept subsequent stimulation; defining a second stimulus phase with a polarity opposite to the first phase polarity, a second phase amplitude which is greater in absolute value than the first phase amplitude, a second phase form and a second phase duration; and apply the first stimulus phase and the second stimulus phase sequentially to the cardiac tissue.
2. The method for producing biphasic electrical heart rate of claim 1, characterized in that the first phase polarity is positive.
3. The method for producing biphasic electric heart rate of claim 1, characterized in that the first phase amplitude is ramping from the baseline value to a second value.
4. The method for producing biphasic electrical heart rate of claim 1, characterized in that the first stimulus phase further comprises a series of stimulus pulses of predetermined amplitude, polarity and duration.
5. The method for producing biphasic electric heart rate of claim 4, characterized in that the first stimulus phase further comprises a series of resting periods.
6. The method for producing biphasic electrical heart rate of claim 5, characterized in that applying the first stimulus phase further comprises applying a resting period of a baseline amplitude after at least one stimulus pulse.
7. The method for producing biphasic electrical heart rate of claim 6, characterized by the period of rest is of equal duration to the stimulus pulse.
8. The method for producing biphasic electrical heart rate of claim 1, characterized in that the first phase amplitude is at a maximum subthreshold amplitude.
9. The method for producing biphasic electrical heart rate of claim 8, characterized in that the maximum sub-threshold amplitude is approximately 0.5 to 3.5 volts. -2 =
10. The device for producing biphasic electric heart rate of claim 1, characterized in that the first phase duration is at least as long as the second phase duration.
11. The method for producing biphasic electric heart rate of claim 1, characterized in that the first phase duration is from about 1 to 9 milliseconds.
12. The method for producing biphasic electrical heart rate of claim 1, characterized in that the second phase duration is approximately 0.2 to 0.9 milliliters.
13. The method for producing biphasic electrical heart rate of claim 1, characterized 15 because the second phase amplitude is approximately 2 to 20 volts.
14. The method for producing biphasic electrical heart rate of claim 1, characterized in that the second phase duration is less than 0.3. 20 milliseconds and the second phase amplitude is greater than 20 volts.
The method for producing biphasic electrical heart rate of claim 3, characterized in that the second value is at a sub-threshold amplitude 25 maximum. * pty
16. The method for producing biphasic electrical heart rate of claim 15, characterized in that the maximum sub-threshold amplitude is about 0.5 to 3.5 volts.
17. The method for producing biphasic electric heart rate of claim 3, characterized in that the first phase duration is at least as long as the second phase duration.
18. The method for producing biphasic electrical heart rate of claim 3, characterized in that the first phase duration is approximately 1 to 9 milliseconds.
19. The method for producing biphasic electric heart rate of claim 3, characterized by the second phase duration is approximately 0.2 to 0.9 milliseconds.
20. The method for producing biphasic electrical heart rate of claim 3, characterized in that the second phase amplitude is approximately 2 volts at 20 volts.
21. The method for producing biphasic electrical heart rate of claim 3, characterized in that the second phase duration is less than 0.3 milliseconds and the second phase amplitude is greater than 20 volts.
22. The method for producing biphasic electrical heart rate of claim 1, characterized in that the first stimulus phase is initiated greater than 200 milliseconds after completing a heartbeat cycle.
23. A method for producing biphasic electrical heart rate, characterized in that it comprises: initiating the amplitude of a first stimulus phase to precondition the myocardium, wherein the first stimulus phase comprises: a positive polarity; a first phase amplitude, a first phase form; and a first phase duration, wherein the first phase amplitude is approximately 0.5 to 3.5 volts, wherein the first phase duration is approximately 1 to 9 milliseconds and wherein the first stimulus phase is initiated greater than 200 milliseconds after to end a heartbeat cycle; initiate the application of a second stimulus phase, where the second stimulus phase comprises: a negative polarity; a second phase amplitude; a second phase form; and a second phase duration, wherein the second phase amplitude is from about 4 volts to 20 volts and wherein the second phase duration is from about 0.2 to 0.9 milliseconds and applying the first stimulus phase and the second stimulus phase in sequence to the cardiac tissue.
24. An apparatus for biphasic electrical heart rate characterized in that it comprises means for defining a first stimulus phase and capable of supplying a first phase polarity, a first phase amplitude, a first phase form and a first phase duration for pre-conditioning the myocardium to accept subsequent stimulation; means for defining a second phase of stimulus and capable of supplying a polarity opposite to the first phase polarity, a second phase amplitude which is greater in absolute value than the first phase amplitude, a second phase form and a second duration of phase; and means for applying the first phase of stimulation and the second phase of stimulation in sequence to cardiac tissue.
25. The apparatus for producing biphasic electric heart rate according to claim 24, characterized in that the first phase polarity is positive.
26. The apparatus for producing biphasic electrical heart rate according to claim 24, characterized in that the first phase amplitude is ramping from the baseline value to a second value.
27. The apparatus for producing biphasic electrical heart rate of claim 26, characterized in that the second value is a maximum subthreshold amplitude.
28. The apparatus for producing biphasic electric heart rate according to claim 27, characterized in that the maximum subthreshold amplitude is approximately 0.5 to 3.5 volts.
29. The apparatus for producing biphasic electric heart rate according to claim 26, characterized in that the first phase of duration is at least as long as the second phase of duration.
30. The apparatus for producing biphasic electrical heart rate according to claim 26, characterized in that the first phase of duration is approximately 1 to 9 milliseconds.
31. The apparatus for producing biphasic electrical heart rate in accordance with claim 1 26, characterized by the second phase duration is approximately 0.2 to 0.9 milliseconds.
32. The apparatus for producing biphasic electrical heart rate according to claim 26, characterized in that the second amplitude phase is approximately 2 to 20 volts.
33. The apparatus for producing biphasic electrical heart rate according to claim 26, characterized in that the second duration phase is less than 0.3 milliseconds and the second amplitude phase is greater than 20 volts.
34. The apparatus for producing biphasic electric heart rate according to claim 24, characterized in that the first stimulus phase further comprises a series of stimulus pulses of an amplitude., polarity and duration predetermined.
35. The apparatus for producing biphasic electrical heart rate according to claim 34, characterized in that the first stimulation phase further comprises a series of rest periods.
36. The apparatus for producing biphasic electrical heart rate according to claim 35, characterized in that the means for applying the first stimulation phase further comprises means for applying a rest period of a baseline amplitude after at least one pulse of stimulus.
37. The apparatus for producing biphasic electric heart rate according to claim 36, characterized in that the rest period is of equal duration to the duration of the stimulus pulse.
38. The apparatus for producing biphasic electric heart rate according to claim 24, characterized in that the first amplitude phase is in * ». *. a maximum subthreshold amplitude.
39. The apparatus for producing biphasic electric heart rate according to claim 38, characterized in that the maximum subthreshold amplitude is about 0.5 to 3.5 volts.
40. The apparatus for producing biphasic electric heart rate according to claim 24, characterized in that the first phase of duration is at least as long as the second phase of duration.
41. The apparatus for producing biphasic electric heart rate according to claim 24, characterized in that the first phase of duration is approximately 1 to 9 milliseconds.
42. The apparatus for producing biphasic electrical heart rate in accordance with the claim 24, characterized in that the second phase of duration is approximately 1 to 9 milliseconds.
43. The apparatus for producing biphasic electric heart rate according to claim 24, characterized in that the second amplitude phase is from about 2 volts to 20 volts.
44. The apparatus for producing biphasic electric heart rate according to claim 24, characterized in that characterized in that the second phase-duration is less than 0.3 milliseconds and the second amplitude is greater than 20 volts.
45. The apparatus for producing biphasic electric heart rate according to claim 24, characterized in that the first stimulation phase is initiated for above 200 milliseconds after completing the heartbeat cycle
46. An apparatus for producing biphasic electric heart rate, characterized in that it comprises: means for initiating the application of a first stimulus phase for pre-conditioning the myocardium, wherein the first stimulation phase has: a positive polarity, a first phase amplitude, a first phase form; and a first phase duration, wherein the first phase amplitude is about 0.5 to 3.5 volts; the first phase duration is approximately 1 to 9 milliseconds; and the first stimulus phase starts more than 200 milliseconds after finishing a heartbeat cycle; means for initiating the application of a second stimulus phase, wherein the second stimulus phase has: a negative polarity, a second phase amplitude, a second phase form; and a second phase duration, wherein the second phase amplitude is from about 4 volts to 20 volts; and the second phase duration is from about 0.2 to 0.9 milliseconds; and means for applying the first phase of stimulation and the second phase of stimulation in sequence to the cardiac tissue The present invention relates to the increase in conduction and contractility due to biphasic heart rhythm. A first stimulus and stimulus is administered to the muscle tissue. This first stimulus phase has predefined polarity, amplitude and duration. A second stimulus phase is then administered to the muscle tissue. This second phase also has a predefined polarity, amplitude and duration. The two phases are applied sequentially. Contrary to current thinking, the anodic stimulus is first applied, followed by cathodic stimulation. In this way, the conduction of pulse through the cardiac muscle is improved together with an increase in contractility. The technique can also be applied to stimulation of large muscle tissue other than cardiac muscle.