Implantable lead assembly

Abstract

The invention relates to an implantable lead assembly comprising an implantable first lead, an implantable second lead and a control unit, the first and second leads being electrically connected to the control unit by a connector wire, wherein the control unit is configured to establish a potential difference between the first and second leads such that a current can flow between the two leads, the first lead is configured to be positioned in the right ventricle of the heart, and the second lead comprises a coil comprising a non-insulated portion at its distal end, wherein the non-insulated portion is configured to be positioned in the coronary sinus and in the left lateral vein in the left ventricular myocardium, and optionally comprises a central lumen that runs longitudinally through said coil.

Description

Technical Field

[0001] This invention relates to an implantable lead assembly comprising an implantable first lead, an implantable second lead, and a control unit. The first and second leads are electrically connected to the control unit via connector wires. The control unit is configured to establish a potential difference between the first and second leads, allowing current to flow between the two leads. The first lead is configured to be positioned in the right ventricle of the heart, and the second lead includes a coil with a non-insulated portion at its distal end, wherein the non-insulated portion is configured to be positioned in the coronary sinus and a left venous vein in the left ventricular myocardium. Optionally, the second lead includes a central lumen extending longitudinally through the coil. Technical Background

[0002] It has been shown that applying a microcurrent along with an electric field directly to the heart can improve cardiac function in patients with heart failure (Kosevic, Dragana et al. “Cardio-microcurrent device for chronic heart failure: first-in-human clinical study.” ESC heart failure vol. 8,2(2021): 962-970). For this purpose, a microcurrent is applied between an epicardial patch lead placed outside or inside the pericardium on the free wall of the left ventricle and a coil lead placed in the right ventricle. Examples of such patch leads are disclosed, for example, in WO2016 / 016438 or WO 2006 / 10132.

[0003] Furthermore, it can be shown that, at the level of cultured cardiomyocytes, the application of microcurrents modulates myofibroblasts for cardiac repair and regeneration (Somesh DB et al. “Microcurrent-Mediated Modulation of Myofibroblasts for Cardiac Repair and Regeneration”. International Journal of Molecular Sciences. 2024, 25, 3268. doi.org / 10.3390 / ijms25063268).

[0004] To place the patch wire on the heart, the chest cavity is opened surgically—an invasive procedure with inherent risks, making it less acceptable to patients. It also requires collaboration between cardiologists and cardiothoracic surgeons, making the procedure more laborious. Furthermore, because the patch wire has a larger conductive surface area compared to, for example, common coil leads, the battery charge is depleted more quickly, necessitating a higher ampere count to achieve the current density required for effective treatment of the target tissue.

[0005] Therefore, there is a need for a lead assembly system that can be implanted minimally invasively and can ensure long-term and effective treatment of the heart. Summary of the Invention

[0006] In order to address the needs described above, the object of the present invention is to provide a lead assembly that is implanted via a vein and enables effective and prolonged treatment of the heart, and allows the system to be implanted entirely percutaneously.

[0007] The present invention provides an implantable lead assembly comprising an implantable first lead, an implantable second lead, and a control unit. The first and second leads are electrically connected to the control unit via connector wires. The control unit is configured to establish a potential difference between the first and second leads, allowing current to flow between the two leads. The first lead is configured to be positioned in the right ventricle of the heart, and the second lead includes a coil with a non-insulated portion at its distal end, wherein the non-insulated portion is configured to be positioned in the coronary sinus and in the left ventricular myocardium.

[0008] According to one embodiment of the invention, the coil included in the second lead includes a central lumen extending longitudinally therethrough.

[0009] According to an embodiment of the present invention, the coil is a multi-strand coil, including 2, 3, 4, 5, 6, 7, or 8 wires, preferably including 4 wires.

[0010] According to another embodiment of the invention, the non-insulating portion includes a cap and / or a welded and polished area at its distal tip, preferably wherein the cap and / or distal tip comprises a non-invasive cylindrical shape.

[0011] According to another embodiment of the invention, the non-insulating portion has a diameter between about 0.70 mm and about 1.10 mm, between about 0.75 mm and about 1.05 mm, even between about 0.80 mm and about 1.00 mm, between about 0.85 mm and about 0.95 mm, or between about 0.87 mm and about 0.92 mm, preferably about 0.9 mm.

[0012] According to one embodiment of the invention, the non-insulating portion has a length of at least about 20 mm, at least about 30 mm, at least about 40 mm, at least about 50 mm, at least about 60 mm, at least about 70 mm, at least about 80 mm, at least about 90 mm, or at least about 100 mm, preferably at least about 50 mm.

[0013] According to another embodiment of the invention, the non-insulating portion has at least about 60 mm. 2 At least approximately 90mm 2 At least approximately 120mm 2 At least approximately 150mm 2 At least approximately 180mm 2 At least approximately 200mm 2 At least approximately 230mm 2 At least approximately 260mm 2 Or at least approximately 290mm 2 Preferably at least about 150mm 2 The conductive surface.

[0014] According to an embodiment of the invention, the second lead includes a first insulating member that encloses its connector wire in a first insulating portion near the non-insulated portion and is configured to be positioned in the coronary sinus.

[0015] According to a specific embodiment of the invention, the first insulating member includes a thickness between about 0.05 mm and about 0.37 mm, or between about 0.05 mm and about 0.26 mm, or between about 0.07 mm and about 0.23 mm, or between about 0.10 mm and about 0.20 mm, or between about 0.13 mm and about 0.17 mm, preferably about 0.15 mm, and / or wherein the first insulating portion has a diameter between about 1.21 times and about 1.80 times, or between about 1.21 times and about 1.45 times, or between about 1.24 times and about 1.42 times, or between about 1.27 times and about 1.39 times, or between about 1.13 times and about 1.36 times, preferably about 1.33 times, of the diameter of the non-insulating portion.

[0016] According to another embodiment of the invention, the second lead includes a second insulation member that encloses its connector wire in a second insulating portion adjacent to the first insulating portion and configured to be positioned in the right ventricle and superior vena cava.

[0017] According to another embodiment of the invention, the thickness of the second insulating member is about 0.15 mm to about 0.80 mm, or about 0.15 mm to about 0.55 mm, or about 0.20 mm to about 0.50 mm, or about 0.25 mm to about 0.45 mm, or about 0.30 mm to about 0.40 mm, preferably about 0.30 mm, of the diameter of the non-insulating portion, and / or the diameter of the second insulating portion is about 1.38 times to about 2.78 times, or about 1.38 times to about 2.18 times, or about 1.48 times to about 2.08 times, or about 1.58 times to about 1.98 times, or about 1.68 times to about 1.88 times, preferably about 1.78 times, of the diameter of the non-insulating portion.

[0018] According to one embodiment of the invention, the non-insulated portion includes a plurality of coil segments configured to operate independently.

[0019] According to a specific embodiment of the invention, the non-insulated portion includes at least 2 coil segments, at least 3 coil segments, at least 4 coil segments, at least 5 coil segments, at least 6 coil segments, at least 7 coil segments, or at least 8 coil segments, preferably 6 coil segments; and at most 12 coil segments, at most 11 coil segments, at most 10 coil segments, and at most 9 coil segments.

[0020] According to another embodiment of the invention, the length of the coil segment is about 3 mm to about 45 mm, about 5 mm to about 40 mm, about 6 mm to about 35 mm, about 7 mm to about 30 mm, about 8 mm to about 27 mm, about 9 mm to about 23 mm, or about 10 mm to about 20 mm of the length of the non-insulated portion; and / or wherein the length of the coil segment is about 0.05 times to about 0.90 times, about 0.10 times to about 0.80 times, about 0.12 times to about 0.7 times, about 0.14 times to about 0.60 times, about 0.16 times to about 0.50 times, about 0.18 times to about 0.4 times, or about 0.20 times to about 0.30 times of the length of the non-insulated portion.

[0021] According to one embodiment of the invention, the second lead includes an attachment member at its distal end, preferably wherein the attachment member has an anchor, hook, screw, or cane shape; particularly preferably wherein the attachment member has an anchor or hook shape with an integrated blood seal.

[0022] According to one embodiment of the invention, an implantable lead assembly is configured to apply a microcurrent between two electrodes to treat heart failure. Attached Figure Description

[0023] This disclosure will be more readily understood when considered in conjunction with the accompanying drawings and by referring to the following detailed description.

[0024] Figure 1This is a schematic illustration of the arrangement of a lead assembly according to a preferred embodiment of the invention, the lead assembly including a control unit (not shown) and first and second leads 10, 20, wherein the control unit is connected to the first and second leads 10, 20 via connector lines 11, 21, the first lead 10 being disposed inside the right ventricle of the heart, and the second lead 20 being disposed inside the myocardium of the left ventricle of the heart.

[0025] Figure 2 This is an illustration of a second lead 20 according to a preferred embodiment of the present invention, schematically showing (A) a second lead 20 including a first insulating portion 26 and a second insulating portion 28, and (B) a cross-sectional view of the second lead 20 according to this embodiment, including a partial cross-sectional view of the central lumen 22 at its distal tip.

[0026] Figure 3 This is an illustration of a second lead 20 according to another preferred embodiment of the invention, schematically showing (A) a second lead 20 including only the first insulating portion 26, and (B) a cross-sectional view of the second lead 20 according to this embodiment.

[0027] Figure 4 This is an illustration of the second lead 20 according to another preferred embodiment of the invention, schematically showing that the non-insulated portion 23 of the second lead 20 includes 6 independent coil segments 29 in (A) and 5 independent coil segments 29 in (B).

[0028] Figure 5 This is a schematic illustration of the arrangement of the internal coil electrodes and the external flat electrodes inside and outside the heart according to a comparative example.

[0029] Detailed description of the preferred implementation scheme

[0030] The invention will be explained in more detail below with reference to the accompanying drawings. In the drawings, the same elements are indicated by the same reference numerals.

[0031] To facilitate understanding of this specification, certain terms are defined first. Additional definitions are provided throughout the detailed description.

[0032] It should be noted that the term "a" or "an" entity refers to one or more of the same entity; for example, "coil segment" is understood to mean one or more coil segments. Therefore, the terms "a," "one or more," and "at least one" are used interchangeably in this document.

[0033] Furthermore, the term “and / or” as used herein should be considered as a specific disclosure of each of the two specified features or components in the presence or absence of the other. Therefore, the term “and / or” as used in phrases such as “A and / or B” herein is intended to include “A and B”, “A or B”, “A” (alone), and “B” (alone). Similarly, the term “and / or” as used in phrases such as “A, B, and / or C” is intended to cover each of the following: A, B, and C; A, B, or C; A or C; A or B; B or C; A and C; A and B; B and C; A (alone); B (alone); and C (alone).

[0034] It should be understood that wherever the terms “include” are used to describe aspects in this document, other similar aspects described by “consisting of” and / or “substantially consisting of” are also provided.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art relating to this disclosure. For example, Korpas, David. Implantable cardiac devices technology. Berlin: Springer, 2013; Troutman, Leslie. Dictionary of Medical Technology. RQ 32.3 (1993): 421-423 provide a general dictionary for those skilled in the art of the many terms used in this disclosure.

[0036] Units, prefixes, and symbols are represented in their International System of Units (SI) accepted form. Numerical ranges include the numerals that define the range. The headings provided herein are not intended to limit the various aspects of this disclosure, which can be obtained by referring to the entire specification. Therefore, the terms defined thereafter are defined more fully by referring to the entire specification.

[0037] The term "about" is used herein to mean approximately, roughly, around, or within its region. When the term "about" is used in conjunction with a numerical range, it modifies the range by extending the boundaries above and below the value. Typically, the term "about" can modify values ​​above and below the value by, for example, a variation of 10% upward or downward (higher or lower).

[0038] The terms "coil lead" or "wound lead" are used interchangeably herein and refer to longitudinally implanted medical devices. In this context, the terms "coil electrode" or "wound electrode" are used interchangeably herein and refer to the conductive portion of a lead capable of conducting current through organic tissue. It should be understood that the design of the coil lead and electrode must ensure their primary function, namely, the distribution of current through organic tissue. Therefore, typically, a coil lead is an assembly comprising at least one wire or filament wound in a coil shape. Such coil leads typically comprise flexible, biocompatible, and biostable materials to conform to the geometry of the target tissue.

[0039] The terms “mounting,” “attachment,” “fixing,” and “fastening” are used to describe the positioning or attachment of a lead to organic tissue. In the context of this disclosure, a lead may be attached by hooking onto or screwing into organic tissue.

[0040] In the context of this invention, the term "organic tissue" refers to external or internal organs, such as, for example, the brain, nervous tissue, heart, kidneys, liver, stomach, intestines, gallbladder, pancreas, and skin.

[0041] The term "biocompatibility" or "biocompatible" describes the appropriate biological requirements of one or more biological materials used in a medical device and the material's ability to function in a particular application under appropriate host response. In the context of this invention, the term "biocompatibility" specifically means the ability of a material in an assembly to function in vivo without causing harmful local or systemic reactions. The term "biostability" or "biostable" refers to the ability of a material to maintain its physical and chemical integrity after implantation into living tissue.

[0042] The term "current" refers to electric current, and can be direct current or alternating current. During the intended medical treatment, the current density at the coil electrodes will preferably be adjusted to 0.1 to 100 μA / cm². 2 More preferably, it is adjusted to 0.5 to 10 μA / cm 2 .

[0043] Therefore, the present invention provides an implantable lead assembly, preferably an implantable DC lead assembly, comprising an implantable first lead 10, an implantable second lead 20, and a control unit. The first lead 10 and the second lead 20 are electrically connected to the control unit via connector lines 11 and 21. The control unit is configured to establish a potential difference between the first lead 10 and the second lead 20, allowing current (preferably DC) to flow between the two leads 10 and 20. The first lead 10 is configured to be positioned in the right ventricle of the heart, and the second lead 20 includes a non-insulated portion 23 at its distal end, wherein the non-insulated portion 23 is configured to be positioned in a left vein in the left ventricular myocardium. The control unit also includes a battery storing electrical energy required to operate the lead assembly.

[0044] According to a preferred embodiment of the invention, the coil included in the second lead 20 includes a central lumen 22 extending longitudinally therethrough.

[0045] According to a preferred embodiment of the invention, the implantable lead assembly is configured to apply a microcurrent to the heart between two leads 10, 20, preferably for the treatment of heart failure.

[0046] Implantable lead assembly can be implanted via veins, thus significantly reducing the invasiveness of the microfluidic approach compared to using patch leads, resulting in less patient discomfort and facilitating the clinical acceptance and frequency of use of this method.

[0047] The two flexible connector wires 11 and 21 of leads 10 and 20 (configured to extend side-by-side from the control unit to the right atrium of the heart and branch there) and the control unit are electrically insulated from the environment. The control unit is configured to create a potential difference between the two distal electrodes of the two leads 10 and 20. The potential difference allows current (preferably direct current) to flow between the two distal electrodes.

[0048] The first lead 10 (hereinafter also referred to as the right ventricular coil lead 10) includes a coil electrode having a non-insulating portion at its distal end configured to be positioned in the right ventricle. Figure 1 The black portion of the first lead 10 in the diagram; similarly shown as... Figure 2 and Figure 3 Part 23 of the second lead in the middle). Figure 1 The non-insulated portion at the distal end of the first lead 10 (similarly shown as...) Figure 2 and Figure 3 The length of the second lead portion 23) is predetermined by the size of the right ventricular cavity between the tricuspid valve and the top of the heart, and can be between 6 cm and 8 cm. The right ventricular coil lead 10 may include an anchoring tip, which is preferably positioned within the right ventricle, contacting the ventricular wall from the inside. However, any attachment component 30 known in the art is also possible.

[0049] The second lead 20 (hereinafter also referred to as the left ventricular coil lead 20) also includes a coil electrode and may have a smaller diameter than the right ventricular coil lead 10 because it can enter the coronary sinus and be pushed into the left ventricular vein, a branch of the left ventricular myocardium, preferably into the posterior ventricle of the left myocardium, or alternatively or optionally into a descending coronary vein, primarily a marginal vein, central vein, or left posterior ventricular vein, preferably into the posterior ventricular vein of the left myocardium.

[0050] The coil of the left ventricular coil lead 20 is preferably a hollow assembly having a central lumen 22 that runs longitudinally through it, and includes a non-insulated (or exposed) portion 23 at its distal end.

[0051] In a preferred embodiment, at least one of the conductive components external to the control unit comprises a metallic material having inherent corrosion resistance, high biocompatibility, and / or radiation impermeability. These properties can be evaluated according to the ISO 10993 series of standards, such as ISO 10993-15, ISO 10993-17, and / or ISO 10993-18. The conductive components external to the control unit may include, but are not limited to, coil leads 10, 20 and connector wires 11, 21. Specifically, at least one of the connector wires 11, 21 and coil leads 10, 20 may include, be primarily composed of, or be made of a conductive material having one or more of the properties specified above.

[0052] In a preferred embodiment, the coil electrodes of the left ventricular coil lead 20 and / or the right ventricular coil lead 10 comprise a metallic material, preferably a metal alloy. The metal alloy may contain platinum or a platinum alloy, such as a platinum-iridium alloy, which exhibits low corrosion tendency due to its high positive standard potential (≥1.18 V). Platinum and its alloys possess inherent corrosion resistance, high biocompatibility, and radiopaque properties, making them suitable candidates for a range of medical applications.

[0053] In another preferred embodiment, all conductive components in the conductive path of at least one lead of the lead assembly are made of the same metallic material. The conductive path of a lead may include a first lead (10) and its connector wire (11) or a second lead (20) and its connector wire (21). If the housing of the control unit is not used as an electrode (as is sometimes implemented in pacemakers), the housing may not be considered a conductive component of the conductive path. If the housing is used as an electrode, it may also be a conductive component of the conductive path. Typically, the housing may preferably be made of titanium or at least comprise titanium. The metallic material of the conductive components in the conductive path of at least one lead of the lead assembly may exhibit inherent corrosion resistance, high biocompatibility, and / or radiation impermeability. Using the same metallic material or alloys of the same group within one or both leads increases stability against corrosion effects by avoiding electrochemical potential differences. Preferably, the metallic material is a metallic alloy, such as a platinum-containing metallic alloy. Even more preferably, the metallic alloy is a platinum-iridium alloy.

[0054] At least one of the coil leads 10 or 20, together with its corresponding connector lines 11 and 21, can be further designed as a single structural element. In other words, the coil leads 10 and / or 20 with connector lines 11 and / or 21 can be configured as a single piece. Therefore, the inner conductor and active electrode surface of each lead and connector line are designed as a structural element / assembly. This mechanically stabilizes the corresponding electrode along its entire length from the lead connector to the lead tip, as there are no potentially weak connection sections that could lead to failure. This minimizes the risk of breakage during implantation, medical treatment, and anticipated explantation. Generally, it minimizes the risk of breakage under any kind of stress, especially tensile stress.

[0055] When a potential difference is applied between the two leads 10 and 20 via the control unit, a direct current flows through the myocardium in the ventricular region. Depending on the preferred direction of current flow, the electrode of either lead 10 or 20 can be set as a cathode or anode.

[0056] The control unit is preferably programmable to predetermine time intervals during which a potential difference is maintained to obtain direct current (DC) flow. These intervals can range from a few minutes, 30 minutes, or an hour to several hours, days, or months, with the first lead 10 acting as the anode to define the current flow. After a predetermined time, the current direction can be reversed, with the first lead 10 becoming the cathode, and a similar time interval is provided after such a first time interval. This changes the direction of current flow. This sequence of reversals in current flow can continue for extended periods, such as months or even years.

[0057] Since the impedance between the two leads 10 and 20 can depend on the direction of current flow, the current intensity can also be changed while reversing the current flow. The amount of direct current is predetermined to be well below the stimulation threshold, specifically chosen to have 0.1 μA / cm. 2 Up to 1mA / cm 2 The current density. The control unit may include controls for maintaining the current density below a maximum threshold.

[0058] The reverse current must be executed quasi-smoothly, that is, the current density is reduced to zero within a few minutes and then raised to a predetermined new DC density level with the opposite leading sign, in order to avoid any rhythm disturbances that could potentially lead to abnormalities or arrhythmias.

[0059] The control unit can also be programmable to apply arbitrary voltage and / or current waveforms. Waveforms can include sine waves, sawtooth waves, square waves, triangle waves, and various forms of pulses. In a particularly preferred embodiment, the control unit can be configured to apply a combination of DC voltage / current and AC voltage / current.

[0060] In one embodiment, the control unit can be configured to apply a DC component of voltage or current and an AC component of voltage or current. More specifically, the absolute voltage or current value of the DC component can be greater than the absolute peak amplitude of the corresponding voltage or current value of the AC component. In this way, the DC voltage or current can be modulated by the AC component without reversing the polarity of the applied voltage or current.

[0061] In another preferred embodiment, the DC component of the voltage or current may be below a threshold for the normal physiological stimulation of the myocardium. When the DC component, which remains below the threshold, is modulated with an additional AC component, the sum of the peak amplitudes of the DC component and the AC component of the voltage or current may be below or above the threshold for the normal physiological stimulation of the myocardium.

[0062] According to the present invention, a finite DC component can be understood as any frequency component of the electric field and / or current below 1 Hz. In other embodiments, it can be referred to as a frequency below 0.1 Hz or even below 0.001 Hz. Accordingly, the frequency components of voltage and / or current above any of these values ​​can be referred to as AC.

[0063] It is understood that the application of direct current according to the present invention is fundamentally different from the application of non-stationary alternating current or current pulses. In particular, current pulses are widely used for pacing or defibrillation purposes. Such current pulses typically have a pulse width of 0.5 ms to 1 ms (but are not limited thereto). Therefore, it will be clear to those skilled in the art that such pulses used in the prior art contain a wide range of high-frequency components, which contrasts sharply with the characteristics of currently used direct current.

[0064] A pacemaker is a device that delivers electrical pulses to the heart, which trigger contractions if the heart's own pulse generator (such as the sinoatrial node) malfunctions for any reason. To ensure these pulses are delivered at the correct time via implanted electrodes, the pacemaker is configured to continuously measure the heart's ECG and check if the heart is generating its own pulses that can trigger contractions. At times when the heart's own pulses are not being recorded, the pacemaker delivers an electrical pulse of sufficient strength to trigger a contraction.

[0065] Therefore, pacemaker electrodes have two functions: (i) sensing the heart's (inherent) ECG, and (ii) conditionally transmitting electrical pulses that trigger contractions.

[0066] Sensing the ECG is a crucial function in pacemaker therapy. To prevent oversensing (when inappropriate electrical activity is misinterpreted as appropriate intrinsic cardiac activity) or undersensing (a lack of perception of cardiac signals [permanent or intermittent]), the electronic input circuitry responsible for sensing has filter characteristics typically tailored for a real ECG and is impermeable to direct current. Similarly, the pulses emitted by the pacemaker do not have a direct current component.

[0067] On the other hand, a defibrillator is a device designed to detect arrhythmias (such as ventricular tachycardia or ventricular fibrillation) that are so pronounced that the heart is no longer able to pump adequately. If these are detected, the defibrillator is configured to deliver a strong electrical pulse (shock) to restore the heart's rhythm.

[0068] Similar to a pacemaker, the heart's ECG is continuously monitored via sensor electrodes to detect corresponding ECG changes. To avoid erroneous or unnecessary pulse delivery, the electronic input circuitry used for sensing is equipped with appropriate filters that prevent any direct current from passing through. The pulses can be configured differently, but there is no DC component.

[0069] Therefore, the current pulses according to the prior art may not be confused with the steady or quasi-steady direct current discussed herein. In fact, as discussed in Dragana Kosevic et al.: "Cardio -microcurrent device for chronic heart failure: first-in-human clinical study", ESC HEART FAILURE, vol.8, no.2, 9 February 2021, the application of direct current according to the present invention has particular advantages for cardiac treatment.

[0070] Effective treatment of the heart by applying continuous microcurrents and corresponding electric fields is primarily due to the fact that a wide distribution of current and electric field can be achieved in confined areas of the myocardium. In this art, this has been achieved by using conductive patch leads (typically approximately 20 to 35 cm long). 2 The conductive area of ​​the patch lead is attached to the pericardium surrounding the affected myocardial wall, primarily the left ventricle, but also potentially the right ventricle. Typically, the coil electrode is placed in the right ventricle and used as the counter electrode. In a configuration where the patch lead is attached to both the pericardium and the right ventricular coil lead, the right ventricular coil lead is permanently in motion due to continuous cardiac activity, while the patch lead remains almost stationary because the pericardium moves minimally during cardiac contraction.

[0071] However, in the arrangement of this invention, where the patch leads are replaced by a left ventricular coil lead 20 in the venous coronary system, a different current and field distribution is generated. Due to the movement of the electrodes of the two leads relative to each other, the three-dimensional movement, rotation, and contraction of the heart result in a corresponding spatial distribution of current and voltage. Both the right ventricular coil lead 10 in the right ventricle and the left ventricular coil lead 20 in the venous coronary system move freely in space. The continuous motion of the heart results in a three-dimensional field distribution, and although the left ventricular coil lead 20 has a smaller area in the venous coronary system compared to typical patch leads, this distribution results in effective and widespread current and voltage penetration into the myocardium.

[0072] The central lumen 22 of the left ventricular coil lead 20 allows for implantation using a coronary guidewire (on-lead wire (OTW)). OTW technology is well-known in the art and is one of the mainstays of percutaneous coronary intervention (PCI) methods, allowing for easy and precise guidance of a medical device to a specific area of ​​the body. OTW technology typically involves guiding an atraumatic guidewire with controllable distal and proximal ends to a specific area of ​​the patient's body in a first step using a natural or artificial body orifice or blood vessel and / or central circulation system. In a second step, the proximal end of the guidewire, external to the body, is inserted into the central lumen 22 of the medical device (in the context of this disclosure, the hollow left ventricular coil lead 20), and the medical device is advanced and guided along the guidewire to the intended atraumatic location (delivery) in the target vessel. The guidewire is then removed. OTW technology has advantages over other implantation techniques because the guidewire, due to its controllable distal and proximal ends and its much smaller diameter than the medical device to be implanted, can be safely and easily implanted by a technician. Then, the guidance provided by the guidewire makes it possible to implant medical devices precisely and easily.

[0073] In order to safely place the left ventricular coil lead 20 into the branch venous system of the heart, it needs to have the necessary flexibility to follow the twists and turns of the vascular system, the necessary tensile and compressive strength to be easy and safe to insert, and must be constructed to be non-invasive.

[0074] The flexibility and tensile and compressive strength of such coils are determined by many factors, such as the material properties of the wires used, the geometry and design of the coil and wires (e.g., shape, diameter, and pitch), coil structure, and manufacturing techniques.

[0075] One way to achieve a favorable balance between good flexibility and good tensile and compressive strength in such coils is to utilize a multi-strand design instead of a single-strand coil. Multi-strand coils (also known as “multi-start,” “multi-thread,” or “multi-wire” coils) have multiple leads (or “starts”) wound around a central axis. This design increases the effective pitch of the coil, allowing it to withstand higher axial loads compared to a single-strand coil with the same lead diameter and material, while allowing a suitable degree of lateral movement. Due to the increased pitch, multi-strand coils are able to transmit greater axial stress while maintaining the same cross-sectional area / profile. The higher pitch helps prevent localized stress concentrations that could lead to premature fatigue or failure, making multi-lead coils more durable. When pulled during implantation and explantation or after extended tension, multi-strand coils can also exhibit reduced elasticity and residual elongation due to their larger pitch, making them more resistant to deformation over time under load. Therefore, according to a preferred embodiment of the present invention, the left ventricular coil lead 20 is a multi-strand coil comprising 2, 3, 4, 5, 6, 7, or 8 wires (preferably 4 wires). The right ventricular coil lead 10 may also be a multi-strand coil having the same or a different number of wires as the left ventricular coil lead 20.

[0076] Due to their structure as wound coils, the coil leads typically include free ends at their terminals. Since the left ventricular coil lead 20 and the right ventricular coil lead 10 are pushed through the vascular system, their tips (hereinafter also referred to as "distal tips") must be configured so as not to damage tissue during the insertion process. Exposed wire ends at the distal tip tip could potentially cause tissue damage during insertion and make insertion significantly more difficult. To prevent tissue damage, according to a preferred embodiment of the invention, the non-insulated portion 23 of the left ventricular coil lead 20 includes a cap 24 and / or a welded polished section at its distal tip, preferably wherein the cap 24 and / or the distal tip comprises a non-invasive cylindrical shape. The cap 24 is configured to cover the lead end but still allow the guidewire to pass through it. Preferably, the cap 24 is securely attached to the distal end of the tip, for example by welding, gluing, crimping, or a combination thereof. The lead ends may also be welded together at the distal tip, and the welded portion is subsequently polished to obtain a smooth and uniform surface at the distal tip. It should be understood that the cap 24 and the weld can be combined, and any shape of the cap 24 and the weld is possible, which is non-invasive and presents the least possible resistance to the blood vessel during insertion.

[0077] The left ventricular coil lead 20 is configured to enter the coronary sinus and be pushed into a branch of the left ventricular myocardium, such as the left ventricular posterior vein, alternatively or optionally into a descending coronary vein, primarily a marginal vein, central vein, or left posterior vein, preferably in the left myocardium. This has the advantage of being able to apply current directly to the myocardium. Therefore, the left ventricular coil lead 20 should preferably have a smaller diameter than the coronary sinus to avoid excessive obstruction of blood flow. According to Gilard et al. (“Angiographic anatomy of the coronary sinus and its tributaries.” Pacing and clinical electrophysiology: PACE vol. 21,11 Pt 2(1998): 2280-4), the central vein has an average diameter of 2.62+ / -1.26 mm, the great cardiac vein has an average diameter of 3.55+ / -1.24 mm, and the left posterior vein has an average diameter of 2.25+ / -1.2 mm. Therefore, according to a preferred embodiment of the invention, the non-insulated portion 23 of the left ventricular coil lead 20 has a diameter between about 0.70 mm and about 1.10 mm, between about 0.75 mm and about 1.05 mm, even between about 0.80 mm and about 1.00 mm, between about 0.85 mm and about 0.95 mm, or between about 0.87 mm and about 0.92 mm, preferably about 0.9 mm.

[0078] The microcurrent, along with the electric field, is preferably applied directly to the myocardium over the largest possible tissue area of ​​the heart to ensure effective cardiac treatment. This can be achieved by determining the size of the non-insulated portion 23 of the left ventricular coil lead 20 to be approximately the same length as the target marginal vein, allowing a field to be established across a large area of ​​tissue. Furthermore, the left ventricular coil lead 20 should be positioned such that the maximum amount of damaged myocardium is between the two leads 10, 20, the electric field and current cover the largest possible volume of myocardium, and the field established between the leads 10, 20 is as homogeneous as possible to achieve the most homogeneous distribution of the field and current. Therefore, according to a preferred embodiment of the invention, the non-insulated portion 23 of the left ventricular coil lead 20 has a length of at least about 20 mm, at least about 30 mm, at least about 40 mm, at least about 50 mm, at least about 60 mm, at least about 70 mm, at least about 80 mm, at least about 90 mm, or at least about 100 mm, preferably at least about 50 mm.

[0079] In order to improve cardiac function in patients with heart failure by applying a microcurrent along with an electric field directly to the heart, it is necessary to achieve a current, preferably at 1.5 μA / cm. 2 With 10μA / cm 2The current density is proportional to the conductive area and the ampere number; that is, the smaller the conductive area and / or the larger the ampere number, the greater the current density. Microcurrent generators have a limited battery charge, which discharges faster as the ampere number increases. By configuring the conductive area of ​​leads 10, 20 to be small, a smaller ampere number is required to achieve a higher current density, thereby achieving a longer battery life. Therefore, according to a preferred embodiment of the invention, the non-insulated portion 23 of the left ventricular coil lead 20 has at least about 60 mm². 2 At least approximately 90mm 2 At least approximately 120mm 2 At least approximately 150mm 2 At least approximately 180mm 2 At least approximately 200mm 2 At least approximately 230mm 2 At least approximately 260mm 2 Or at least approximately 290mm 2 Preferably at least about 150mm 2 The conductive surface.

[0080] It should be understood that prior to implantation, the technician determines and selects the appropriate diameter and length of the left ventricular coil lead 20 for the patient and the target vein.

[0081] According to another preferred embodiment of the invention, the left ventricular coil lead 20 includes a first insulating member 25 that encloses its connector wire 21 within a first insulating portion 26 adjacent to a non-insulating portion 23 and configured to be positioned within the coronary sinus. According to a particular preferred embodiment of the invention, the first insulating member 25 of the left ventricular coil lead 20 includes a thickness between about 0.05 mm and about 0.37 mm, or between about 0.05 mm and about 0.26 mm, or between about 0.07 mm and about 0.23 mm, or between about 0.10 mm and about 0.20 mm, or between about 0.13 mm and about 0.17 mm, preferably about 0.15 mm. According to an alternative preferred embodiment of the invention, the diameter of the first insulating portion 26 of the left ventricular coil lead 20 is between about 1.20 and about 1.64 times the diameter of the non-insulating portion 23, or between about 1.20 and about 1.45 times, or between about 1.24 and about 1.42 times, or between about 1.27 and about 1.39 times, or between about 1.13 and about 1.36 times, preferably about 1.33 times.

[0082] According to a preferred embodiment of the invention, the left ventricular coil lead 20 includes a second insulator 27 that encloses its connector wire 21 within a second insulating portion 28 adjacent to a first insulating portion 26 and configured to be positioned within the superior vena cava. According to a particular preferred embodiment of the invention, the thickness of the second insulator 27 of the left ventricular coil electrode is approximately 0.15 mm to approximately 0.80 mm, or approximately 0.15 mm to approximately 0.55 mm, or approximately 0.20 mm to approximately 0.50 mm, or approximately 0.25 mm to approximately 0.45 mm, or approximately 0.30 mm to approximately 0.40 mm, preferably approximately 0.30 mm. According to another preferred embodiment of the invention, the diameter of the second insulating portion 28 of the left ventricular coil lead 20 is about 1.38 to about 2.78 times, or about 1.38 to about 2.18 times, or about 1.48 to about 2.08 times, or about 1.58 to about 1.98 times, or about 1.68 to about 1.88 times, preferably about 1.78 times, of the diameter of the non-insulating portion 23.

[0083] like Figure 1 As shown, the connector wires 11, 21 of the left ventricular coil lead 20 and the right ventricular coil lead 10 are configured to extend side-by-side from the control unit (not shown) to the right atrium of the heart, branching from the right atrium into the right ventricle and coronary sinus, respectively. Due to its proximity to the right ventricular coil lead 10 and the continuous movement of the heart, the second insulation 27 of the left ventricular coil lead 20 must have a greater thickness than the first insulation 25 to prevent insulation failure due to possible lead-to-lead abrasion between the left ventricular coil lead 20 and the right ventricular coil lead 10. The smaller diameter of the second insulation portion 28 further ensures that blood flow in the coronary sinus, which is narrower than the superior vena cava, is restricted as little as possible.

[0084] The first and second insulating elements 25 and 27 preferably comprise flexible materials with good biocompatibility, chemical resistance, formability and stability, such as various medical-grade silicone resins.

[0085] For reference Figure 3 In the preferred embodiment shown, the first insulating member 25, which encapsulates the connector wire 21 within a first insulating portion 26 near the non-insulating portion 23, is configured to have a substantially homogeneous thickness along the entire length of the insulating portion 26 of the connector wire 21. In other words, the first insulating member 25 is the only insulating member used for the second lead 20, such that only one insulating member is used for the entire length of the second lead 20. Therefore, the first insulating member 25 can be positioned in the coronary sinus and the superior vena cava.

[0086] According to this particular preferred embodiment of the invention, the first insulating member 25 of the left ventricular coil lead 20 includes a thickness between about 0.05 mm and about 0.37 mm, or between about 0.05 mm and about 0.26 mm, or between about 0.07 mm and about 0.23 mm, or between about 0.10 mm and about 0.20 mm, or between about 0.13 mm and about 0.17 mm, preferably about 0.15 mm. According to an alternative preferred embodiment of the invention, the diameter of the first insulating portion 26 of the left ventricular coil lead 20 is between about 1.20 times and about 1.80 times, or between about 1.20 times and about 1.45 times, or between about 1.24 times and about 1.42 times, or between about 1.27 times and about 1.39 times, or between about 1.13 times and about 1.36 times, preferably about 1.33 times, of the diameter of the non-insulating portion 23.

[0087] In another specific embodiment of the present invention, such as Figure 4 As shown, the non-insulated portion 23 includes multiple coil segments 29 configured to operate independently. These coil segments 29 are configured to be activated or deactivated based on their location and the desired therapeutic area, thus providing greater flexibility in tailoring therapy to the individual needs of the patient. In cases requiring extensive therapy over a large electrode surface, multiple segments can be activated. This allows for broad treatment of the desired area. However, in cases requiring special care to avoid undesirable effects, such as, for example, therapeutic current bypass, where the therapeutic current is redirected to the right ventricular coil lead 10 via blood flow and the coronary sinus, or phrenic nerve stimulation, only one or a few coil segments 29 may be activated. This allows for greater targeting and adaptation of the therapy to each patient's individual condition. Therefore, the coil segments 29 can improve therapeutic efficacy and reduce undesirable effects. Furthermore, by selecting different segments of the lead, a more homogeneous electric field and current distribution can be obtained.

[0088] According to a particular preferred embodiment of the invention, the non-insulated portion 23 includes at least 2 coil segments 29, at least 3 coil segments 29, at least 4 coil segments 29, at least 5 coil segments 29, at least 6 coil segments 29, at least 7 coil segments 29, or at least 8 coil segments 29, preferably 6 coil segments 29; and at most 12 coil segments 29, at most 11 coil segments 29, at most 10 coil segments 29, and at most 9 coil segments 29.

[0089] According to another preferred embodiment of the invention, the length of the coil segment 29 is between about 3 mm and about 45 mm, between about 5 mm and about 40 mm, between about 6 mm and about 35 mm, between about 7 mm and about 30 mm, between about 8 mm and about 27 mm, between about 9 mm and about 23 mm, or between about 10 mm and about 20 mm. According to another preferred embodiment of the invention, the length of the coil segment 29 is about 0.05 times to about 0.90 times, about 0.10 times to about 0.80 times, about 0.12 times to about 0.7 times, about 0.14 times to about 0.60 times, about 0.16 times to about 0.50 times, about 0.18 times to about 0.4 times, or about 0.20 times to about 0.30 times the length of the non-insulated portion 23.

[0090] In any embodiment herein, the first and / or second insulators 25, 27 may be mechanically secured to the corresponding coil lead 20 and / or connector wire 21. Preferably, mechanical securing can be achieved by at least one stable engagement positioned between the insulators of the first and / or second insulators 25, 27 and the inner conductors of the coil lead 20 and / or connector wire 21. In a preferred embodiment, a stable engagement is applied at each end of the first and / or second insulators 25, 27. This can further minimize the risk of deformation and breakage during implantation and anticipated explantation.

[0091] Similarly, the insulating portion of the coil lead 10 can be mechanically secured to its inner conductor. This can be applied to any portion of the insulation of the coil lead 10, including the connector wire 11. As described above, at least one stable connection can be located between the insulating portion of the coil lead 10 and its inner conductor. Preferably, a stable connection can be applied at each end of each insulating portion of the coil lead 10.

[0092] According to a preferred embodiment of the invention, the left ventricular coil lead 20 includes an attachment member 30 at its distal end (e.g., ...). Figure 1 (as shown in coil lead 10), preferably, wherein the attachment part 30 includes an anchor, hook, screw or cane shape; particularly preferably, wherein the attachment part 30 includes an anchor or hook shape with an integrated blood seal.

[0093] The attachment component 30 is configured to securely anchor the left ventricular coil electrode to the target tissue, enabling stable electrode positioning and ensuring effective conductivity for medical applications. Figure 1 As shown, the attachment component 30 can also be used in the right ventricular coil lead 10.

[0094] The attachment component 30 may be selected from a list including anchors or barbs (anchors or barbs can engage with surrounding tissue to ensure secure positioning of the lead located at the distal tip of the lead and screwed into the tissue), mechanical fasteners including clips and clamps, and tissue integration and capsule formation that stabilize the electrode and provide a natural anchor over time around the lead. It should be understood that a suitable attachment component 30 is selected by those skilled in the art and depends on various factors such as the application of the lead, tissue type, and expected stress. The attachment component 30 of the present invention is preferably configured to ensure a strong, biocompatible, and durable anchoring.

[0095] All embodiments of the invention described herein are considered to be possible in any combination unless those skilled in the art consider such combination to have no technical significance.

[0096] List of reference numerals

[0097]

Claims

1. An implantable lead assembly, comprising an implantable first lead (10), an implantable second lead (20), and a control unit, wherein the first lead (10) and the second lead (20) are electrically connected to the control unit via connector wires (11, 21), wherein The control unit is configured to establish a potential difference between the first lead (10) and the second lead (20), allowing current to flow between the two leads (10, 20). The first lead (10) is configured to be positioned in the right ventricle of the heart, and The second lead (20) includes a coil, the coil having a non-insulating portion (23) at its distal end, wherein the non-insulating portion (23) is configured to be positioned in a left vein in the left ventricular myocardium.

2. The implantable lead assembly according to claim 1, wherein the coil in the second lead (20) includes a central lumen (22) extending longitudinally through the coil.

3. The implantable lead assembly according to claim 1 or 2, wherein... The control unit can be programmed to maintain the potential difference for direct current flow within a predetermined time interval, and / or wherein... The control unit includes controls to maintain the current density below a stimulation threshold, optionally at 0.1 μA / cm². 2 Up to 1mA / cm 2 The current density.

4. The implantable lead assembly according to any one of claims 1 to 3, wherein the non-insulating portion (23) is configured to be located in a branch of the coronary sinus, optionally in one of a marginal vein, a central vein, a posterior cardiac vein and a great cardiac vein, preferably in the posterior cardiac vein.

5. The implantable lead assembly according to any one of claims 1 to 4, wherein the coil is a multi-strand coil comprising 2, 3, 4, 5, 6, 7, or 8 wires, preferably 4 wires.

6. The implantable lead assembly according to any one of claims 1 to 5, wherein the non-insulating portion (23) includes a cap (24) and / or a soldered and polished area at the distal tip of the non-insulating portion (23), preferably wherein the cap (24) and / or the distal tip includes a non-invasive cylindrical shape.

7. The implantable lead assembly according to any one of claims 1 to 6, wherein the non-insulated portion (23) has a diameter between about 0.70 mm and about 1.10 mm, between about 0.75 mm and about 1.05 mm, even between about 0.80 mm and about 1.00 mm, between about 0.85 mm and about 0.95 mm, or between about 0.87 mm and about 0.92 mm, preferably about 0.9 mm.

8. The implantable lead assembly according to any one of claims 1 to 7, wherein the non-insulated portion (23) has a length of at least about 20 mm, at least about 30 mm, at least about 40 mm, at least about 50 mm, at least about 60 mm, at least about 70 mm, at least about 80 mm, at least about 90 mm or at least about 100 mm, preferably at least about 50 mm.

9. The implantable lead assembly according to any one of claims 1 to 8, wherein the non-insulated portion (23) has a length of at least about 60 mm. 2 At least approximately 90mm 2 At least approximately 120mm 2 At least approximately 150mm 2 At least approximately 180mm 2 At least approximately 200mm 2 At least approximately 230mm 2 At least approximately 260mm 2 Or at least approximately 290mm 2 Preferably at least about 150mm 2 The conductive surface.

10. The implantable lead assembly according to any one of claims 1 to 9, wherein at least one of the connector wires (11, 21) or both, the first lead (10), and the second lead (20) comprises a metallic material having inherent corrosion resistance, high biocompatibility and radiation impermeability, said metallic material optionally being a metal alloy, preferably a platinum-containing metal alloy, and more preferably a platinum-iridium alloy.

11. The implantable lead assembly according to any one of claims 1 to 10, wherein all conductive components in the conductive path of at least one of the leads of the lead assembly are made of the same metallic material, wherein the conductive component of at least one lead preferably includes the first lead (10) and its connector wire (11) and / or the second lead (20) and its connector wire (21), wherein the metallic material has inherent corrosion resistance, high biocompatibility and radiation impermeability, and the metallic material is optionally a metal alloy, preferably a platinum-containing metal alloy, more preferably a platinum-iridium alloy.

12. The implantable lead assembly according to any one of claims 1 to 11, wherein the first lead (10) having a corresponding connector wire (11) and / or the second lead (20) having a corresponding connector wire (21) are conductive materials, preferably metallic materials, designed as a single structural element, said metallic material being optionally a metal alloy, preferably a platinum-containing metal alloy, more preferably a platinum-iridium alloy.

13. The implantable lead assembly according to any one of claims 1 to 12, wherein the second lead (20) includes a first insulating member (25) that encloses the connector wire (21) of the second lead in a first insulating portion (26) adjacent to the non-insulating portion (23) and is configured to be positioned in the coronary sinus, wherein the first insulating member (25) is mechanically secured to the second lead (20) and / or the connector wire (21), wherein the mechanical securing can be achieved by at least one stabilizing engagement positioned between the first insulating member (25) and the inner conductor of the second lead (20) and / or the connector wire (21), and / or wherein at least two stabilizing engagements are applied at each end of the first insulating member (25).

14. The implantable lead assembly according to claim 13, wherein the first insulating member (25) encapsulating its connector wire (21) in a first insulating portion (26) near the non-insulating portion (23) is configured to have a substantially homogeneous thickness along the entire length of the insulating portion of the connector wire.

15. The implantable lead assembly of claim 14, wherein the first insulator (25) is configured to be positioned in the coronary sinus and superior vena cava.

16. The implantable lead assembly according to any one of claims 12 to 15, wherein the first insulation member (25) comprises a thickness between about 0.05 mm and about 0.37 mm, or between about 0.05 mm and about 0.26 mm, or between about 0.07 mm and about 0.23 mm, or between about 0.10 mm and about 0.20 mm, or between about 0.13 mm and about 0.17 mm, preferably about 0.15 mm; and / or The diameter of the first insulating portion (26) is between about 1.20 and about 1.80 times the diameter of the non-insulating portion (23), or between about 1.20 and about 1.45 times, or between about 1.24 and about 1.42 times, or between about 1.27 and about 1.39 times, or between about 1.13 and about 1.36 times, preferably about 1.33 times.

17. The implantable lead assembly according to any one of claims 1 to 16, wherein the second lead (20) includes a second insulation (27) that encloses the connector wire (21) of the second lead in a second insulation portion (28) adjacent to a first insulation portion (26) and configured to be positioned in the right ventricle and superior vena cava, optionally wherein the second insulation (27) is mechanically secured to the second lead (20) and / or the connector wire (21), wherein the mechanical securing is achievable by at least one stabilizing engagement located between the second insulation (27) and the inner conductors of the second lead (20) and / or the connector wire (21), and / or wherein at least two stabilizing engagements are applied at each of the second insulation (27).

18. The implantable lead assembly according to claim 17, wherein the second insulation member (27) comprises a thickness between about 0.15 mm and about 0.80 mm, or between about 0.15 mm and about 0.55 mm, or between about 0.20 mm and about 0.50 mm, or between about 0.25 mm and about 0.45 mm, or between about 0.30 mm and about 0.40 mm, preferably about 0.30 mm; and / or The diameter of the second insulating portion (28) is between about 1.38 times and about 2.78 times the diameter of the non-insulating portion (23), or between about 1.38 times and about 2.18 times, or between about 1.48 times and about 2.08 times, or between about 1.58 times and about 1.98 times, or between about 1.68 times and about 1.88 times, preferably about 1.78 times.

19. The implantable lead assembly according to any one of claims 1 to 18, wherein the non-insulated portion (23) comprises a plurality of coil segments (29) configured to operate independently.

20. The implantable lead assembly according to claim 19, wherein the non-insulated portion (23) comprises at least 2 coil segments (29), at least 3 coil segments (29), at least 4 coil segments (29), at least 5 coil segments (29), at least 6 coil segments (29), at least 7 coil segments (29), or at least 8 coil segments (29), preferably 6 coil segments (29); and at most 12 coil segments (29), at most 11 coil segments (29), at most 10 coil segments (29), and at most 9 coil segments (29).

21. The implantable lead assembly according to claim 19 or 20, wherein the length of said coil segment (29) is between about 3 mm and about 45 mm, between about 5 mm and about 40 mm, between about 6 mm and about 35 mm, between about 7 mm and about 30 mm, between about 8 mm and about 27 mm, between about 9 mm and about 23 mm, or between about 10 mm and about 20 mm; and / or The length of the coil segment (29) is approximately 0.05 to 0.90 times, approximately 0.10 to 0.80 times, approximately 0.12 to 0.7 times, approximately 0.14 to 0.60 times, approximately 0.16 to 0.50 times, approximately 0.18 to 0.4 times, or approximately 0.20 to 0.30 times the length of the non-insulated portion (23).

22. The implantable lead assembly according to any one of claims 1 to 21, wherein the second lead (20) includes an attachment member (30) at its distal end, preferably The attachment part (30) has the shape of an anchor, hook, screw, or cane; particularly preferably The attachment part (30) has an anchor or hook shape with an integrated blood seal.

23. The implantable lead assembly according to any one of claims 1 to 22, wherein the implantable lead assembly is configured to apply a microcurrent between two electrodes to treat heart failure.

24. A method for treating or preventing heart failure, comprising the following steps: A first lead (10) is implanted, wherein the first lead (10) is configured to be positioned in the right ventricle of the heart. A second lead (20) is implanted, wherein the second lead includes a coil, the coil including a non-insulating portion (23) at its distal end, wherein the non-insulating portion (23) is configured to be positioned in a left vein in the left ventricular myocardium, and A potential difference is established between the first lead (10) and the second lead (20) so that a direct current flows between the two leads (10, 20).

25. The method of claim 24, wherein Maintaining the potential difference to obtain direct current flow within a predetermined time interval, and / or wherein The current density is maintained below the stimulation threshold, preferably at 0.1 μA / cm. 2 Up to 1mA / cm 2 The current density.

26. The method according to claim 24 or 25, wherein the non-insulating portion (23) is configured to be located in a branch of the coronary sinus, optionally in one of a marginal vein, a central vein, a posterior cardiac vein, and a great cardiac vein, preferably in the posterior cardiac vein.

27. The method according to any one of claims 24 to 26, wherein the coil of the second lead (20) includes a central lumen (22) extending longitudinally therethrough.

28. The use of a lead assembly for treating or preventing heart failure, said lead assembly comprising a first lead (10) and a second lead (20), wherein The first lead (10) is configured to be positioned in the right ventricle of the heart. The second lead (20) includes a coil configured to be positioned in the left vein of the left ventricular myocardium, and A potential difference is established between the first lead (10) and the second lead (20) so that a direct current flows between the two leads (10, 20).

29. Use of the lead assembly according to claim 28, wherein the coil of the second lead (20) includes a non-insulated portion (23) at its distal end, wherein the non-insulated portion (23) is configured to be located in a branch of the coronary sinus in the left ventricular myocardium, the branch of the coronary sinus generally having a central venous vein, a posterior venous vein and a great venous vein, optionally located in the posterior venous vein.

30. Use of the lead assembly according to claim 28 or 29, wherein the lead assembly includes a control unit, the first lead (10) and the second lead (20) being electrically connected to the control unit via connector lines (11, 21), wherein the control unit is configured to establish the potential difference between the two leads (10, 20).

31. The use of the lead assembly according to claim 30, wherein... The control unit can be programmed to maintain the potential difference at a predetermined time interval to obtain direct current flow and / or The control unit includes controls to maintain the current density below a stimulation threshold, preferably at 0.1 μA / cm². 2 Up to 1mA / cm 2 The current density.

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