WO2008139396A2

WO2008139396A2 - Electrode catheter for univentricular and biventricular cardiac electrostimulation

Info

Publication number: WO2008139396A2
Application number: PCT/IB2008/051839
Authority: WO
Inventors: Vakeriy Khursenko
Original assignee: Chamed Srl
Priority date: 2007-05-11
Filing date: 2008-05-09
Publication date: 2008-11-20
Also published as: EP2155321A2; WO2008139396A3; DE202007018527U1

Abstract

The present invention relates to a electrode catheter with sliding coaxial spirals for univentricular and biventricular cardiac stimulation, comprising an electrode with stimulation tip for the left ventricle, a stimulation ring for the right ventricle, and a common return ring for both of the stimulation tips. A transeptal pacing lead is described.

Description

TRANSLATION (RULE 12.3) ^{04 June 2008}

Single electrode catheter for univentricular and biventricular cardiac electrostimulation

Field of the invention

The present invention relates to an electrode catheter for pacemakers for both left and right ventricular electrostimulation.

State of the art

As is known in the field of cardiac electrostimulation, in particular cases it is necessary to carry out a bi-ventricular electrostimulation, i.e., a stimulation directed at both ventricles. This occurs in those cases in which it is essential to ensure a perfect synchronism between the contractions of the two ventricles, the right one and the left one. In the cases of ventricular desynchronization, the purpose of electrical therapy is to improve the mechanical performance of the heart by means of a re-synchronization of the ventricular activity obtained with a different sequence of activation. The right and left ventricles are stimulated in order to minimize intraventricular mechanical delay and synchronize opening of the pulmonary and aortic valves. Biventricular electrical stimulation can be guided by a sinus rhythm (DDD mode) or, in patients with atrial fibrillation, can be conducted with the WI mode. Stimulation of the left ventricle can be obtained both with epicardial electrodes and with endocardial electrodes. The epicardial approach, which is far more invasive and involves greater risks of arrhythmic complications, is not very much used. Currently used in the vast majority of cases is the endocardial approach, which, notwithstanding the considerable improvement in materials, can present some DE1455PTWO PCT/IB2008/051839

Chamalow S.A.

technical difficulties on account of the anatomy of the coronary venous system, it being necessary to position the electrodes in the left cardiac vein, traversing the coronary sinus. Pacemakers and defibrillators are apparatuses based upon a parallel-circuit configuration, which simultaneously enables functions of sensing and pacing of the two ventricles, with different programming modes (unipolar or bipolar). The therapy of cardiac re- synchronization is technically feasible, safe and reliable, as it is witnessed by the increasing number of implantations. In addition, the effectiveness of this type of electrical therapy in the marked improvement of the haemodynamic parameters and the left- ventricular-ejection fraction of patients with cardiac decompensation has been ) demonstrated in a series of studies. In addition to improving the indices of left ventricular performance, biventricular pacing has proven able to reduce the degree of mitral rigurgitation and reduce the left ventricular volumes, thus configuring a phenomenon of inverse remodelling of the left ventricle.

5 The implantation of a biventricular pacemaker has induced other non-negligible positive effects, such as an easier optimization of the multipharmacological therapy, and a significant reduction in hospitalizations due to cardiac decompensation.

At present, bi- ventricular stimulation requires, in addition to implantation of the atrial electrode catheter, the implantation of two ventricular electrode catheters, one in the right ventricle and the other, for the left ventricle, in a superficial branch of the great cardiac vein, which is reached by the electrode catheter through the coronary sinus. However, DE1455PTWO PCT/H32008/051839

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positioning of the second electrode for stimulation of the left ventricle, in the case of a biventricular stimulation, is quite a complex operation. In effect, since the second electrode is inserted in a superficial branch of the great cardiac vein, it must be positioned by traversing the coronary sinus. Said positioning involves the use of special instruments for the introduction and the use of a contrast liquid for the radiological observation of the operation.

In addition, following upon the operation of insertion of the second ventricular electrode, serious post-operative complications are not infrequent, which are due to micro- and I macro-displacements of the tip of the electrode and a marked increase in the cardiac threshold current, which is frequently not compatible with the characteristics of the pacemaker implanted.

Consequently, at present execution of an implantation for bi-ventricular i electrostimulation is a complicated operation that is not without considerable drawbacks deriving from the presence of an atrial electrode and two ventricular electrode catheters and from the complicated technique of implantation of the latter.

Aim of the invention

) The aim of the present invention is thus to overcome the aforesaid drawbacks by providing an electrode catheter structured so that its insertion in the right ventricle will enable bi-ventricular electrostimulation without the need for implantation of a second DE1455PTWO PCT/IB2008/051839

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electrode catheter aimed at stimulating the left ventricle. In other words, the aim of the electrode catheter according to the invention is to make available a structure made in such a way as to enable bi-ventricular electrostimulation, overcoming the need to use two ventricular electrode catheters, in association, as is the usual case, with the atrial electrode, hi addition, another aim of the present invention is to provide an electrode catheter for bi-ventricular electrostimulation that can be positioned without any difficulty and in a stable way over time, thus solving the inconveniences of the prior art.

Description of the invention The problems indicated above are solved by an electrode catheter according to Claim 1, which enables left or right ventricular stimulation, or sequential stimulation of the left ventricle and right ventricle. Further advantages of the invention are defined in the dependent claims.

For a better understanding of the subject of the present invention reference will be made to the attached figures, wherein:

Figure 1 is a side view of the electrode according to the present invention, in a position of use;

Figure 2 is a cross-sectional view of the electrode catheter; and Figure 3 illustrates the optimal positioning of the electrode catheter within the heart. DE1455PTWO PCT/EB2008/051839

Chamalow S. A.

The electrode according to the present invention is a single electrode catheter with sliding coaxial spirals 20, 40, 60 for univentricular and biventricular cardiac stimulation, the electrode comprising the following parts:

- a spindle 10 that terminates inside the stimulation tip 1 for the left ventricle; 5 - a first stimulation ring 2 for the right ventricle; and

- a second common return ring 3 for both of the stimulation tips 1 and 2.

An instrument of this sort enables elimination of the problem linked to the necessary use of two different electrodes, one for the left ventricle, the other for the right ventricle, which complicates considerably application of the pacemaker. It is, in fact, an electrode ) with three coaxial spirals, within which the spindle slides, as indicated in Figure 2.

Elongation of each spiral according to a pre-set maximum length, enables the stimulation tips 1, 2 to position themselves optimally at the right height of the ventricle, thus offering the advantage of a simpler arrangement and hence a more immediate operativeness.

5

The maximum distance between the tip 1 and the tip 2 is comprised between 8 mm and 10 mm, which is the usual thickness of the interventricular septum. The maximum distance between the tip 2 and the ring 3 is comprised between 25 mm and 35 mm in such a way as to enable an effective return of stimulation signals.

0 DE1455PTWO PCT/IB2008/051839

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A spindle 10 of adequate dimensions constitutes the load-bearing shaft of the electrode bestowing thereupon just the right rigidity for introduction of the tip into the interventricular septum.

The turns 20, 40, 60 are separated by an insulator 30, 50, 70, as illustrated in the cross section represented in Figure 2.

The bi-ventricular stimulation electrode according to the present invention can be inserted according to normal surgical procedures within the right ventricle and then pushed, via elongation of the turns 20, 40, 60, through the interventricular septum up to the left ventricle.

The compactness of this electrode and the presence of the appropriate spindle facilitate said operation. According to a preferential embodiment, there is envisaged the use of three or more spindles having a mechanical resistance and diameters that differ according to the resistance of the interventricular septum.

The tip 1 can present various configurations: it may be conical, shaped like a fixed screw, or shaped in some other way so as to enable a greater penetration through the interventricular septum. The spindle is threaded in the internal part of the tip 1 so as to render it stiffer to facilitate the step of its introduction into the interventricular septum.

The tip 2 is constituted by a ring having a circumference comprised between 3 mm and 7 mm and is crimped to the spiral 40.

The ring 3, instead, is crimped to the spiral 60 and has a circumference comprised between 10 mm and 15 mm.

The optimal configuration of positioning is the one indicated in Figure 3, which is obtained automatically once the tip 1 is well positioned in the interventricular septum.

Claims

1. A single electrode catheter with sliding coaxial spirals (20, 40, 60) for univentricular and biventricular cardiac stimulation, comprising the following parts: a spindle (10) with threaded tip; an electrode with stimulation tip (1) for the left ventricle; a ring (2) for stimulation of the right ventricle; and a ring for common return (3) for both of the stimulation tips (1) and (2).

2. The electrode according to Claim 1, wherein the spindle (10) is threaded in the ) internal part of the tip (1) and slides within the spiral (20).

3. The electrode according to any one of the preceding claims, wherein the tip (2) is constituted by a ring having a circumference comprised between 3 mm and 7 mm and is fixed to the spiral (40).

5

4. The electrode according to any one of the preceding claims, wherein the ring (3) has a circumference comprised between 10 mm and 15 mm and is fixed to the spiral (60).

D 5. The electrode according to Claim 2, wherein the spirals (20, 40, 60) are separated from one another by an insulator (30, 50, 70).

6. The electrode according to Claim 1 or Claim 2, wherein stimulation tip (1) for the left ventricle is a screw tip or conical tip.

7. The electrode according to any one of the preceding claims, wherein the maximum distance between the tip (1) and the tip (2) is comprised between 8 mm and 10 mm.

8. The electrode according to any one of the preceding claims, wherein the maximum distance between the tip (2) and the ring (3) is comprised between 25 mm and 35 mm.

9. The electrode according to any one of the preceding claims, wherein the diameter and the material of the spindle (10) are selected according to the resistance of the interventricular septum.