JP2020081217A - Ablation catheter and cardiac therapy system - Google Patents

Abstract

To provide a novel ablation catheter and a cardiac therapy system capable of suppressing occurrence of ventricular fibrillation itself.SOLUTION: An ablation catheter 1A is used for ablation of a cardiac tissue, and comprises: a slender and flexible insulating body 10; an electrode part 20 provided on an outer circumferential surface of the body; and wiring connected to the electrode part. A dimension of the electrode part in a longitudinal direction of the body is greater than 1 cm and equal to or smaller than 15 cm. The cardiac therapy system comprises: the catheter ablation; a high frequency current generation unit connected to the wiring; a stimulation device for pacing connected to the wiring; an electrocardiograph connected to the wiring; and an indifferential plate part which forms a circuit together with the wiring while sandwiching a living body between the indifferential plate part and the wiring.SELECTED DRAWING: Figure 1A

Description

The present invention relates to ablation catheters and cardiac treatment systems.

Currently, the treatment methods for arrhythmia diseases include drug therapy using antiarrhythmic drugs, implantable cardiac electrical devices such as pacemakers and implantable cardioverter defibrillators (ICDs), and percutaneous catheter ablation. And non-drug treatment method by. Among them, conventional ventricular fibrillation does not always improve the long-term prognosis for ventricular fibrillation, which is the main cause of sudden cardiac death, and ventricular fibrillation has a complex and disordered excitatory pattern, which makes it a target site for treatment. However, since the treatment method by catheter ablation has not been established, treatment by ICD is the main focus. ICD is a device that constantly monitors the patient's heartbeat and automatically stops high-voltage direct current (shock) when ventricular fibrillation occurs. It has a high probability of stopping ventricular fibrillation. it can. Large-scale clinical trials in the past have shown an excellent prognosis-improving effect in patients with severe heart failure considered to be in a high risk group for sudden cardiac death.

On the other hand, in recent years, basic research centered on animal experiments has revealed that during the onset, maintenance and recurrence of ventricular fibrillation (unsuccessful defibrillation), the division of the ventricular fibrillation wave front at the junction of the left and right ventricles (interventricular groove). It has been clarified that (Wavebreak) plays an important role (for example, see Non-Patent Document 1).

Bourgeois EB et al., “Panoramic optical mapping shows wavebreak at a consistent anatomical site at the onset of ventricular fibrillation.”, Cardiovascular Research, Vol. 93, Issue 2, p272-279, 2012.

However, even if the ICD is implanted in the body, the energization output required to stop ventricular fibrillation is high, and defibrillation may be unsuccessful. Be aware that, with a great deal of emotional distress from fear, there is a risk of coexisting mental illness such as depression and adjustment disorders, that there are many restrictions in daily life such as prohibition of car driving, etc., It has been pointed out that there are multiple limitations to IDC treatment, and patient satisfaction with ICD treatment is by no means sufficient. These limitations arise from the fact that IDC treatment is a symptomatic treatment and does not have the effect of suppressing the occurrence of ventricular fibrillation itself. Therefore, there is a demand for a safer and less invasive treatment method for ventricular fibrillation by suppressing the occurrence of ventricular fibrillation itself.

The present invention has been made in view of the above circumstances, and provides a novel ablation catheter and cardiac treatment system capable of suppressing the occurrence of ventricular fibrillation itself.

As a result of intensive studies to achieve the above object, the present inventors have provided an elongated and flexible insulating main body, and an electrode portion provided on the outer peripheral surface of the main body, It is possible to suppress the occurrence of ventricular fibrillation itself by linearly cauterizing the junction between the left and right ventricles using an ablation catheter in which the size of the electrode part in the longitudinal direction of the main body is longer than the electrode part of a conventional ablation catheter. Heading out, the present invention has been completed.

That is, the present invention includes the following aspects.
The ablation catheter according to the first aspect of the present invention is an ablation catheter used for cauterization of heart tissue, and includes an elongated and flexible insulating main body and an electrode portion provided on the outer peripheral surface of the main body. And a wire connected to the electrode portion, and the dimension of the electrode portion in the longitudinal direction of the main body is more than 1 cm and 15 cm or less.
The electrode portion has a plurality of cauterizing electrodes arranged side by side in the longitudinal direction of the main body at intervals, the wiring is arranged so as to be able to independently conduct electricity to the plurality of cauterizing electrodes, The dimension of the ablation electrode in the longitudinal direction of the main body may be 1.5 times or more the interval.
The ablation catheter according to the first aspect may be used for ablation of the junction between the left and right ventricles.
A heart treatment system according to a second aspect of the present invention is an ablation catheter according to the first aspect, a high-frequency current generator connected to the wiring, a pacing stimulator connected to the wiring, and the wiring. And an electrocardiograph connected to the electrocardiograph, and a counter electrode portion that forms the wiring and the circuit with the living body interposed therebetween.
The cardiac treatment system according to the second aspect further includes a second catheter including an electrode, and a three-dimensional mapping device that constructs a three-dimensional mapping image of the heart from the intracardiac potential obtained by the electrode. Good.
The heart treatment system according to the second aspect may further include a probe including a magnetic sensor, and an ultrasonic image diagnostic apparatus that constructs a three-dimensional mapping image of the heart from the ultrasonic waves generated by the magnetic sensor.
The heart treatment system according to the second aspect may further include an X-ray image diagnostic apparatus.
The heart treatment system according to the second aspect may be used for treatment of ventricular fibrillation.

According to the ablation catheter and the heart treatment system of the above aspect, the occurrence of ventricular fibrillation itself can be suppressed.

It is a perspective view showing the ablation catheter concerning a 1st embodiment of the present invention. FIG. 3 is a perspective view of the tip of the ablation catheter according to the first embodiment of the present invention. It is a longitudinal cross-sectional view of the distal end of the ablation catheter according to the first embodiment of the present invention. It is a schematic structure figure showing a heart treatment system concerning one embodiment of the present invention. 3 is a three-dimensional mapping image of a porcine heart constructed using the intracardiac ultrasonic imaging device in Test Example 1. 7 is an electrocardiogram before and after a linear cauterization treatment of a junction (interventricular groove) between the left and right ventricles in Test Example 1.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, in each drawing, a part not related to the description may be omitted.

≪Ablation catheter≫
The ablation catheter of this embodiment is an ablation catheter used for ablation of heart tissue. The ablation catheter of the present embodiment includes an elongated and flexible insulating main body, an electrode portion provided on the outer peripheral surface of the main body, and wiring connected to the electrode portion. The dimension of the electrode portion in the longitudinal direction of the main body is more than 1 cm and 15 cm or less.

In recent years, it has been clarified that the wavefront division of the ventricular fibrillation (Wavebreak) plays an important role in the onset, maintenance and recurrence of ventricular fibrillation (unsuccessful defibrillation) at the junction of the left and right ventricles (interventricular groove). However, since ventricular fibrillation is disordered and suddenly occurs, the target site for catheter ablation treatment has not been clarified. The present inventors have found that the occurrence of ventricular fibrillation itself can be suppressed by linearly cauterizing the joint portion (interventricular groove) of the left and right ventricles, as shown in Examples described later, and complete the present invention. Came to.
In addition, in the conventional ablation catheters, in order to perform linear ablation, it was necessary to repeat point ablation several times. On the other hand, the ablation catheter of the present embodiment can easily linearly cauterize the junction between the left and right ventricles by providing an electrode portion that is longer than the conventional electrode portion, and prevent the occurrence of ventricular fibrillation itself. Can be suppressed.

<First Embodiment>
FIG. 1A is a perspective view showing an ablation catheter according to the first embodiment of the present invention.
The ablation catheter 1A shown in FIG. 1A includes an elongated and flexible insulating main body 10, an electrode portion 20 provided on the outer peripheral surface of the main body 10, and wiring connected to the electrode portion 2 (see a later-described figure). 1C), and. The ablation catheter 1A can further include a handle portion 40. By operating the electrode part bending knob 41 arranged on the handle part, the electrode part 20 can be bent in a living body, and the electrode part 20 is arranged along the interventricular groove from the endocardium side. You can

The dimension of the electrode portion 20 in the longitudinal direction of the main body is more than 1 cm and 15 cm or less, preferably 1.5 cm or more and 14 cm or less, more preferably 3 cm or more and 13 cm or less, and further preferably 5 cm or more and 12 cm or less. Since the length of the human (adult) heart is about 12 cm or more and 15 cm or less when the size of the electrode part is within the above range, the electrode part 20 may be arranged along the junction between the left and right ventricles. It is possible to linearly cauterize the junction between the left and right ventricles more easily.
The size of the electrode portion 20 in the circumferential direction of the main body 10 is preferably ¼ or more of the outer circumference of the main body 10, more preferably ⅓ or more, and ½ or more. More preferably, it is particularly preferably ⅔ or more, particularly preferably ⅓, that is, it is most preferable that the electrode portion 20 covers the entire outer periphery of the main body 10. When the ratio of the dimension of the electrode part 20 in the circumferential direction of the main body 10 to the outer circumference of the main body 10 is equal to or more than the lower limit value, the electrode part 20 can be flexed more flexibly in the living body, and the joint part of the left and right ventricles. Can be cauterized more easily.

FIG. 1B is a perspective view of the tip of the ablation catheter according to the first embodiment of the present invention, and FIG. 1C is a longitudinal cross-sectional view of the tip of the ablation catheter according to the first embodiment of the present invention.
The electrode portion 20 has a plurality of ablation electrodes 21a arranged side by side at intervals 22 in the longitudinal direction of the main body. The wiring 40 is arranged so that the plurality of ablation electrodes 21a can be independently energized. Since the ablation catheter 1A has a plurality of ablation electrodes 21a, it is possible to perform a plurality of point ablation at the same time without moving the catheter, and shortening the treatment time is expected.
Further, the dimension X of the ablation electrode 21a in the longitudinal direction of the main body is preferably 1.5 times or more, more preferably 1.6 times or more, and 1.7 times the length Y of the interval 22. It is more preferably at least 2.0 times, particularly preferably at least 2.0 times, and most preferably at least 2.5 times. When the ratio of the dimension X of the ablation electrode 21a to the length Y of the space 22 in the longitudinal direction of the main body 10 is equal to or less than the upper limit value, the joint portion between the left and right ventricles can be more efficiently linearly cauterized.

The ablation electrode 21a is made of a conductive material such as platinum. The dimension X of the ablation electrode 21a in the longitudinal direction of the main body 10 is preferably more than 1 mm, more preferably 3 mm or more, still more preferably 5 mm or more. On the other hand, the upper limit of the dimension X of the ablation electrode 21a in the longitudinal direction of the main body 10 is not particularly limited, but may be about 1 cm, for example.
The dimensions X of the plurality of ablation electrodes 21a may be the same or different, but it is preferable that they are the same because they can be ablated uniformly.
The number of the ablation electrodes 21a may be within the range of the dimension of the electrode portion 20 in the longitudinal direction of the main body 10, and may be, for example, 2 or more and 20 or less, and 2 or more and 15 or less. The number can be set to 3 or more and 10 or less.

The main body 10 is made of, for example, a thermoplastic material such as silicone rubber. The size of the main body 10 in the longitudinal direction can be set to be approximately the same as the size of a known ablation catheter, for example, 500 mm or more and 2000 mm or less, and 750 mm or more and 1500 mm or less. Similarly, the inner diameter of the main body can be made approximately the same as the inner diameter of a known ablation catheter, for example, 1 mm or more and 10 mm or less, and 2 mm or more and 7 mm or less.
Moreover, the length Y of the gap in the longitudinal direction of the main body 10 is preferably less than 5 mm, more preferably 3 mm or less, and further preferably 2 mm or less. On the other hand, the lower limit of the length Y of the gap in the longitudinal direction of the main body 10 is not particularly limited, but can be set to, for example, about 1 mm.
The lengths Y of the plurality of gaps may be the same or different, but are preferably the same because uniform cauterization is possible.

The ablation catheter of the present embodiment is not limited to the one shown in FIGS. 1A to 1C, and a part of the configuration shown in FIGS. 1A to 1C is changed or deleted within a range that does not impair the effects of the present embodiment. Alternatively, another configuration may be added to the one described so far.

For example, in the ablation catheter shown in FIGS. 1A to 1C, one or more holes are formed in the electrode portion (at least one of the main body such as the ablation electrode and the gap), and the inside of the main body is communicated from the handle portion to the hole. A flow path may be provided. As a result, the fluid is caused to flow out of the hole through the flow path, and the outer surface of the ablation electrode and the tissue after ablation contact the fluid, whereby overheating can be prevented and blood around the ablation electrode can be prevented. Can be diluted to prevent blood clotting. Examples of the fluid include those commonly used in medical applications such as physiological saline.

For example, in the ablation catheter shown in FIGS. 1A to 1C, a flow path that can circulate a fluid may be provided inside the main body and adjacent to the electrode portion. As a result, the fluid comes into contact with the inner surface of the ablation electrode to prevent the ablation electrode and the tissue after cauterization from being overheated.

≪Heart treatment system≫
The cardiac treatment system of the present embodiment, the catheter ablation, a high-frequency current generator connected to the wiring, a pacing stimulator connected to the wiring, an electrocardiograph connected to the wiring, And a counter electrode plate portion that forms a circuit with the wiring while sandwiching a living body.

The heart treatment system according to the present embodiment having the above-described configuration can easily linearly cauterize the junction between the left and right ventricles, and suppress the occurrence of ventricular fibrillation itself.

FIG. 2 is a schematic configuration diagram showing a heart treatment system according to an embodiment of the present invention.
The heart treatment system 100 shown in FIG. 2 includes an ablation catheter 1A, a high-frequency current generator 101, a stimulator 103, an electrocardiograph 104, and a counter electrode plate 102. The ablation catheter 1A is connected to the high-frequency current generator 101 via wiring. By including the ablation catheter 1A, the heart treatment system 100 can easily perform linear ablation without moving the catheter as described above, and shortening the treatment time is expected.

The stimulator 103 is connected to the ablation catheter 1A via a wire, and has a pacing unit that stimulates the heart to control contraction, and a sensing unit that senses the stimulus. The electrocardiograph 104 is connected to the ablation catheter 1A via wiring and is used to record the intracardiac potential obtained from the electrodes. Recording of the intracardiac potential in the stimulator 103 and the electrocardiograph 104 and stimulation of the heart may be performed using an ablation electrode, as shown in FIG. 2, or via a second catheter including the electrode. You may. A temporary (external) pacing catheter can be used as the second catheter, for example. In addition, the electrocardiograph 104 may further include one or more spot electrodes that acquire a cardiac potential from the body surface. As a result, the cardiac potential can be acquired from both the inside of the heart chamber and the body surface, and the cardiac potential can be measured more accurately. The counter electrode plate portion 102 is placed under the subject during the catheter ablation treatment, and forms wiring and a circuit with the living body of the subject being sandwiched therebetween.

The heart treatment system of the present embodiment is not limited to that shown in FIG. 2, and within the range in which the effect of the present embodiment is not impaired, a part of the configuration shown in FIG. Other configurations may be added to those described above.

For example, the heart treatment system shown in FIG. 2 may further include the control unit 105. When the ablation catheter 1A having a plurality of ablation electrodes is used, the control unit 105 causes the plurality of ablation electrodes to be sequentially energized from the distal side, or the ablation electrode designated among the plurality of ablation electrodes. The high frequency current generator can be controlled so that only the electrodes are energized.
In addition, when the pump 111 that feeds the fluid 112 is connected to the ablation catheter 1A via the flow path, the control unit 105 causes the fluid to flow to the ablated site during or after the ablation electrode is energized. Or the pump can be controlled so that the fluid contacts the ablation electrode after energization within the body. This can prevent overheating of the ablation electrode and the tissue after ablation.
The control unit 105 may further include a foot switch 106. This makes it possible to control the start and stop of energization of the ablation electrode using either the foot switch 106 or the power supply of the high-frequency current generator 101.
Further, the control unit 105 may be connected to the data output unit (computer) 110 via the wiring from the data output port 108. As a result, data such as the output value of the current, the treatment time, and the intracardiac potential can be output.

For example, the cardiac treatment system shown in FIG. 2 may further include a second catheter including electrodes and a three-dimensional mapping device. The three-dimensional mapping device can construct a three-dimensional mapping image of the heart from the intracardiac potential obtained from the electrode included in the second catheter. By using the constructed three-dimensional mapping image, the electrode part in the ablation catheter 1A can be arranged so as to cauterize the junction between the left and right ventricles.

For example, the cardiac treatment system shown in FIG. 2 may include a probe including a magnetic sensor and an ultrasonic diagnostic imaging apparatus. The ultrasonic diagnostic imaging apparatus can construct a three-dimensional mapping image of the heart from the ultrasonic waves generated by the magnetic sensor. By using the constructed three-dimensional mapping image, the electrode part in the ablation catheter 1A can be arranged so as to cauterize the junction between the left and right ventricles.

For example, the heart treatment system shown in FIG. 2 may further include an X-ray image diagnostic apparatus. By using the X-ray image of the heart of the subject obtained from the X-ray image diagnostic apparatus, the electrode part in the ablation catheter 1A can be arranged so as to cauterize the junction between the left and right ventricles.

<How to use>
A method of using the heart treatment system 100 of this embodiment will be described below.
Similar to the conventional catheter ablation treatment, the ablation catheter 1A is inserted from the femoral vein of the subject, and the electrode portion bending knob 41 is operated to bend the electrode portion 20 so that the left and right ventricles are moved from the endocardium side. The electrode portion 20 is arranged along the joint (groove between chambers). In particular, at this time, the three-dimensional mapping image of the heart constructed by the three-dimensional mapping device from the intracardiac potential, the three-dimensional mapping image of the heart constructed by the ultrasonic image diagnostic device from ultrasound, and the X-ray image diagnostic device. The electrode section 20 can be positioned using at least one image selected from the group consisting of X-ray images of the heart obtained from FIG. Next, the control unit 105 turns on the power of the high frequency current generator 101 when the electrode unit 20 is arranged at an appropriate position in the inter-chamber groove. As a result, the high-frequency current generator generates a current that is transmitted to the heart of the subject through the ablation electrode, and returns from the counter electrode plate 102 disposed under the subject to the high-frequency current generator 101. , A circuit is formed. At this time, heat is generated by Joule heat at the contact portion between the ablation electrode and the myocardium, and myocardial ablation is performed. The output value of current, energization time, and the like can be appropriately controlled by the control unit 105 according to the age, symptoms, and the like of the subject. When an ablation catheter having a plurality of ablation electrodes is used, the control unit 105 sequentially energizes the plurality of ablation electrodes from the distal side, or a designated ablation electrode among the plurality of ablation electrodes. The high-frequency current generator is controlled so that only the working electrode is energized. In the heart treatment system 100 of the present embodiment, since the electrode portion 20 is arranged along the entire length of the interventricular groove, linear cauterization can be easily performed, and shortening of treatment time is expected.

As a target site for ablation of the heart, at least one of the anterior (ventral) interventricular groove and the posterior (dorsal) interventricular groove may be cauterized. It is preferable to cauterize at least the anterior (ventral side) interventricular groove, because the splitting of the ventricular fibrillation wavefront (Wavebreak) occurs more easily in It is more preferable to cauterize both of the inter-chamber grooves.

Simultaneously with or after cauterization, the controller controls the pump 111 to send the fluid 112 to the cauterizing electrode and the cauterizing part of the heart through the flow path and to cool the pump. This can prevent the ablation electrode and the ablation part of the heart from overheating.

The subject may be a patient with myocardial infarction, cardiomyopathy, or heart failure, who may develop ventricular fibrillation, or a patient who has already developed ventricular fibrillation. When the subject is the former, application of the cardiac treatment system can be preventive of ventricular fibrillation.

The heart treatment system according to the present embodiment is suitably used for treatment of ventricular fibrillation, as shown in Examples described later.

Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited to the following examples.

[Test Example 1] Catheter ablation test for ventricular fibrillation using pig heart Protocol From the jugular vein and femoral vein of a pig (body weight of about 30 kg) under general anesthesia, an electrode catheter for recording and inducing ventricular fibrillation (Johnson and Johnson, model number: 36B33R), an ablation catheter equipped with an electrode for myocardial ablation ( Johnson & Johnson, Model: 36H35M) Three-dimensional mapping device (Johnson & Johnson, Model: CARTO3) interlocked intracardiac ultrasound imaging device (Siemens, Model: Acuson X300) probe (Johnson) And Johnson Co., Ltd. make, model number: 10438577) was inserted. Ventricular fibrillation was induced by frequent ventricular stimulation from an electrode catheter placed in the heart. When ventricular fibrillation appeared, DC defibrillation was performed with a patch electrode previously attached to the body surface and immediately stopped.

2. Examination of whether or not the induction of ventricular fibrillation can be suppressed by catheter ablation at the left and right ventricular junctions. The left and right ventricles are joined by imaging with an X-ray image diagnostic device (Philips, model number: Allura Xper FD10) and intracardiac ultrasonic imaging device. Grasping the position of the anterior part (anterior and posterior interventricular groove), along which a linear line is drawn from the endocardial side of the right ventricle to the anterior (ventral) and posterior (dorsal) interventricular Cauterization was performed (see FIG. 3, black circles indicate cauterization position) to interrupt the conduction between the left and right ventricles via the junction. Before the ablation procedure, after the ablation procedure of the anterior (ventral side) interventricular groove, and after the ablation procedure of the anterior (ventral side) and the posterior (dorsal) interventricular channel, frequent ventricular stimuli were applied to the ventricular fibrillation. Inducibility was evaluated. When ventricular fibrillation was induced, it was immediately stopped by direct current application. The evaluation result is shown in FIG.

From FIG. 4, it was clarified that after the linear cauterization treatment of the anterior (ventral side) and the posterior (dorsal) interventricular groove, ventricular fibrillation was not induced even with frequent ventricular stimulation. From this, it is considered that the cardiac treatment system of the present embodiment using catheter ablation is effective as a fundamental treatment for ventricular fibrillation.

According to the ablation catheter and the cardiac treatment system of the present embodiment, the occurrence of ventricular fibrillation itself can be suppressed, and it is effective for the treatment of ventricular fibrillation.

1A... Catheter ablation, 10... Main body, 20... Electrode section, 21a... Cauterization electrode, 22... Interval, 30... Wiring, 40... Bundle section, 41... Electrode section bending knob, 100... Heart treatment system, 101... High frequency Current generator, 102... Counter electrode part, 103... Stimulator, 104... Electrocardiograph, 105... Control part, 106... Foot switch, 107... Pump port, 108... Data output port, 109... Power supply, 110... Data output section, 111... Pump, 112... Fluid

Claims (8)

An ablation catheter used for cauterization of heart tissue,
An elongated and flexible insulating body,
An electrode portion provided on the outer peripheral surface of the main body,
Wiring connected to the electrode part,
Equipped with
An ablation catheter, wherein the dimension of the electrode portion in the longitudinal direction of the main body is more than 1 cm and 15 cm or less. The electrode section has a plurality of cauterizing electrodes arranged side by side in the longitudinal direction of the main body at intervals.
The wiring is arranged so that the plurality of cauterization electrodes can be independently energized,
The ablation catheter according to claim 1, wherein a dimension of the ablation electrode in the longitudinal direction of the main body is 1.5 times or more the interval. The ablation catheter according to claim 1 or 2, which is used for cauterization of the junction between the left and right ventricles. An ablation catheter according to any one of claims 1 to 3,
A high-frequency current generator connected to the wiring;
A pacing stimulator connected to the wiring;
An electrocardiograph connected to the wiring,
A counter electrode part that forms a circuit with the wiring while sandwiching a living body,
A heart treatment system comprising: A second catheter including an electrode;
A three-dimensional mapping device for constructing a three-dimensional mapping image of the heart from intracardiac potentials obtained by the electrodes,
The heart treatment system according to claim 4, further comprising: A probe including a magnetic sensor,
An ultrasonic image diagnostic apparatus for constructing a three-dimensional mapping image of the heart from the ultrasonic waves generated from the magnetic sensor;
The heart treatment system according to claim 4, further comprising: The heart treatment system according to claim 4, further comprising an X-ray image diagnostic apparatus. The cardiac treatment system according to any one of claims 4 to 7, which is used for treatment of ventricular fibrillation.