JP2736541B2 - Pacing catheter - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a pacing catheter mainly used for emergency treatment.

[Related Art] When an atrioventricular block of the heart occurs, or when a right leg block occurs due to severe arrhythmia, myocardial infarction, or the like, temporary pacing is applied as an emergency treatment. Here, temporary pacing refers to one in which a pacemaker is not implanted in the body. That is, in temporary pacing, the distal end of the electroded catheter is outside the patient. The connection between the wires connected to the electrodes and the pacemaker is made outside the patient, and the pacemaker is usually
Installed outside the body.

In contrast, in implantable pacing, the connection between the implantable pacemaker and the implantable pacemaker lead is implanted in the body. A pacemaker is also usually implanted in the patient.

Implantable pacemakers are very expensive and are not practical for emergency treatment in terms of medical economy, and the present invention seeks to reduce the size of low cost temporary pacemakers.

As a treatment method of the temporary pacing catheter, for example, a peripheral vein, for example, a femoral vein or a subclavian vein is punctured from an incision in the skin with a catheter introducer. A temporary pacing catheter is inserted through the introducer and its distal end is placed at the right ventricular apex. Connect the positive and negative lead wires at the proximal end of the catheter to each terminal of the temporary pacemaker, switch on and start the pacemaker, start pacing, number of stimulations, stimulation output and ECG input sensitivity etc. Is adjusted to a desired value, and the skin insertion portion of the catheter is sutured and fixed.

Conventionally used temporary pacemakers are generally of the demand type. For example, the number of stimulations can be adjusted to a desired value in an analog manner (for example, 30 to 150 beats per minute), and the stimulus output is similarly analogized to a desired value (for example, 0.1 to 15 V), and has a mechanism for manually adjusting the electrocardiographic input sensitivity in the same manner (for example, 0.5 to 20 mV). For such analog adjustment, it is necessary to incorporate three or more variable resistors.

Of course, there are other temporary pacemakers having a mechanism that can be adjusted in an analog manner, but they have at least the above three adjustment functions. Also, each variable resistor must be robust enough to withstand repeated use, and the operating shaft of the variable resistor must have a structure that takes into account waterproofness, sterilization, and the like. Generally, such a variable resistor is a round type with a diameter of 19 mm and a thickness of about 20 mm, so it becomes a large size of about 15 cm in length, 10 cm in width and about 3 cm in height as a pacemaker, and it is difficult to fix it on the patient's body surface Therefore, it had to be installed away from the body surface, and the handling was very inconvenient. Further, when the patient is transported, the catheter is easily pulled by the temporary pacemaker and the catheter is likely to come off, which is a problem particularly.

Yet another important issue is the connection of a temporary pacing catheter to a temporary pacemaker. To prevent infection, the surgeon inserting the catheter carefully disinfects the fingers and operates the catheter. In order to confirm that pacing is performed smoothly, a trial run is performed after connecting the catheter with a temporary pacemaker. Temporary pacemakers are used without sterilization because they are non-sterile structures or are too heavy to sterilize. If pacing is not performed properly, the operator may operate the catheter again. Thus, the surgeon cannot be touched by an unsterile, unclean temporary pacemaker. Normally, another operator adjusts the three or more variable resistors according to the patient, but it is often difficult to gather two operators in an emergency such as at night. The above situation is an urgent problem in emergency rescue procedures.

[Problems to be Solved by the Invention] In order to solve the above-mentioned problems, the inventors have found that if a temporary pacemaker function is miniaturized and integrated with a pacing catheter, it can be used attached to the patient's body. If the inconvenience is eliminated and the catheter integrated with the temporary pacing function is wrapped in an aseptic condition, the second surgeon conventionally required to connect the temporary pacemaker to the pacing catheter is unnecessary. In consideration of the above, the present inventors have repeatedly studied to enable integration and sterilization, and have completed the present invention.

Means and Action for Solving the Problems The inventors reconsidered the functions of the conventional temporary demand-type pacemaker, selected the minimum necessary functions as a temporary pacemaker in an emergency, and as a result, The number of stimulations and the stimulation output, which may be constant, are fixed, and the electrocardiographic input sensitivity is automatically adjusted. That is, in the short-term emergency life-saving treatment, the number of stimulations is a specific value between 60 and 120 beats per minute, for example, 100 beats per minute, and the stimulus output is a constant pulse output such as a pulse width of 1 to 5 msec and a pulse peak value of 1 to 5 V
There is no problem even if it is set to a specific value of, for example, 3 msec and 2.5 V, so by providing a function to fix the pulse width and pulse peak value and to automatically adjust the electrocardiographic input sensitivity, The size was reduced to about 7 cm, about 3 cm in width, and about 1 cm in height.

An embodiment of the pacing catheter according to the present invention is shown in FIGS. 1 and 2 in perspective views.

In FIG. 1, (1) is a catheter section with a balloon, and a lead wire is embedded in the catheter section, which is connected to a temporary pacemaker (2). The catheter proximal end (3) communicates with the catheter section and includes a balloon (7).
Is connected and inserted. The balloon is expanded or deflated by manipulating the syringe (4). The syringe section and the temporary pacemaker are connected to the catheter at a bifurcation (5). The distal end of the catheter is provided with electrodes (8), (8 ') and a balloon (7).

FIG. 2 shows that a temporary pacemaker is provided at the branch portion in FIG. 1. The operability at the time of catheter insertion is improved as compared with the embodiment of FIG. In addition, in the embodiment of FIG. 2, a drug injection lumen opening (9) and a drug injection lumen (10) are additionally provided.

As the catheter part, a semi-floating catheter, a stylet catheter, or the like is used in addition to a balloon catheter.

Temporary pesmaker shown in Fig. 1 and Fig. 2 (2)
May be connected to another pacemaker so that the latter temporary pacemaker can be used if necessary. By doing so, even if a malfunction occurs in the former integrated temporary pacemaker, it can be switched to the latter temporary pacemaker without removing the catheter.

Next, the temporary pacemaker will be described below. Use in general temporary pacing is performed as follows. That is, if the temporary pacing catheter is in normal contact with the patient's heart, the energy required for stimulation will be relatively small. The relationship between the pulse width of the stimulus output and the pulse peak value required when stimulating living tissue using a DC power source is approximated by a rectangular hyperbola, and the Weiss (Weiss)
iss) is known as the equation. If a large stimulation threshold is required, it is expected that the contact position of the electrode of the temporary pacing catheter is bad or constant contact is not maintained. Such pacing failure is ameliorated by manipulating the distal position of the temporary pacing catheter. Conventionally, in the case of cardiac pacing,
Note that the distal end of the temporary pacing catheter is located at a position where the stimulation pulse height threshold at which pacing is possible is confirmed to be 1 V or less when the pulse width of the stimulation output is about 2 msec. Also, the pulse peak value of the stimulus threshold is
It is well known that it rises over time and is usually set to at least 2V or more, at least twice the threshold for each patient. In other words, in an emergency, even if the pulse width and the pulse crest value are fixed to certain values or more, reliable pacing can be performed as long as the distal end of the temporary pacing catheter is placed at an appropriate position. Yes, short-term patient support is possible.

In the present invention, the pulse width is set in consideration of the actual clinical situation.
Since the pulse peak value can be fixed at 2.5 V for 3 msec, the stimulus output is fixed, and the first variable resistor for adjusting the stimulus output in the circuit block diagram of the demand-type pacemaker shown in FIG. The vessel was removed. This reduces the size of the pacemaker of the present invention, although not sufficiently. Even with such miniaturization, it becomes possible to use the temporary pacer section and the catheter section integrally in the form shown in FIG.

Further, the demand-type pacemaker monitors the intracardiac electrocardiogram of the natural heart via a temporary pacing catheter as shown in FIG. 3 (A). That is, the intracardiac electrocardiogram is amplified via the preamplifier, and a waveform in which the noise component and the electrocardiographic component other than the intended QRS wave are suppressed via the filter is obtained.

The waveform subjected to such processing is compared with a variable but constant comparison potential, and in the case of FIG. 3B, a QRS wave is detected when a condition equal to or higher than the comparison potential is satisfied. The condition equal to or higher than the comparison potential or equal to or lower than the comparison potential depends on whether the QRS wave is directed upward or downward, depending on the preamplifier and the filter. However, by providing an absolute value circuit, either condition can be satisfied. .

As a result of such a comparison, if a QRS wave is detected in the intracardiac electrocardiogram within a predetermined time, a suppression output is output in FIG. 3A and the timer is reset. as a result,
Suppress stimulus output. If the QRS wave is not detected within a certain period of time, the timer is not reset, and after a certain period of time, the pulse generation circuit is activated, the stimulus is output through the temporary pacing catheter, and the heart beats to the patient. Prompt.

Adjusting this fixed time corresponds to adjusting the number of times of stimulation. In order to maintain the patient's short-term life in an emergency, this fixed time may be, for example, 70 to 70 beats per minute or 50 to 150 beats per minute.
00 beats per minute. According to the present invention, the second variable resistor for adjusting the heart rate can be eliminated by using one fixed value or a method of selecting two or more fixed values, thereby enabling further miniaturization. .

As a method for selecting the two or more fixed values, a switch may be generally used. Such a reduction in size makes it possible to use the temporary pacer section and the catheter section integrally.

Further, setting the variable constant comparison potential to a state in which pacing can be stably performed with respect to an intracardiac electrocardiographic potential obtained from a patient via a temporary pacing catheter is to adjust electrocardiographic input sensitivity. Equivalent to. That is, in FIG. 3 (B), when (1) the electrocardiographic input is large, and (2) when the electrocardiographic input is low, the comparison potentials A and A 'indicated by broken lines are respectively obtained for the amplified and filtered waveforms. It must be set so as to cross only the peak pulse of the waveform. Furman et al. Have studied in detail the size of the QRS wave on the intracardiac electrocardiogram obtained from the patient, especially the R wave having the largest wave height (Vincent DeCaprio, Philip Hurz).
eler, Seymour Furman: A comparison of Unipolar and B
ipolar Electrograms for Cardiac Pacemaker Sensing
CIRCURATION 56; 750, 1977), and it has been found that when pacing can be performed normally, it is 2 to 20 mV.

If the electrocardiographic input sensitivity is not properly adjusted, the suppression function does not work properly, and pacing pulses are output to the natural heart at irregular intervals, which may lead to ventricular fibrillation.

Fig. 3 (B) shows an example where the ECG input sensitivity is not set properly
It will be described based on. (1) In FIG. 3 (B), the comparison potential B indicated by the dashed line in the example of large electrocardiographic input corresponds to the sensitive side of the electrocardiographic input sensitivity, that is, when the setting of the comparative potential is too low.
In this example, unnecessary suppression occurs due to an intracardiac electrocardiogram other than the QRS wave, for example, a P wave or a T wave, and a stimulus output may not be performed at an appropriate timing. (2) In FIG. 3 (B), the comparison potential B 'indicated by a dashed line in the example of the small electrocardiographic input corresponds to the insensitive side of the electrocardiographic input sensitivity, that is, when the setting of the comparative potential is too high. In this example, the QRS wave cannot be detected, the necessary suppression does not work, and the unnecessary stimulus output continues.

In the present invention, the circuit is configured such that the comparison potential in the comparison circuit is monotonically decreased or monotonically increased to the sensitive side starting from the immediately preceding QRS input. Whether to use monotonic decrease or monotone increase depends on the positive or negative direction of the QRS wave as the comparison input.

Hereinafter, the embodiments will be described on the assumption that the QRS wave is positive. FIG. 4 shows a circuit of the first embodiment corresponding to a comparison circuit portion surrounded by a broken line in FIG. 3 (A). When given cardiac inwardly conductive through the filter from the <C>, the comparative potential applied to the <B>, the larger the input given to <C>, the output of comparator A ₁ <A> Swings very large.
This output <A> simultaneously charges C through R ₁ and R ₃
To raise the comparison potential of <B>. Finally <B
> Comparison potential is larger than heart inwardly conductive input through the filter <C>, the output <A> of comparator A ₁ is largely fluctuates in the negative or zero. As a result, as shown in FIG.
In A>, a positive square wave is generated at a position corresponding to the QRS wave in the intracardiac electrocardiographic input of <C>. Comparison potential of <B> from this point, the charge stored in C shown in FIG. 4 is R ₁ and R ₂
, Monotonically decreases with time as shown in FIG.

FIG. 5 shows the potentials of <A>, <B>, and <C> over time. The comparison potential of <B> is pushed up every time the QRS wave is detected, and in other words, in other words, the QRS
When the S wave is detected, the ECG input sensitivity is set to a value that cannot be detected unless the QRS wave has the same peak value as the detected QRS wave, and the ECG input sensitivity gradually increases over time from that point on the sensitive side It is equivalent to changing to. The time course of such an electrocardiographic input sensitivity, through a filter, still in the remaining Q-wave or T-wave, it is possible to prevent the comparator A ₁ is actuated,
At the same time, the QRS wave accompanying the next heartbeat can be reliably detected. More specifically, the comparison potential of <B> at the time when each peak value appears is sufficiently higher than the peak value of the P wave or T wave remaining through the filter. comparator A ₁ is not activated.

Further, since the peak value of the comparison potential of <B> shown in FIG. 5 is constantly set by the immediately preceding QRS wave, the QRS wave detection is performed stably for a wide intracardiac electrocardiographic input (2 to 20 mV). obtain.

Further, by adding a circuit capable of giving an offset indicated by a dotted line in FIG. 4 to the potential at point <C>, an offset indicated by a broken line in <C> in FIG. 5 can be added. . By giving such an offset, it is possible to prevent the pulse generation circuit from being suppressed by noise when the electrocardiographic input sensitivity is on the sensitive side. By replacing such a circuit in FIG. 4 with a broken line in FIG. 3 (A), a conventional operator adjusts the electrocardiographic input sensitivity according to each patient, but this operation becomes unnecessary. Succeeded in removing the third variable resistor for this adjustment.

It is important how the temporal change of the comparison potential in the above <B> is performed on the electrocardiographic input. In this regard, as a second embodiment, as shown in the circuit diagram of FIG.
By replacing the one-shot timer and R ₄ and Q ₁ with R ₂ , the start of the monotonous decrease of the comparison potential of <B> can be freely changed. FIGS. 7A to 7E show FIGS.
The time change of the potential at the point E> is shown. Here, QR of <A>
The one-shot miter is activated by the S-wave detection output. The waveform at this time is shown in FIG. 7 <E>. <E> rises a certain time after the detection of the QRS wave. During this time,
Unlike FIG. 5B, the comparison potential shown in FIG. 7B hardly decreases and remains constant. Next, the one-shot timer is started at the fall of <E>. The output of the one-shot timer at this time is shown in FIG. 7 <D>. While the output of the <D> is out, Q ₁ shown in FIG. 6 is turned ON, the discharge of C is effected through the Q _1, R _4. Therefore, as shown in FIG. 7 <B>, the potential of <B>, which has been kept constant until then, monotonously decreases while the output is present at <D>. When <D> falls, <B> stops decreasing and the next
Prepare for QRS wave detection.

In the example shown in FIG. 6, from the example shown in Figure 4, since the high comparison potential of <B> for T wave having a higher peak value, safe for operation of the comparator A ₁ . or,
In the example shown in FIG. 6, although the number of components is increased, in this example too, it is significantly smaller than the above-mentioned variable resistor for manual adjustment. Even one-shot timers are 2mm thick and several mm square
An IC having a size of about 1 mm is used.

Of course, by combining the discharging method of C shown in FIGS. 4 and 5 with the method shown in FIGS. 6 and 7,
It is also possible to further change the potential of the point <B> with time in various shapes.

Also, the circuit is not limited to these two types and combinations.
That is, the input peak value of the intracardiac electrocardiogram to <C> is detected and held using the output <A> at the time of QRS wave detection, and this is used as the starting point of the comparison potential for the next QRS wave detection. If the potential at the starting point is changed over time to the sensitive side, the input sensitivity automatic adjustment for QRS wave detection is practically sufficient.

These functions can be implemented by A / D converters and microprocessors and software, or other digital and analog circuits. This embodiment shows a specific method of relatively simple implementation.

By incorporating such an electrocardiographic input sensitivity automatic adjustment function, the third variable resistor shown in FIG. 3A could be eliminated. By fixing the stimulus output and the number of stimuli, and using the circuit according to the present embodiment, all of the first to third variable resistors shown in FIG. 3A could be removed. Also, by removing all variable resistors, the second
It has become possible to adopt a preferred form in which a temporary pacemaker is integrally provided in the branch portion as shown in the figure. Needless to say, the embodiment shown in FIG. 1 may be used.

Such a miniaturized temporary pacemaker previously connected to the pacing catheter and integrated with the pacing catheter can be easily sterilized and used, and furthermore can be packaged under aseptic conditions in a packaging container. May be stored and handed over to the surgeon at the time of treatment.

According to the present invention, a temporary pacing catheter is integrated with a pacemaker, and the temporary pacemaker is sufficiently small and can be fixed to an appropriate position on the patient's body, so that the patient can be transported. Very convenient.

Furthermore, if the present pacing catheter is packaged under aseptic conditions, the manpower conventionally required for connecting the catheter to the pacemaker and performing various adjustments can be omitted, so that manpower required for emergency treatment is reduced, and clinical contribution is made. There is something great.

[Brief description of the drawings]

1 and 2 are perspective views of an embodiment of a pacing catheter according to the present invention. FIG. 3 (A) is a circuit block diagram of a general temporary pacemaker, and FIG. 3 (B).
FIG. 4 is a diagram schematically showing an appropriate comparison potential and an inappropriate comparison potential with respect to a QRS wave. FIG. 4 is a comparison circuit diagram according to an embodiment of the present invention, and FIG. <B> and <C
FIG. 6 is a diagram showing a change in potential waveform over time in FIG. 6; FIG. 6 is a comparison circuit diagram according to the second embodiment of the present invention; FIG. 7 is a diagram showing the potential waveform over time in <A> to <E> in FIG. FIG. 3 (B), 5 and 7
In each of the drawings, the vertical axis represents potential, and the horizontal axis represents time. (1) ... catheter part, (2) ... temporary pacemaker, (3) ... catheter proximal end, (4) ... syringe, (5) ... branch part, (7) ... balloon, ( 8),
(8 ') ... electrode, (9) ... chemical injection lumen opening,
(10) ... Drug lumen.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hideto Yoshida 156-11 Minowa-cho, Kohoku-ku, Yokohama-shi, Kanagawa Prefecture (72) Inventor Masayuki Horikawa 13-2-105, Higashi-Seriyaya, Konan-ku, Yokohama-shi, Kanagawa 105

Claims (4)

(57) [Claims] 1. A temporary pacing catheter integrally provided with a temporary pacemaker function. 2. A temporary pacing catheter integrally comprising a temporary pacemaker in which one or both of the number of stimulations and the stimulation output are fixed. 3. A temporary pacing catheter integrally provided with a temporary pacemaker provided with an electrocardiographic input sensitivity automatic adjustment mechanism. 4. A means for receiving an electrocardiographic input, a means for generating a comparison potential for comparison with the potential of the electrocardiographic input, and a means for comparing the potential of the electrocardiographic input with the comparison potential to generate a suppressed output. The means for generating the comparison potential increases the absolute value of the comparison potential almost at the same time as detecting the QRS wave in the electrocardiogram input and transmitting the suppression output by the means for transmitting the suppression output, and thereafter increasing the comparison potential. An electrocardiographic input sensitivity automatic adjustment mechanism for generating a comparison potential controlled so as to gradually decrease an absolute value.