RADIO-FREQUENCY RECEIVER (CRR) FOR TEMPORARY HEART

STIMULATION FROM THE OUTSIDE, PRE-ARRANGED FOR

PERMANENT STIMULATION

This invention relates to equipment with an in¬ corporated cardiac radioreceiver (CRR) for temporary heart stimulation from the outside in case of open- heart operation, suitable to be left in situ to pro- vide a permanent stimulation if subsequently necessar The equipment is formed by an electrode with an epi- cardial stimulation tip, a cardiac radio-frequency receiver, and a quick jack-type connection emerging from said cardiac radio-frequency receiver and sui- table to rapidly and easily connect a permanent pa¬ cemaker .

As known, during open-heart surgical operations, the possibility of temporary artificial stimulation of the heart is always maintained; this is achieved by utilizing an electrode, the stimulation tip of which is temporarily fixed with a simple technique to the epimyocardium in a position corresponding to the left ventricle.

When the patient's thorax is closed, the free extremity of the electrode comes out through the thoracic wall and is connected to an external pace¬ maker .

After the prescribed period of rest and when artificial stimulation of the heart is no longer necessary, tne electrode is extracted from the out¬ side simply by pulling it. By doing so, whenever the patient's need for artificial stimulation becomes evident, it is necessary to perform another opera-

tion in order to implant a normal pacemaker.

The equipment described overcomes said drawback and offers more advantages.

According to the invention, the equipment with epi-cardial electrode is provided, in fact, with an incorporated cardiac radio-frequency receiver for temporary stimulation in case of open-heart opera¬ tion, and is provided also with a device for connec¬ tion to a permanent pacemaker. After the necessary period of rest, the recei¬ ver is left permanently in situ.

Preferably, the device for connecting the elec¬ trode to a permanent pacemaker is essentially consti¬ tuted of a quick jack-type connection, as described later. The equipment is implanted during the open- heart operation with the quick connection duly insu¬ lated, but the stimulating tip of the electrode is permanently fixed to the epimyocardiu .

In this way the following objectives are at- tained: a) The extremity of the electrode is not connect¬ ed to an external pacemaker and does not pass through the thoracic wall since the temporary stimulation is supplied, via the cardiac radio-frequency receiver, by an external radio-frequency transmitter (Perso¬ nal pacemaker); since the extraction of the electro¬ de is not required, risks of sepsis are avoided; b) In the event of the patient needing artificial stimulation of the heart, subsequent to the prescπ- bed period of rest, it is always possible to supply

such stimulation in a timely way from the outside using the Personal pacemaker; c) In the event of persistence of the need of ar¬ tificial stimulation (indication of a need for a permanent pacemaker implantation) it is possible to implant a pacemaker with a simple superficial opera¬ tion since only the pacemaker pocket has to be pre¬ pared; then the pacemaker can be connected to the cardiac radio-frequency receiver (CRR) using a length of electrode equipped with the plug for connecting it to the pin of the jack.

The advantages for the patient are: Elimination of the electrode through the thoracic wall during the phase of temporary stimulation and reduction of the risks of sepsis.

Elimination of the always bothersome intervention of extracting the temporary electrode.

Possibility to maintain a temporary stimulation from the outside, for urgent needs. - Possibility to maintain a temporary stimulation from the outside in case of urgent indication of need for the permanent stimulation.

Great simplicity of the operation for the implan¬ tation of a permanent pacemaker when indicated. - Possibility to maintain the stimulation during the above-mentioned operation.

Possibility of periodic ln-hospitai checks of the pathological conditions of the patient (by means of the Personal pacemaker in the "laboratory" ver- sion) .

Possibility of therapeutical interventions in the event the patient undergoes arrhythmic events; this therapy requires the use of the Personal pace¬ maker in the "antiarrhyth ic" version that is capa- ble to carry out the following antiarrhyth ic pro¬ grams: overdrive; underdrive; coupled stimulation; burst stimulation.

- Great phychological support to the patient and his family since the Personal pacemaker can be easi- ly operated by non-specialized persons who have been given the necessary instructions.

The invention will now be described in more detail with reference to the attached figures where: Fig. 1 is -a schematic view of the equipment and of the heart that has to be stimulated;

Fig. 2 is a schematic view of the equipment of Fig. 1 as implanted in a patient;

Fig. 3 is a view, similar to that of Fig. 1, of a second embodiment of the invention; Fig. 4 is a view, similar to that of Fig. 2, concerning the equipment of Fig. 3;

Fig. 5 is a view similar to that of Fig. 1 of a third embodiment of the invention;

F g. 6 is a view similar to that of Fig. 2 con- cerning the equipment of Fig. 5.

From the view of Fig. 1, the equipment is essen¬ tially formed of: an epi-cardial um-polar electro¬ de 11, one extremity of which stimulates the heart CC of the patient; a receiver of radic-frequency 12,

clamped on um-polar electrode 10 without interrup¬ ting its mechanical continuity; a quick jacktype con nection 13 for connecting the other extremity 14 of the uni-polar electrode 10.

The equipment is permanently implanted during the operation by stitching stimulation tip 11 of e- lectrode 10 on the epimyocardium of heart CC of the patient; the radio-f equency receiver 12, constitu¬ ted by a passive coil with a plate for the return signal closing through the patient's tissue, is lo¬ cated in a subcutaneous position (Fig. 2) .

The cardiac stimulation that should it be the case would be required during or immediately after the operation is supplied by an external pacemaker (Personal pacemaker) transmitting the stimulation si gnals by radio-frequency to radioreceiver 12. The re turn signal closes from the epi-cardial electrode on to the radioreceiver plate through the patient's tis sue.

The equipment is then left in situ after the necessary period of rest has elapsed.

In case artificial stimulation of the patient's heart CC subsequently becomes necessary, immediate and temporary use of a Personal pacemaker can be made, or, in the event permanent stimulation is in¬ dicated, a permanent uni-polar pacemaker can easily and rapidly oe implanted oy simply opening the skin at the location of radioreceiver 12 and connecting it to permanent pacemaker 15 using a length of uni-

polar electrode 16 connected to the extremity 18 by means of quick connection 13.

As an alternative embodiment of the invention, it is possible to utilize, instead of the quick jack- type connection 13 emerging from radio-frequency re¬ ceiver 12 as in Fig. 1, a well-insulated free length of uni-polar electrode of suitable length indicated as 119 in Fig. 3, emerging from radio-receiver 112, that can easily be connected to permanent uni-polar pacemaker 115 by a universal adaptor of a known type (not shown); the permanent pacemaker is implanted in a sub¬ cutaneous pocket previously prepared as normally done m permanent pacemaker implantations, as show in Fig. 3 and 4. The return signal closes from the epimyo- cardical electrode onto radio-frequency receiver 12 through the patient's tissue. It may be noted that the equipment in this second version is identical to that of Fig. 1 as regards the uni-polar electrode, here referred to by 110, stimulating tip 111 thereof and the radioreceiver referred to by 112. Radiorecei¬ ver 112 is clamped on electrode 110 at a certain di¬ stance from its free extremity m order to leave a free length or "tail" of uni-polar electrode 110 to which the permanent pacemaker, as mentioned, can ea- sily be connected.

From Fig. 5, it is possible to observe an alter¬ native of the invention wherein use is made of an epi-cardial bipolar embodiment electrode 211 formed by two stimulation tips screwed on the eoimyocardium

and positioned by means of a base 220 made of the ma¬ terial known under the Trade Mark Tygon or other bio- compatible material stitched to the epimyocardium.

In this version the length of electrode 210 is bipolar and radio-frequency receiver 212 has the advantage of being miniaturized since its dimensions are no longer determined by the size of the signal return plate, which in this case is absent; moreover, the absence of the signal return plate avoids muscu¬ lar contractions which are always possible due to accidental tipping of the radio-frequency receiver or to high current density.

The length of electrode 219 intended to connect permanent pacemaker 215 can be indifferently uni-po¬ lar or bipolar, according to the type of permanent pacemaker utilized uni-polar or bipolar. The connec¬ tion between permanent pacemaker 215 and electrode 219 is easily obtained by utilizing a universal a- daptor of a known type, uni-polar or bipolar as ap¬ propriate (not shown) .

The advantages obtained with this third embodiment of the invention are:

Avoiding contractions of muscles always possible in patients .

Complete miniaturization of the radio-frequency receiv r.

It can be noted that in this third embodiment of the invention the equipment is identical with the equipment of Fig. 1 in its conceptual design, but the

same utilizes a length of bipolar electrode 210, a bipolar epi-cardial electrode with two stimulation tips 211 screwed on the epimyocardium and positio¬ ned by means of a base 220 of a bio-compatible ma¬ terial stitched to the heart CC , and a radio-frequency receiver 212, clamped on the conductors of bipolar electrode 210. Owing to the absence of the signal return plate this equipment is quite small.