1960s

The epicardial leads already in use proved to be the solution. They consisted of a core of terylene [polyester] around which 4 thin bands of stainless steel were wound and the lead was then insulated with polyethylene.

I received the first ones in early 1962. They were made of cylindrical stainless steel with a diameter of 2.5 mm, 6 mm long and had a spherical ending.

On February 24^th [1962], a fourteen-year-old boy with complete heart block due to myocarditis was brought into the clinic for emergency treatment. Since we thought that he would need pacing only until his myocarditis had healed, we decided that he was a suitable candidate for the new electrode. The boy was brought into the cineangiographic room in the afternoon. He was first given heparin intravenously because we considered the risk of pulmonary emboli from the electrode to be great. His right external jugular vein was then dissected with local anesthesia and the electrode introduced under roentgen-TV control into the apex of the right ventricle. The free end of the lead was then drawn subcutaneously anteriorly to the third intercostal space where it was taken out through the skin. An anodal plate-electrode of stainless steel was also placed in this region, and the leads connected to an external pulse generator. The boy who had previously been very tired and quiet became talkative as soon as the pacemaker was switched on and his heart followed the new rhythm. The next day he was walking around the ward, proudly showing his new gadget to the other patients. We gave him dicumarol and stopped the heparin as soon as his prothrombin index had come down. He is now well and being paced with his third intra-cardial electrode. The first one was unintentionally pulled out at another hospital after one month and the second ceased to function in October, 1974. Up until then he refused to have the pacemaker implanted subcutaneously.

Lagergren: lead and close-up of electrode

After two years of experimental work in the animal laboratory the patient shown in the photograph was referred to me. 77 years old, he was in complete heart block. The operation was completed in June 1960. His subsequent course was uneventful until he died two years later of natural causes. He was the first patient whose heart block was corrected successfully, on a long-term basis (years) by an implanted pacemaker carrying its own power supply. The case was reported in 1960 and I am gratified and grateful that the statements in the title of the report are still valid.

Chardack WM, Gage AA, Greatbatch W. A Transistorized, Self-contained, Implantable Pacemaker For The Long-Term Correction of Complete Heart Block. Surgery 1960; 48:643-664

This invention relates to electronic equipment for the treatment of cardiac disorders.

Classic treatment of most cardiac arrythmias involves the use of various drugs, such as quinidine, procainamide, digitalis, and the like. It has been known, also that electrical depolarizing impulses of rather high voltage and amperage can be effective in reverting certain arrythmias to normal sinus rhythm. However, due to the rather high mortality incident to the use of such depolarizing technique, it has heretofore been limited to use in conjunction with terminal events, for example ventricular fibrillation, and even here, usually only in those cases where the classic treatment, open chest cardiac resuscitation, is not indicated. In accord with the present invention, a therapeutic electrical stimulus derived from a charged capacitance is applied in controlled, timed relation to the cardiac cycle, it having been found that the high mortality previously associated with electrical depolarizing is due to application of the depolarizing impulse during one or both of two critical periods during the cardiac cycle. Of primary concern in connection with the present invention, then, is the provision of means enabling a physician to apply a capacitance discharge depolarizing impulse at a selected and precise point during the cardiac cycle which lies outside the above mentioned known critical areas. To achieve this effect, the present invention employs means for detecting the electrical activity of successive cardiac cycles and electrical depolarizing means controllable in timed relation to a known reference point occurring during a cardiac cycle as established from the means for detecting so as to intelligently apply the depolarizing impulse as aforesaid.

In general, this invention envisages equipment capable of providing electrical stimuli either directly or indirectly to a patient’s heart for the purpose of reverting cardiac arrythmias.

FIG. 5 is a waveform showing normal sinus rhythm;

FIG. 6 is a waveform showing the output of the trigger synchronized with the R waves of FIG. 5;

FIG.7 is a waveform showing the output of the trigger synchronized with the R waveform of FIG. 6.

FIG. 8 is a waveform showing the output of the delay means; and

FIG. 9 is a waveform showing the output of the defibrillator.

Initially, bulky pulse generators were implanted abdominally with the leads, exiting from the top, tunneled subcutaneously, anteriorly to the veins in the neck, lying smoothly with the patient supine. With body motion, sitting, bending, slouching, significant angulation of the wires occurred creating fulcra about which repetitive motion facilitated breakage. Similarly, shoulder implants responded to motion of the arm over head.

Later, based on these findings, redesign, with pulse generator wires exiting sidewards for easy loops and abdominal tunnels displaced laterally, breakage reduced markedly. Ultimately, shoulder implants with shorter wires took over. Factors causing wire breaks in implanted pacemakers:

Escher D J.W„ et al, Montefiore Hospital, New York, N.Y. Proc.7th Inter-American Cong.of Cardiology, Montreal, Canada, June 1964

The Universal Pacer - Synchronized Demand Pacer - VDD

Rogel: block diagram of the universal pacemaker (syncronized demand)

In June 1964 I have submitted to the Technion, Israel Institute of Technology, my M.Sc. thesis on Electronic Cardiac Pacers under the supervision of the late Prof. Shlomo Rogel, M.D. As part of the project I have built a P Synchronized Pacemaker, the schematic of which is herewith shown.

In the conclusion of the thesis I wrote: "The next stage of pacer development will be a synchronized pacer that…stops its stimulation if the ventricle is triggered by the atrium via the normal conduction system."

The Universal Pacer was based on our synchronized pacer with the addition of another amplifier for the ventricular sensing, Interval to Amplitude converter, comparator and an AND gate.

The Universal Pacer: S. Rogel and Y. Mahler (1971). J. Thoracic & Cardiovascular Surgery 61: 466-471.

On October 6, 1961 the first pacemaker implantation in Germany was performed by H.K. Sykosch, Düüsseldorf, using a Greatbatch-Chardack fixed rate pacer. On March 8, 1963 experimental implantation in a dog was carried out with a then called "Inductive Switch-Off Pacemaker" for intermittent pacing. With a separate implanted receiving antenna picking up the ventricular potentials the stimuli of this special pacer was inhibited. Successful implantation in a 22-year old patient with intermittent AV bloc followed. The patient is still alive presenting now a total AV bloc.

This graph shows the pacemaker used at this time:

First row: Fixed rate pacing
Second row: Switch-off pacing (receiving antenna is already incorporated in the pacer)
Third row: P-wave synchronized pacing

HJ Sykosch-Düsseldorf: Langenbecks Archiv für klinische Chirurgie, Band 308 (1964) 54. Inplantierbare Schrittmacher zur permanenten und intermittierenden Stimulation des Herzens.

This pacemaker consists of an external pulse generator (a), an external transmitting coil (b), an internal receiving coil (c), and myocardial electrode (d). Both the transmitting and receiving coils contain an iron-core strip, with which effective electromagnetic coupling between the coils is achieved, thus inducing stimulating pulses in the receiving coil without high frequency carrier waves.

From 1964 to 1968, the pacemaker was used in fourteen patients at the University of Tokyo Hospital. The average period of usage was forty months (two months to ten years and four months).

Suma, K. et al: Direct induction pacemaker. Digest 6th Int Conf Med Elect Biol Eng (Tokyo) 1965; 96-97.

L'etude que nous avons faite d'un certain nombre de traces de fibrillation ventriculaire recueillis dans ie service de reanimation de l'hopital Lariboisiere comportait une description et une hypothese.

Pour ie cardiologue habitue a reconnaltre des ventriculogrammes et a ne rencontrer que des variations brusques de ('amplitude du trace, lors de l'extra-systole par exemple, la description mettait ('accent sur la succession ininterrompue d'oscillations irregulieres presentant dans ('ensemble des variations progressives d'amplitude autour d'une ligne de reference, en fuseaux. Nous en avons recontre au cours des accidents syncopaux du bloc complet du faisceau de His,dont ('aspect en torsades de points parait relever d'une tachycardie ventriculaire a deux foyers opposes variables.

English Summary: Torsade de pointes is a specific form of dangerous ventricular tachycardia in which an undulating series of ventricular beats appear on the QRS axis. These may be considered a specific form of ventricular flutter wave. Dessertenne first described these torsades de pointes waves in 1966 when he observed this rhythm disorder in an 80-year-old female patient with complete intermittent AV block. In this case.the cause of her recurring syncopal episodes was the torsades de pointes tachycardia rather than third degree AV block or bradyarrhythmias, as was originally suspected.

Dessertenne F. La tachycardie ventriculaire a deux foyers opposes variables. Arch des Mal du Coeur 1966; 59:263

Competitive Ventricular Fibrillation

Bilitch: diagram of competitive impules in patiend being paced

The data that has been presented would indicate that a competitive state between intrinsic and artificial foci, either in the acute or chronic state, is capable of evoking repetitive ventricular rhythms, and that it constitutes a significant factor in the death of patients who are artificially paced. It is quite evident, on the basis of other studies that competition is a much greater, hazard in the presence of acute myocardial infraction and electrolyte imbalance than it is in the stable patient. The ability to document that ventricular fibrillation does occur when pacer impulses fall in the vulnerable period of the QRS-T cycle has caused us to conclude that this is much more likely to be an electrical than a mechanical event. The circumvention of competitive rhythm is best accomplished by the use of triggered pacemakers. These may be two varieties, those that are R-wave inhibited and those that are R-wave synchronous. The R-wave-inhibited pacemakers have the potential hazard of being inactivated by external stimuli. With good shielding it should have the disadvantage of having a relatively long refractory period. Te particular pacemaker used in this study had a refractory period of 0.5 second. Because of this, extrasystoles or conducted impulses occurring with a frequency of greater than 120 per minute would not be sensed by the pacemaker, and thus competition could still occur. It is of interest to not that both patients who died in our competing group with demand pacemakers had early extrasystoles, and thus were capable of having pacemaker stimuli fall in the T-wave of the patient-induced impulses.

Bilitch M, Cosby RS, Cafferky EA. Ventricular Fibrillation and Competitive Pacing. New England J. Med 1967;276:598-604

Figure 2A. A comparison of His bundle pacing and normal sinus rhythm. Traces from above: leads a VR, a VL, and a VF. Pacing the His bundle with electrode catheter at a rate slightly higher that the normal sinus rate.

Figure 2B. The same QRS configuration can be seen in three leads in both panels. However, there is no P wave shown in A and the stimulus-R interval is markedly shorter that the P-R interval in B. Lower panel: lead a VF; HBE His bundle electrogram. Note that the His bundle electrogram (arrows) precedes the QRS in time as the stimulus precedes the QRS during His bundle pacing (A). Interval between time lines equals 1 second.

Berkovitz: typical ECGs with an implantable demand pacemaker

Demand pacemakers function as an artificial automatic fiber with an electronically controlled escape. They stimulate with a preset interval after the preceding ventricular depolarization. This depolarization may be spontaneous or pacemaker induced. When the intrinsic R-R interval is shorter than the escape interval of the pacemaker, the artificial pacemaker remains dormant; similar to an automatic fiber, it continues to be dormant until the interval after a ventricular depolarization is long enough to permit pacemaker escape with resulting stimulation. This stimulation continues with the same escape interval until a spontaneous beat occurs. Thus.in patients with intermittent block, such instruments provide stimulation to the myocardium only when such stimulation is needed, and may even compensate for a single missing beat.

Continuous stimulation of the heart has been used successfully in the treatment of symptomatic atrioventricular conduction disturbances. Recent reports have stressed the possible occurrence of pacemaker-induced repetitive firing during coaction of natural and artificial rhythms. Repetitive firing (more than one response to a single stimulus falling in the preceding T-wave) has been observed fourteen times in our department: (a) during intermittent paired electrical stimulation, three cases, one requiring countershock; (b) at the onset of pacing during complete atrioventricular block, five cases; (c) during coaction of sinus rhythm and continuous asynchronized pacers (chronic block, three [unreported] cases, in two of which the spikes that triggered repetitive firing fell on an extrasystolic T-wave); (d) in acute myocardial infarction during coaction of supraventricular and continuous pacemakers,three cases, one requiring countershock. Stimuli fell on the T-waves of supraventricular complexes. It is for precisely this purpose that other forms of pacing have been developed.

Castellanos A, Maytin 0, Lemberg L, Berkovits BV. Part VIII. Rhythm Disturbances and Pacing: Pacemaker induced cardiac rhythm disturbances. Ann NY Acad Sci 1969; 903-910

Ruben: illustrated cross section of mercury cell

In 1942, the only commercially available dry cell system for portable communication was the zinc-carbon cell. A number of fundamental factors were found necessary to produce a sealed zinc-mercuric oxide alkaline cell and overcome the limitations met in the early attempts to use mercuric oxide as a cathode element. These were: (1 ) a high-density cathode for maximum capacity per unit of volume; (2) amalgamated anodes having an adequate ratio of effective electrode area to cathode coulombic capacity, to eliminate polarization within the rated discharge limits; (3) an alkali-resistant and -absorptive barrier spacer of a submicroporous material in contact with the cathode, to eliminate internal bridging paths due to transportable conductive solids; (4) an alkaline electrolyte containing a saturated zinc ion component, to minimize local chemical action at the anode; (5) quantitative balance between anode and cathode coulombic capacities, to eliminate generation of hydrogen when the cathode is completely reduced; (6) an anode contactor of nonelectrolytically consumable but amalgamable metal, making the zinc anode the only current- generating element, and insulated from the cell container by an elastomeric plastic grommet; and (7) a sealed structure, provided by crimping the container against the insulated anode contactor, to eliminate the effect of atmospheric impurities such as carbon dioxide on the alkaline electrolyte.

Ruben S. Sealed Zinc-Mercuric Oxide Cells for Implantable Cardiac Pacemakers. Ann NY Acad Sci 1969; 167:627-634

"Brainstorming" session (CCU Weekly Conference, September 20, 1967) where Louis Lemberg recalled events surrounding the development of the original external VVI pacemaker. (Lemberg, Castellanos and Berkovits, JAMA 1965; 191-106) and Berkovits presented the concept of what was later known as DVI pacing subsequently introduced as "Bifocal demand pacemaker" by Berkovits, Castellanos and Lemberg in Circulation 1969; 40:III; 57.

An Implantable, Synchronous Pacemaker for the Long-Term Correction of Complete Heart Block

Keller: illustration of synchronous pacemaker

"An implantable, synchronous cardiac pacemaker for long-term correction of complete heart block has been developed. It has been successfully used in dogs for periods up to eight months. The performance of the pacemaker during normal sinus rhythm and atrial arrhythmias is illustrated with electrocardiograms. After implantation of the pacemaker, the dogs have returned to completely normal activity and have tolerated all physical exercises well."

Nathan DA, Center S, Wu C-Y, Keller JW. An implantable synchronous pacemaker for the long term correction of complete heart block. Circulation 1963; 27:682-685.

Illustration: Keller JW. Atrial and Ventricular Synchrony. Annals NY Acad Sci 1969;167:875