Download 1 - Circulation Research

Cardiac Arrhythmias Following Condenser
Discharges and Their Dependence Upon
Strength of Current and Phase of
Cardiac Cycle
By Bohumil PeleSka, M.D., C.Sc.
With the technical assistance of Z. Blaxek, M. R6bl, and E. Sladkova and the statistical evaluation of Z. Roth
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• The effect of electric currents upon cardiac
activity has attracted increasing interest in
connection with electrical defibrillation of the
heart. In many cases resuscitation depends
largely upon cardiac massage and ventricular
defibrillation, whether the chest is open or
closed.1"12 Although defibrillation of the exposed heart has been adequately studied theoretically as well as practically13"19 there is
still no uniform opinion on transthoracic
defibrillation.
It is generally agreed that both high voltage
and high intensity of current are needed to
stop ventricular fibrillation in a closed
chest.7- 20~22 This puts great demands upon
the construction of a suitable apparatus, the
output of which must range from tens to hundreds of watts. At present a condenser discharge, which enables us to provide within a
short time the quantity of energy necessary
to induce defibrillation, seems to be the most
satisfactory solution. It also seems to be the
only solution for portable defibrillators with
their own power source, independent of electrical power lines, the urgent need of which
is increasingly apparent in clinical practice
as well as in field emergencies.
Defibrillation in a closed chest can be
achieved by various types of electrical impulses. Akopyan et al.23 used a condenser
discharge (16-24 /*F) up to 6000 volts, Hosier
and Wolf0 an alternating current up to 1000
volts, Kouwenhoven et al.7 450-900 volts, PeFrom the Institute for Clinical and Experimental
Surgery, Prague, Czechoslovakia.
Received for publication January 3, 1963.
Circulation Reaeareh, Volume XIII, July 19GS
leska10 a condenser discharge of 16 i±F up to
5000 volts, etc. Such high voltages are capable of damaging the myocardium and the
prognosis of resuscitation may thus be adversely affected.
Several authors21-24> 25 have attempted to
clarify the question of the effect of the high
voltage itself, whether of alternating current
or condenser discharges, upon the myocardium, but the problem is complicated by lack
of agreement as to what strength and type
of impulse is most suitable for transthoracic
cardiac defibrillation. Our earlier work26
demonstrated that defibrillation impulses
may, under special conditions, cause a certain
degree of either morphological or functional
damage. Some authors described various degrees of morphological changes ranging from
insignificant damage to burns, necroses, and
various degenerative changes of individual
areas or fibres. Other authors categorically
deny the possibility of any damage. The cardiac effects of electric currents of the intensity necessary for defibrillation seem to depend upon the voltage, the density of current
per cm2, the duration of the impulse, the
overall energy, the condition of the myocardium and, particularly, upon the presence or
absence of repeated applications.
We began to work upon this problem several years ago. Although we were unable to
check thoroughly all of the forms of defibrillation impulses employed, we believe that our
work portrays the general aspects of the effects of electric currents upon the heart. At
the outset we did not know whether damage
21
22
PELESKA
electrocardiograph
trigger and
delay circuit
discriminator
electrocard ioscope
electronically
controlled
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experimental
animal (dog)
discharge
impulses
switch
FIGURE 1
Diagram of electronic devices used for applying condenser discharges in specified phases
of the cardiac cycle.
to the tissues is caused by the total quantity
of electric energy, by the voltage, or by other
variables. Therefore we chose a wide range
of energy (from 0.06 to 1800 watts), as well
as of voltage (from 500 to 6000 volts). We
used condensers with capacities of 0.5 to 100
JXF, which cover the range of capacities hitherto employed for defibrillation. The calculation of energy for certain values of voltage
and capacities is shown in table 1. In the
present study we were particularly interested
in the pathophysiology of the effect of a high
voltage electric current upon the myocardium
at different phases of the cardiac cycle, a
question which is interesting in relation to
sequelae of injuries by electric current and
the explanation of their mechanism.
Methods
To carry out this work we constructed an
apparatus which made it possible to apply a
condenser discharge in any phase of the cardiac
cycle. Its components are shown in figure 1. The
apparatus works on the following principles: The
electric potentials of cardiac activity are amplified by the electrocardiograph and led to the discriminator, which passes only the highest amplitude, i.e., the R wave. This amplified R wave
is used as the impulse for the trigger and delay
circuit which controls the timing of the impulse
TABLE 1
Values of Electric Energy (in watts) Used in Experimental Discharges.
kV
0.5/iF
1 /iF
2/iF
4/tF
8/iF
12 /iF
16 nF
20 tiF
24/iF
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
6.0
0.06
0.25
0.56
0.12
0.25
0.5
1
1.12
2.25
4
1.56
2.25
3.06
3.125
6.25
12.5
4.5
9
18
6.12
12.25
24.5
4
8
16
32
2.0
8
18
32
50
72
98
128
162
200
242
288
2.5
10
2
1.0
4
9
16
25
36
49
64
81
100
121
144
1.5
6
1
0.5
2
4.5
8
3.0
12
27
48
75
108
147
192
243
300
363
432
5.06
6.25
7.56
10.12
12.5
15.12
20.25
40.5
25
50
30.25
60.5
9
18
36
72
13.5
24
37.5
54
73.5
96
121.5
150
181.5
216
22.5
40
62.5
90
122.5
160
202.5
250
302.5
360
32 tiF
4.0
16
36
64
100
144
196
256
324
400
484
576
50/iF
6.25
25
56.25
100
100/iF
12.5
50
112.5
200
156.25
312.5
225
450
306.25
612.5
400
800
506.25
625
756.25
900
1012.5
1250
1512.5
1800
Circulation Research, Volume XIII, July 1903
23
CARDIAC ARRHYTHMIAS
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applied to the dog by an electronically controlled
switch from the condensers.
The electrocardiograph is protected from damage by a relay connected to the input lead, and
is also controlled electronically from the delay
circuit which at the same time synchronizes the
switching off and on of the electrocardiograph.
The apparatus is put into operation by the trigger
circuit which, after releasing the impulse, blocks
the further activity of the apparatus from accidental impulses. The application of the impulse
in the pre-set phase of the cardiac cycle is checked
by the electrocardioscope and recorded by the
electrocardiograph during the experiment.
By means of this apparatus we studied the effect
of condenser discharges upon cardiac activity in
the three phases shown in figure 2, i.e., I, absolute
refractory period (ARP) ; II, relative refractory
Deriod (RRP) ; III, period of excitability (EP).
The designations of the phases are the same for
figure 5.
We carried out the experiments on mongrel
dogs (20 to 25 kg) because the cardiac physiology
of these animals closely resembles that of man,
according- to our own experience and to that of
others.7 The dogs were anesthetized with thiopental
intravenously, repeated as required during the
entire experiment. The standard electrocardioeraphic leads of the extremities were recorded
on the Mingograph 42.
The electrodes for the application of the condenser discharge measured 15-17 cm2. They were
placed on opposite sides of the thorax, at sites
previously shaved and treated with electrocardio2'raphic paste. Blood pi'essure was recorded directly from a femoral artery. At the beginning of the
experiment an electrocardiogram was made and by
a test discharge into a.n artificial load we set the
parameters of the delay circuit so that the discharge would be applied to the chosen phase of
the cardiac cycle. The discharge Avas applied to
the dog only after the delay circuit was accurately
set. About 12 discharges were tested in every
dog, beginning with discharges of high energy
which were then gradually lowered. Thus the dogsurvived a greater number of experimental discharges. After every discharge there was an interval of 5-15 minutes to allow the cardiac rhythm
to i*ecover.
When changes of cardiac rhythm of a permanent
character or of long duration occurred, we discontinued the experiment. We also discarded those
dogs in which ventricular fibrillation occurred after
the discharge. In every case of fibrillation we
attempted external defibrillation in order to elucidate the reversibility of fibrillation produced by
different parameters of condenser discharges. We
carried out and evaluated statistically a total of
2160 discharges in 240 dogs.
Circulation Research, Volume XIII, July 196S
R
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FIGURE 2
Electrocardiogram (schematic) showing the phase
of cardiac cycle in which a condenser discharge
tvas applied. I: S toave, corresponding ARP. II:
T ivave, corresponding RRP. Ill: P xoave, corresponding EP. Arroxos: sites of exact application.
Method of Evaluation
Changes of cardiac rhythm were classified from
electi'ocardiographic recordings made during and
after the experimental discharge. The recorded
arrhythmias were divided according to their severity into five groups, as follows: (1) no chaaiges
of rhythm following the discharge, with regular
sinus rhythm immediately afterward (fig. 3A),
(2) mild arrhythmias of brief duration, e.g., sevei'al extrasystoles, temporary tachycardia or bradycardia (fig. 3B), (3) moderate but fully reversible
arrhythmias involving longer lasting changes of
rhythm such as bigeminy, ventricular extrasystoles,
idioventricular rhythm, ventricular tachycardia,
bradycardia, atrioventricular dissociation, etc. (fig.
3C), (4) severe changes of rhythm (fig. 4D) such
as marked electrocardiographic deformations and
ventricular rhythm lasting up to several minutes,
which usually caused a decrease of blood pressure,
(5) severe arrhythmias changing into ventricular
fibrillation. Figure 4E shows such an arrhythmia
changing after approximately two contractions into
fibi'illation. In the majority of cases, however,
the transition to fibrillation required several seconds
up to several minutes, but in some instances (fig.
4F) ventricular fibrillation occurred immediately
after application of a condenser discharge.
Results
The individual results are summarized in
figure 5. For evaluation we always took five
values from different experimental animals in
one column with identical parameters of
voltage and capacity. For each phase of the
cardiac cycle we obtained and evaluated 720
experimental discharges. We are presenting
this figure to draw attention to two types of
24
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Electrocardiogram and blood pressure record before and after condenser discharge.
A. No significant change} no arrhythmia. B. Several interpolated extrasystoles, example
of slight arrhythmia. C. Ventricular rhythm and, bigeminy evaluated as moderate
arrhythmia.
Circulation Research, Volume XIII. July 196X
25
CARDIAC ARRHYTHMIAS
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FIGURE 4
Electrocardiogram ancl blood pressure record before and after condenser discharge.
D. Marked electrocardiographs abnormality, ventricular rhythm, alteration of blood
pressure following discharge; evaluated as severe changes. E. Ventricular rhythm
changing after several contractions into fibrillation. F. Ventricular fibrillation beginning
immediately after discharge.
Circulation Rusenrch, Volume XIII, July 10C.1
26
PELE§KA
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FIGURE 5
Survey of evahuition of individual results in 2160 experiments. I: A.RP, II: RB,P, III:
EP. Explanation of different degrees of arrhythmias in figure.
mechanism involved in fibrillation. In one
type, fibrillation sets in with relatively low
voltages (about 1 Irv) and is of a benign char-
acter, easily restored to normal. The other
type follows high voltages (over 5 kv) and
is more serious because it is often associated
Circulation
Research,, Volume XIII, July 1!)GS
27
CARDIAC ARRHYTHMIAS
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FIGURE 6
Statistical evaluation of 720 experimental discharges aiicl their effect upon cardiac
rhythm in the ABP. I: area without arrhythmias. II: area of slight arrhythmias. Ill:
area of moderate arrhythmias. IV: area of severe arrhythmias. V: area of fibrillation
or changes of severe arrhythmia into fibrillation.
with inhibition of the electrical activity of
the conduction systems and with morphologically demonstrable damage to the myocardium. These morphological changes will be
described in another paper.
The results of our experiments were statistically evaluated and expressed in graphs by
Z. Roth. Figure 6 shows the results of condenser discharges applied in the absolute refractory period (AEP). The vertical axis
shows kv linearly, the horizontal axis fxF in
a logarithmic progression. The individual
curves limit the areas of different degrees of
functional damage of the myocardium. This
division was obtained by statistical methods,
i.e., by calculating for each capacity (Korber's method for LD-50), a voltage at which
50% of the animals had arrhythmias more
severe than one point, e.g., one and two
points; or one, two and three points, etc. The
term "point" is explained in the following
paragraph. Up to four values were thus obtained for each capacity and these, when connected by a continuous line in the figure, gave
Circulation Research, Volume XIII, July 19GS
five different areas in which there is always
one dominating type of arrhythmia. Area I
is without arrhythmias. Area II includes
slight arrhythmias and Area III moderate
arrhythmias. An important part of the figure
is the area of severe arrhythmias, area IV,
and the smallest is area V, i.e., ventricular
fibrillation. Figure 7 demonstrates a corresponding statistical evaluation of discharges
applied in the relative refractory period
(RRP) and figure 8 shows the results in the
period of excitability (EP).
RELATION OF PHASE OF CARDIAC CYCLE
TO THE EFFECTS OF STIMULUS
We first tested the hypothesis that the arrhythmia produced by a condenser discharge
is unrelated to the phase at which it is applied. For this purpose a response without
arrhythmia was given one point, slight arrhythmia two points, moderate arrhythmia
three points, severe arrhythmia four points,
and fibrillation five points. For each group a
score of points was calculated. Decision depended upon the score of points that was the
28
PELEsKA
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100
FIGURE 7
Statistical evaluation of 720 experimental discharges and their effect upon cardiac
rhythm in the RHP. I: area without arrhythmias. II: area of slight arrhythmias. Ill:
area of moderate arrhythmias. IV: area of severe arrhythmias. V: area of fibrillation
or changes of severe arrhythmia into fibrillation.
FIGURE 8
Statistical evaluation of 720 experimental discharges and their effect upon cardiac
rhythm in the EP. I: area without arrhythmias. II: area of slight arrhythmias. Ill: area
of moderate arrhythmias. IV: area of severe arrhythmias. V: area of fibrillation or
changes of severe arrhythmia into fibrillation.
Circulation Research, Volume XIII, July 19GS
29
CARDIAC ARRHYTHMIAS
0
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os FIGURE 9
Statistical evaluation of 2160 experimental discharges a<ncl their effect upon cardiac
rhythm regardless of the phase of the cardiac cycle. I: area xoithout arrhythmias.
II: area of slight arrhythmias. Ill: area of moderate arrhythmias. IV: area of severe
arrhythmia's. V: area of fibrillation or changes of severe arrhythmias into fibrillation.
The curves in the figure intersect points of identical energies (25, 50, 100, and 150 watts)
loith various voltage and capacity values.
larger when two phases were compared at the
same voltage and capacity. We used the
statistical sign test according to Dixon and
Mood27 and Maly.2S
We found that the score in the EP is significantly smaller than that in the ARP and
REP (P < 0.01). The differences between the
ARP and the RRP are not significant. We
conclude that arrhythmias caused by a condenser discharge of constant intensity are
smaller in the EP than in the ARP or the
RRP.
Discussion
Arrhythmias produced by the effect of
electric current upon the myocardium depend
upon two factors. The first is the height of
absolute voltage. This dependence is much
more pronounced than the second one, the
total quantity of energy acting upon the
heart. Both these relations are illustrated in
figure 9 which is a statistical evaluation of
all three phases of the cardiac cycle, obtained
by the process just described.
If we trace a series of curves in this figure
Circidation Research. Volume XIII, July 19GS
connecting the points of identical energies,
we find that the same curve intersects almost
all grades of arrhythmia, from severe to none
at all. If the degree of functional damage to
cardiac activity is approximately parallel to
the degree of morphological damage, we can
derive a clear idea of the proper parameters
for the impulses of condenser defibrillators.
Morphological studies made during these experiments indicate that the functional changes
are indeed parallel to morphologically demonstrable changes in the myocardium. It follows
that the defibrillation impulse should have
parameters which will avoid all but the least
functional damage to rhythm.
Our studies also cast some light on the dynamics and the sequelae associated with cardiac arrhythmias. Injuries by electric current, particularly the frequent accidents
caused by undischarged condensers when repairing transmitters or other high voltage
sources either in laboratories or industrial
plants, have characteristic time courses. As
demonstrated in figure 5, two kinds of ven-
30
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tricular fibrillation may be caused by condenser discharges. One of these, sudden fibrillation, occurs most frequently with lower
voltages and lower energies, as shown in the
upper half of figure 5. According to our experience, such fibrillations can easily be
stopped by one adequate defibrillation impulse. Usually there is no subsequent recurrence of fibrillation.
The other type of fibrillation caused by the
application of high voltage (5-6 kv) and high
energies (300 watts) is more serious. In such
cases there are marked changes of rhythm,
such as bradycardia, even total inhibition of
the electric activity of the heart and severe
ventricular tachycardia, which often precedes
fibrillation. In many of these cases we observed, immediately after a high energy discharge, a normal sinus rhythm which, after
several seconds, was interspersed with supraventricular or ventricular extrasystoles. Gradually thereafter a picture of severe arrhythmia developed, ending within one or more
minutes in ventricular fibrillation. We observed 28 such eases of transition of severe
arrhythmias into fibrillation.
After some discharges of great intensity
we could still record the electrical activity of
the heart but mechanical contractions were
weak or absent, and blood pressure was low
or not recordable. These types of heart failure
are reminiscent of some of the fatal cases
after injury with electric current which were
encountered by us and by others.29"84
Our findings indicate that the appearance
of fibrillation following a condenser discharge
is most likely when it occurs in the phase of
the cardiac cycle corresponding with the T
wave. In our cases we observed the development of fibrillation 56 times in the RRP, 37
times in the ARP, and only 15 times in the
EP. Our finding that the relative refractory
period of the cardiac cycle is most dangerous
for the development of fibrillation confirms
the conclusions drawn by Kouwenhoven et
al.,24- 35 Milnor et al.,25 Mackay, Leeds21 and
others. The period of excitability is the least
favorable for fibrillation. The damage to car-
PELESKA
diac rhythm at this time is smaller than in
either of the two former phases.
We should like to add that in constructing
condenser defibrillators induction coils of
various types are sometimes incorporated in
the discharge circuit. This inductance changes
the shape and the duration of the condenser
discharge and considerably lowers the voltage
delivered. The electrical resistance of the coil
also reduces the energy of the impulse as
applied to the heart. The intensity of arrhythmia caused by a condenser discharge is different if there is an inductance connected to
the circuit. These questions will be considered in more detail elsewhere.
Summary
To improve technics for electrical defibrillation of the heart, an apparatus was constructed for the application of a condenser
discharge at any selected phase of the cardiac
cycle. With this apparatus 2160 discharges
were applied through the intact chests of 240
dogs under thiopental anesthesia. The voltage
ranged from 0.5 to 6 kv, the condenser capacity from 0. 5 to 100 /iF, the total energy from
0.06 to 1800 watts. The associated changes in
cardiac rhythm were graded from one (no
abnormalities) through two (mild, brief extrasystoles), three (more protracted but fully
reversible periods of bigeminy, extrasystoles,
block, etc.), four (severe but reversible
changes lasting several minutes, usually with
fall in blood pressure), to five (severe arrhythmias changing into ventricular fibrillation) .
The severity of the arrhythmias increased
progressively as the voltage was increased,
and to a much smaller extent with increases
in the total amount of electrical energy. Arrhythmias also were significantly more severe
when the shock was delivered during the refractory period (S-T interval) than during
the excitable (P interval) stage of the cardiac cycle. Two types of ventricular fibrillation of very different prognosis were revealed.
One came on suddenly after low voltage
shocks and could easily be terminated by a
single adequate defibrillation impulse. The
Circulation Research. Volume XIII, July 196S
31
CAEDIAC ABRHYTHMIAS
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other came on more gradually after high voltages and energies and tended to be irreversible.
Observations thus far made indicate that
the severity of the arrhythmia following condenser shocks gives an approximate indication
of the severity of pathological changes in the
heart. Excessive currents could damage the
heart to such an extent that myocardial contractions were weak or absent although electrical activity persisted. Therefore the parameters of condenser discharges used for
clinical defibrillation should be such that they
will produce only the mildest and briefest
arrhythmias.
kammerflimmerns bei geoffnetem oder geschlossenem Brustkorb. KOVO-Tschechoslow.
Exportzeitschrift 9: 5, 1959.
13. BECK, C. S., PRITCHAED, W. H., AND FEIL, H. S.:
Ventricular fibrillation of long duration abolished by electric shock. J. Am. Med. Assoc.
135: 985, 1947.
14. HOOKER, D.
3. GUYTON, A. C, AND SATTERFTELD, J.:
Factors
concerned in electrical defibrillation of heart
particularly through unopened chest. Am. J.
Physiol. 167: 81, 1951.
4. HOSLER, R. M.: Cardiac resuscitation. Nebraska
State Med. J. 42: 391, 1957.
5. HOSLER, R. M., AND WOLFE, K.:
6.
7.
8.
9.
10.
11.
12.
Closed-chest
resuscitation. A.M.A. Arch. Surg. 79: 31, 1959.
JUDE, J. R., KOUWENHOVEN, W. B., AND KNICKERBOCKER, G. G.: Clinical and experimental
application of a new treatment for cardiac
arrest. Surg. Forum 46th Annual Clinical Congress 11: 252, 1960.
KOUWENHOVEN, W. B., MlLNOR, W. R., KNICKERBOCKER, G. G., AND CHESMUT, W. R.: Closed
chest defibrillation of the heart. Surgery 42:
550, 1957.
KOUWENHOVEN, W. B., JUDE, J. R., AND KNICKERBOCKER, G. G.: Closed chest cardiac massage.
J. Am. Med. Assoc. 173: 1064, 1960.
KOUWENHOVEN, W. B., JUDE, J. R., AND KNICKERBOCKER, G. G.: Heart activation in cardiac
arrest. Modern Concepts of Cardiovascular
Disease 30: 639, 1961.
PELESKA, B.: Transthorakalni a pfima defibrilace.
Rozhl. Chir. 36: 731, 1957.
PELESKA, B.: La defibrillation transthoracique et
directe a haute tension. Anesthfisie Analg6sie
15: 238, 1958.
PELESKA, B.: Der "Universal defibrillator
Prema," ein Gerat zur Beseitigung des Herz-
dreulation Retearch, Volume XIII, July 1968
KOUWENHOVEN, W.
B., AND
electrical currents on the heart. Am. J. Physiol.
103: 444, 1933.
15.
KOUWENHOVEN, W. B., HOOKER, D. R., AND
LANGWORTHY, O. R.: The current flowing
through the heart under conditions of electric
shock. Am. J. Physiol. 100: 344, 1932.
16. LEEDS, S. E.,
MACKAY, R. S., AND MOOSLIN,
K. E.: Production of ventricular fibrillation
and defibrillation in dogs by means of accurately measured shocks across exposed heart.
Am. J. Physiol 165: 179, 1951.
References
1. GuRVicz, N. L.: Vosstanovleniye zhiznennikh
funktsiy organizma posle smertelnoy elektrotravmy. Tr. konf. posv. probl. patofisiologii
i terapii term. sost. (XII-1952) p. 127, Medgiz
1954.
2. GUBVICZ, N. L.: Fibrilyaciya i defibrilyaciya
serdtsa. Medgiz 1957, Moscow.
R.,
LANG WORTHY, O. R.: Effect of alternating
17. MACKAY, R. S., MOOSLIN, K. E., AND LEEDS, S.:
The effects of electric current on the canine
heart with particular reference to ventricular
fibrillation. Ann. Surg. 134: 173, 1951.
18. WIQGERS, C. J.: The mechanism and nature of
ventricular fibrillation. Am. Heart J. 20: 399,
1940.
19. WIGGERS, C. J.: The physiologic basis for cardiac
resuscitation from ventricular fibrillation—
method for serial defibrillation. Am. Heart J.
20: 413, 1940.
20. GURVICZ, N. L.: Vosstanovleniye zhisnennikh
funktsiy organizma posle smertelnoy elektrotravmy. Klin. Med. 30: 60, 1952.
21. MACKAY, R. 8., AND LEEDS, S. E.: Physiological
effects of condenser discharges with application to tissue stimulation and ventricular
defibrillation. IRE, Trans. Med. Electron. Vol.
ME-7: 104, 1960.
22. PELESKA, B.: A high voltage defibrillator and
the theory of high voltage defibrillation. Proc.
Third Intern. Conf. Med. Electron., London,
1960, p. 265.
23. AKOPYAN, A. A., GURVICZ, N. L., ZHUKOV, I. A.,
AND NTEGOVSKI, V. A.: O vozmozhnosti ozhivleniya organizma pri fibrillyacii serdtsa vozdeystviem impulsnovo toka. Elektrichestvo 10:
43, 1954.
24.
KOUWENHOVEN, W. B., AND MlLNOR, W. R.: The
effects of high voltage, low capacitance electrical discharges in the dog. IRE, Trans. Med.
Electron. PGME-H: 41, 1958.
25. MILNOR, W.
R.,
KNICKERBOCKER, G.
G., AND
KOUWENHOVEN, W. B.: Cardiac responses to
transthoracic capacitor discharges in the dog.
Circulation Res. 6: 60, 1958.
32
PELESKA
26. ZAK, F., AND PELESKA, B.: Morf ologickS zmgny
v myokardu po defibrilaci. Rozhl. Chir. 36:
727, 1957.
-""
27.
DIXON, W. J., AND MOOD, A. M.: The statistical
sign test. J. Am. Statist. Assoc. 41: 1957.
28. MALY, V.: N£kter6 neparametrick§ testy pro
statisticka hodnoceni ve zdravotnick 6m vyzkumu. Acta Univ. Carolinea-Medica 5: 641,
1958.
29.
hazards in the laboratory. IEE, Trans. Med.
Electron. ME-7: 111, 1960.
32. SCHEDEL, F.: Electrical accidents. Muench. Med.
Wochschr. 101: 2011, 1959.
33. WEGRIA, R., AND WIGGERS, C. J.: Factors deter-
mining the production of ventricular fibrillation bj' direct currents. Am. J. Physiol. 131:
104, 1940.
34.
lung und Beurteilung von Unfallen durch
elektrischen Strom. Ztsehr. arztl. Fortbild.
53: 967, 1959.
30. LINKE, H.: Der elektrische Unfall und seine
Behandlung. Z. artzl. Fortbild. 53: 971, 1959.
31. MACKAY, E. S.: Some electrical and radiation
WEGRIA, R., AND WIGGERS, C. J.: Production of
ventricular fibrillation by alternating current.
Am. J. Physiol. 131: 119, 1940.
FKUCHT, A. H., AND TOPPICH, E.: Zur Behand35.
KOUWENHOVEN, W . B . , KNICKERBOCKER, G. G.,
CHESMUT, R. W., MILNOR, W. B., AND SASS,
D. J.: A-C shocks of varying parameters affecting the heart. Communication and electronics.
Am. Inst. Elec. Eng., May, 1959.
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-•3';, ..I C V \ ,
"•
h-
Circulation
Research. Volume XIII, July 19G3
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Cardiac Arrhythmias Following Condenser Discharges and Their Dependence
Upon Strength of Current and Phases of Cardiac Cycle
BOHUMIL PELESKA, Z. Blazek,, M. PRábl,, E. Sládková and Z. Roth
Circ Res. 1963;13:21-32
doi: 10.1161/01.RES.13.1.21
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