Download Current Status of the Treatment of Complete Heart Block

Current Status of the Treatment of Complete Heart Block*
I. RICHARD
ZUCKER,
M.D.,P.c.c.P.** VICTORPARSOXNET.
M.D.***
LAWRLNCE
GILBERT.M.D..F.c.c.P.~AND ARTHURBERNSTEIN.
M.D.F.c.c.P.~
Newark, N e z Jerrey
n-CE
THE TIME THAT S I R T H O M A S
Lewis stated "for serial fits or for unconsciousness due to very slow heart action,
many remedies have been tried without
success."'
. "meat strides have been made in
the treatment of complete heart block.
Medical therapists now have a wider, more
effective armamentarium, but response is
neither constant nor stable giving rise to
patient and physician insecurity. Recentl!,
electric pacing using relatively simple technics with power sources of long duration
and yet sufficiently small for implantation
have offered an entirely new therapeutic
approach.
Syncope or such distressing symptoms
as dizziness, clouded sensorium, weaknes,
easy fatiguability, breathlessness, or other
manifestations of tissue anoxia may result
from complete heart block, incomplete
heart block alternating with sinus rhythm,
very slow sinus bradycardia, or arrhythmias of ventricular tachycardia, fibrillation
or standstill.
S
TREATMENT
Electric. .
Pacin~
~
Despite medical treatment, there remains
the group of patients with heart block and
syncope and that larger group of patients
without syncope, who do not respond to
medical therapy. Established complete heart
block associated with arteriwlerotic heart
disease, myocardial infarction, or corunaq
insufficiency canies a serious prognosis. In
those patients with uncomplicated complete
heart block, the prognosis is better; yet,
*Fmm the Hemadynamics Department, Nwark
Beth Israel Hospital.
**Dimtor, Hernodynamics Department and
Chief, Cardiac Catheterization Laboratory.
***Attending in Surgery.
tAttending in Thoracic Surgery.
:Attending in Medicine.
half of these patients will die within two
to four years. Since optimal control is not
possible medically, electric pacing of the
heart offers an alternate therapeutic a p
proach.
I . Dipolar T r a n s ~ ~ e n o uParing.
s
In view of the poor prognosis of the
disease, we have elected to treat many patients with heart block by electric pacing.
However, the implantation of a pacemaker
and the suturing of wires in an irritable
myocardium is a major procedure. Induction of anesthesia is an added risk. Too
frequently, patients requiring such treatment are old and in poor condition. The
preliminary use of an intracardiac dipolar*
(Fig. I ) electrode catheter l e n s the
urgency for immediate definitive long term
therapy and permits an opportunity to
build up support poor risk patients.
.4. Indications.
Indications for the use of intracardiac
dipolar pacing include chronic atriovascular block with Stokes-.4dams seizures refracton to medical therapy, preparation
of patients for implantation of permanent
pacemakers or other major surgery, congestive heart failure due to complete heart
block, emergency treatment of StokesAdarns syndrome, evaluation of the need
for permanent pacing in acute heart block
with s!ncope, established complete heart
block without syncope but with symptoms
of tissue anoxia refractory to medical therapy, and asymptomatic complete heart
block with rates under 40 per minute.'
The dipolar catheter electrode is preferred over the unipolar because endocardial
contact is not necesan, placement at any
~ i t ein the right ventricle is relatively sim*Dipolar m d bipolar
interchangeable, referring to an electrode with two pole I cm apart
at the tip.
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Volvm 17. No. 3
M.mh 1%)
TREATMENT OF COMPLETE HEART BLOCK
ple, and stimulating voltage is lower.'
B. Technique.
The method of using the dipolar catheter is as follows: before the patient is
brought to the catheterization laboratory,
an intravenous infusion is started to provide
a route for emergency medication and a
portable external pulse generator is strap
ped to the patient's chest. In the catheterization room, a monitor pacemaker is
connected to the chest electrcdm and an
external defibrillator is available for emergency use. Under local anesthesia, a small
incision is made over either external jugular vein and a dipolar electrode is introduced. Under fluoruscopic control, the
catheter tip is advanced to the outflow tract
or to the apex of the right ventricle (Fig.
2 ) as in a routine right heart catheterization.
The external leads of the catheter electrode are attached to a pulse generator and
ventricular capture is achieved. A large
loop in the catheter may press against the
tricuspid valve and produce extrasytoles
or will ~ e r m i the
t electrode to advance into
pulmonary artery where high voltages are
required for pacing. Correction of position
by slow withdrawal until the tip is properly
placed results in immediate capture. Firm
fixing with an over-and-over wrapping of
the catheter with a skin suture at the site
of insertion will prevent the advancement
of the tip into the pulmonary artery or its
withdrawal into the right atrium. The skin
is closed with silk sutures and a plastic
spray dresing is applied. In the fint cases
of our series, anticoagulants and antibiotics
were used, but they have been discontinued.' On the following day, patients am
ambulatory and at ease carrying the portable pulse
(Fig. 3 ) .
. snerator.
C. Emergency Transvenous Pacing
There were nine patients intractable to
aU forms of medical therapy who were
treated as acute emergencies' (Table 1 ).
The emergencies included one instance of
shock from an acute myocardial infarct,
one coma following a cerebrovascular accident, one of a glossophanngeal neuralgia
that induced frequent episodes of cardiac
standstill on swallowing, one of repeated
episodes of ventricular fibrillation, four of
sustained cardiac standstill, and one of
severe congestive heart failure accompanied
by cerebral smptoms.
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ZUCKER, PARSONNET, GILBERT A I D BERSSTEIX
D. Tramvenous Pacing without Implantation of Pacemaker.
Ten patients were treated by tramvenous
pacing only (Table 2). Five patients were
too ill to withstand a thoracotomy and the
suturing of electrode wires into the myocardium. They were paced with a transvenous dipolar electrode until their death.
The cause of death in one was the result
of shock following a massive myocardial
Dluaur of
the Ch",
infarct. In the second, death followed in
four d a y after progressive renal failure and
anuria. The third, moribund when brought
to the catheterization m m , was in terminal
congestive heart failure and died during
catheterization. The fourth died in 48
hours in pro%gmsi\fecoma despite adequate
pacing.. The cause of death was not determined. The fifth died of pneumonia after
two months following a four week period
of apparent recovery. The cause of death
in each of these patients cannot be said to
be due to their complete heart block nor
directly to the temporary pacing, but rather
to the -uavitv
. of the primarv and concurrent disease.
The pacing electrode was removed in
two patients after adequate pacing had so
improved their condition that it was believed an implantable pacemaker was not
neccsrary. One of the patients, a three-dayold infant, had a marked improvement in
the heart rate, and reduction in heart size
and is currently well at six months of age.
In the other, there was a trial of pacing
because of a 2 to 1 block with a ventricular
rate of 40 per minute. Two were protected
during other major surxery and the electrodes were removed after their recovery.
The tenth, an 82-year-old man t w ill to
withstand thoracotomy. was paced with an
implanted pacemaker connected to the intracardiac transvenous electrode. Pacing
continued satisfactorily for 60 days until
the pacemaker system failed. He had imoroved sufficientlv durine that time to withnand a thoracotom\ on hic second admission. and is still well 20 months later.
E. Complications during Catheterization.
In the entire group of 40 patients, there
were three instances when a wire of the
dipolar electmde broke during the manipulative positioning, all occurring during
the first few cases of the series (Table 3).
By using the electrode as a unipolar lead
with an indifferent electmde in the skin,
effective ventricular capture and pacing
waq achieved.
Arrhythmias included an episode of ventricular fibrillation which was terminated
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Volumc 17. S o . 3
Marrh 1965
T R E A T M E S T OF COMPLETE HEART BLOCK
with external electric counter shock. \Ye
cannot be certain in this instance of the
etiology of the ventricular fibrillation, since
the patient was moribund prior to catheterization. Four episodes of ventricular standstill were treated with external pacing until
the intracardiac electrode was positioned to
capture the ventricles for effective pacing.
Many patients exhibited frequent isolated
premature ventricular contractions when
too large a catheter loop pressed against
the tricuspid valve or the catheter tip
touched the intraventricular septum. P r o p
er positioning either stopped the extras)%
roles or reduced the irritability markedl?.
After pacing for a few hours, the irritability
disappeared. One having continual Stokes.\dams seizures due to ventricular fibrillation experienced a similar episode during
catheterization which was controlled with
external alternating current counter-shock.
Therefore, we do not believe this was a
complication of catheterization.
In five patients, the electrode tip was
introduced into the coronan sinus. In this
site, pacing was ineffective, required high
voltages, and was accompanied infrequently by somatic muscular contractions. In two
cases at operation for implantation of a
permanent pacemaker, bloody fluid was
found in the pericardial cavity although
no site of myocardial perforation was %en.
We can assume only that damage had been
done during catheterization. There was no
untoward effect from these incidents.
F. Late Complications of Transvenous
Pacing.
In one patient who died three da)s after
an acute myocardial infarct, a small thrombus on the positive pole of the dipolar electrode was found in srtu at necropsy.' In all
other cases, there was no clinical evidence
of thrombosis or embolization.
In four patients after ventricular capture
and pacing for several days, pacing ceased
suddenly. Fluoroscopic examination revealed that the tip of the pacing electrode had
advanced into the pulmonar). a r t e n in
three and had withdrawn into the right
3'7
atrium in one. Under fluoroscopic visualization, the catheter was repositioned in the
right ventricle from which site adequate
pacing was resstablished.
O n one occasion, the patient fell out of
bed and pacing ceased because the portable
pulse generator was broken. The electrode
terminals were reconnected to the jacks of
another external pulse generator.
In one, the external cable broke at its
connection with the pulse generator. The
cable connection was resoldered and adequate pacing followed.
In two a short circuit developed within
the sheath of the catheter. \\'hen the fault
was discovered to be in the catheter, the
patients were recatheterized and adequate
pacing followed.
In one pacing failed because the batteries
of the portable pulse generator ran down.
KO infection was encountered at the site
of entry of the catheter of such severity to
alter the planned treatment program for
the patient. There was no unexplained
fever, nor was t h e r e evidence of fever,
thought to be due to an "endoelectroditis."
11. Permanent Pacemaker Implantation.
In all patients, an interim intracardiac
dipolar electrode is used prior to the final
decision for definitive therapy. Various
pacemaken have been introduced with a
predetermined rate and with as few components as possible.',' At present we feel
that for practical purposes we must use the
simplest and most reliable unit available.
.\ variety of units can be obtained, however, including those with internally or
externally adjustable rates and amplitude
control, with external power sources, such
as induction coupling or radio frequency
circuits, and with P-wave synchronv?
After review of the advantages and disadvantages of aIl the pacemakers. we are
using a blocking oscillator pulse generator
set at a prefixed rate of 70 to 74 impulses
per minute. Despite the theoretic disadvantages of a fixed rate a~ynchronouspacemaker, we believe these are outweighted
by fewer connection$ and circuits, relative
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318
ZUCKER,
PARSONNET, GILBERT AND
simplicity of implantation, and independence of an external unit. The battery Life
of such units is said to be five years.
.at the present time, the pulse generator
is inserted in the left upper abdomen retroperitoneally; the wires are led through a
subcutaneous tunnel and inserted into the
left ventricular myocardium through a left
fifth interspace thoracotomy incision.
.4. Results of Implanted Pacemaker.
In our series of 40 patients, 31 had a
permanent pacemaker implanted (Table
4 ) . There were 19 men with an average
age of 62.1 years (youngest 37, oldest 82)
and 12 women with an average age of 66
years (?oungest 49, oldest 76). The average age of the group was 61 years. All
except two were paced temporarilb transvenously prior to implantation of a permanent unit. The oldest implant was done
34 months ago. Five have died of causer
unrelated to their implantation. One expired 20 months later of a brain tumor.
One died of a cerebrovascular accident two
months later. Another expired of multiple
sclerosis after 13 months. One with a
marked aortic nenosis died suddenlv after
two months. There was only one operative
death, occurring five days postoperatively
from a cerebrovascular accident and m a s
sive gastro-intestinal hemorrhage. The remaining 26 patients are currently well.
The period of observation since the first
pacemaker implant is 497 patient months,
with a n average postoperative survival of
15 months including all in the series. Of
those, if the 14 operated on within the past
years are excluded, the average survival of
all the remaining 17 is 21 months. Since
14 of these patients are still alive and well,
it appears that the use of implanted pacemaken will prove significant in increasing
longevity in those with heart block.
B. Comphcations of Implanfed Pacemaker
Of the 40 patients, all except two were
paced temporarily with the intracardiac dipolar electrode until the time for more
definitive therapy. T h i r t y m e had a permanent pacemaker implanted. In this group,
12 returned for correction of failures of the
BERSSTEIN
Dzvrvr of
thc an,
pacemaker s)stem and four returned once
again for other pacemaker corrections"
(Table 5 ) . The complications occurred
mainly in the earlier patients; in recent
ones the complications were less frequent.
There were seven failures of the pulse generator; in two patients, an increase in the
myocardial wire t h r e s h o l d developed; in
six an electrode wire broke; two developed
severe infection around the pulse generator; one experienced the breaking of a test
lead wire (pig-tail) and another a dislodged m\ocardial electrode. In almost every instance, the dipolar catheter was inserted as a preliminary procedure for the
protection of the patient during definitive
corrective surgery. The only exceptions to
this occurred when the patient with an
intermittent heart block was fortuitously
in a phase of regular sinus rhythm at the
time insertion of the pacemaker was done,
or if the corrective procedure did not require the use of general anesthesia.
C . Significance of Competing Pacemakers
In the 19 instance of pacemaker correction procedures, 15 were paced t e m p
orarily with the intracardiac dipolar electrode. Regardless of the type of asynchronous pacemaker used, competing pacing mechanisms may develop. The following t y p s
of pacemaker competition were seen: between sinc-atrial and electric pacemakers;
between two electric pacemakers, one of
which was faltering; and between a combination of a sino-atrial and two electric
pacemakers, one of which was faltering.
Long periods of competition have been obsensed. In some cases, competition has
been seen over a period of many months.
In all these instances of competition, pacing impulsg from the sin-atrial or electric
pulse generators appeared in the cardiac
cycle at every possible phase of the m)ocardial activity. There was no instance of
ventricular fibrillation when stimuli occurred during the "super-normal" period.
Altered conduction occurred whenever an
impulse appeared early in the relative refractory phase. The total of all these experiences amounts to many patient-months
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Velum 4'. S o . 3
Much 1%)
T R E A T M E S T OF
COMPl.ETE
of c o m p e t i t i o n during which time there
were no recognized instances of ventricular
fibrillation and no deaths. This leads one to
believe that the induction of ventricular
fibrillation by impulses introduced during
the supernormal period must be exceedingly rare.
Ventricular fibrillation can be induced
by electric stimuli 10 to 20 t i m a greater
than the threshold of myocardial contraction with stimuli of ? milliseconds' duration, or if the duration as well as the amplitude of the stimulus is increased." rilthough
there would appear to be a wide margin of
safety of voltage amplitude and impulse
duration in c u m n t pacemakers. the margin may be reduced somewhat by mocardial h>poxia and ischemia, drug intoxication, and electrolyte imbalance.
Ventricular fibrillation also has been reported due to improper grounding of recording equipment." The r i ~ kof such a
derangement in rhythm can be minimized
or excluded completely by the proper selection of stimulus amplitude and duration as
well as unipotential grounding of all equipment.
Medical management of complete heart
block affords hut a temporary control neither stable nor dependable and its failure is
too frequently unheralded and fatal. Electric pacing by interim transvenous stimulation provides immediate, stable, and dependable control.
Indications for transr.enous pacing or
pacemaker implantation should include not
only Stokes-Adams disease, but heart block
with signs and symptoms of diminished
cardiac output and with heart rates under
40 per minute as well. Patients with complete heart block are protected best by
pacing with a transvenous intracardiac dipolar electrode preparaton to and during
anesthesia for surgery.
A series of 40 patients is presented. There
was a total of 56 catheterizations. There
were nine emergencies requiring immediate
transvenous pacing. In this group, there
HEART BLOCK
319
were five deaths due to extensive intercurrent disease. This stresses the importance
of the use of the dipolar electrode in patients too ill for permanent implantation,
because despite their desperate medical
condition, four of these patients were supported sufficiently so that subsequent permanent implantation was done without a
fatality.
Permanent as)nchronous i m p l a n t a b l e
p a c e m a k e r s , though requiring battery
change, are relatively simple to insert and
are preferable to externally worn units. Of
the 31 patients who have had permanently
implanted pacemakers, there was one postoperative death. The four othen died
months later of unrelated disease, and the
remaining patients, despite corrective episodes of pacemaker failure are all well, free
of s)mptoms of heart block, and rehabilitated to activity normal for their age.
Those patients who returned because of
permanent pacemaker system failure and
were paced transvenously, and those patients with intermittent regular sinus rhythm
exhibited competitive pacing mechanisms.
Electric or sino-atrial impulses appearing
during any phase of the cardiac cycle did
not precipitate ventricular fibrillation.
The most satisfactory medical treatment
of complete heart block is neither dependable nor stable. It has been suggested that
medical therapy should be confined to an
emergencF- problem until electric pacing
can be established. In most cases eventually, it will be necessary to insert a permanent pacemaker, with reasonable expectancy of success in rehabilitating the patient to a normal functional life and preventing sudden death due to complete
heart block.
ADDENDUM: From the time that this manuscript
has been submitted for publication, to November
9, 1964, the total number d patienu in the series
has increased to 72. The number of tranrvenoul
catheterizztionr totaled 105. Sixn/-eight permanent
pacemaker implantations were performed on 57
patients. The total number of surgical p m e d u m
including the complete operations for pacemaker
replacement and minor corrections of system failure war 83. There were nine deaths. There were
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320
ZUCKER, PARSONNET, GILBERT Ahm BERA'STEIN
no a d d i t i o n a l major complicatiom. M i o r complicatiow remained of the order mported.
Resuut
Le traitement mtdical le plus ratisfairant du
bloc auriculoventriculaire complet n'est ni certainement efficace, ni stable. On a suggtrt que le
trairement mtdical devrait Etre limit6 i un orobI h e d'urgence, jusqu'h ce que I'entrainement
Clectrique puisse Crre dtabli. Dans de nombreaux
car, il sera Cventuellement ntcersaire d e placer
un stimulateur pennanent, avec un espoir raisonnable d e pouvoir ramener le malade
une vie
fonctionnellernent normale et d'tviter le mon
subite doe au bloc complet.
Sca~tssmu;eavac
Auch die a m meisten befriedigende internistische Behandlung einer kompletten Herzblockes
i n weder verlaslich noch dauerhaft. EE wurde
vorgeschlagen, die konselvative Behandlung auf
den akuten Notfall N k h r h k e n . namlich solange, bis ein elektrLEher Schrittmacher angelegt
sein kann. In den meisten Fallen wird a wahrscheinlich notwendig sein, einen Schrittmacher
fur dauernd aruulegen, und man kann dabei eine
angemesene Erfolgrquote fur die Rehabilitierung
der Pauenten erwanen, der ein funktionell normales Leben fiihn, und auf diese Weise einen
ploalichen H e m o d infolge kompletten Herrblocks verhiiten.
REFE~ESCE~
I L e w s , T . L.: Clinical Duordrrr of the Heart
B ~ a r ,7th Ed., S h a m 8 Sou Ltd., 1933.
2 ZUCUEP,I. R., PMSOSNET,V., GILBERT,L..
* s o ASA. M. M.: "Dipolar Electrode in H e m
Block," 1 . A M . A . . 184:549, 1963.
3 Z c c u ~ a ,I. R., P ~ S O ~ N EV.,T ,GILBERT,L.,
As*, M. M. AND SHAH, I. H.: "A New Dipolar Catheter Electrode for the Treatment of
Complete Heart Block and Stokn-Adam, Syndrome," ]N.B.I.H., 13: 159, 1962.
4 P u s o s s e r , V., ZL.CKEI, I. R., GILBELT,L.
* s o As*, M. M.: "An Intracardisr Bipolar
Electrode for Interim Treatment of Complete
Heart Block," Am. 1 . Cardiol., 10:261, 1962.
5 Zccuen, I. R., P M S O N ~ E TV.,
, G~LBERT,
L..
B E ~ S S T E IA.~ , AND As*, M. M.: "Emergency
CATECHOLAMINE METABOLISM
Csthecholarmne meUlbollrm In normal penom Is
dl-Ued,
wllh emphasis on the diEerenn In the
metabollw of exogenous and endopenous norepinephrlne. Daytlme cateeholamlne and estffhollmlne
rnetabollte exmtlon 1s mmpared In 73 patlenu wlth
euentlal hgpertenslon and 47 normal eonmlr. The
hypertenrlve patlenU as a gmup show slgnllomt
dldlerenees. wUeh may be semndary to reduced
OympatheUc actlvlty when blood p-ure
11 m l l p
Dcvrwr
the C h noft
Treatment of Complete Heart Block and
Stoker-Adamr Syndrome," J.N.B.I.H., in prcu.
6 P ~ a r o s s ~ V.,
r , Z v c u ~ a , I. R.. G t ~ a ~ a L.
r,
ASD As*, M. M . : "Emergency Treatment of
Complete Heart Block and Stoker-Adam Syndrome by Crc of an Intracardiac Dipolar Electrode Catheter." 1. Am. Gerior. Soc.. 10:919,
t qfi7
7 CH&RDACK.
W. M..GAGE..4. .4 AND GREATa*cn, W.: "A Transistorized Implantable
Pacemaker for Long-Term Correction of Complete Heart Block," Surgery, 48:643, 1960.
Zo~r,P. M. LXD ~ N E N T H N . , A. J.: "LongTerm Electric Pacemaken for Stoker-AdDisease." Circulntion, 22:341, 1960
W ~ l a t c n ,W. L , GOTT, V. L. A X O LILLEHEI,
C. W.: "Treaunent of Complete Hean Block
bv Combined Uw of Mvocardial Electrode and
~ r t i f i c i a l Pacemaker." ' s u r g . Forum, Clinical
Con-,
8: 360, 1957 ChicagltAmcrican College of Surgmns, 1958.
1Y5Y.
11 MOLSWADE,
G. R. * s o L r s ~ a m s C.:
,
"Induetion Pacemaker for Contml of Complete Hcart
Block," 1. T h o r . and Cnrdiocarc. Surg., 44:
246. 1962
12 KANTROWITZ,
A , COHES, R., ~ I L L M D , H.,
SCHMDT,J. AND FELDMAS,D.: "The Treatment of Comolete Heart Block with an Implanted ~ o n t k ~ a b lPacemaker,"
e
Surg., Gynrc.
and Obrtrr., 115.415. 1962.
13 NATHAN,D. A,, CENTER,S., Wu, C. Y. AND
Kerrea, W.: "An Implantable Synchronous
Pacemaker for the Long-Term Correction of
Complete Heart Block," Circulatron, 27:682,
1963.
14 P ~ ~ r o s s V.,
~ r ,G I L B E ~ TL, , ZUCKEP,I. R.
r s o As*, M. M . : "Complications of the Implanted Pacemaker-A Scheme for Determining the Caule of the Defect and Methods for
Correction." J T h o r . and Cardiovac. S u r g ,
45:501, 1963.
15 RACE,D., STIILLISO,
G. R., EYLPOY,P. AND
B n r m s ~ n , J.: "Electrical Stimulation of the
Heart." Ann. Surg., 158:100, 1963.
16 B c a c ~ ~ r H.
r , B ; : "Hidden Hazards of Cardiac Pacemakers, Circulolzon, 24: 161, 1961.
-
For re rino please write Dr. Zucker, Newark Beth
lrrael Lospkal, ~ c w a r k .
IN ESSENTIAL HYPERTENSION
talned by same other meehantsm: In 19 per cent.
the ratio of imethanephrlne + normetanephrine)/
vanlllglmandellc seld Is markedly elevated. Indicating
an abnormality of catecholamlne metabollw. In
these patlenrr. abnormal catecholamlne deacflvatlon
may be the cause of the hypertension.
Icrar, M. C.: "Eiimts o f Mcrhrldep.
189'188. 1944.
lAMA.
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in Hypcmnuon."