Download The Significance of Bilateral Bundle Branch Block in the

The Significance of Bilateral Bundle Branch
Block in the Preoperative patient*
A Retrospective Electrocardiographic and
Clinical Study in 30 Patients
Gerald R. Berg, M.D. and Morris N . Kotler, M.D., M.R.C.P. (Edin.)
Thirty patients with electrocardiographic evidence of bilateral bundle branch
block (BBBB) underwent 36 surgical procedures. Despite an 83 percent incidence
of significant cardiac dlease, the overall mortality was 10 percent. In no case
was death attributable to complete heart block, though one patient was found at
postmortem to have sdfered acute myocardial infarction. Patients with previous
syncopal episodes showed no increased incidence of arrhythmias and no patient
bad a documented Stokes-Adams attack. It would appear that the routine use
of temporary cardiac pacemakers is not justified in the preoperative patient with
presumed BBBB. However, since the factors that ultimately cause complete heart
block are not known in patients with BBBB, constant cardiac monitoring is
mandatory in the intraoperative and immediate postoperative period.
he significance of disease of both bundle
Tbranches has recently been appreciated with the
finding that a significant proportion of patients with
electrocardiographic evidence of bilateral bundle
branch block ( BBBB ) will eventually develop complete heart, block.' In addition, a history of syncope
or transient dizziness in these patients may indicate
that episodes of heart block have occurred.
The question then of how to manage the patient
with BBBB (as defined by various electrocardiographic criteria below) who presents for elective
minor and major surgery is an important one. To
manage such patients properly, knowledge of the
natural history of patients with BBBB undergoing
surgery would be of value. It is the aim of this study
to determine retrospectively from a group of patients with BBBB the incidence of intraoperative
and postoperative cardiac abnormalities, particularly the development of complete heart block in
response to surgical and anesthetic stress.
'From the Electrocardiogram Laboratory and Department of
Medicine, Albert Einstein College of Medicine, Bronx, New
York.
The reports of approximately 25,000 ECGs taken at the
Hospital of the Albert Einstein College of Medicine were
reviewed for the presence of BBBB in patients scheduled for
surgery. The ECG criteria for BBBB in our patients were as
follows:
a ) Right bundle branch block (RBBB), with major left
axis deuiation (LAD);'-4 ( 1 ) QRS duration of 0.12 sec
or more; ( 2 ) mean QRS axis in standard leads more
negative than -30"; ( 3 ) the presence of a small R
wave of at least 0.04 sec in duration in leads I1 and 111;
( 4 ) QRS configuration in V1 consisting of a notched R
wave, rR', rSR' or rsR' complex.
b ) Left bundle branch block (LBBB) with first degree
h a r t block5 ( 1 ) QRS duration of 0.12 sec or more;
( 2 ) QRS configuration over left precordial leads consisting of a notched r wave, rR', rSR', or rsR' complex;
( 3 ) S-T segment and T wave changes in leads over the
left ventricle and ( 4 ) PR interval greater than 0.20 sec.
The charts of these patients were then assessed for:
a ) the presence of significant underlying risk factors
b ) history of syncope or dizziness
c ) history of previous cardiac disease
d ) abnormal physical findings
e ) nature of operation
f ) type of anesthesia
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PREOPERATIVE SIGNIFICANCE OF BBBB
Table 1-Age
No. patients
2
Distribution
1
1
0
1
1
5
1
g ) intraoperative complications
h ) postoperative course with emphasis on the development of arrhythmias, myocardial infarction, or
Stokes-Adams attacks.
This study group consisted of 30 patients (25 men
and five women) who underwent a total of 36
operative procedures. The mean age of our patients
was 68.8 (distribution in Table 1).The clinical data
are recorded in Table 2.
Underlying Risk Factors
A significant proportion ( 83 percent of patients )
showed evidence of underlying cardiac or circulatory disease manifested by angina pectoris, congestive heart failure, arrhythmias, and syncope or dizziness (Table 2). The most common findings were
hypertension and previous myocardial infarction.
Of the noncardiac or noncirculatory risk factors,
diabetes mellitus was most commonly found (23
percent ). One patient presented with muscular
dystrophy, the significance of which will be discussed below.
Of the two ECG patterns of BBBB mentioned
above, 26 patients (87 percent) exhibited RBBB
and major LAD and four patients (13 percent)
exhibited LBBB and first degree heart block.
Surgey and Anesthesia
Thirty-six procedures were performed in 30 patients with one patient undergoing three separate
procedures. Of the 36 procedures, 12 (33 percent)
were considered major and 24 (66 percent) minor
Table L P a t i e n t Material
Number of patients
Average Age
Number of Surgical Procedures
30
68.8 years
36
Major
Minor
Evidence of associated cardiac or circulatory disease 25
History of myocardial infarction
History of angina pectoris
History of congestive heart failure
History of cardiac arrhythmia
Hypertension
Prior dizziness or syncope
Associated findings:
Diabetes rnellitus
Rheumatoid arthritis
Muscular dystrophy
Gout
(arbitrarily defined by an anesthetic time of 20
minutes). Of the patient group, 18 (50 percent)
underwent general anesthesia, seven ( 19 percent)
spinal and 11 (31 percent) local anesthesia.
Intraoperative Complications
There were no inoperative deaths. Three patients developed hypotension and in one patient
there was an episode followed by ventricular fibrillation, which responded to lidocaine ( Xylocaine )
and DC countershock.
Postoperative Complications
There were numerous overall medical and surgical complications; however, only half of the patients
exhibited cardiac abnormalities: four patients (11
percent) exhibited arrhythmias, three (8.5 percent)
experienced dizziness or syncope and eight (22
percent) exhibited ST-T wave changes on ECG.
There were no documented cases of complete heart
block, although the occurrence of heart block could
not be entirely ruled out in one patient (see case
report of patient 2 ) .
There were three deaths. Only one appeared to
be related directly to the surgery. Postmortem
examination revealed a fresh thrombus occluding
the right coronary artery and a six-day-old posterior
myocardial infarction, ( which coincided with the
day of operation). The other two patients died from
non-cardiac causes; one succumbed to overwhelming sepsis and respiratory failure and another died
on the 31st postoperative day after a prolonged
period of severe electrolyte imbalance. It is noteworthy that all three patients were considered poor
surgical risks preoperatively and all were operated
upon under spinal anesthesia.
In analyzing the group of three patients experiencing dizziness or syncope postoperatively, three
were hypertensive preoperatively; one had n history
of congestive heart failure; all were considered to
have BBBB on the basis of RBBB and LAD; two
underwent spinal anesthesia and one general anesthesia and all three underwent major surgical procedures.
In the two patients with a preoperative history of
dizziness or syncope undergoing a total of four
procedures ( three local and one spinal anesthesia ) ,
complete heart block was not noted either intraoperatively or postoperatively.
The following case reports illustrate some of the
difficulties encountered in evaluating the postoperative course in patients with BBBB.
CHEST, VOL. 59, NO. 1, JANUARY 1971
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BERG AND KOTLER
FIGURE1. ( Case 2 ) . An example
of the pattern of complete RBBB
with left anterior parietal block
(1) QRS duration is 0.15 sec;
( 2 ) Mean QRS axis -52"; ( 3 )
RSR' configuration in lead V1;
( 4 ) APC in lead AVR.
A 75-year-old white man was well (except for a history of
dyspnea on exertion on climbing three flights of stairs) when
he presented with a fiveday history of dysuria, hesitancy and
diminished urinary stream. He was admitted for acute urinary retention.
Physical examination revealed: blood pressure UX)/90 mm
Hg; pulse 80 and regular; a harsh basilar systolic ejection
murmur, distended bladder and absent ( R ) testicle. Laboratory data were normal except for an ECG that revealed
RBBB and major left axis deviation ( Fig 1) .
Transurethal resection of the prostate was performed under spinal anesthesia with tetracaine (Pontocaine). There
were no complications during the one hour and 15 minute
procedure, but immediately postoperatively, the patient developed hypotension (blood pressure 120/80 mm Hg) and
puke rate of 4O/minute. ECG during the episode revealed
sinus bradycardia; the patient responded to the intravenous
administration of atropine sulfate, (1.0 mg), with a return
to previous blood pressure and pulse. Serial ECGs were
unchanged and there was no elevation of serum glutamic
onloacetic transaminase.
Comment
right cranial nerve VII palsy, scattered rhonchi, and a grade
2/6 basilar systolic murmur.
Laboratory data were within normal limits except for an
ECG showing RBBB and LAD ( Fig 2).
Prior to surgery, she was found to have a right hydronephrotic kidney and she developed a transient episode of atrial
fibrillation that subsided spontaneously. Myocardial infarction
could not be detected and the patient underwent cholecystectomy and right nephrectomy under general anesthesia with
nitrous oxide and halothane without intraoperative complications.
Her postoperative course was complicated by multiple
episodes of dizziness and syncope, associated with paroxysmal rapid atrial fibrillation, M y controlled with quinidine
sulfate 200 mg qid. She was discharged in regular sinus
rhythm.
The patient was readmitted one year after her cholecystectomy with a history of multiple episodes of syncope associated with rapid atrial fibrillation, and persistence of BBBB
(Fig 3). Her symptoms were finally controlled with digitalis
and procaine amide.
Comment
Although the impression of the physicians in attendance
was that of a vasovagal reaction to the pain and anesthesia,
transient complete heart block could not be led out.
This patient illustrates the fact that certain patients with
BBBB may present postoperative complications that may be
interpreted as Stokes-Adam attacks, but which are actually
secondary to rapid arrhythmia.
A 63-year-old white woman presented for elective cholecystectomy. Her past history indicated that she had "hypertension," frequent episodes of palpitations, dyspnea on exertion and Bell's palsy.
Physical examination revealed an obese woman, blood
pressure 220/110 mm Hg, pulse 88/minute and regular, a
Wilson and associates? drew attention to the
unusual electrocardiogram of RBBB and major
LAD and subsequent investigators2.0 found extensive involvement of both left and right bundle
branches in patients displaying this pattern. Grant*
CHEST, VOL. 59, NO. 1, JANUARY 1971
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PREOPERATIVE SIGNIFICANCE OF BBBB
FIGURE2. (Case 29). An example
of complete RBBB with LAD in
a patient with palpitations: ( 1 )
QRS duration of .12 sec; ( 2 )
mean QRS axis of -43"; ( 3 )
P-R interval of .20.
found that the marked LAD was attributed to
involvement of the anterior superior division of the
left bundle by either d i h s e fibrosis ("left anterior
parietal block'.') or by microscopic infarcts ("left
anterior peri-infarction block). The work of
Mahairne and Lenegre2 have complemented these
observations and show that complete atrioventricular block may result from lesions involving both
bundles, but sparing the common bundle.
.
Several studies have demonstrated the various
ECG presentations of disease of both bundle
branches.2.4-7.9.10 Thus, anatomic BBBB has been
correlated with:
1. Left bundle branch block masquerading as
right bundle branch block, (complete LBBB
in the limb leads and complete RBBB in the
precordial leads ) .10
2. Alternating bundle branch block (either in the
FIGURE3. ( Case 29). With LAD
and RBBB during episode of
dizziness. Patient now manifests:
( 1 ) rapid atrial fibrillation, ( 2 )
QRS 0.12, (3) mean QRS axis
of -70".
CHEST, VOL. 59, NO. 1, JANUARY 1971
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BERG AND KOTLER
same or different tracings, beats of both the
LBBB and RBBB type are present)."
3. Complete RBBB.and major LAD.','
4. RBBB with major RAD implying a lesion of
the posterior ramus of the left bundle and
characterized by: a ) QRS pointing inferiorly
and to the right at greater than +120°, b )
presence bf S in I and Q in 111 and, c ) large R
waves in 11, 111 and aVF.4
5. QRS greater than 0.12 sec whether the pattern
suggests RBBB or LBBB or is of the anomalous or atypical intraventricular block type,
plus first degree heart block."." While this
last pattern is not invariably associated with
bilateral bundle branch disease, the association is consistent enough to be considered
suspicious of such disease.
Of the five ECG patterns mentioned, only the
third (RBBB and LAD) is relatively common
having been observed in 1 percent of routine
hospital records in two large series'," and in 26 of
30 preoperative patients with BBBB in our series.
The frequency of the association of RBBB and the
involvement of the anterior superior division of the
left bundle is explained by the proximity of these
portions of the cardiac conduction system to the
anterior portion of the intraventricular septum at
which point a common blood supply from the left
anterior descending artery is shared. 1 1
The etiology of BBBB is highly variable and is
summarized by the clinico-pathologic study of
Lenegre.? Of his 62 patients with histologic BBBB:
a ) 39 exhibited coronary atherosclerosis ( 13 with
hypertension and 28 with evidence of myocardial
infarction ), b ) seven exhibited aortic valve disease,
c ) two (the youngest patients in the series) had
muscular dystrophy and d ) the remaining 19 patients had no apparent etiology for the sclerosis seen
in the conduction system. An even lower incidence
of clinichl cardiac disease was noted in a more
recent study:' in which only 50 percent of 65
patients exhibited cardiac symptoms ( only criteria
used). Other less common etiologies of BBBB such
as idiopathic myocardopathyl2 and Chagas diseaselz{have been described as well.
In our present series a larger proportion of
patients had evidence of heart disease ( 83 percent),
though postmortem studies were available in only
one patient. Of note is case 6, the youngest patient
in our series, who presented with muscular dystrophy. The association of muscular dystrophy and
the pattern of RBBB and LAD has recently been
reported in a patient with external ophthalmoplegia
(considered a variant of muscular dystrophy by the
author,'.' ) and the abnormalities of the conduction
system found in muscular dystrophy have been well
described. 1"
It is estimated that 10 percent of patients with the
pattern of RBBB and LAD will develop complete
heart block.' It should be noted that the pattern of
RBBB and RAD carries a significantly poorer prognosis since 75 percent of 28 patients exhibiting that
pattern in Rosenbaum's series4 developed complete
heart block. The question then of what clinical
factors precipitate complete heart block in patients
with RBBB must be assessed in light of the present
series of patients. In general, either extension of the
underlying fibrotic process or superimposed myocardial infarction would be the factors most likely to
precipitate complete heart block. However, in the
absence of these events, major surgical stress with
its attendant hypotension, anesthesia, fluid depletion, acid-base and electrolyte imbalance may theoretically tip the delicate balance and throw a patient
with BBBB into complete heart block. It would
appear from the data collected in the present series
that this combined stress was not sufficient to
precipitate complete heart block in our patients.
iVhether such patients will develop complete heart
block in the future cannot be answered from the
data presented, but it would seem a measure such
as placement of pacemakers prophylactically in
such patients, particularly those without a history of
prior syncopal episodes, is not warranted at this
time.
Despite the apparent benignity of BBBB in our
patients, the natural history of the disease necessitates careful preoperative evaluation with emphasis
on selection of appropriate operative and anesthetic
technique. Routine postoperative care should include careful continuous cardiac monitoring (even
in patients undergoing minor procedures) in an
attempt to recognize the early development of
potentially fatal heart block.
1 Laser RE, Haft JI, Friedberg CK: Relationship of right
bundle branch block and marked left axis deviation (with
left parietal or periinfarction block) to complete heart
block and syncope. Circulation 37:429, 1968
2 Lenegre J : Etiology and pathology of bilateral bundle
branch block in relation to complete heart block. Progr
Cardiovasc Dis 6:409, 1964
3 Watt TJ Jr, Pruitt RD: Character, cause and consequence
of combined left axis deviation and right bundle branch
block in human electrocardiograms. Amer Heart J 77:460,
1969
4 Rosenbaum hlB: Types of right brindle branch block and
their clinical significance Electrocardiol 1 :221, 1968
5 hlcNally EM, Benchimol A: lledical and physiological
considerations in the use of artificial cardiac pacing, Part
I . Amer Heart J 75:380, 1968
6 htahaim 1: Les htaladies Organiques du Faisceau de His-
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PREOPERATIVE SIGNIFICANCE OF BBBB
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10
Tawara, Paris, Maison et Cie, 1931
Wilson FN, Johnson FD, Barker PS: Electrocardiogram of
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Reprint requests: Dr. Moms Kotler, Sinai Hospital, Baltimore
21215
Hedonism by Force of Circumstances
T h e Middle Ages, immersed in heaving seas of trouble,
and lifted heavenward by great spiritual emotions, had
scant breathing space for the cultivation of nerves. Men
endured life and enjoyed it. Their endurance and enjoyment were unimpaired by the violence of their fellow
men or the vision of an angry Fate. Cruelty, which w e
cannot bear to read about, and a hell, which w e will not
bear to think about, failed signally to curb the zest with
which they lived their days. There is no reason to
suppose that Dante, whose fervid faith compassed the
redemption of mankind, disliked his dream of hell, or
that it irked him to consign to it so many eminent and
agreeable people. T h e Renaissance gave itself un-
reservedly to all the pleasures that could b e extracted
from the business of living. If the men and women who
lived through those highly colored, harshly governed
days had fretted too persistently over the misfortune of
others, or had spent their time questioning the moral
intelligibility of life, the Renaissance would have failed
of its fruition, and the world would b e a less engaging
place for us to live in now.
Repplier A: T h e Divineness of Discontent, in Connolly FX (editor) :Literature,
the Channel of Culture. New York, Harcourt, Brace, 1948
CHEST, VOL. 59, NO. 1, JANUARY 1 9 7 1
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