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European Journal of Cardio-thoracic Surgery 18 (2000) 187±193
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Signi®cance of right bundle branch block in the diagnosis of myocardial
ischemia in patients undergoing coronary artery bypass grafting
Rainald Seitelberger a,*, Thomas Wild a, Nermin Serbecic a, Severin Schwarzacher b,
Meinhard Ploner a, Andrea Lassnigg c, Bruno Podesser a
a
Department of Cardiothoracic Surgery, University of Vienna, AKH Vienna, WaÈhringerguÈrtel 18±20, 1090 Vienna, Austria
b
Department of Cardiology, University of Innsbruck, Innsbruck, Austria
c
Department of Cardiothoracic and Vascular Anaesthesia and Intensive Care, University of Vienna, 1090 Vienna, Austria
Received 12 October 1999; received in revised form 28 February 2000; accepted 7 March 2000
Abstract
Background: Perioperative diagnosis of myocardial ischemia following cardiac surgical procedures remains a challenging problem.
Particularly, the role of new conduction disturbances as markers of postoperative ischemia is still questionable. The goal of this study was to
elucidate the diagnostic signi®cance of new postoperative right bundle branch block (RBBB) for the detection of perioperative myocardial
ischemia in patients undergoing elective coronary artery bypass grafting (CABG). Methods: In 169 consecutive patients, three-channel
Holter monitoring and serial assessment of serum enzymes were performed for 48 h, and 12-lead ECG repeated for up to 5 days postoperatively. Postoperative events were classi®ed as either myocardial infarction (MI), transient ischemic events (TIE) or various conduction
disturbances. Results: Transient (n ˆ 9) or permanent (n ˆ 4) RBBB occurred in 13 patients (8%); 14 patients (8%) showed signs of
perioperative MI and 18 patients (11%) evidence of TIE. Peak activity of creatine-kinase (CK, 561 ^ 135 vs. 316 ^ 19, P , 0:05) and CKMB (22.7 ^ 3.2 vs. 13.4 ^ 0.8, P , 0:01) were higher in patients with RBBB than in patients without perioperative ischemic events. Peak
CK-MB levels were signi®cantly higher in patients with MI as compared to those with RBBB (33.4 ^ 7.6 vs. 22.7 ^ 3.2, P , 0:05). Patients
with TIE had similar perioperative enzyme levels as patients with no events. Conclusion: It is concluded that the combined assessment of
repeated 12-lead ECG, continuous Holter monitoring and enzyme analysis allows a reliable diagnosis of perioperative myocardial ischemia
and conduction disturbances. The occurrence of new RBBB following elective CABG is indicative of perioperative myocardial necrosis and
thus serves as a valuable tool for the diagnosis of new, perioperative ischemic events. q 2000 Elsevier Science B.V. All rights reserved.
Keywords: Right bundle branch block; Coronary artery bypass grafting; Myocardial ischemia; Enzyme analysis; Holter monitoring
1. Introduction
Ventricular conduction disturbances following coronary
artery bypass surgery (CABG) are a common phenomenon
with a prevalence of up to 43% [1±4]. However, their significance as a diagnostic and prognostic indicator of perioperative myocardial ischemia and clinical outcome remains
controversial. Although some studies demonstrated that
the postoperative occurrence of new left bundle branch
block (LBBB) may have an unfavorable impact on survival
and long-term clinical prognosis [1,2], other investigations
were unable to con®rm these data [3,5,6]. Accordingly,
there is no conclusive answer to the question, whether or
not the occurrence of transient or permanent new right
* Corresponding author. Tel.: 143-1-40400-5620/5630; fax: 143-1-4405309.
E-mail address: [email protected] (R. Seitelberger).
bundle branch block (RBBB) is related to considerable perioperative myocardial ischemia and/or associated with
worsened clinical outcome [2±4,6,7].
Caspi et al. reported that 62% of patients with new postoperative LBBB and only 20% with RBBB showed elevated
creatine kinase (CK)-MB levels of more than 5% of total
serum CK and abnormal time±release curves [1]. These
data, however, were not directly compared with those of
patients with either perioperative myocardial infarction
(MI) or an uneventful postoperative course. In contrast,
Hake et al. demonstrated impaired left ventricular function
and elevated enzyme levels in patients with new, permanent
RBBB following CABG [7]. In patients with coronary
artery disease, the occurrence of even transient intraventricular conduction disturbances including RBBB is a reliable
indicator of myocardial ischemia during exercise testing [8].
The goal of the present study was to investigate the significance of transient or permanent RBBB in the diagnosis of
1010-7940/00/$ - see front matter q 2000 Elsevier Science B.V. All rights reserved.
PII: S 1010-794 0(00)00424-3
188
R. Seitelberger et al. / European Journal of Cardio-thoracic Surgery 18 (2000) 187±193
perioperative myocardial ischemia. One hundred and
seventy-three consecutive patients undergoing CABG
were monitored by means of 12-lead ECG and Holter monitoring, and serial assessment of serum enzyme levels. Data
of patients with new RBBB were then compared with those
having either an uneventful postoperative course, or demonstrating electrocardiographic signs of MI or transient
myocardial ischemia (TIE).
2. Patients and methods
The study was performed on 173 consecutive patients,
who underwent CABG. Patients with preoperative LBBB
or RBBB, atrioventricular block, previous coronary bypass
grafting, recent MI …,3 weeks), additional operative procedures, or need of rethoracotomy because of excessive postoperative bleeding were excluded from the study. Early
mortality (de®ned as death occurring during hospitalization
or within 30 days after operation) was 2.3% (four patients).
Since none of these patients had signs of a new LBBB or
RBBB or met the follow-up criteria, they were excluded
from the study, leaving 169 patients for analysis.
Patients were premedicated with midazolam and received
standard general anesthesia with midazolam, etomidate,
fentanyl and pancuronium. Controlled mechanical ventilation with oxygen/air was provided to achieve normoventilation. The cardiopulmonary bypass circuit consisted of a
hollow-®ber oxygenator (Bard HF 5701, C.R. Bard Inc.,
Havorhill, MA) primed with Ringer's lactate 2000 ml,
mannitol 20 g, heparin 8000 IU (Immuno, Vienna, Austria)
and aprotinin 1 000 000 IU (Trasylol Bayer, Leverkusen,
Germany). Flow during CPB was maintained at 2.5 l/min
per m 2 and mild hypothermia (348C) was employed.
Myocardial protection consisted of cold, intermittent
blood cardioplegia administered ante- (induction) and retrogradely. Body rewarming began during completion of the
last distal anastomose. A partial occlusion clamp was used
for the proximal anastomoses. For continuous monitoring of
perioperative arterial and pulmonary artery pressure, a
radial artery cannula and a Swan±Ganz catheter (percutaneously into the pulmonary artery via the jugular vein) were
inserted preoperatively.
2.1. Holter monitoring and electrocardiographic recordings
Two methods were used to assess perioperative electrocardiographic changes.
(1) Continuous three-channel Holter monitoring was
performed using Marquette Holter Recorders (Series
8500). The evaluation was performed on a semiautomatic
basis using a Marquette Laser Holter XP device. Monitoring
began 2 h after opening of the aortic cross-clamp and lasted
for 48 h. The electrodes were placed so that channels 1±3
approximated ECG-leads V2, V5 and aVF, respectively.
(2) Twelve-lead ECG recordings were performed shortly
before and 2, 4, 6, 8, 12, 16, 20, 24, 36 and 48 h after
operation, as well as every day until the sixth postoperative
day.
All Holter tapes and ECG-recordings were reviewed by
the same investigator. Five different forms of perioperative
myocardial events were de®ned by the combined analysis of
electrocardiographic and Holter recordings using the
following criteria.
2.1.1. Transient ischemic event (TIE)
Horizontal or downsloping ST-segment depression of
$1 mm and lasting at least 1 min measured 60±80 ms
from the J-point in at least one Holter channel with no
signs of evolving MI.
2.1.2. Myocardial infarction
(a) Persistent typical ST-segment elevation of $2 mm,
measured 60±80 ms from the J-point in at least one Holter
channel and development of a new Q wave ….0:04 s in
duration and more than one quarter of the following R
wave in amplitude) in the corresponding 12-lead ECG
after 6 days and/or during the 48 h observation period
after surgery.
(b) Persistent negative coronary T wave of .3 mm in 12lead ECG during the 48-h postoperative observation period
and/or 6 days after surgery without occurrence of a new Q
wave.
2.1.3. Right bundle branch block
New occurrence of minimum QRS duration of $0:12 s
with typical RSR con®guration in V1 and/or in V2 and with
deep, late S waves in I, V5 and/or V6 for more than 48 h
duration and at discharge-ECG (permanent), and less than
48 h in duration (transient).
2.1.4. Left anterior hemiblock (LAHB)
New occurrence of a frontal axis . 2308 with a small Q
in I and aVL, small R waves in II, III and aVF, and S waves
in V1±V6.
2.1.5. Left axis deviation
New occurrence of a frontal axis . 2308 with a small Q
in I and aVL, small R waves in II, III, and aVF, and no S
waves in V1±V6.
2.1.6. Left bundle branch block
New occurrence of minimum QRS duration of .0:12 s
with an absent Q wave, a notched or slurred R in I, V5 and/
or V6, and wide right precordial S waves.
2.2. Biochemical analysis
Creatine kinase (CK, units/l, normal values: 0±70) and
the MB-isoenzyme of CK (CK-MB, units/l, normal values:
0±10) were assessed immediately before surgery and 4, 8,
12, 16, 20, 24, 36 and 48 h after aortic cross-clamp time
using enzymatic ¯uorometric methods.
R. Seitelberger et al. / European Journal of Cardio-thoracic Surgery 18 (2000) 187±193
2.3. Statistical analysis
Table 2
Incidence of perioperative events
All data are presented as mean ^ standard deviation
(SD). An analysis of variance (ANOVA) was used to
compare CK and CK-MB values. Since those values demonstrated a non-normal distribution, adequate transformations
were performed: peak values were assessed in a logarithmic
fashion and compared. (signi®cance level: P , 0:05). In
addition, the time corrected area under the curve (AUC)
for CK and CK-MB data was assessed in a logarithmic
fashion and compared (signi®cance level: P , 0:05). Pairwise comparisons were performed using the correction of
Tukey (signi®cance level: P , 0:05). Spot-checks of peak
values were carried out using empiric quantiles and
summarized using box-and-whiskers plots.
For statistical data analysis, the SPSS 9.0 (SPSS Inc.)
statistical package was used.
3. Results
Clinical and anamnestic characteristics of all patients
included in the study are presented in Table 1. Table 2
shows the incidence of perioperative MI and transient ischemia as well as of new postoperative transient or permanent
RBBB. In patients with perioperative MI, 12 developed a
new Q wave and two had a persistent, negative coronary T
wave. None of the patients investigated showed electrocardiographic signs of new LBBB. Two of the 13 patients with
new RBBB (one transient, one permanent) had an additional
LAHB and two had additional ®rst-degree atrioventricular
block. Six patients with RBBB also showed ECG-signs of
left axis deviation but none of the patients had evidence of
concomitant MI.
Table 3 compares surgical data of all patients with regard
to the incidence of perioperative events such as RBBB, TIE
or MI. No relevant differences with regard to aortic crossclamp time, incidence of endarterectomy and total number
of distal anastomoses was detected between the groups of
patients with RBBB and MI as compared to those without
events.
There was no obvious difference with regard to catechoTable 1
Preoperative data
Variable
a
No. of patients
Female
Male
Age (years)
Two-vessel disease
Three-vessel disease
Left main stenosis
History of MI
NYHA class I±II
NYHA class III±IV
a
189
No. of patients
169
34 (20%)
135 (80%)
64.5 ^ 1.6
40 (24%)
129 (76%)
36 (21%)
82 (49%)
24 (14%)
145 (86%)
MI, Myocardial infarction; NYHA, New York Heart Association.
Perioperative event a
Patients (n ˆ 169)
MI
TIE
RBBB ± all
RBBB ± transient
RBBB ± permanent
RBBB and LAHB
RBBB and AV block I
RBBB and LAD
14 (8 b)
18 (11 b)
13 (8 b)
9 (70 c)
4 (31 c)
2 (15 c)
2 (15 c)
6 (40 c)
a
MI, Myocardial infarction; TI, transient ischemic event; RBBB, right
bundle branch block; LAHB, left anterior hemiblock; AV, atrioventricular;
LAD, left axis deviation.
b
Calculated as percentage of all patients.
c
Calculated as percentage of RBBB ± all.
lamine support during the postoperative course between
patients with or without perioperative ischemic events
(seven out of 27 patients with either RBBB or MI, 23 out
of 142 patients with either TIE or no event). Peak values of
postoperative CK and CK-MB for patients with either an
uneventful postoperative course or electrocardiographic
signs of RBBB, TIE or MI are presented in Figs. 1 and 2
(box-and-whiskers plots). Since no obvious difference in
peak CK and CK-MB values and the respective time curves
were observed between patients with either transient or
permanent postoperative RBBB, or between those with or
without additional left axis deviation or left anterior hemiblock, the enzyme data of these subgroups of patients were
not analyzed separately.
Patients with either MI or RBBB developed signi®cantly
higher peak CK and CK-MB values as compared to those
with an uneventful postoperative course. Whereas the CKpeak values between patients with MI and RBBB did not
reach statistical difference due to the high variability of CK
values in the RBBB group, all other groups demonstrated
signi®cant differences between each other (P , 0:001;
Tukey corrected for paired data: P , 0:001). However,
the analysis of CK-MB-peak values revealed signi®cant
differences between all four groups (overall: P , 0:001;
Tukey-corrected P , 0:001 for all paired comparisons).
Table 3
Surgical data a
Variable
RBBB
MI
TIE
No event
No. of patients
ACC time (min)
ECC time (min)
IMA grafts
CEA (%)
No. of DA/patient
13 (8%)
51.1 ^ 5.0
101 ^ 33
12 (92%)
2 (15%)
3.5 ^ 0.5
14 (8%)
54.1 ^ 4.4
99 ^ 38
12 (86%)
2 (14%)
3.3 ^ 1.0
18 (11%)
48.4 ^ 4.9
95 ^ 35
16 (89%)
2 (11%)
3.1 ^ 0.8
124 (73%)
53.2 ^ 1.9
102 ^ 18
111 (90%)
14 (11%)
3.4 ^ 0.9
a
RBBB, Right bundle branch block; MI, myocardial infarction; TIE,
transient ischemic event; ACC, aortic cross-clamp; E, extracorporeal circulation; IMA, internal mammary artery; CEA, coronary endarterectomy;
DA, distal anastomoses.
190
R. Seitelberger et al. / European Journal of Cardio-thoracic Surgery 18 (2000) 187±193
The time courses of CK-MB values for all groups until 48
h after the operation are depicted in Fig. 3. Due to the
inadequate ef®ciency of analyzing single values at respective time points, the AUC for each group was evaluated. The
AUC was proportional to the mean values over the 48-h
observation period. According to this analysis, all four
groups were signi®cantly different among each other (overall: P , 0:001; Tukey-corrected P , 0:001 for all paired
comparisons).
4. Discussion
Coronary artery bypass grafting has become a routine
operative procedure designed to eliminate the various symptoms of angina pectoris, to decrease the incidence of MI and
to extend long-term survival in patients with coronary artery
disease. Myocardial preservation during aortic cross-clamping has substantially improved and operative mortality has
reached a remarkably low level. However, the incidence of
early postoperative myocardial ischemia of various degrees
remains a rather common complication with a variance of
2±20% for the prevalence of new MI [9±11] and up to 40%
for TIE [11,12]. Due to the various methodological
problems in the diagnosis of ischemia during the early postoperative period, the true incidence of postoperative ischemia may be even higher.
Apart from diagnostic methods with high sensitivity and
speci®city such as myocardial uptake of technetium-99m
pyrophosphate on a scintigram or transesophageal echocardiography for detection of regional functional changes,
which cannot be used for routine follow-up, the analysis
of ECG and enzyme release constitute the standard methods
for the diagnosis of postoperative myocardial ischemia. In
most reports, new MI (de®ned as the development of a new
Q wave with or without preceding ST segment elevation)
remains the gold standard for de®ning the postoperative
complication of myocardial ischemia. However, various
reports also emphasized the possible diagnostic signi®cance
of the new occurrence of conduction disturbances such as
RBBB or LBBB [1±3,7].
Whereas the signi®cance of LBBB as an indicator of
perioperative myocardial ischemia is widely accepted
[1,7], the diagnostic signi®cance of the occurrence of new
RBBB after coronary bypass grafting remains controversial
[2±7]. In nonsurgical patients the occurrence of transient or
permanent RBBB at rest or during exercise is usually associated with small vessel disease concomitant to ®brodegenerative changes, severe proximal left anterior descending
coronary artery disease or induced by right ventricular
involvement in inferior wall left ventricular MI [8,13±15].
Especially in combination with MI, RBBB is also associated
with poorer prognosis and increased in-hospital and 1-year
postdischarge mortality [14±16].
Following coronary bypass grafting, increased CK-MB
activities, impaired postoperative regional myocardial function, greater demand for catecholamines or complicated
postoperative course have primarily been observed in
patients who developed a new permanent RBBB [2,7].
The results of the present study clearly show that new
transient and/or permanent RBBB are associated with markedly higher perioperative CK-MB levels than in patients
Fig. 1. Box-and-whiskers plot of peak serum CK levels for all groups. NE, patients with no event; TIE, patients with transient ischemic events; RBBB, patients
with right bundle branch block; MI, patients with myocardial infarction. Data are given as percentiles. The central box shows the data between the quartiles
(25- and 75-percentiles), with the median represented by a bold line.
R. Seitelberger et al. / European Journal of Cardio-thoracic Surgery 18 (2000) 187±193
with an uneventful postoperative course. Consequently, the
occurrence of new RBBB must be linked to myocardial cell
necrosis and appears indicative of perioperative myocardial
ischemia. However, since perioperative CK-MB values of
patients with ECG-proven transmural MI were higher than
in patients with new RBBB, the extent of the ischemic
damage of myocardial cells is certainly smaller in these
patients and does not reach the average extent of cell necrosis induced by a transmural MI.
The signi®cance of a certain conduction disturbance as an
indicator of myocardial ischemia must be based on a reliable, ischemia-speci®c diagnostic parameter in order to
compare its diagnostic value with other, widely acknowledged, indicators of perioperative myocardial ischemia. In
this study, myocardial ischemia was de®ned either by the
occurrence of new MI or of a TIE. Perioperative time
courses and peak values of CK and CK-MB as indicators
of the extent of myocardial cell necrosis were then used to
compare patients with new MI or TIE to those with conduction disturbances.
The diagnosis of MI was based on the combined analysis
of repeated ECG and continuous Holter recordings, and
required the existence of a persistent ST segment elevation
of .2 mm prior to the development of a new Q wave in the
corresponding lead. In addition, a negative coronary T wave
of .3 mm persisting throughout the 6-day observation
period was also classi®ed as MI [11]. Whereas this de®nition of MI is widely accepted, con¯icting reports have been
published about the diagnostic accuracy of serum enzymes
191
for the detection of signi®cant myocardial ischemia, such as
MI.
Although CK-MB release seems to be a reliable biochemical indicator for perioperative MI, the lack of a generally
accepted cutoff value (de®ned as peak activity or total quantity) and the interpatient variability of CK-MB levels
compromise its diagnostic sensitivity [17,18]. Nevertheless,
in this study, both CK as well as CK-MB levels were markedly higher in patients with perioperative MI assessed by the
combined analysis of ECG and Holter monitoring recordings than in patients with either an uneventful postoperative
course or with TIE only. Given the assumption that serum
enzyme levels re¯ect, at least to a certain degree, the amount
of damaged myocardial tissue [17], the signi®cantly higher
CK and CK-MB values of patients with RBBB as compared
to those with no event or only TIE indicate that RBBB does
re¯ect the occurrence of myocardial ischemia in patients
undergoing coronary bypass grafting.
In contrast to other reports, we did not detect any relevant
differences in postoperative enzyme release patterns
between patients with transient or permanent RBBB [2,7].
However, since the latest follow-up ECG in this study was
only 6 days after surgery, our de®nition of permanent RBBB
as any RBBB lasting at least 48 h during the postoperative
period may have overestimated the true number of patients
with permanent RBBB.
Several reasons have been implicated to cause postoperative conduction disturbances such as a higher incidence of
preoperative MI, a higher number of diseased coronary
Fig. 2. Box-and-whiskers plot of peak serum CK-MB levels for all groups. NE, patients with no event; TIE, patients with transient ischemic events; RBBB,
patients with right bundle branch block; MI, patients with myocardial infarction. Data are given as percentiles. The central box shows the data between the
quartiles (25- and 75-percentiles), with the median represented by a bold line.
192
R. Seitelberger et al. / European Journal of Cardio-thoracic Surgery 18 (2000) 187±193
Fig. 3. Bar graph of serum CK-MB levels before surgery (pOp) and for 48 h after opening of the aortic cross-clamp. MB, MB-isoenzyme of creatine kinase;
NE, patients with no event; TIE, patients with transient ischemic events; RBBB, patients with right bundle branch block; MI, patients with myocardial
infarction. Data are given as mean ^ SD. Data were analyzed by calculating the AUC for each group. All groups were signi®cantly different among each other
(overall: P , 0:001; Tukey-corrected for all paired comparisons: P , 0:001).
vessels and applied bypass grafts, longer aortic cross-clamp
time and the use of cold potassium cardioplegia [1,3,5,19±
22]. In the present study, however, we were unable to identify risk factors for the perioperative occurrence of RBBB.
Whereas the relatively low number of patients in our study
with new RBBB did not allow a stepwise analysis of
variance of preoperative clinical data predictive of perioperative myocardial ischemia, intraoperative data such as
aortic clamp time, incidence of coronary endarterectomy
and number of grafts were comparable between patients
with and without ischemia or conduction disturbances.
However, it has to be mentioned that the overall low incidence of new RBBB and/or new MI in conjunction with the
relatively low maximum CK and CK-MB values in those
patients is in line with the assumption that the use of ante/
retrograde blood cardioplegia may provide more effective
intraoperative myocardial protection than crystalloid cardioplegic solutions [4,19,21,22]. This would also explain the
fact that we did not observe relevant perioperative complications such as hemodynamic instability in patients with
perioperative RBBB or even MI.
In conclusion, this study on patients undergoing coronary
bypass grafting demonstrates that the perioperative occurrence of new transient or permanent RBBB is indicative of
myocardial ischemia and is associated with myocardial cell
necrosis. The extent of myocardial damage associated with
new RBBB, however, appears less in comparison to patients
with new MI and is not associated with signi®cant hemodynamic complications during the early postoperative period.
References
[1] Caspi Y, Safadi T, Ammar R, Elamy A, Fishman NH, Merin G. The
signi®cance of bundle branch block in the immediate postoperative
electrocardiograms of patients undergoing coronary artery bypass. J
Thorac Cardiovasc Surg 1987;93:442±446.
[2] Westhof FB, Pokar H, Kalmar P. Fascicular conduction defects
related to coronary artery bypass grafting: etiology and clinical significance. Z Kardiol 1989;78:300±305.
[3] Wexelman W, Lichstein E, Cunningham JN, Hollander G, Greengart
A, Shani J. Etiology and clinical signi®cance of new fascicular
conduction defects following coronary bypass surgery. Am Heart J
1986;111:923±927.
[4] Mustonen P, Hippelainen M, Vanninen E, Rehnberg S, Tenhunen-Eskelinen M, Hartikainen J. Signi®cance of coronary artery bypass graftingassociated conduction defects. Am J Cardiol 1998;81(5):558±563.
[5] Chu A, Califf RM, Pryor DB, et al. Prognostic effect of bundle branch
block related to coronary artery bypass grafting. Am J Cardiol
1987;59:798±803.
[6] Tuzcu EM, Emre A, Goormastic M, Loop FD, Underwood DA. Incidence and prognostic signi®cance of intraventricular conduction
abnormalities after coronary bypass surgery. J Am Coll Cardiol
1990;16:607±610.
R. Seitelberger et al. / European Journal of Cardio-thoracic Surgery 18 (2000) 187±193
[7] Hake U, Iversen S, Erbel R, Drexler M, Neufang A, Meyer J, Oelert
H. New bundle branch block after coronary bypass grafting: evaluation by CK-MB isoenzyme analysis and transesophageal echocardiography. Eur Heart J 1990;11:59±64.
[8] Williams MA, Esterbrooks DJ, Nair CK, Sailors MM, Sketch MH.
Clinical signi®cance of exercise-induced bundle branch block. Am J
Cardiol 1988;61:346±348.
[9] Guiteras Val P, Pelletier LC, Galinanes Hernandez M, Jais JM, Chaitman BR, Dupras G, Solymoss BL. Diagnostic criteria and prognosis
of perioperative myocardial infarction following coronary bypass. J
Thorac Cardiovasc Surg 1983;86:878±886.
[10] McGregor CGA, Muir AL, Smith AF, Miller HC, Hannan WJ, Cameron
EWJ, Wheatley DJ. Myocardial infarction related to coronary artery
bypass graft surgery. Br Heart J 1984;51:399±406.
[11] Seitelberger R, ZwoÈlfer W, Huber S, Schwarzacher S, Binder TM,
Peschl F, Spatt J, Holzinger C, Podesser B, Buxbaum P, Weber H,
Wolner E. Nifedipine reduces the incidence of myocardial infarction
and transient ischemia in patients undergoing coronary bypass grafting. Circulation 1991;83:460±468.
[12] Knight AA, Hollenberg M, London MJ, Tubau J, Verrier E, Browner
W, Mangano DT. Perioperative myocardial ischemia: Importance of
the preoperative ischemic pattern. Anaesthesiology 1988;68:681±
688.
[13] Moreno AM, Alberola AG, Tomas JG, Chavarri MV, Soria FC,
Sanchez EM, Sanchez JG. Incidence and prognostic signi®cance of
right bundle branch block in patients with acute myocardial infarction
receiving thrombolytic therapy. Int J Cardiol 1997;61(2):135±141.
[14] Suarez G, Herrera M, Vera A, Torrado E, Ferriz J, Arboleda JA. Prediction on admission of in-hospital mortality in patients older than 70
years with acute myocardial infarction. Chest 1995;108(1):83±88.
[15] Hod H, Goldbourt U, Behar S. Bundle branch block in acute Q wave
[16]
[17]
[18]
[19]
[20]
[21]
[22]
193
inferior wall myocardial infarction. A high risk subgroup of inferior
myocardial infarction patients. The SPRINT Study Group. Secondary
prevention Reinfarction Israeli Nifedipine Trial. Eur Heart J.
1995;16(4):471±477.
Ricou F, Nicod P, Gilpin E, Henning H, Ross Jr J. In¯uence of right
bundle branch block on short-and long-term survival after inferior
wall Q-wave myocardial infarction. Am J Cardiol 1991;67:1143±
1146.
Devine JE, Wiens RD, Halstead JM, Codd JE. Quantitation of CKMB release: diagnostic utility in coronary bypass grafting. Clin Chim
Acta 1986;156:145±150.
Van Lente F, Martin A, Ratliff NB, Kazmierczak SC, Loop FL. The
predictive value of serum enzymes for perioperative myocardial
infarction after cardiac operations. J Thorac Cardiovasc Surg
1989;98:704±710.
Ueyama K, Jones JW, Ramchandani M, Beall AC, Thornby JI. Clinical variables in¯uencing the appearance of right bundle branch block
after cardiac surgery. Cardiovasc Surg 1997;5(6):574±578.
Mosseri M, Meir G, Lotan C, Hasin Y, Applebaum A, Rosenheck S,
Shimon D, Gotsman MS. Coronary pathology predicts conduction
disturbances after coronary artery bypass grafting. Ann Thorac Surg
1991;51(2):248±252.
Pehkonen EJ, Honkonen EL, Makynen PJ, Kataja MJ, Tarkka MR.
Conduction disturbances after different blood cardioplegia modes in
coronary artery bypass grafting. Including comparison with an earlier
patient series. Scand J Thorac Cardiovasc Surg 1996;30(3-4):149±
155.
O'Connell JB, Wallis D, Johnson SA, Pifarre R, Gunnar RM. Transient bundle branch block following use of hypothermic cardioplegia
in coronary artery bypass surgery: high incidence without perioperative myocardial infarction. Am Heart J 1982;103:85±91.