Chinese Medicine, 2009, 1, 15-18
Published Online September 2009 in SciRes (www.SciRP.org/journal/cm)
Surgical Outcome and Clinical Follow-up in Patients
with Symptomatic Myocardial Bridging
ABSTRACT
From 1997 to 2006, 37 463 patients received selective coronary angiography in the Fuwai Cardiovascular Hospital,
Beijing, China. Of these, 484 patients had angiographic diagnosis of myocardial bridging. Of the 484 patients, 35 un-
derwent surgery for treatment of myocardial bridging with significant systolic arterial compression. Among the surgical
treatment patients, 24 presented with other cardiac disorders, and the remaining 11 symptomatic patients with isolated
myocardial bridging were included in the follow-up study.
Keywords: myocardial bridging, myocardial ischaemia, myotomy, coronary artery bypass grafting, coronary
angiography
1. Introduction
Muscle overlying the intramyocardial segment of an
epicardial coronary artery is termed a myocardial bridg-
ing, and it is generally confined to the middle segment of
the left anterior descending artery (LAD)1. Traditionally,
myocardial bridging is considered a benign condition2,3,
but it may be associated with myocardial ischaemia4,
acute coronary syndromes and sudden death5. Surgery
has been attempted in selected patients6,7. However, there
is little information about the prognosis of patients with
this anomaly, especially the outcome of surgical treat-
ment for myocardial bridging. Therefore, we analyzed
the clinical, angiographic and functional followup after
surgical treatment in patients with isolated symptomatic
myocardial bridging.
2. Methods
2.1. Patient Selection
From 1997 to 2006, 37 463 patients received selective
coronary angiography in the Fuwai Cardiovascular Hos-
pital, Beijing, China. Cardiac catheterization was per-
formed with the use of a standard Judkins technique and
images were obtained in multiple views, in which sys-
tolic compression of the anterior descending coronary
artery could be observed clearly in every patient. Of
these, 484 patients had angiographic diagnosis of myo-
cardial bridging. Out of the 484 patients, 35 underwent
surgical treatment of myocardial bridging with signifi-
cant systolic arterial compression. The patients who had
a diagnosis of moderate or severe aortic stenosis, moder-
ate or severe left ventricular hypertrophy of any origin or
hypertrophic cardiomyopathy were excluded. Patients
with coronary artery disease, understood as fixed steno-
sis of more than 50% at some point of the coronary net-
work, were also excluded. From these 35 patients, 8 men
and 3 women with myocardial bridging but without other
cardiac diseases were included in the followup study.
The coronary angiographies and medical histories of
these 11 patients were reviewed.
2.2. Follow-up
Follow-up was carried out by telephone and completed
with a review of the medical histories of the patients who
had new admissions and medical records at the hospital.
Clinical evaluation was also accomplished by direct in-
terview of the patients at clinic visits. Clinical symptoms,

X. H. HUANG ET AL.
16
daily activities without chest pain or anginal symptoms,
current medical treatment, and events experienced
(myocardial infarction, need to repeat coronary angio-
graphy or revascularization) were analyzed throughout
the follow-up period.
3. Results
The 37 463 patients with selective coronary angiographic
analysis included 484 with myocardial bridging; a
prevalence of 1.3%. Of these 484 patients, 35 received
surgical treatment for myocardial bridging with systolic
compression of the left anterior descending artery.
Among the surgically treated patients, 24 presented with
other cardiac disorders: hypertrophic cardiomyopathy in
3 cases, coronary heart disease in 3, and valve and other
cardiac diseases in 18. We only studied the remaining 11
patients with isolated myocardial bridging. All of their
coronary angiographies revealed myocardial bridging in
the middle segment of LAD with systolic compression
≥75% (ranging from 75% to 90%).
The mean age of the male patients was 48.4 years
(SD=8.9 years). Four patients had arterial hypertension
and 6 were active smokers at the time that coronary an-
giography was performed. The clinical presentation was
typical angina in 10 patients and atypical chest pain in 1.
Two patients had previous anterior myocardial infarction.
ECG stress testing showed significant ST segment de-
pression or T wave inversion from the anterior leads
during exercise in six of the 11 patients, while five had a
positive Tc-99m Sestamibi SPECT (single photon emis-
sion computed tomography) test with filling defects dur-
ing stress, which were reversible at rest. Ventricular
function was normal in all of these patients. Surgical
myotomy was performed in 3 patients and CABG in 8.
Eight patients were operated on with an off-pump ap-
proach and 3 patients with a cardiopulmonary bypass
technique after medial sternotomy. Conversion to on
pump CABG surgery was necessary in 1 patient because
of perforation of the right ventricle. The left internal
mammary artery (LIMA) was the graft used in all the
patients with CABG. The acute clinical success rate was
100% with respect to the absence of myocardial infarc-
tion, death or other in-hospital complications. Complete
recovery was achieved in the postoperative period in all
patients.
All of the patients were followed up clinically. The
median follow-up was 35.3 months (range: 6 to 120
months). Nine patients were free from symptoms and
one of them continued taking beta-blockers. The re-
maining 2 patients with myotomy had symptoms of
atypical chest pain. One of them received coronary an-
giography again and no stenosis was found at two years
after operation; while exercise testing was performed in
the other patient and revealed no evidence of myocardial
ischaemia. Both of them were taking beta-blockers and
symptoms were controlled. No myocardial infarction or
other major adverse cardiac events were encountered in
these patients during follow-up.
4. Discussion
Myocardial bridging was recognized at autopsy in 1737
and first described angiographically in 1960. The current
best method for diagnosing myocardial bridging is selec-
tive coronary artery angiography and the typical an-
giographic finding is systolic narrowing of an epicardial
artery. The incidence of myocardial bridging reported in
angiographic studies ranged from 0.5% to 40%. The lim-
ited frequency of myocardial bridging observed an-
giographically is in contrast with that of autopsy studies,
which have reported a frequencies of 5% to 86%1. In the
present study of selective coronary angiography with
more than 37 000 patients, the prevalence of myocardial
bridging is 1.3%. Variation between autopsy and an-
giography may in part be attributable to small and thin
bridges causing little compression. New imaging tech-
niques like intravascular ultrasound, intracoronary Dop-
pler ultrasound and electron beam tomography and mul-
tislice CT8 as noninvasive imaging techniques can be
used for diagnosis of functional and morphological status
of bridging.
Though bridging is considered as a harmless anatomi-
cal vessel malformation in most cases, the intramural
course of certain portions in the left anterior descending
coronary artery may cause myocardial ischaemia and
infarction4. The mechanism by which myocardial bridg-
ing causes myocardial ischaemia is not very clear but
associated with decreased coronary flow reserve9. Indeed,
intravascular ultrasonography and Doppler imaging have
demonstrated that vessel compression during systole is
followed by a delay in the increase in luminal diameter
during diastole, thus affecting the predominant phase of
coronary perfusion, especially during episodes of tar-
chycardia10,11. In the present follow-up study, at baseline
before operation, all of the patients had angina and two
had myocardial infarction of the anterior wall.
In symptomatic cases, there are several therapeutic
options available. The medications of choice are
beta-blockers10,12, whose mechanism of action is through
a negative inotropic and chronotropic effect. Sometimes
medical treatment is insufficient and other interventions
are required. The efficacy and long term outcome of
stent implantation in symptomatic myocardial bridging is
still controversial13, though several studies have demon-
strated that stenting can prevent external compression of

X. H. HUANG ET AL.17
bridged coronary artery segments, with increase in lu-
minal diameter and improve symptoms. Haager et al14
evaluated the results of coronary stenting in 11 patients
with symptomatic myocardial bridging of the central
portion of the LAD. Followup angiography at 7 weeks
demonstrated mild to moderate or severe stent stenosis in
5 patients; revascularization was repeated in 4 patients.
High restenosis15,16 or major periprocedural complica-
tions17, including perforation of the artery have been re-
ported in other studies. Thus, the rate of restenosis of
stent implantation in myocardial bridging has been too
high to generally recommend this approach in sympto-
matic patients.
Surgical treatment with dissection of the overlying
myocardium (myotomy)6,7 or coronary artery bypass
grafting18 is limited to patients with symptoms that per-
sist despite medical treatment. Surgical myotomy, first
reported by Binet et al, abolishes clinical symptoms and
is associated with reversal of local myocardial ischaemia
and an increase in coronary flow6. However, this treat-
ment strategy carries certain risk. The unpredictable in-
tramural course of the coronary artery may require deep
incision of the ventricular wall, potentially leading to
subsequent perforation of the right ventricle7,19. There is
little information about the prognosis of surgical treat-
ment for symptomatic myocardial bridging.
In the present study, for all 11 patients, isolated myo-
cardial bridging had caused more than 75% compression
of the middle portion of the anterior descending coronary
artery and was refractory to oral medication. Myotomy
was performed in 3 patients and CABG in 8 patients.
The LIMA was the graft used in all of the patients. One
patient suffered a right ventricular perforation that was
successfully repaired by change to on pump CABG. The
others had no serious surgical complications and they
were discharged from the hospital uneventfully. During
the middle- and long-term follow-up of 3 years (range: 6
to 120 months), 2 had atypical chest pain and were con-
trolled by medical treatment. The other 9 patients were
symptom free without the need for further invasive di-
agnostic studies. No myocardial infarction or other major
adverse cardiac events occurred during follow-up study.
Therefore, surgery either by myotomy or CABG is rela-
tively safe and is an option for the treatment of selected
patients with symptomatic myocardial bridging. Addi-
tional studies are needed to investigate which patients
should be selected for surgical therapy and to assess the
long term prognosis of the surgical treatment.
There were several limitations in this study. Patients
were included in the study based on a coronary an-
giography made before the study was designed, so there
was no established protocol for the coronary angiogra-
phy. Not every patient received intracoronary nitroglyc-
erine at the time of angiography in our study, thus the
prevalence could be underestimated. Additionally after
operation during followup, only one of our patients un-
derwent coronary angiography again.
In conclusion, myocardial bridging, a congenital ves-
sel anomaly, is a relatively common angiographic find-
ing20.
Although usually a benign condition, myocardial
bridging can occasionally generate clinically important
complications. Medication is the initial therapy for
symptomatic patients. Surgical myotomy or CABG
should be limited to patients who are refractory to oral
medication. Benefits with low operative risk and excel-
lent middle- and long-term results can be achieved by
surgical relief of myocardial ischaemia due to systolic
compression of intramyocardial coronary arteries. When
surgery is chosen, the decision to perform myotomy or
CABG is made on a case by case basis. In arteries that
take a very deep course through the septum, approaching
the right ventricular subendocardium and surgical expo-
sure of the intramuscular coronary artery may be difficult,
CABG is preferred to myotomy and the LIMA is the best
choice of graft.
5. Conclusions
Myocardial bridging is a relatively common an-
giographic finding. Surgical myotomy or CABG should
be limited to patients who are refractory to oral medica-
tion. Surgical relief of myocardial ischaemia due to sys-
tolic compression of intramyocardial coronary arteries
can be accomplished with low operative risk and excel-
lent middle- and long-term results.
References
[1] Möhlenkamp S, Hort W, Ge J, Erbel R. Update on myo-
cardial bridging. Circulation 2002; 106: 2616-2622.
[2] Lozano I, Baz JA, Palop RL, Pinar E, Picó F, Valdes M,
et al. Long-term prognosis of patients with myocardial
bridge and angiographic milking of the left anterior de-
scending coronary artery. Rev Esp Cardiol 2002; 55:
359-264.
[3] Juilliere Y, Berder V, Suty-Selton C, Buffet P, Danchin
N, Cherrier F. Isolated myocardial bridges with an-
giographic milking of the left anterior descending coro-
nary artery: a long-term followup study. Am Heart J 1995;
129: 663-665.
[4] Cottin Y, Laurent G, Gabrielle F, Andre F, Baudoin N,
Blettery B, et al. Acute myocardial infarction related to
myocardial bridging. Eur Heart J 1995; 16: 2002-2003.
[5] Yetman AT, McCrindle BW, MacDonald C, Freedom

X. H. HUANG ET AL.
18
RM, Gow R. Myocardial bridging in children with hy-
pertrophic cardiomyopathy–a risk factor for sudden death.
N Engl J Med 1998; 339: 1201-1209.
[6] Betriu A, Tabau J, Sanz G, Magrina J, Lavarro-Lopaz F.
Relief of angina by periarterial muscle resection of myo-
cardial bridges. Am Heart J 1980; 100: 223-226.
[7] Baryalei MM, Tirilomis T, Buhre W, Kazmaier S,
Schoendube FA, Aleksic I. Off pump supraarterial de-
compression myotomy for myocardial bridging. Heart
Surg Forum 2005; 8: E49- E54.
[8] Konen E, Goitein O, Leonid S, Eshet Y, Shemesh J,
Segni D. The prevalence and anatomical patterns of in-
tramuscular coronary arteries. J Am Coll Cardiol 2007;
49: 587-593.
[9] 9. Mays AE, Mchake PA, Greenfield JC. Transmural
myocardial blood flow in a canine model of myocardial
bridging. Circ Res 1981; 49: 726-732.
[10] 10. Schwarz ER, Klues HG, vom Dahl J, Klein I, Krebs
W, Hanrath P. Functional, angiographic and intracoro-
nary Doppler flow characteristics in symptomatic patients
with myocardial bridging: effect of short-term intrave-
nous beta-blocker medication. J Am Coll Cardiol 1996;
27: 1637-1645.
[11] 11. Klues HG, Schwarz ER, vom Dahl J, Reffelmann T,
Reul H, Potthast K, et al. Disturbed intracoronary hemo-
dynamics in myocardial bridging: early normalization by
intracoronary stent placement. Circulation 1997; 96:
2905-2913.
[12] 12. Nair CK, Dang B, Heintz MH, Sketch MH. Myocar-
dial bridges: effect of propranolol on systolic compres-
sion. Can J Cardiol 1986; 2: 218-221.
[13] 13. Berry JF, von Mering GO, Schmalfuss C, Hill JA,
Keresky PA. Systolic compression of the left anterior de-
scending coronary artery: a case series, review of the lit-
erature, and therapeutic options including stenting.
Catheter Cardiovasc Interv 2002; 56: 58-63.
[14] 14. Haager PK, Schwarz ER, Dahl J, Klues HG, Reffel-
mann T, Hanarath P. Long term angiographic and clinical
follow up in patients with stent implantation for sympto-
matic myocardial bridging. Heart 2000; 84: 403-408.
[15] 15. Wang NF, Pan H, Tong GX. The evaluation on stent
implantation efficacy of myocardial bridge and severe
atherosclerosis lesions in the segments proximal to the
myocardial bridge. Chin J Cardiol (Chin) 2005; 33:
684-686.
[16] 16. Yan HB, Wang J, Zhu XL, Gao H, Li N, Hui A. Fre-
quency of infarct-related artery with myocardial bridging
in patients with ST-elevation myocardial infarction and
its impact upon percutaneous coronary intervention. Chin
Med J 2006; 119: 539-543.
[17] 17. Broderick TM, Kerelakes DJ, Whang DD, Toltzis RJ,
Abbottsmith CW. Myocardial bridging may predispose to
coronary perforation during rotational atherectomy. J In-
vasive Cardiol 1996; 8: 161-163.
[18] 18. Pratt JW, Michler RE, Pala J, Brown DA. Minimally
invasive coronary artery bypass grafting for myocardial
muscle bridging. Heart Surg Forum 1999; 2: 250-253.