Cardiovascular Journal of Africa: Vol 28 No 1 (January/February 2016)

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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 28, No 1, January/February 2017 AFRICA e1
Hypertrophic angulation deformity of the basal
interventricular septum combined with abnormality of
the papillary muscle and chordae tendineae
Yi Wang, Luwei Ye, Lixue Yin, Jie Zeng
Abstract
A Chinese woman was admitted to our hospital because of
syncope. Transthoracic echocardiography revealed a hyper-
trophic basal interventricular septum of 15 mm with a
sharp angle protruding into the left ventricular outflow
tract. Moreover, an anomalous anterolateral papillary muscle
(maximum width of 11 mm) was inserted into the left ventric-
ular outflow tract, with short chordae tendineae connecting
both basal interventricular septum and anterior leaflet of
the mitral valve. All of these abnormalities resulted in a left
ventricular outflow gradient of 136 mmHg. Surgical septal
myectomy of the sharp angle combined with partial papil-
lary muscle resection and removal of the abnormal chordae
tendineae was selected to relieve the left ventricular outflow
obstruction. This was a rare combination of deformity of
the angulation of the focal basal interventricular septum and
abnormalities of the papillary muscle and chordae tendineae,
which led to left ventricular outflow obstruction.
Keywords: angulation deformity, interventricular septum, papil-
lary muscle, hypertrophic cardiomyopathy
Submitted 24/7/15, accepted 6/4/16
Cardiovasc J Afr 2017; 28: e1–e3
DOI: 10.5830/CVJA-2016-050
Case report
A 43-year-old Chinese woman was admitted to our hospital
because of syncope. Physical examination showed a loud systolic
ejection murmur radiating to the neck. The electrocardiogram
was normal. Transthoracic echocardiography revealed a
hypertrophic basal interventricular septum (IVS) of 15 mm with
a sharp angle protruding into the left ventricular outflow tract
(LVOT). Moreover, an anomalous anterolateral papillary muscle
(PM) (maximum width of 11 mm) was inserted into the LVOT,
with short chordae tendineae connecting both the basal IVS
and anterior leaflet of the mitral valve. All these abnormalities
resulted in a LVOT gradient of 136 mmHg (Fig. 1A–D).
In order to verify the large gradient and exclude other
associated abnormalities, cardiac catheterisation was performed.
There was no stenosis of the coronary artery, but after the
catheter was put into the left ventricle, it immediately went into
the aorta, which indicated a large gradient of the LVOT. Left
ventriculography also demonstrated a narrow LVOT with a
sharp angle.
Surgery was selected to relieve the LVOT obstruction. Intra-
operative transoesophageal echocardiography clearly showed
the presence of a focal hypertrophic IVS and malposition of
the PM (Fig. 1E). Through a standard median sternotomy,
cardiopulmonary bypass was instituted by aortic/bicaval venous
cannulation. After aortic cross-clamping, crystalloid cardioplegia
solution was administered via the aortic root. The sharp angle of
the IVS and the abnormal PM were demonstrated clearly after
the extended transaortic approach was used (Fig. 2A, B).
The first step was septal myectomy of the sharp angle via the
aortic valve. Partial PM resection was also performed to relieve
the obstruction. Unfortunately, after recovery of the heart beat,
transoesophageal echocardiography showed that the LVOT
gradient was still about 100 mmHg because of the malposition
of the PM and the short chordae tendineae (Fig. 2C). The
surgeon then removed the abnormal chordae tendineae and
the anomalous muscular attachments of the PM in the LVOT
until a bougie of 20 mm passed through the LVOT smoothly.
The saline injection test revealed trivial mitral and aortic valve
regurgitation.
Histological examination showed cardiomyocyte hypertrophy
and disarray, as well as interstitial fibrosis and inflammation,
indicating a possible diagnosis of hypertrophic cardiomyopathy
(HCM) (Fig. 3A, B). Unfortunately, the patient was unwilling to
do any genetic testing.
At the two-month follow up, transthoracic echocardiography
demonstrated a LVOT gradient of 23 mmHg and no significant
mitral valve insufficiency (Fig. 3C). In addition, the patient had
no syncope or other uncomfortable symptoms. Institutional
review board permission was obtained to report this case.
Institute of Ultrasound Medicine, Sichuan Academy
of Medical Sciences and Sichuan Provincial People’s
Hospital, Chengdu 610072, China
Yi Wang, MD
Luwei Ye, MD
Lixue Yin, PhD
Department of Cardiology, Sichuan Academy of Medical
Sciences and Sichuan Provincial People’s Hospital,
Chengdu 610072, China
Jie Zeng, MD, ;
Case Report