Abstract
The hydatid disease of heart, caused by Echinococcus granulosushas an incidence of 0.5%-2% , in the sheep grazing areas of the
developing and under-developed countries. The cyst of interventricular
septum has a 5%-9% incidence with complications of conduction block
and arrythmias. Transesophageal echocardiography(TEE) is useful for
intraoperative cyst localization and excision. Our image review
highlights the TEE findings of our young patient with multiple hydatid
cysts of interventricular septum , with the septal tricuspid leaflet
adherent to the cyst membrane.
Key words : Hydatid cyst , Transesophageal echocardiography
Hydatid cyst(HC) of the heart, caused by the metacestode stage ofEchinococcus granulosus , is a rare and constitutes 0.5%- 2% of
all hydatid diseases. 1 These are usually solitary and
primary, and multiple cysts are secondary in nature and present after
rupture of any primary cyst. The most common cardiac site is the left
ventricle(LV) free wall (55%-60%) , embolized through the left
anterior descending artery ; interventricular septum(IVS) (5-9%) ;
right atrial(RA) (3-4%) , right ventricular(RV) (15%), left atrium(LA)
(8%) , and pericardium (8%). 2
The symptoms that patients develop depend upon the site of the cyst. The
LV cysts may cause heart failure or rupture into LV cavity resulting in
pulmonary embolism. The IVS cysts presenting with conduction blocks and
arrythmias with the other non-specific symptoms like dyspnea , chest
pain or weight loss.1 Our patient , was a 25-year-old
male , with symptoms of breathlessness at rest and chest pain was
diagnosed with a single HC of IVS with calcified cyst of segment VII of
liver and multiple lung nodules. He was treated with Albendazole and
Praziquental in the pre-operative period after the serology test turned
positive for hydatid.
Transesophageal echocardiography (TEE) has an advantage over MRI and
transthoracic echocardiography as an aid in intraoperative diagnosis and
guiding surgical excision. The WHO informal working group proposed
ultrasonic classification of cysts on the basis of wall thickness,
activity, septations and presence of daughter cysts. Our hydatid cyst ,
as seen on TEE examination was a moderate sized (5.2*6.8cm)
,thick-walled , oval, unilocular cysts with honeycombed appearance
representing daughter cysts, in the interventricular septum(Type
CE2)(Figure 1, Video 1). This was seen to be obliterating both the RV
and LV , (Figure 2A,B)without any outflow tract obstruction.
Additionally , the septal tricuspid leaflet was found to be adherent to
the cyst membrane without any significant regurgitation(Figure 3). The
cysts were removed successfully with preservation of STL and IVS(Figure
4).