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).