Discussion

Human hydatid disease is caused by infection with the canine tapeworm E. granulosus and is highly endemic in developing countries, including Syria. ^{Reference Gessese1,Reference Dakkak2} One major challenge in these areas is delayed diagnosis due to limited healthcare infrastructure and low public awareness. ^{Reference Khuroo3} While the liver and lungs are the most frequently affected organs, cardiac hydatidosis remains rare, comprising only 0.5–2% of all cases. ^{Reference Banisefid, Baghernezhad and Beheshti4} Cardiac hydatid cysts located in the interventricular septum are typically intramyocardial, in contrast to sub-epicardial left ventricle cysts. ^{Reference Perez-Gomez, Duran, Tamames, Perrote and Blanes6,11} The myocardium is usually infected via haematogenous spread through the coronary arteries, although other routes, such as the thoracic duct, vena cava, or pulmonary veins, have been proposed. ^{Reference Kahlfuß, Flieger, Roepke and Yilmaz5} The left ventricle is the most frequently involved site, followed by the right ventricle, left atrium, pericardium, interventricular septum, and pulmonary arteries. ^{Reference Kahlfuß, Flieger, Roepke and Yilmaz5,Reference Perez-Gomez, Duran, Tamames, Perrote and Blanes6} Sub-epicardial cysts tend to expand towards the pericardial cavity, potentially growing to large sizes, whereas sub-endocardial cysts more often grow intracavitary. ^{Reference Besim, Karayalçin, Hamamci, Güngör, Korkmaz and Tezcaner12} Ventricular wall cysts may expand in either direction. Due to the slow-growing nature of the disease, a long latency period often precedes clinical manifestation. Thus, paediatric cases are exceedingly rare but possible. ^{Reference Brunetti, Kern and Vuitton8,Reference Oueslati, Saïd and Saaidi13} The clinical presentation of cardiac hydatid disease is highly variable and depends on the cyst’s location, size, age, and complications. Because of slow growth, symptoms rarely appear in childhood. Early stages are often asymptomatic or discovered incidentally. When symptoms occur, they may include chest pain, palpitations, dyspnoea, or syncope due to arrhythmia or obstruction, as seen in our patients. ^{Reference Perez-Gomez, Duran, Tamames, Perrote and Blanes6,Reference Oueslati, Saïd and Saaidi13} Other possible symptoms include fever, weight loss, or cough. Life-threatening complications such as cyst rupture, tamponade, embolism, valvular regurgitation, allergic reactions, and sudden death may also occur. ^{Reference Banisefid, Baghernezhad and Beheshti4,Reference Dursun, Terzibasioglu and Yilmaz7,Reference Lahmidi, Boutaybi, El Ouazzani, Elouafi and Bazid10} Septal involvement may lead to conduction block and arrhythmias. ^{Reference Yaliniz, Tokcan, Salih and Ulus14} Cardiac hydatidosis should always be considered in the differential diagnosis of cardiac masses in endemic regions. ^{Reference Banisefid, Baghernezhad and Beheshti4,Reference Kahlfuß, Flieger, Roepke and Yilmaz5} Transthoracic echocardiography is the primary diagnostic tool, providing information about cyst size, number, and location. ^{Reference Dursun, Terzibasioglu and Yilmaz7} However, serological testing has limited value due to high false-negative rates—up to 50% in cardiac cases. ^{Reference Wadhawa, Shah and Doshi9} Electrocardiographic changes are non-specific, including QRS abnormalities, atrioventricular block, or ST elevation due to myocardial compression. ^{Reference Yaliniz, Tokcan, Salih and Ulus14} Cardiac CT and MRI are important complementary tools to confirm the diagnosis and define surgical planning. ^{Reference Dursun, Terzibasioglu and Yilmaz7} In our cases, the diagnosis was established based on clinical symptoms (palpitations, syncope), physical examination (cardiac murmur), echocardiographic and CT findings, hepatic involvement, and the epidemiologic context of an endemic area. ^{Reference Wadhawa, Shah and Doshi9,Reference Oueslati, Saïd and Saaidi13} According to WHO guidelines, surgical excision is the gold standard for treatment, followed by long-term antiparasitic therapy with albendazole for at least two years. ^{Reference Brunetti, Kern and Vuitton8,11} Surgery is necessary because of the high risk of life-threatening complications, with reported cure rates of up to 90% in properly selected cases. ^{Reference Lahmidi, Boutaybi, El Ouazzani, Elouafi and Bazid10} Intraoperative measures to prevent cyst content spillage include the use of scolicidal agents such as 2% formalin, 30% hypertonic saline, 5% cetrimide, or 1% iodine. ^{Reference Besim, Karayalçin, Hamamci, Güngör, Korkmaz and Tezcaner12} The surgical approach depends on the cyst location. Most left or right ventricular cysts can be excised without cardiopulmonary bypass, but interventricular septal cysts are best treated under cardiopulmonary bypass to minimise intraoperative risk. ^{Reference Yaliniz, Tokcan, Salih and Ulus14,Reference Seth, Mishra, Khandekar, Raut, Mohapatra and Ammannaya15} Gentle manipulation of the heart prior to aortic cross-clamping is advised. ^{Reference Lahmidi, Boutaybi, El Ouazzani, Elouafi and Bazid10} Although early postoperative mortality may reach 10%, long-term outcomes are generally favourable, with recurrence rates of approximately 10%—often due to intraoperative spillage. ^{Reference Brunetti, Kern and Vuitton8,Reference Yilmazkaya, Yondem, Gurkahraman, Yukselen, Circi and Tasdemir16} In our patients, no recurrence was observed. Routine echocardiographic and serologic follow-up is essential for at least five years postoperatively. ^{Reference Brunetti, Kern and Vuitton8} Screening programmes in endemic regions may aid in earlier detection. ^{Reference Gessese1}