Introduction: Ingestion of the larval stage of the parasite Echinococcus granulosus via contaminated food, water, or soil leads to formation of hydatid cysts. Cysts commonly present in the liver and lung, but <2% present in the heart. Cardiac cysts have a predilection for the left ventricle (55-60%) and intraventricular (IV) septum (10-20%). The location of the cyst, the presence of cyst rupture, and mass-effect determines symptomatic presentation, commonly nonspecific EKG changes.[2,3] Contrary to cysts in other locations, surgery is mandatory even for asymptomatic lesions. Operative management prevents cyst rupture and larval embolization which results in life-threatening anaphylaxis. We describe cardiac echinococcosis of the IV septum that presented with syncope due to mass effect mimicking hypertrophic cardiomyopathy.
Case Presentation: A 47-year-old Sudanese male presented following 6-months of chest pain and syncope. An ECG showed non-specific T wave inversions, with a stress test negative for ischemia. CT evaluation revealed a 5 x 5 x 4.7 cm septal mass, then confirmed by transthoracic echocardiography. MRI confirmed a cystic mass concerning for cardiac echinococcosis given exposure to endemic regions. Albendazole therapy was initiated, and the decision was made for surgical resection.
After median sternotomy and initiation of cardiopulmonary bypass (CPB) the hydatid cyst was removed via a right ventriculotomy. Prophylactic famotidine, diphenhydramine, and methylprednisolone was given in case of cyst rupture. The cyst was wrapped in hypertonic 20% saline soaked gauze, then 95% EtOH to decrease parasite load and prevent cyst rupture. The cyst and septum were resected enbloc requiring patch closure of the ventricular septal defect (VSD). On initial wean from CPB, obstruction of the right ventricular outflow tract and severe tricuspid regurgitation mandated bioprosthetic tricuspid valve replacement and septal VSD revision. The total cross clamp time was 42 minutes and the total CPB time was 364 minutes.
The postoperative course was complicated by hemorrhage, prolonged mechanical ventilation, acute renal injury, and severe right ventricular (RV) dysfunction requiring inotropes, intra-aortic balloon pump, and right ventricular assist device (RVAD). On postoperative day (POD) 45, the RVAD was explanted. The patient was discharged home on POD 103 and returned to his job. He is followed in heart failure clinic for small, residual VSD.
Discussion: Cardiac echinococcosis is an exceptionally rare diagnosis, making up 0.5% to 2% of all hydatid infections. Surgery is the treatment of choice even for asymptomatic cardiac hydatid cysts. Both medical and surgical management were necessary to treat this complicated cyst and transesophageal echocardiography was key to guiding safe and complete excision of a large hydatid cyst located in the heart.