Intracardiac Echinococcal Cyst Causing Biventricular Cavity Obliteration
A 47-year-old male presented to the emergency room after an episode of exertional syncope. He denied palpitations, incontinence, dyspnea, or any prior syncope. An ECG and serum cardiac enzymes were normal. A computed tomographic angiogram performed to rule out pulmonary embolism revealed an intracardiac mass in the ventricular septum, measuring 5.0×5.0×4.7 cm (Figure [A]). Subsequent transthoracic echocardiography demonstrated cavity obliteration of the right ventricle from the mass.
Cardiac magnetic resonance imaging demonstrated the intramyocardial mass within the interventricular septum respecting a thin rim of normal myocardium around its periphery. Prior to gadolinium contrast, the mass had shorter T1 and longer T2 than myocardial tissue (Movie IA and IB in the Data Supplement). On first-pass imaging and delayed contrast imaging, there was no appreciable contrast enhancement of the mass. These studies, including the egg shell calcification of the outer edge of the mass seen by computed tomography, suggested that the diagnosis was Echinococcus granulosus (hydatid cyst). The patient was started on albendazole. Liver ultrasound and brain magnetic resonance imaging did not show any hepatic or central nervous system involvement. Echinococcus IgG returned negative.
The patient underwent surgical resection of the mass confirming the diagnosis of an echinococcal cyst (Figure [B]). The surgery was difficult given the extensive replacement of the ventricular septum with the cyst. After cyst removal, the septum was patched and the patient required bioprosthetic tricuspid valve replacement. His postoperative course was complicated by the need for a right ventricular assist device and renal failure, requiring dialysis. He was discharged home in a stable condition and was weaned off dialysis.
Echinococcal cysts occur mostly in patients exposed to livestock.1 Although cysts occur mostly in the liver, they rarely occur in the heart. Within the heart, the left ventricle is the most commonly involved site, although most reports describe cysts in the epicardial borders of the ventricle. Our patient was rare given the extensive replacement of the ventricular septum. Patients usually present with symptoms, such as chest pain, dyspnea, syncope, recurrent fevers, and weight loss. Perforation is the most common and feared complication. Surgery, if possible, is the treatment of choice, with adjunctive antibiotic therapy with albendazole. Computed tomography and magnetic resonance imaging of the heart, as demonstrated in this case, are diagnostic.
The Data Supplement is available at http://circheartfailure.ahajournals.org/lookup/suppl/doi:10.1161/CIRCHEARTFAILURE.117.004830/-/DC1.
Circ Heart Fail is available at http://circheartfailure.ahajournals.org.
- © 2018 American Heart Association, Inc.