An unexpected threat in the heart: Hydatid cyst in the interventricular septum

Hydatid cyst is a protozoal disease that most commonly affects the liver and lungs, rarely involves the heart, and is frequently seen in countries, where animal husbandry is widespread.^[1] This study presents a case of a hydatid cyst located in the interventricular septum.

A 58-year-old female patient engaged in livestock farming in a rural village admitted to the emergency department approximately one week earlier with complaints of severe abdominal pain, dyspnea, and chest pain. During physical examination, her blood pressure was 148/80 mmHg, pulse rate 96 beats/min, respiratory rate 20/min, and her general condition appeared agitated. Chest radiography revealed no significant pathology, and laboratory results were within normal limits. Transthoracic echocardiography demonstrated a cystic lesion measuring 2.5 cm×2.5 cm in the interventricular septum (IVS), closer to the right ventricle. Left ventricular hypertrophy and diastolic dysfunction were also noted. Abdominal and thoracic computed tomography (CT) scans revealed multiple cystic lesions in the liver and a cardiac cyst. Surgical excision of the cardiac cyst under cardiopulmonary bypass (CPB) was planned (Figure 1).

Figure 1.

(a, b) Multiple cystic lesions in the liver and (c) a cyst located in the interventricular septum of the heart (arrow), as seen on thoracic computed tomography.

Written informed consent was obtained from the patient. Under general anesthesia, the patient was positioned supine, and a median sternotomy was performed, and then the pericardium was opened. The right ventricle was incised with a 2 cm longitudinal cut at the level of the IVS, and the right ventricular cavity was entered. A cystic lesion was observed within the IVS. After aspiration of the cyst content, the cystic structure was excised, and the residual cavity was irrigated thoroughly with abundant fluid (Figure 2). Following a CPB duration of approximately 70 minutes, the patient was successfully weaned from bypass.

Figure 2.

(a) Aspiration of the cyst content, (b, c) excision of the cyst from the interventricular septum (arrow), and (d) cyst specimen (arrow).

The patient was transferred to the intensive care unit, where postoperative echocardiography revealed no residual cyst. She was discharged on postoperative day 6 and was instructed to continue oral albendazole therapy at a dose of 10 mg/kg/day for 3 months. Hydatid cysts were followed up by the general surgery department, and surgical excision of these cysts was planned at her one-month control visit.

Cardiac hydatid cyst is a rare disease that may involve any chamber of the heart. The most frequently affected regions are the left ventricle (55-60%) and the right ventricle (15%), whereas IVS involvement is uncommon.^[1]

The clinical presentation varies depending on cyst size, growth rate, and localization. Cardiac involvement may manifest with symptoms such as chest pain, dyspnea, palpitations, and persistent cough. Cysts located near atrial or ventricular orifices can create valvular dysfunction-like effects. However, cyst rupture represents the most feared complication of this disease. Ruptured cysts may result in serious outcomes, including pericardial tamponade, systemic or pulmonary embolization, pulmonary hypertension, and anaphylactic reactions.^{[1, 2]}

Transthoracic echocardiography is the preferred initial diagnostic modality for the identification and localization of cardiac hydatid cysts. CT and magnetic resonance imaging may also aid diagnosis.^[3] In patients with hepatic or pulmonary hydatid disease, echocardiography is recommended to avoid missing potential cardiac involvement.^[4]

Due to the high risk of rupture, surgical excision remains the treatment of choice, even in asymptomatic patients.^[1] Manipulation of the heart should be avoided before aortic cross-clamping. To minimize the risk of contamination, aspiration of the cyst contents and irrigation of the residual cavity with hypertonic solution are advised.^[3]

Although recurrence after surgery is rare, the possibility of incomplete cyst removal and persistence of risk despite albendazole therapy should be considered. Therefore, patients must be monitored with echocardiography and serological testing for several years to evaluate the effectiveness of treatment.^{[1, 2]}

In conclusion, cardiac hydatid cyst is a rare but serious disease for which surgical intervention is the primary treatment modality. Surgical management requires meticulous technique to prevent contamination and myocardial damage. Patients should undergo long-term follow-up to assess the efficacy of both surgical and anti-helminthic therapy.

Ethics

Informed Consent: Written informed consent was obtained from the patient.