Pediatric Cardiac hydatid cysts: A fatal manifestation of the disease

Hydatis, in Greek, means a drop of water, an expression that ers to the fluid containing cysts brought about by the larval stage of Echinococcus granulosus, in which the human acts as an accidental intermediate host [1],[2]. Upon arrival of the embryo to the liver, it either settles there or bypasses it through the lymphatics or systemic circulation to reach the lungs and other organs. The most commonly affected organs are the liver and lungs 70% and 20% respectively. The other locations include the spleen and kidneys, which account for 2% each [3],[4]. Very rarely, hydatid cyst (HC) affects other organs including chest and abdominal walls, diaphragm, spine, posterior mediastinum and lower limbs [5],[6],[7].

Cardiac involvement is unusual, though the exact percentages are differently recorded in the literature, it is about 0.05-2% and they have been increasingly reported [2], [8],[9]. The embryo makes its path to the myocardium via the coronary circulation. Occasionally, it reaches the right side of the heart through the venous return from there to the left side via patent foramen ovale or through the pulmonary veins.

Despite the discrepancy in reported percentage of different parts of the heart, most of the reports in the literature are in agreement that the most commonly affected part is the left ventricle (LV) followed by the interventricular septum, right ventricle (RV), right atrium (RA) with left atrium (LA) and sinus of Valsalva being the least commonly affected [2],[4],[8],[10].

Due to the absence of uniform clinical presentation, a high index of suspicion is crucial especially in endemic areas like Middle East countries [10]. Early diagnosis with an effective treatment plan can change outcomes dramatically, keeping surgical intervention as a priority even in the asymptomatic cases [2],[4].

In this clinical vignette, a unique case of right-sided congestive heart failure combined with severe pulmonary hypertension secondary to cardiac involvement with hydatid cyst is presented with a brief review of the literature.

A 14-year-old girl erred to the cardiac center with severe pulmonary hypertension and right side heart failure (NYHA class III) secondary to multiple cardiac and pulmonary hydatid cysts.

The patient was from a rural area, remote from the city, have had contact with the animal. She recalls the earliest symptoms emerging a year ago in the form of cough, progressive dyspnea inclining into orthopnea and generalized body edema including abdominal distension. Early in the presentation, her symptoms ascribed to the renal cause, as one of her abdominal ultrasound (US) showed prominent pelvic calyceal systems with few internal echoes. Abdominal US revealed severe ascites, pleural effusion, and mild pericardial effusion, echocardiography demonstrated severe right side dilatation, mildly compressing left side with multiple cystic lesions inside the pericardial space posteriorly and apically, one of them was inside the left atrium causing pulmonary venous flow obstruction and pulmonary hypertension with peak gradient of 69 mmHg in one record and 80 mmHg in another, right ventricle systolic pressure was 95 mmHg, with moderate tricuspid regurgitation and normal other valve function.

Subsequently, chest computed tomography (CT) scan was performed which showed multiple cysts involving LV myocardium with LA lumen & mediastinum encasing and compressing the pulmonary artery (Figure 1). Upon the above findings, the patient was prepared for urgent operation. Intraoperatively, there were signs of generalized tissue edema, extending to the skin and subcutaneous tissue, confirming the severe right side failure.

There was mild pericardial effusion, but no pericardial cysts, the cysts were in the wall of the myocardium of the LV, RV extending to outflow tract and aortopulmonary window, LA and pulmonary veins (Figure 2). A process of femoral arterial cannulation, with bicaval cannulation and cardioplegic arrest, was commenced. The contents of the cysts were aspirated, the cavities were washed with povidone-iodine, and cystectomies performed with the closure of the residual cavities.

Lamentably following cross-clamp removal, the patient could not be weaned off bypass and death declared on the table.

Cardiac HC, a sparse event yet with dreadful consequences, as described in the literature as a silent bomb [10]. The clinical presentation can be very wide, ranging from asymptomatic to sudden death. Depending on the cardiac structure the cyst invades or compresses and the degree of interference with cardiac function presenting as tamponade, pericarditis, arrhythmias, conduction disturbances, symptoms resembling coronary artery disease, emboli and others [8],[9]. Though the combination of severe pulmonary hypertension and congestive right side failure as it was with the current case has not been reported according to our knowledge. The most probable explanation for this ruinous presentation is attributed to the site of the cysts, as one of them was involving the RV outflow tract causing RV dilatation with failure, the other cysts were involving the LV compressing the pulmonary veins leading to severe pulmonary hypertension. We found one case of cardiac HC involving the pulmonary veins but luckily that patient had a patent foramen ovale which could have act as a pop of that prevented against the development of severe pulmonary hypertension [11].

Another case reported in the literature in which multiple hydatidoses including cardiac cysts led to patient death, in that patient both pulmonary arteries were obstructed due to embolization of the cysts resulting in severe pulmonary hypertension, followed by a rocky postoperative course and eventual death [2].

This might highlight the perils of such presentation in cardiac HC and triggers further investigations in management strategy.

In view of the line of management of cardiac HC, we stand firm with other authors’ opinions that consider the surgical intervention is urgently necessary whenever cardiac hydatid cyst is diagnosed even in asymptomatic cases, as 20% of fatal cases who presented with sudden death were asymptomatic. In consequence, the earliest the action the better the results and the least the undesirable consequences [2],[4],[8],[9].

Cardiac HC is a very rare variant of the disease, it may present in various scenarios ranging from asymptomatic one to severe right side failure and pulmonary hypertension. Surgical intervention is the only hope of survival.