Synergistic Manifestations in Cardiac Cysticercosis Complicated by Snake Bite: A Case Report and Literature Review

Cysticercosis presents a prevalent issue on a global scale. Nevertheless, disseminated cysticercosis (DCC) is infrequent; even rarer is asymptomatic DCC. Here, we present a unique case of asymptomatic DCC involving the heart in a young male who came to medical attention following a fatal snake bite, ultimately leading to his demise. Despite the widespread dissemination of cysticercosis affecting multiple organs, the individual remained asymptomatic for the condition. We present a case of a 23-year-old male who was brought to the emergency department with a history of alleged snake bites. The patient was declared dead upon arrival at the All India Institute of Medical Sciences (AIIMS), Rishikesh, India. Autopsy findings revealed multiple significant cardiac abnormalities, including atheromatous changes with calcification in the root of the aorta and aortic valve, along with numerous collateral vessels originating from the left main coronary artery. Additionally, cystic nodules containing cysticercus larvae were identified within the myocardium, suggesting cardiac cysticercosis. The cause of death was determined to be complications related to the snakebite. This case emphasizes the importance of considering multiple potential etiologies in complex clinical presentations, especially in the tropics.


Introduction
Cysticercus represents the larval stage of the tapeworm Taenia solium.In humans, the definitive host, adult tapeworms, inhabit the small intestine, while the larval forms are located in the skeletal muscle of the intermediate host, typically pigs.The development of cysticercosis in humans involves their role as an alternative to pigs in the T. solium life cycle, where eggs must mature within the human small intestine as they would in a pig's intestine.The entry of eggs into the human small intestine can occur through autoinfection, ingestion, or inhalation of food or water contaminated with eggs.Subsequently, these cysticercus migrate through the intestinal wall and are transported by the bloodstream to various tissues, including muscles, brain, and subcutaneous tissues, resulting in clinical symptoms.Disseminated cysticercosis (DCC) represents a rare presentation of a prevalent illness [1].In 2010, the World Health Organization (WHO) designated it as a neglected tropical disease (NTD), while in 2014, the Food and Agriculture Organization of the United Nations (FAO) classified it as a negligible zoonotic disease (NZD) [2].
We present a case of a young male who suffered a snakebite, and upon examination, significant cardiac abnormalities and cysticercosis were discovered, ultimately contributing to his demise.

Case Presentation
A 23-year-old male was brought to the emergency department on 06/08/2022 with a reported history of a snakebite that occurred around 2 PM the same day.Upon examination, two incised wounds were noted on the upper limb, where the nearby individuals attempted to suck out the venom.Despite efforts to save the patient, he was declared dead upon arrival at All India Institute of Medical Sciences (AIIMS), Rishikesh, India, at 07:22 PM on 06/08/2024.

Autopsy findings
The body was of average build, with a red tourniquet present over the left upper arm.The eyes were congested, and their corneas were hazy.Postmortem hypostasis was present over the dependent parts and the back, except the pressure points, and was fixed.Rigor mortis was present all over the body and well-developed.
The heart of the deceased was examined during the postmortem examination, revealing a heart weighing 320 grams.The root of the aorta and aortic valve exhibited atheromatous changes with calcification.Multiple collateral vessels were observed, originating from the left main coronary artery and extending along its course.The left main coronary artery itself showed atheromatous changes with a 40% lumen blockage, situated 0.5 cm distal to its origin.Furthermore, numerous cystic nodules with calcified margins containing muddy fluid were discovered on the surface of the left ventricle, the base of the aorta, and the left atrium (Figures 1-3).A similar cystic nodule was identified on the interventricular septum (Figure 4).Microscopic examination of heart sections revealed unremarkable cardiac myocytes with focal areas of fibrosis, indicative of an old infarct.Additionally, one of the coronary arteries showed thrombosis with hyalinization of the wall, accompanied by a dense chronic inflammatory cell infiltrate.Intriguingly, during the histopathological examination, a cyst was identified within the myocardium, which was confirmed to contain a cysticercus larva.These features were consistent with cardiac cysticercosis (Figures 5, 6).

Discussion
This case illustrates the complexity of clinical presentations and the importance of a comprehensive autopsy examination.The patient's history of a snakebite initially seemed to be the apparent cause of death.However, upon further investigation, several significant cardiac abnormalities, including atheromatous changes, coronary artery blockage, and the presence of collateral vessels, were identified.The larval stage of the parasite T. solium causes cysticercosis.In regions where the infection is expected, the prevalence of cysticercosis is approximately 1%-2%.The condition primarily affects the central nervous system, subcutaneous tissues, skeletal muscles, abdominal organs, and eyes.Cardiac involvement is considered uncommon in cases of cysticercosis [3].Autopsy studies have shown that the frequency of cardiac involvement among individuals with DCC can reach up to 27%.
Cysticerci, the larval stage of T. solium, can be detected in various heart parts, including the subendocardium, myocardium, and epicardium.They have been found in the left and right ventricular walls, the interventricular septum, the valvular apparatus, and the papillary muscles.These cysticerci typically appear as thin-walled, semi-transparent structures filled with serous fluid.They are oval, measuring up to 30 mm in diameter, and possess a characteristic scolex [3].As far back as 1912, British Army medical officers stationed in India reported the widespread dissemination of cysticerci throughout the human body [4].Following those initial reports, subsequent studies should have emphasized this clinical presentation due to its relative rarity [5].The primary characteristics of DCC encompass intractable epilepsy, dementia, muscle enlargement, and subcutaneous and lingual nodules.
Notably, focal neurological signs or apparent indications of raised intracranial pressure are generally absent, at least until the later stages of the disease [3,6].The precise impact of immunity on restricting the frequency or widespread occurrence of the disease in humans is not firmly established.However, an autopsy survey conducted in Mexico revealed a connection between immunodeficiency and neurocysticercosis in children [7].As observed in this case report, the generalized form of cysticercosis may remain asymptomatic, often detected only during autopsies.Nonetheless, it is plausible that the ultimate cardiac dysfunction exhibited by our patient was exacerbated by the extensive cardiopulmonary infestation [8].Cysticercosis involving the pulmonary and cardiac systems is infrequent.Typically, the diagnosis is confirmed by observing the resolution of lesions following medical treatment with praziquantel or albendazole [9].Identifying a scolex within a cystic lesion often indicates a diagnosis of cysticercosis [10].Recognizing DCC clinically and conducting suitable radiological investigations are crucial as this condition requires wellstructured therapeutic management.Patients under treatment with active cysts still carry the risk of encountering severe complications [11].
Additionally, the unexpected discovery of cardiac cysticercosis highlights the importance of considering alternative etiologies in cases with atypical findings.Cysticercosis, caused by the larval stage of T. solium, is not typically linked with incidents such as snakebites.Nevertheless, its presence in this case emphasizes the significance of a thorough autopsy examination to uncover all potential contributing factors to the patient's demise.A literature review of cases reported worldwide involving the heart is presented in tabulated form (Table 1) .

References
Case report location Patient Presentation Site of disease

Conclusions
This case report describes a snakebite complicated by significant cardiac abnormalities and cardiac cysticercosis.The findings underscore the importance of conducting detailed autopsy examinations to evaluate complex clinical cases comprehensively.Recognizing atypical presentations and concurrent pathologies is crucial for gaining a comprehensive understanding of the cause of death, thus informing future medical practices and interventions.Diagnosing disseminated cardiac cysticercosis and conducting required investigations are essential as this condition necessitates strategic therapy.Patients undergoing treatment and still exhibiting active cysts remain vulnerable to severe complications.

FIGURE 1 :
FIGURE 1: Cystic lesions over the surface of the left atrium

FIGURE 2 :FIGURE 3 :FIGURE 4 :
FIGURE 2: Cystic lesions over the surface of the left ventricle