Clinical manifestations of major helminth infections that may affect the heart direct or indirectly
| Disease | Aetiological agent | Major clinical syndromes | Major cardiovascular manifestations |
| Schistosomiasis | Schistosoma mansoni, S. japonicum, S. intercalatum, S. mekongi | Acute phase: usually asymptomatic; fever, diarrhoea, abdominal pain, hepatomegaly, non-productive cough with pulmonary infiltrates on chest radiography and eosinophilia are common in non-immune people. Chronic phase: usually asymptomatic; diarrhoea, abdominal pain or discomfort (intestinal form); hepatomegaly (hepatointestinal form); portal hypertension with hepatosplenomegaly, portosystemic collaterals and hypersplenism (hepatosplenic form); pulmonary hypertension (see text). | Pulmonary hypertension and cor pulmonale (see text). |
| S. haematobium | Acute phase: usually asymptomatic; haematuria, dysuria. Chronic phase: usually asymptomatic; haematuria, dysuria (mild urinary form); obstruction of urine flow with hydroureter, hydronephrosis (obstructive uropathy). | ||
| Cysticercosis | Cysticercus cellulosae (larval cyst of Taenia solium) | Commonly asymptomatic; neurological involvement causing mass effects and/or seizures; cysts outside the central nervous system (ocular, cutaneous, muscular or cardiac). | Usually asymptomatic and characterised by multiple and randomly distributed cysts in the subpericardium, subendocardium and myocardium (online supplementary material). Surrounding myocardial inflammation especially when the cysts degenerate may lead to granuloma formation or fibrosis that can cause arrhythmias and conduction abnormalities.2 4 Echocardiography and MRI may demonstrate the cysts.2 4 |
| Echinococcosis | Echinococcus granulosus (cystic echinococcosis) | Hydatid cysts (unilocular cysts) tend to form in the liver or lung but may be found in any organ, including the heart. Most patients present a single-organ involvement and harbour a solitary cyst and are asymptomatic. Symptoms are often due to the mass effect. Cyst leakage or rupture may cause severe allergic reaction and may be followed by spread of daughter cysts, which may cause significant morbidity and mortality. | Frequently, the cysts are discovered incidentally. They may be located in the intramyocardial, pericardial or paracardial regions, or may be intracavitary. Intracardiac rupture of a cyst can cause germinative membrane or secondary cysts embolisation to the lungs or to organs supplied by the systemic circulation. Intrapericardial rupture of a cardiac hydatid cyst can lead to acute pericarditis, cardiac tamponade or eventually constrictive pericarditis.4 Cysts may also cause valvular dysfunction. ECG may show a variety of conduction defects, and ST and T changes, which may be non-specific or resembling ischaemia. A typical echocardiogram reveals a unique cystic, which is an echolucent mass with internal trabeculations, but the mass may be solid and the cysts may be multiple.2 |
| E. multilocularis (alveolar cyst echinococcosis) | More aggressive than the cystic form, but much less frequent. Symptoms are usually of gradual onset, relating to the organ involved (most commonly the liver). The cysts gradually invade adjacent tissue in a tumour-like fashion, and sections of the parasite may spread to distal parts of the body. | ||
| E. vogeli; E. oligarthrus (polycystic or neotropical echinococcosis) | The cysts have the capacity for endogenous and exogenous proliferation. After proliferation in the liver, the cysts may continue exogenous proliferation in the peritoneal cavity, affecting other abdominal and chest structure. | ||
| Trichinellosis | Trichinella spiralis and other species | Usually asymptomatic. Intestinal phase: watery diarrhoea. Systemic phase: periorbital oedema, fever, weakness, rash, conjunctivitis, myositis. High infection burdens may cause myocarditis, encephalitis or pneumonia. | Asymptomatic cardiomegaly; eosinophilic myocarditis (may present with chest pain mimicking acute myocardial infarction); arrhythmias (considered the most common cause of death in trichinellosis); non-specific ECG changes, first-grade and second-grade AV block; pericardial effusions.2 4 23 |
| Tropical endomyocardial fibrosis | Helminths especially filarial infections | Acute phase: fever, eosinophilia, pancarditis, facial swelling, urticaria and neurological manifestations. Chronic phase: restrictive cardiomyopathy. | Restrictive cardiomyopathy that may be associated with mural thrombus formation, arrhythmias and occasionally pericarditis (see text). |
| Tropical pulmonary eosinophilia |
Wuchereria bancrofti, Brugia malayi | Commonly asymptomatic. Lymphatic filariasis: acute adenolymphangitis with fever and swelling of an upper or lower limb or male genitalia. Repeated episodes can lead to chronic lymphatic involvement that manifests as lymphoedema. | Nocturnal wheezing and cough, weight loss and fever due to pulmonary infiltrates with eosinophils; periferal eosinophilia. If untreated, this condition can cause progressive interstitial fibrosis and restrictive lung disease that may lead to pulmonary hypertension and cor pulmonale.2 |
| Visceral larva migrans (toxocariasis) | Toxocara canis, T. catis | Cough, fever, hepatomegaly, eosinophilia and leucocytosis. | In severe toxicariasis, endomyocarditis, cardiac pseudotumour and cardiac tamponade may be observed.2 |
Based on data from Bennett et al 24 and also from other specific references.
AV, atrioventricular.