A Quick Medical Overview
Nearly 25% of patients infected with T. cruzi will develop the chronic, cardiac form of Chagas – which happens to be the most serious manifestation of the disease. As we mentioned in our previous post, Chagas can be cured if detected early. However, once a patient enters the chronic phase, less hope for a cure exist. In fact, just managing the patient’s symptoms (while not even altering the disease course), can be extremely challenging.
Patients with the cardiac form of Chagas suffer from electrical conduction abnormalities (bradyarrhythmias, RBBB, and LAFB among the most common). In essence, this means the heart’s electricity – which drives its mechanical pumping action – becomes deranged. Subsequently, blood sits statically in the poorly pumping heart, thereby leading to clots (aka thromboembolisms) and further heart failure (more blood Þ more for an exhausted heart to pump Þ further exhaustion). Therefore, hallmarks of Chagas heart disease are sustained ventricular tachycardia (85%; results from failure of the circuitry in the inferior-lateral wall of the left ventricle) and apical aneurysms (weakened areas of blood stasis near the heart’s apex; also in the left ventricle).
Heart failure typically ensues as a late manifestation of Chagas heart disease. Resulting from a dilated cardiomyopathy (cardiomyopathy = inflammation of the heart muscle itself), Chagas heart failure is unique in that it’s one of the few causes of right-sided heart failure. This right heart-dominant failure leads to congestion in areas with the most supply of blood to the heart: the head (JVD), portal blood system (hepatomegaly and ascites), and legs (edema).
Currently, a multi-national study is investigating the efficacy of using Benznidazole to treat the chronic form of Chagas, but previous randomized controlled trials have shown 50% efficacy at best. Regardless of attempted treatment, the 5-year mortality for Chagas heart patients is >50%. And, sudden death is the main cause of mortality (67%).
To get you thinking
That said, you would expect a certain level of fear of this destructive disease, right? Wrong. Much like the diabetes epidemic in the U.S., the Chagas situation in Bolivia appears to be coated with a sense of indifference. It’s as if familiarity has breed numbness.
Your dad died of Chagas heart disease at age 45?
Yes, and my grandparents both had “mal de Chagas” as well.
Are you worried about having the same problems?
No. What can I do? If I get it, I get it.
On any given day, around 5-10 of 20 patients in the male ward have Chagas cardiomyopathy. This week nearly every patient has “mal de Chagas” affecting their corazon (heart). Many of these patients will die from their Chagas heart disease, yet there is little fear of the illness. Why?
Our team has anthropologists coming to Bolivia in January to study this phenomenon, which should hopefully shed more light on the situation…