Which complication is primarily associated with untreated Chagas disease?

Untreated Chagas disease, caused by the protozoan parasite Trypanosoma cruzi, primarily leads to significant cardiac complications over time, the most notable being congestive heart failure. This disease affects the heart muscle and the surrounding tissues, causing a chronic inflammatory response that can result in cardiomyopathy, arrhythmias, and ultimately congestive heart failure.

The pathophysiology involves a gradual degeneration of the heart tissue due to the direct effects of the parasite and the immune response to the infection. As the heart muscle weakens and doesn't function effectively, the heart struggles to pump blood adequately, leading to symptoms of heart failure such as fatigue, shortness of breath, fluid retention, and swelling in the legs.

While other complications can arise from Chagas disease, such as gastrointestinal issues or even neurogenic disorders, the direct and severe impact on the cardiovascular system makes congestive heart failure the primary complication associated with untreated cases of this disease. This highlights the importance of early detection and treatment to prevent significant heart-related complications in affected individuals.