Early detection of myocardial dysfunction in Chagas disease using novel echocardiographic indices

The first manifestation of cardiac involvement in Chagas disease could be sudden death or rapid deterioration in cardiac function. The aim of this study was to identify a non-invasive method for early detection of cardiac involvement in patients with Chagas disease. During a 6-month period in 2001, 133 people were studied using echocardiography and electrocardiography in Honduras; 88 were seropositive for Trypanosoma cruzi, of which 31 were asymptomatic, and 45 were seronegative controls. The echocardiographic assessment included geometrical and time interval derived indices. Patients with asymptomatic Chagas disease had increased left and right myocardial performance index (MPI) when compared with seronegative controls (P= 0.003 and P= 0.023, respectively) with 36% having a left MPI above the upper limit of the normal range. They also had a reduced diastolic posterior wall thickness (P= 0.005) and lower posterior wall thickness to left ventricular cavity (PWT:LVC) ratio (P= 0.002). Our results show that the MPI, a simple Doppler parameter, and the PWT:LVC ratio are useful in the early detection of myocardial involvement in asymptomatic patients with Chagas disease. These parameters could serve as useful screening tools and monitor the disease progression in these patients.