[Function of the left atrium in Chagas' cardiomyopathy]

To study the function of the left atrium in carriers of dilated cardiomyopathy of chagasic etiology and relate it to the diastolic function and to the functional class.

We studied 75 chagasic with cardiomyopathy patients from July to 1999 to May to 2001, submitted to clinical exams, electrocardiogram and transesophageal echocardiogram. The left atrium function was assessed by means of the velocities in the left atrial appendix and the atrial reverse in the pulmonary vein. The control group consisted of 20 normal patients.

The age was 48 +/- 13 years old and 69% were men. Most of patients (88%) were in functional classes I and II, under a conventional treatment for cardiac insufficiency. The fraction of ejection of the left ventricle was 39 +/- 13%. The indicators of diastolic function associate to those of systolic function and the functional class. Patients with pseudonormal or restrictive pattern of diastolic dysfunction presented a larger diameter of the left atrium, lower flow velocities in the left atrial appendix and a longer duration of the atrial reverse. There was no difference among the patients with normal pattern and abnormal diastolic relaxation in relation to the control group.

The left atrial function is an important parameter in the assessment of patients with chagasic myocardiopathy and it is related to the systolic and diastolic functions of the left ventricle.