Is autonomic function associated with left ventricular systolic function in Chagas heart disease patients undergoing treatment for heart failure?

INTRODUCTION The association between cardiac autonomic and left ventricular (LV) dysfunction in Chagas disease (ChD) is controversial. METHODS A standardized protocol that includes the Valsalva maneuver, a respiratory sinus arrhythmia (RSA) test, and an echocardiographic examination was used. Spearman correlation coefficients (rho) were used to investigate associations. RESULTS The study population consisted of 118 ChD patients undergoing current medical treatment, with an average LV ejection fraction of 51.4±2.6%. The LV ejection fraction and diastolic dimension were correlated with the Valsalva index (rho=0.358, p<0.001 and rho=-0.266, p=0.004, respectively) and the RSA (rho=0.391, p<0.001 and rho=-0.311, p<0.001, respectively). CONCLUSIONS The impairment of LV function is directly associated with a reduction of cardiac autonomic modulation in ChD.