The purpose of this study is to determine acute effect the transctutaneous electrical nerve stimulation in sympathetic and parassympathetic system in individuals with heart failure.

Heart failure (HF) is the inability of the heart to maintain adequate levels of blood supply to tissues. In recent years there has been an increased prevalence of heart failure (HF), in Brazil there are about two million people diagnosed with HF and 240,000 new cases per year. Thus, the IC constitutes the most serious problem now and in the fields of cardiology and public health. Sympathetic activity is increased and correlates with a worse prognosis and survival in these patients. Currently, the pharmacological blockade of the sympathetic system by chronic use of beta-blockers are commonly used to treat hyperactivity, but these interventions have side effects. The transcutaneous electrical nerve stimulation (TENS) has been used successfully to control pain in different clinical conditions and may be a noninvasive strategy to reduce drug and not the severity of increased sympathetic.

Inclusion Criteria:

• Possess stable heart failure grade II or III according to NYHA;
• Ejection fraction <40% determined by echocardiography;
• Having no change in drug therapy one month before being included in the study;
• There have been Myocardial Infarction (AMI) three months before study entry;

Exclusion Criteria:

• Patients with grade IV heart failure according to NYHA;
• Acute respiratory;
• Unstable angina;
• Ventricular arrhythmia, unstable until three months before the start of the study;
• Pacemaker;
• Active smoking;
• Diabetes mellitus;
• And fever or infectious disease.