Methods
heart failure, diabetic, hypertensive, pain
HEART FAILURE
A prospective, double-blind, randomized clinical study, with sham methodology, evaluating patients with HF and ejection fraction < 50% on an outpatient basis. Patients from the HF outpatient clinic of the Cabo Frio Health Secretariat (CADHI-Center for diabetic, hypertensive, and heart failure care) and patients referred by other physicians to the outpatient clinic of Hospital Santa Izabel in Cabo Frio were treated.When we stimulate the afferent vagus nerve at the auricular level, the intrinsic cardiac autonomic nervous system is modulated to achieve the cardioprotective effect. Patients were stimulated at the auricular level until they felt tingling at the stimulus site, well below the pain threshold, which made the procedure feasible and comfortable.To prevent the researcher from knowing who received taVNS or sham, nurse Rafaela dos Santos Cardoso Carneiro was chosen, who, after adequate training and preparation, carried out the interventions and applied the tests. Data were collected through patient follow-up and non-invasive cardiological tests such as echocardiography and 24-hour HOLTER ECG. The 6MWT addressed functional assessment, and the NYHA functional class and the Minnesota quality of life questionnaire (MLHFQ) were also used.Our study used the EL-30 electrical stimulation equipment (NKL Electronic Products, Brusque, SC) with the following stimulation parameters: pulse width of 500 µs, intensity below the painful threshold, 5 seconds 2 Hz / 5 seconds 15 Hz. Recent studies have shown that low frequencies have a greater effect on decreasing sympathetic activity,A high image and processing quality echocardiogram was used, the Vivid S70N-GE, with the XDclear Matrix Sector probe.The Holter Cardiolight-Cardios digital recorder, with digital signal acquisition technology at 800 points per second with real-time processing (DSP), was employed in our study.The intervention (taVNS) took 30 minutes from Monday to Friday, totaling 20 sessions. Assessments and data collection were performed before starting the study and after the last session of each participant.From 2021-02-03 to 2022-01-05, 52 patients were initially recruited, but due to the COVID-19 pandemic, we lost the follow-up of 9 patients. Therefore, 43 patients completed the study, 22 in the taVNS group and 21 in the
Randomization was carried out through an electronic raffle and the creation of sealed envelopes distributed in a binary way. As participants were recruited, an envelope was opened: when ‘0’ (zero) came up, they received the
Thus, patients were allocated into 2 groups:Group 1 (22 patients) received the taVNS intervention, with a transcutaneous electrode on the superior concha (cimba) and the other on the right lobe, at frequencies 2/15 Hz over 30 minutes. This way, we stimulate the superior concha’s vagus nerve and the lobe’s great auricular nerve. Such sites were chosen based on the innervation of the ear, the technical facility for placing the electrodes and standardizing the treatment.Group 2 (21 patients) received the

