Nonpharmacological Correction of Hypersympatheticotonia in Patients with Chronic Coronary Insufficiency and Severe Left Ventricular Dysfunction

Abstract

Background: Control of sympathetic hyperactivity is pivotal for treatment of heart failure (HF) in patients with coronary artery disease (CAD). Our earlier studies demonstrated that the auricular pulsed electrical stimulation of the vagus nerve (VNS) beneficially affected condition of CAD patients with HF. The aim of our study was to evaluate changes in heart rate (HR) and the levels of heat shock proteins in peripheral blood lymphocytes in patients with CAD in the course of VNS.

Methods: The study comprised 70 individuals aged 50-68 years with chronic coronary insufficiency, severe left ventricular dysfunction, and NYHA functional class (FC) III-IV HF. Main group included 63 patients who received VNS course (group 1). Control patients (n = 7) received sham therapy (group 2).

Results: According to the results of 6-minute walk test and 24-hour ECG monitoring, administration of VNS improved clinical condition of 58 of 63 patients, decreased HF FC, and attenuated HR. Clinical condition in sham therapy group did not change. Immunoenzyme method demonstrated that hsp70 and hsp60 contents in peripheral blood lymphocyte lysate increased by 58% and 48% (P < 0.05), respectively, in patients who initially had HR < 80 bpm. The hsp70 level significantly increased and hsp60 level remained unchanged in patients with initial HR > 80 bpm.

Conclusions: Correction of autonomous nervous status by VNS attenuated HR and improved functional state of the heart in CAD patients. Cardiotropic effect of VNS was the most pronounced in patients with preserved endogenous stress-limiting systems associated with hsp60 and/or hsp70.

Keywords: autonomous nervous system; coronary artery disease; heart failure; heart rate, heat shock proteins; vagus nerve stimulation.

Figure 1

Afferent nerve endings of cranial nerves on a surface of an auricle, (1) n. facialis; (2) r. auricularis n. vagi; and (3) parotid salivary gland.

Figure 2

Mean values of heart rate in patients before and after the course of vagus nerve stimulation or sham treatment. *P < 0.05 compared with initial pretreatment values. 1: patients received VNS treatment. 1a: patients from group 1 whose pretreatment heart rate was ≤80 bpm. 1a1: patients from subgroup 1a whose heart rate decreased after VNS course. 1a2: patients from subgroup 1a whose heart rate did not change after VNS course. 1b: patients from group 1 whose pretreatment heart rate was >80 bpm. 1b1: patients from subgroup 1a whose heart rate decreased after VNS course. 1b2: patients from subgroup 1a whose heart rate did not change after VNS course. 2: patients received sham treatment.

Figure 3

Individual points for mean heart rate before and after VNS. Group 1: patients received VNS treatment. Subgroup 1a: patients from group 1 whose pretreatment heart rate was ≤ 80 bpm. 1b: patients from group 1 whose pretreatment heart rate was >80 bpm. Subgroup 2: patients received sham treatment.