Acute Cardiovascular Effects of Non-Invasive Electrical Spinal Cord Stimulation: Results from a Pilot Study in Humans.

We aimed to determine if non-invasive electrical spinal cord stimulation (NIE-SCS) is associated with acute changes in systemic and pulmonary hemodynamics and cardiac electrophysiology at rest. Nine subjects without structural heart disease referred for catheter ablation of cardiac arrhythmia were included. NIE-SCS was performed in each patient at vertebral levels T1, T7, and T11. Higher systolic BP (BPs) was detected during T1 NIE-SCS as compared with baseline (147.9 ± 22.5 vs 135.4 ± 17.4 mmHg; P = 0.02). Atrioventricular nodal effective refractory period (AVN ERP) was shorter during stimulation at T1 and T7, when compared with baseline values (baseline 303.3 ± 15.0 vs 272.0 ± 19.2 for T1 vs 278.0 ± 8.3 ms for T7; P < 0.05). NIE-SCS at the T1 level is associated with an elevation of BPs. NIE-SCS at the T1 and T7 levels shortens AVN ERP. Further studies are needed for the evaluation of chronic effects.

The Autonomic Regulation of Circulation and Adverse Events in Hypertensive Patients during Follow-Up Study.

PURPOSE: Comprehensive study of autonomic regulation assessed during follow-up could provide new detailed information about the risks stratification for hypertensive patients. Therefore, we investigated the associations of these indices with death, stroke, and revascularization during the follow-up observation of 55 patients. METHODS: All patients were with target organ damage, and 27 of them had associated clinical conditions (ACC). Mean age of patients with and without ACC was 62.6 ± 4.2 and 51.9 ± 9.9 (mean ± SD) years, respectively. Follow-up was from 66 to 95 months. At entry, autonomic regulation was assessed by the tilt test, Valsalva maneuver, hand-grip test, and cold-stress vasoconstriction. Hemodynamic parameters were measured by continuous blood pressure monitoring, occlusion plethysmography, and electrocardiography. Re-examination of patients was carried out by questioning and physical and laboratory examination. RESULTS: We found that fatal outcomes were associated with a lower Valsalva index (1.34 ± 0.16 vs. 1.69 ± 0.37, P < 0.05) and depressed cold vasoconstriction (0.20 ± 0.02 vs. 0.39 ± 0.16%, P < 0.05) and depressed cold vasoconstriction (0.20 ± 0.02 vs. 0.39 ± 0.16%, P < 0.05) and depressed cold vasoconstriction (0.20 ± 0.02 vs. 0.39 ± 0.16%, P < 0.05) and depressed cold vasoconstriction (0.20 ± 0.02 vs. 0.39 ± 0.16%, P < 0.05) and depressed cold vasoconstriction (0.20 ± 0.02 vs. 0.39 ± 0.16%, P < 0.05) and depressed cold vasoconstriction (0.20 ± 0.02 vs. 0.39 ± 0.16%, P < 0.05) and depressed cold vasoconstriction (0.20 ± 0.02 vs. 0.39 ± 0.16%. CONCLUSIONS: This study shows that such autonomic regulation indices as Valsalva index, blood pressure dynamics in the tilt test, cold-stress vasomotor reactivity, and BPV are important for prognosis of hypertension course.