Table 1.
Non-invasive auricular electrical stimulation and changes in blood pressure and heart rate
| Study (author/year/design) | Subjects/age | Laterality/location of stimulation | Duration of stimulation | Frequency/amplitude | Changes in BP (mmHg) and HR (b.p.m.) before and after stimulations |
|---|---|---|---|---|---|
| Sellaro et al., 20159: sham controlled | The 24 healthy young: male 13%: mean 19 (18–22) years | Lt. ear lobe (control), Lt. tragus (active) | 8 min (3 times) | 25 Hz: 0.5 mA | In the sham stimulation, SBP/DBP/HR before and after stimulation were 119 ± 16/72 ± 10/82 ± 13 and 119 ± 14/73 ± 10/74 ± 11, respectively. In the active stimulation, SBP/DBP/HR before and after stimulation were 118 ± 15/70 ± 10/80 ± 14 and 116 ± 15/71 ± 8.8/80 ± 14, respectively. |
| Fischer et al., 201811: sham controlled | The 21 healthy young: male 14%: 20 ± 1 years | Lt. ear lobe (sham), Lt. concha (active) | 36 min | 25 Hz: 1.3 (active)/1.5 (sham) mA | In the sham stimulation, SBP/DBP/HR before and after stimulation were 112 ± 7.3/73 ± 7.8/75 ± 2.3 and 109 ± 7.3/73 ± 6.4/66 ± 2.8, respectively. In the active stimulation, SBP/DBP/HR before and after stimulation were 112 ± 12/72 ± 9.6/77 ± 13 and 108 ± 8.7/74 ± 6.4/66 ± 9.6, respectively. |
| Ventura-Bort et al., 201812: sham controlled | 21 healthy young males: male 14%: 20 ± 1 years | Lt. ear lobe (sham), Lt. concha (active) | 35 min | 25 Hz: 1.3 (active)/1.5 (sham) mA | In the sham stimulation, SBP/DBP/HR before and after stimulation were 112 ± 7.5/73 ± 8.2/75 ± 14 and 109 ± 7.4/73 ± 6.6/66 ± 9.3, respectively. In the active stimulation, SBP/DBP/HR before and after stimulation were 112 ± 13/72 ± 5.6/78 ± 13 and 108 ± 9.1/74 ± 6.9/66 ± 9.8, respectively. |
| Giraudier et al., 202013: sham controlled | 60 healthy young males: male 23%: 24 ± 5 years | Lt. ear lobe (sham), Lt. concha (active) | 23 min | 25 Hz 1.5 (active)/1.3 (sham) mA | In the sham stimulation, SBP/DBP/HR before and after stimulation were 116 ± 9.8/78 ± 7.1/73 ± 12 and 109 ± 12/74 ± 6.5/70 ± 7.9, respectively. In the active stimulation, SBP/DBP/HR before and after stimulation were 116 ± 12/77 ± 8.3/74 ± 14 and 108 ± 11/73 ± 7.6/71 ± 9.0, respectively. |
| Gauthey et al., 202014: crossover controlled | 28 healthy young males: male 100%: 27 ± 4 years | Rt. ear lobe (control), Rt. concha (active) | 10 min | 5 Hz, 20 Hz: NA (amplitude) | The SBP/DBP/HR before and after stimulation at control, at 5 Hz and at 20 Hz were 115 ± 11/59 ± 9/62 ± 8.4 and 115 ± 12/59 ± 9/61 ± 7.7, 116 ± 11/59 ± 9/61 ± 9.2 and 115 ± 10/59 ± 9/61 ± 8.7, and 115 ± 12/59 ± 9/62 ± 8.3 and 115 ± 10/59 ± 8/61 ± 8.3, respectively. |
| Sinkovec et al., 202315: sham controlled | The 50 healthy young: male 52%: mean 26 (20–39) years | Rt. tragus-no-stimulation (control), Rt. tragus stimulation (active) | 20 min | 20 Hz: 90 μA, 130 μA | In the control, SBP/DBP/HR was 113 ± 12/71 ± 8.9/65 ± 7.8, respectively. In the active stimulation at 90 μA and at 130 μA, SBP/DBP/HR were 113 ± 11/71 ± 8.1/65 ± 8.1 and 113 ± 13/72 ± 9.5/65 ± 8.4, respectively. |
| Hatik et al., 202316: sham controlled | The 90 healthy young: male 50%: 18–35 years | Bi. concha/tragus-no-stimulation (sham, n = 30) Lt. concha/tragus stimulation (active, n = 30), Bi. concha/tragus stimulation (active, n = 30) |
20 min (4 days) | 20 Hz: NA (amplitude) | In the group with bilateral sham stimulation, the values in SBP/DBP/HR at control and after stimulation were 164 ± 5.5/94 ± 9.2/134 ± 11 and 153 ± 5.8/90 ± 9.2/116 ± 11, respectively. In the active group with left tragus stimulation, the values in SBP/DBP/HR at control and after stimulation were 163 ± 6.1/92 ± 7.2/133 ± 8.2 and 142 ± 6.2/86 ± 6.7/109 ± 9.0, respectively. In the active group with bilateral tragus stimulation, the values in SBP/DBP/HR at control and after stimulation were 160 ± 6.4/91 ± 8.9/129 ± 7.8 and 130 ± 6.1/82 ± 8.6/102 ± 6.1, respectively. |
| de Moraes et al., 202317: parallel-group controlled | 30 patients with metabolic syndrome: male 33%: 43 ± 9 (active, n = 20)/46 ± 10 (control, n = 10) years | Lt. concha no-stimulation (control) Lt. concha stimulation (active) |
30 min once a week (8 weeks) | 25 Hz: 0.1–5.0 mA | In the control group, the values in SBP/DBP/HR before and after stimulation (8 weeks) were 135 ± 21/80 ± 10/74 ± 10 and 133 ± 21/83 ± 10/76 ± 10, respectively. In the active group, the values in SBP/DBP/HR before and after stimulation (8 weeks) were 137 ± 21/81 ± 10/72 ± 7 and 121 ± 11/77 ± 8/68 ± 8, respectively. |
| Percin et al., 202418: sham controlled | The 76 healthy young: male 53%: mean 25–26 years | Bi. tragus no-stimulation (sham, n = 19), Bi. tragus stimulation (active, n = 19), Bi. behind-ear no-stimulation (sham, n = 19), Bi. behind-ear stimulation (active, n = 19) | 20 min | 25 Hz: 0.13–50 mA | In the sham group at tragus, the values in SBP/DBP/HR before and after stimulation were 125 ± 15/88 ± 10/93 ± 15 and 123 ± 13/87 ± 12/95 ± 9.5, respectively. In the active group at tragus, the values in SBP/DBP/HR before and after stimulation were 136 ± 12/93 ± 14/90 ± 14 and 119 ± 16/82 ± 14/82 ± 5.3, respectively. In the sham group at behind-ear, the values in SBP/DBP/HR before and after stimulation were 119 ± 15/86 ± 8.5/93 ± 10 and 118 ± 16/88 ± 10/92 ± 5.9, respectively. In the active group at behind-ear, the values in SBP/DBP/HR before and after stimulation were 120 ± 15/86 ± 8.4/91 ± 13 and 107 ± 16/77 ± 10/88 ± 6.1, respectively. |
| Mbikyo et al., 202419: sham controlled | 40 patients with Grade 1 hypertension: male 58%: 29 ± 5.4 (sham, n = 19)/31 ± 7.1 (active, n = 21) years | Tragus (Lt. or Rt. not specified) | 60 min. a day, 5 days a week (12 weeks) | 20 Hz: 1 mA | In the sham group, the values in SBP/DBP/HR before and those after stimulation (12 weeks) were 143 ± 8.6/92 ± 6.1/71 ± 6.3 and 137 ± 8.0/88 ± 5.3/72 ± 5.9, respectively. In the active group, the values in SBP/DBP/HR before and those after stimulation (12 weeks) were 143 ± 8.2/90 ± 5.8/70 ± 8.7 and 129 ± 7.1/81 ± 6.0/69 ± 9.0, respectively. |
| Gentileet al., 202420: sham controlled | 16 patients with chronic heart failure with ejection fraction < 50%: male 63%: mean 65 ± 8 years | Lt. tragus stimulation (n = 16), Rt. tragus stimulation (n = 16) | 10 min | 20 Hz: Lt. median 23 mA, Rt. median 23 mA | The SBP/DBP/HR at baseline and after Lt. and Rt. tragus stimulation were 106 ± 13/60 ± 11/76 ± 11, 107 ± 11/62 ± 10/78 ± 10, and 108 ± 13/61 ± 10/77 ± 10, respectively. |
BP, blood pressure; SBP, systolic blood pressure; DBP, diastolic blood pressure; HR, heart rate.