In this study the researchers looked at .5, 1,5 and 10 hz.  They found that 1 HZ at PC4 was the most effective to decrease pulse and blood pressure.  I don’t think I’ve ever used PC4 on purpose, so I will try it!  None of my electrodevices go as low as 1 Hz, so that’s a problem.

http://www.ncbi.nlm.nih.gov/pubmed/26695399

Clin Auton Res. 2015 Dec 22.
[Epub ahead of print]
Golden Chinese Sage Statues

Ancient Wisdom Through the Ages

Abstract

PURPOSE:

Acupuncture stimulation is known to act on the autonomic nervous system and elicits depressor and bradycardic effects. However, previous studies on humans did not conduct quantitative analyses on optimal acupuncture conditions such as the stimulation frequency and duration to achieve maximum depressor and bradycardic effects. The aim of the present study was to investigate the effects of varying stimulation frequencies of electroacupuncture on time-dependent changes in blood pressure and heart rate in humans.

METHODS:

Twelve healthy volunteers participated in the study. An acupuncture needle was inserted at the Ximen acupoint (PC4 according to WHO nomenclature), located at the anterior aspect of the forearm. An electrical stimulation was delivered through the acupuncture needle at an intensity of 1 V, pulse width of 5 ms, and stimulation frequencies of 0.5, 1, 5, and 10 Hz in a random order. The duration of electroacupuncture was 6 min, during which blood pressure and heart rate responses were monitored.

RESULTS:

Group-averaged data indicated that 1-Hz electroacupuncture decreased blood pressure and heart rate. Blood pressure was significantly decreased from the prestimulation baseline value of 86.6 ± 2.9 to 81.4 ± 2.3 mmHg during 4-6 min of 1-Hz electroacupuncture (mean ± SE, P < 0.01). Heart rate was also significantly decreased (from 66.2 ± 2.0 to 62.7 ± 1.7 beats/min, P < 0.01).

CONCLUSIONS:

These results provide fundamental evidence that bradycardiac and depressor responses are effectively produced by electrical acupuncture in humans.