Complementary Alternative Cardiovascular Medicine

178 Alternative Cardiovascular Medicine
rather than exact choice of Chinese acupuncture points. The combined
study suggests a mutual mechanism underlying the acupuncture-induced
improvement in pressure-rate-product during exercise and an increase in
local skin temperature; a decrease in sympathetic tone, induced by segmental
nerve stimulation is a possible explanation.
Level A Scientific Studies. Several experiments on animals support
the clinical findings in patients with angina pectoris.
In one study, experimental myocardial ischemia was produced in 30
rabbits by ligation of the ventricular branch of the left coronary artery.
The rabbits were randomly allocated to electroacupuncture at Per. 5
(acupoint Jianshi) (60 Hz for 10 min) or no treatment. Using ST depression
as a measurement of myocardial ischemia, the acupuncture group
showed a decrease in ST depression after release of the ligation, when
compared to the control group (p < 0.05), and a normal ST amplitude
was obtained after 50 min in the acupuncture group only (26). In another
study with the same design, 48 rabbits were randomly allocated to (1)
control, (2) acupuncture, (3) electrolytic destruction of the hypothalamus
without acupuncture, and (4) electrolytic destruction of the hypothalamus
with acupuncture. Again, when compared to the control group,
the acupuncture group showed improved recovery after release of the
ligation, measured as ST depression (p < 0.05). Although lesion of the
hypothalamus did not affect the recovery, the effect of acupuncture in
the group with a destroyed hypothalamus was no longer significant when
compared to the control group (27).
A Chinese American group of scientists have conducted a series of
impressive experiments on anesthetized cats, elucidating the effects of
acupuncture on bradykinin stimulated, reflex-induced myocardial ischemia
(28–30). To produce a controlled reduction in regional coronary blood flow
(CBF), the left anterior ascending artery was totally (5 cats) or partially
occluded (7 cats). Regional wall movement measured by Doppler was
used to assess myocardial function in response to the induced ischemia.
Electroacupuncture at the median nerve (corresponding to acupoint Per.
6: Neiguan) significantly improved wall function when compared to
controls (p < 0.05). The improvement in regional function with stimulation
of the median nerve was accompanied by a diminished pressor
response, as indicated by significantly reduced increments in blood pressure
and pressure-rate-product (p < 0.05). The inhibitory effect of acupuncture
on the reflex-induced myocardial ischemia was blocked by
naloxone, administrated either intravenously or directly into the cardiovascular
reflux center of the medulla spinalis, suggesting that the decrease
in myocardial oxygen demand was mediated by stimulation of
opioid receptors in the medulla spinalis exercising an inhibitory effect on
cardiovascular sympathetic reflexes (29).