Objective To observe the correlation between the referred pain regions of stable angina pectoris(SAP)and the acupoints in coronary heart disease(CHD)patients and to investigate the rule of regional sensitized point distribution in rats.Methods A total of 1 046 CHD patients with SAP from 8 hospitals in China were recruited in the present study.The tenderness was palpated along the left and right chest

back

shoulder

upper limb

etc.by a specially-assigned researcher in each hospital.Among them

77 patients accepted pain threshold(PT)measurement by using a hand-held esthesiometer.In animal experiments

14 SD rats were subjected to occlusion of the left anterior descending branch of the left coronary artery for 4 hfor establishing myocardial ischemia(MI)model

and other 4 normal rats were used as the sham-operation control group.Four hours after MI

all the rats accepted tail venous injection of 5% Evans blue(50 mg/kg)for examining the distribution of the blue dye exudation spots at the body surface where the mechanical PT was also detected by a von Frey.Results In 1 046 CHD patients

987(94.36%)were found to have at least one tenderness spot.The tenderness spots were found at the left chest(87.47%)

right chest(13.67%)

left arm(ulnar side

41.30%)

right upper limb(4.68%)

left shoulder back(30.21%)

right shoulder back(7.07%)

etc.

accompanied with rash or pigmentation

subcutaneous induration

cord-like tissue contracture

skin sag

etc.The mechanical PT level was significantly lower at the tenderness spots of the left upper limb than at non-tender points of the right upper limb in CHD patients(P<0.001).Tenderness and cutaneous abnormal changes in angor pectoris patients distributed mostly on the left chest

back

shoulder and upper limb

and some also on the right.Tender points scattered on

near or outside acupoints.A similar distribution of the blue exudation spots and lower mechanical PT spots were found in MI rats

but not in shamMI rats.Conclusion In the case of MI

a regular"referred sensitization"response frequently occurs in the dermatomere area innervated by the corresponding segments(T 1-T 5)in both CHD patients and MI rats

which may be closely associated with the formation of acupoints in ancient China.