[The tourniquet test in evaluating the analgesic action of antianginal preparations]

Twenty-two patients with coronary heart disease (CHD) were examined for pain threshold and pain tolerance by a tourniquet test. The relationships between pain and ST segment depression were studied simultaneously during bicycle exercise. Pain sensitivity was measured in response to action of various antianginal drugs (isosorbide dinitrate, verapamil, nifedipine, diltiazem, propranolol, atenolol) and placebo. Reproducibility of the tourniquet test proved satisfactory. There were significant correlations between tourniquet test evidence and clinical patterns of ischemic myocardial episodes: significant differences in the values of pain threshold and pain tolerance in patients with painful myocardial ischemia, in combination of angina of effort with painless myocardial ischemia (p < 0.0001). Significant were also correlations between tourniquet test findings at bicycle exercise and value describing the proportion of ST depression to pain. As for the drugs, verapamil appeared most active in the tourniquet test (p < 0.02 and p < 0.05 for pain threshold and pain tolerance, respectively). Pain tolerance changes due to isosorbide dinitrate were somewhat greater than for placebo (p = 0.06). The study provided evidence in support of the adequacy of the tourniquet test for assessment of general pain sensitivity and pain sensitivity to myocardial ischemia as well as of analgetic effects of the drugs. Verapamil and isosorbide dinitrate are suggested to have analgetic activity.