Acetylsalicylic acid effects on pain sensitivity to myocardial ischemia and skin sensitivity in anginal patients

Aim, To clarify if pain-relieving action of acetylsalicylic acid (ASA) is a ssociated with lowered sensitivity of anginal patients to pain due to myoca rdial ischemia. Materials and methods. A double blind randomized placebo-controlled trial e nrolled 10 males aged 42-69 years with stable effort angina (EA) of functio nal class II-III. When exposed to exercise tolerance test (treadmill, stres s-system Sicard 460S, computed ECC), the patients developed EA attack with at least 1 mm decline of ST segment on ECG. The exercise test was made befo re, 2 and 4 hours after administration of ASA and placebo. Sensitivity to i schemia,vas estimated by the total depth of the ST segment decline in 11 EC G leads (Sigma(ST)) registered at the attack onset. Tactile and pain thresh olds (TT and PT) were sturdied with a highly reproducible technique. TT and PT were measured before, 2 and 4 hours after ASA and placebo administratio n. Results, 2 and 4 hours after intake of 100 mg of ASA, Sigma(ST) and TT sign ificantly rose compared to the baseline level and placebo. PT significantly rose vs the baseline level. Conclusion. ASA deteriorates sensitivity of anginal patients to myocardial ischemia, skin tactile and pain sensitivity and thus can deprive the EA pat ient of the pain attack signal. This leads to the risk of overexercising an d emergence of painless myocardial ischemia.