SUSCEPTIBILITY TO PAIN IN HYPERTENSIVE AND NORMOTENSIVE PATIENTS WITHCORONARY-ARTERY DISEASE - RESPONSE TO DENTAL-PULP STIMULATION

An association between a decreased responsive ness to varying painful stimuli and arterial hypertension both in animals and in humans has be en documented. The relationship between essential hypertension and sil ent myocardial ischemia in coronary artery disease (CAD) populations i s not well understood. The aims of this study in CAD patients with and without essential hypertension were (1) to determine dental pain thre shold and reaction to tooth pulp stimulation and (2) to ascertain whet her hypertensive CAD patients differ from normotensive ones in reactiv ity to pain. This study involved 182 patients who were affected by mil d and moderate hypertension (G1) and 174 normotensive patients (G2). T he inclusion criteria were reproducible exercise-induced myocardial is chemia, CAD documented at angiography, and dental formula suitable for pulp test. All patients underwent an ergometric stress test, coronary angiography, and pulp test. Our CAD hypertensive patients showed a lo wer prevalence of angina during daily life (64.8% in G1 versus 81.6% i n G2. P<.05) and a higher incidence of exercise-induced silent myocard ial ischemia (60.4% in G1 versus 48.8% in G2, P<.05) than the normoten sive group. The mean anginal pain intensity, which was suffered both d uring spontaneous transitory episodes of ischemia and/or during acute myocardial infarction, was significantly lower in G1 than in G2 patien ts (P<.05). During pulp test, 31.8% of G1 and 13.7% of G2 referred no symptoms, even at the highest current intensity of 500 mA. The hyperte nsive patients with symptoms during pulp test had a higher mean dental pain threshold and lower mean threshold reaction and maximal reaction than did the normotensive symptomatic ones. In patients of both group s, a positive correlation between the mean maximal reaction during pul p test and the prevalence of angina during daily life was also found. In conclusion, patients with CAD and essential hypertension differ fro m normotensive CAD patients in reactivity to pain. Significantly highe r pain thresholds and lower reactions to tooth pulp stimulation charac terized patients with increased blood pressure values.