Association between angina pectoris and ischemic indexes during exercise testing and ambulatory monitoring

Psychological and physiological predictors of angina during exercise-induced ischemia in patients with coronary artery disease

OBJECTIVE

This study compares sensory-biological, cognitive-emotional, and cognitive-interpretational factors in predicting angina on an exercise treadmill test (ETT).

METHODS

A total of 163 patients with ETT-induced ischemia and coronary artery disease in the National Heart, Lung, and Blood Institute Psychophysiological Investigations of Myocardial Ischemia study were given an ETT, during which 79 patients reported angina. We assessed the following as potential predictors of self-reported anginal pain: sensory-biological factors (β-endorphin reactivity, hot pain threshold, and maximal ST-segment depression), cognitive-emotional factors (negative affect and symptom perception), and cognitive-interpretational factors (self-reported history of exercise-induced angina). Models were covariate adjusted with predictors examined individually and as part of component blocks.

RESULTS

Logistic regression revealed that history of angina (odds ratio [OR] = 17.41, 95% confidence interval = 7.16-42.34) and negative affect (OR = 1.65, 95% confidence interval = 1.17-2.34), but not maximal ST-segment depression, hot pain threshold, β-endorphin reactivity, or symptom perception, were significant predictors of angina on the ETT. The sensory-biological block was not significantly predictive of anginal pain (χ(2)block = 5.15, p = .741). However, the cognitive-emotional block (χ(2)block = 11.19, p = .004) and history of angina (cognitive-interpretation; χ(2)block = 54.87, p < .001) were predictive of ETT angina. A model including all variables revealed that only history of angina was predictive of ETT pain (OR = 16.39, p < .001), although negative affect approached significance (OR = 1.45, p = .07).

CONCLUSIONS

In patients with ischemia, cognitive-emotional and cognitive-interpretational factors are important predictors of exercise angina.

Contemporary management of silent ischemia: the role of ambulatory monitoring

Silent ischemia is highly prevalent among patients with ischemic heart disease and is associated with a poor prognosis in moderate/high risk outpatients who either exhibit exercise- or pharmacological-induced myocardial ischemia, or in those patients who demonstrate silent ischemia following an acute coronary syndrome. Pharmacotherapy, including beta-blockers, angiotensin-converting enzyme inhibitors, statins, calcium channel antagonists and antiplatelet agents, have all demonstrated a reduction in silent ischemia and an improvement in cardiac prognosis. The management of patients with ischemic heart disease is currently based on patients' report of anginal symptoms: documentation of silent ischemia, usually using ambulatory electrocardiography, is not incorporated into the routine management of coronary artery disease. Yet studies comparing ambulatory electrocardiography with exercise testing have shown these tests to be complementary. We review the evidence concerning the prognostic value of ambulatory electrocardiography for monitoring silent ischemia and the prognostic value of attenuating silent ischemia. Mitigation of silent ischemia improves cardiac prognosis and ambulatory electrocardiographic monitoring before and after treatment of silent ischemia can play a valuable role in the management of coronary artery disease.

Silent ischaemia and hypertension

For many years now, silent ischaemia has been recognized as a distinct clinical entity, and its relevance in different patient groups has been established. However, a number of basic questions have not been answered. In explaining the pathophysiology of silent ischaemia, factors affecting both the demand and the supply side are now being recognized. With the exception of certain well-defined groups, it is not clear why some patients are mostly symptomatic, while other patients are predominantly asymptomatic. There appear to be many factors influencing the ischaemic pain threshold. Studies investigating the prevalence of silent ischaemia show a remarkably high prevalence of silent ischaemia in different patient groups. Patients with hypertension but without coronary artery disease form a specific and vulnerable high-risk population that is particularly prone to silent ischaemia. Since changes at the macrovascular level are not responsible, various factors negatively influencing either cardiac supply or demand have been investigated. A reduced coronary reserve is central in explaining the increased prevalence of silent ischaemia in hypertensives. Left ventricular hypertrophy renders meaningful detection of ST segment changes difficult, but a possible solution dealing with this problem is offered by applying more stringent criteria in terms of minimal ST depression in the definition of ischaemia. The treatment of silent ischaemia is largely the same as for angina pectoris, but whether therapy should be directed at elimination of all ischaemic episodes or only of symptomatic episodes depends on further prospective work addressing this question.

Relationship between dental pain perception and 24 hour ambulatory blood pressure: a study on 181 subjects

OBJECTIVE

To investigate dental pain perception in a large group of essential hypertensive subjects.

METHODS

A total of 130 hypertensive patients together with 51 normotensive subjects were submitted to tooth-electrical stimulation to determine the dental pain threshold (occurrence of pulp sensation) and tolerance (time when the subject asked for the test to be stopped). Blood pressure was measured at rest, before pain perception evaluation, and during a 24 h period by ambulatory monitoring.

RESULTS

The normotensive and hypertensive subjects differed with regard to pain threshold (P = 0.002) and tolerance (P = 0.01). Pain perception variables were significantly correlated with both resting blood pressure and 24 h, diurnal and nocturnal arterial pressures, the correlation between pain threshold and 24 h systolic blood pressure being the most significant (r = 0.31, P < 0.0001). By contrast, parameters indicating 24 h blood pressure variability (percentage of nocturnal blood pressure reduction and 24 h blood pressure variation coefficients) were not associated with pain perception. Moreover, among the hypertensives only, a significant relationship was observed between pain sensitivity and both baseline and 24 h pressures. No association was found when pain perception and blood pressure were correlated in the normotensive group.

CONCLUSIONS

The correlation between both baseline and 24 h blood pressure and pain perception has been confirmed in a large group study of normotensive and hypertensive subjects. Moreover, even among the hypertensive range of blood pressure, the higher the blood pressure is, the lower the sensitivity to pain is. These findings strengthen the hypothesis of a role of the degree of blood pressure elevation in modulating pain sensitivity.

Relationship between a genetic predisposition to hypertension, blood pressure levels and pain sensitivity

INTRODUCTION

The aim of this study was to determine whether the degree of blood pressure elevation and/or a genetic predisposition to hypertension have a major role in determining a reduced pain perception in hypertensives. The reasons underlying the relationship between blood pressure elevation and pain perception mechanisms are not completely understood.

METHODS

One hundred and four untreated hypertensive patients (65 subjects with and 39 without a positive parental history of hypertension) together with a control group of 42 subjects (20 normotensive offspring of normotensive parents, and 22 normotensive offspring of hypertensive parents) were submitted to standard blood pressure evaluation, 24-h blood pressure monitoring and dental pain perception evaluation.

RESULTS

Both pain threshold and tolerance were found to be higher in hypertensive than normotensive subjects (P < 0.0001 and P < 0.015, respectively). Positive significant correlations were found between both 24-h systolic and diastolic pressure and the pain perception variables. When a 2 x 2 ANOVA test was performed, factoring for the effects of both blood pressure status and family history of hypertension on pain sensitivity, a significant effect was revealed only for blood pressure status. Moreover, after controlling for blood pressure by a covariate analysis, no significant difference was found between the subjects with or without hypertensive parents as regards pain perception variables.

CONCLUSIONS

Pain sensitivity is correlated to blood pressure levels whereas the parental history of hypertension per se does not affect the pain perception pattern. Thus, the degree of blood pressure elevation, more than a genetic predisposition to hypertension may influence the mechanisms leading to hypalgesia in hypertension.