Induction of silent myocardial ischemia with mental stress testing: relation to the triggers of ischemia during daily life activities and to ischemic functional severity.

OBJECTIVES: This study examined the relations among the triggers of ischemia during the activities of daily life, mental stress-induced ischemia in the laboratory and functional severity of ischemia on exercise testing. BACKGROUND: Myocardial ischemia is readily induced with exercise testing, but most episodes of ischemia in daily life occur during relatively sedentary activities. Although mental and emotional arousal are known to trigger myocardial ischemia, mental stress testing induces ischemia in only approximately 50% of patients with active coronary disease. It is not known whether such patients are particularly susceptible to nonexertional ischemia during daily activity. METHODS: We studied 45 men (mean age +/- SD 58 +/- 9 years) with coronary artery disease by means of 48-h Holter ambulatory electrocardiography for ST segment analysis and quantification of physical and mental activity with a structured diary system. These data were cross-tabulated with new left ventricular dyssynchrony (detected on two-dimensional echocardiography) induced by two mental stressors and by bicycle exercise. RESULTS: During mental stress testing, 24 patients (53%) (Group I) had a new wall motion abnormality; the other 21 patients (Group II) did not. The average wall motion dyssynchrony score increased from 1.20 +/- 0.29 to 1.34 +/- 0.36 (p = 0.001), but the increase was less than that with exercise stress (1.52 +/- 0.41, p = 0.001). The total duration of ischemia during sedentary activities was greater in Group I (22.9 +/- 24.5 min) than in Group II (3.6 +/- 3.9 min, p = 0.025). Group I had more ischemic events while sedentary (23 of 290 diary entries) than did Group II (8 of 256 diary entries, p = 0.015). The magnitude of dyssynchrony with mental stress and the number of mental stressors capable of triggering ischemia were related to severity of ischemia with exercise. CONCLUSIONS: Patients with ischemia during mental stress testing also have increased ischemia during sedentary activities in daily life. This finding may reflect greater functional severity of coronary artery disease or a propensity toward coronary vasoconstriction while sedentary.

Effects of mental stress on coronary epicardial vasomotion and flow velocity in coronary artery disease: relationship with hemodynamic stress responses.

OBJECTIVES: This study examines the prevalence and hemodynamic determinants of mental stress-induced coronary vasoconstriction in patients undergoing diagnostic coronary angiography. BACKGROUND: Decreased myocardial supply is involved in myocardial ischemia triggered by mental stress, but the determinants of stress-induced coronary constriction and flow velocity responses are not well understood. METHODS: Coronary vasomotion was assessed in 76 patients (average age 59.9 +/- 10.4 years; eight women). Coronary flow velocity responses were assessed in 20 of the 76 patients using intracoronary Doppler flow. Repeated angiograms were obtained after a baseline control period, a 3-min mental arithmetic task and administration of 200 microg intracoronary nitroglycerin. Arterial blood pressure (BP) and heart rate assessments were made throughout the procedure. RESULTS: Mental stress resulted in significant BP and heart rate increases (p < 0.001). Coronary constriction (>0.15 mm) was observed in 11 of 59 patients with coronary artery disease (CAD) (18.6%). Higher mental stress pressor responses were associated with more constriction in diseased segments (rdeltaSBP = -0.26, rdeltaDBP = -0.30, rdeltaMAP = -0.29; p's < 0.05) but not with responses in nonstenotic segments. The overall constriction of diseased segments was not significant (p > 0.10), whereas a small but significant constriction occurred in nonstenotic segments (p = 0.04). Coronary flow velocity increased in patients without CAD (32.2%; p = 0.008), but not in patients with CAD (6.4%; p = ns). Cardiovascular risk factors were not predictive of stress-induced vasomotion in patients with CAD. CONCLUSIONS: Coronary vasoconstriction in angiographically diseased arteries varies with hemodynamic responses to mental arousal. Coronary flow responses are attenuated in CAD patients. Thus, combined increases in cardiac demand and concomitant reduced myocardial blood supply may contribute to myocardial ischemia with mental stress.

Fatal and non-fatal deliberate self-harm in the Wellington region 1978: a social analysis.

Some characteristics of the people who deliberately harmed themselves in the Wellington Hospital Board region in 1978, and who were either admitted to hospital or died, are described. Records show 32 people killed themselves and 306 people were admitted to hospital. Twenty-six people were admitted twice. The rate of non-fatal events was nine persons per 10000 population. For fatal events, males and unemployed people were at greater risk. Drugs were used in nine out of 32 cases. The characteristics of people at greater risk in 1978 of non-fatal deliberate self-harm were female; aged 15 to 24 years if female and 15 to 29 years if male; unemployed, sickness beneficiary or in a service occupation; domiciled in the inner city; and separated from their spouse. Drugs were used in 96.5 percent of non-fatal events. The length of stay in hospital for 48.5 percent of admissions was one day.

Mental health and the use of alcohol, tobacco, analgesics and vitamins in a secondary school population.

A survey of mental health in relation to patterns of alcohol, tobacco, pharmaceutical drug use and reducing diets was carried out in six Hobart high schools and matriculation colleges. A response rate of 89% was achieved, yielding a sample of 2,419 teenagers. Psychiatric disorder was assessed by the 60-item General Health Questionnaire. A statistically significant association was found between the probability of psychiatric disturbance and the use of alcohol, cigarettes, analgesics, vitamin supplements and weight-reducing diets.

The circadian variation of cardiovascular stress levels and reactivity: relationship to individual differences in morningness/eveningness.

Two studies assessed the circadian variation of cardiovascular responses to stress in healthy and coronary artery disease (CAD) populations. In within-subjects designs, stressors were administered to healthy male subjects and male CAD patients both in the morning and afternoon, and subjects were classified as either morning or evening types using the Morningness-Eveningness Questionnaire (Horne & Ostberg, 1976, International Journal of Chronobiology, 4, 97-110). No consistent circadian variation in blood pressure or heart rate responses was observed in the aggregate sample of either healthy subjects or CAD patients. However, there were significant interactions between circadian type and time of day. In both populations, morning subjects exhibited higher cardiovascular levels during the morning session, and evening subjects exhibited higher levels during the afternoon session. Analyses of cardiovascular reactivity revealed less consistent evidence for this interaction. Self-reports of stress revealed interactions between time of day and morningness/eveningness only in the CAD sample. In CAD patients, preliminary analysis of myocardial wall function, an index of myocardial ischemia, did not reveal a significant interaction between morningness/eveningness and time of day, perhaps due to small sample size. The presence of differing circadian patterns in stress response based on individual differences in morningness/eveningness is discussed in terms of its methodological implications for psychophysiological research and in terms of the role of stress as an acute trigger of CAD.

Hostility and myocardial ischemia in coronary artery disease patients: evaluation by gender and ischemic index.

Two studies assess relationships of hostility to extent and severity of exercise-induced cardiac ischemia and daily life ischemia in patients with coronary artery disease (CAD). CAD patients (N = 80) who underwent exercise tomographic thallium testing to assess myocardial perfusion completed the Cook-Medley Hostility Inventory (Ho). A Composite Hostility (Chost) score obtained from the Ho scale was also used. Statistically controlling for the effects of gender in the full sample (N = 80), Chost was positively correlated with severity of perfusion defects (r = 0.22, p < 0.05). This relationship was nonsignificant in the 63 male patients, but was significant among women (N = 17, r = 0.42, p < 0.05) and among middle-aged men (less than 60 years, N = 17, r = 0.55, p < 0.05). In an overlapping sample of 42 CAD patients with ischemia (ST-segment depression > or = 1 mm) during 24 to 48 hours of ambulatory electrocardiographic monitoring, after controlling for gender, both Ho and Chost were positively correlated with total minutes of ischemia (r = 0.28 and r = 0.29, respectively, p < 0.05). In addition, there was a significant gender x hostility interaction, with stronger relationships with hostility evident for women. Results from these two studies indicate that in patients with coronary artery disease, hostility traits are significantly correlated with extent of daily life ischemia and with severity of exercise-induced myocardial ischemia. These relationships appear to be significant among female and middle aged male patients, but may be less evident among older male patients.

Doppler broadening of in-flight positron annihilation radiation due to electron momentum.

We report the first observation of electron momentum contributions to the Doppler broadening of radiation produced by in-flight two-photon annihilation in solids. In these experiments an approximately 2.5 MeV positron beam impinged on thin polyethylene, aluminum, and gold targets. Since energetic positrons easily penetrate the nuclear Coulomb potential and do not cause a strong charge polarization, the experimental annihilation line shapes agree well with calculations based on a simple independent-particle model. Moreover, annihilations with the deepest core electrons are greatly enhanced.