Pheochromocytoma of the heart.

This is a presentation of a unique case of cardiac pheochromocytoma during pregnancy. The case is significant because pheochromocytoma is a difficult diagnosis and its rarity during pregnancy may lead to this important diagnosis being overlooked, even though treatment is specific and highly successful.

Impact of arterial stiffening on left ventricular structure.

Aging of the vasculature results in arterial stiffening and an increase in systolic and pulse pressures. Although pressure load is a stimulus for left ventricular hypertrophy, the extent to which vascular stiffening per se, independent of blood pressure, influences left ventricular structure is uncertain. Two hundred seventy-six subjects (79 normotensive and 197 otherwise healthy hypertensive individuals) underwent echocardiography to assess left ventricular structure. Arterial stiffness was estimated by the pressure-independent stiffness index, beta, and the pressure-dependent elastic modulus derived from simultaneous carotid ultrasound and applanation tonometry. Systemic arterial compliance (the inverse of stiffness) was estimated by the arterial compliance index. In multivariate analysis, beta was related to age (P<0.001) and smoking history (P<0.01) but not mean pressure, whereas elastic modulus was related to age and mean pressure (both P<0.001). The arterial compliance index was only related to age. Whereas systolic and diastolic pressures and the elastic modulus were positively associated with left ventricular mass (all P<0.001), primarily because of increases in wall thicknesses, beta and the arterial compliance index bore no relation to left ventricular mass. beta was inversely related to chamber diameter and directly related to left ventricular relative wall thickness, the ratio of wall thickness to chamber radius. Younger and older hypertensive subjects had comparable left ventricular mass, despite higher systolic and pulse pressures in the older group, whereas older hypertensives had higher mean relative wall thickness, associated with a significant increase in arterial stiffness (beta, 7.06 versus 5.17; elastic modulus, 595 versus 437 dyne/cm(2) x10(-6)) and reduction in the arterial compliance index (0.87 versus 1.05 mL/mm Hg per square meter) (all P<0.001). Thus, the extent to which arterial stiffness relates to left ventricular hypertrophy is dependent on the method by which arterial stiffness is estimated. Pressure-dependent methods show an association with left ventricular hypertrophy, whereas the pressure-independent stiffness index, beta, and the arterial compliance index are most strongly associated with aging and left ventricular concentric remodeling but not hypertrophy.

Association of sleep-disordered breathing, sleep apnea, and hypertension in a large community-based study. Sleep Heart Health Study.

CONTEXT: Sleep-disordered breathing (SDB) and sleep apnea have been linked to hypertension in previous studies, but most of these studies used surrogate information to define SDB (eg, snoring) and were based on small clinic populations, or both. OBJECTIVE: To assess the association between SDB and hypertension in a large cohort of middle-aged and older persons. DESIGN AND SETTING: Cross-sectional analyses of participants in the Sleep Heart Health Study, a community-based multicenter study conducted between November 1995 and January 1998. PARTICIPANTS: A total of 6132 subjects recruited from ongoing population-based studies (aged > or = 40 years; 52.8% female). MAIN OUTCOME MEASURES: Apnea-hypopnea index (AHI, the average number of apneas plus hypopneas per hour of sleep, with apnea defined as a cessation of airflow and hypopnea defined as a > or = 30% reduction in airflow or thoracoabdominal excursion both of which are accompanied by a > or = 4% drop in oxyhemoglobin saturation) [corrected], obtained by unattended home polysomnography. Other measures include arousal index; percentage of sleep time below 90% oxygen saturation; history of snoring; and presence of hypertension, defined as resting blood pressure of at least 140/90 mm Hg or use of antihypertensive medication. RESULTS: Mean systolic and diastolic blood pressure and prevalence of hypertension increased significantly with increasing SDB measures, although some of this association was explained by body mass index (BMI). After adjusting for demographics and anthropometric variables (including BMI, neck circumference, and waist-to-hip ratio), as well as for alcohol intake and smoking, the odds ratio for hypertension, comparing the highest category of AHI (> or = 30 per hour) with the lowest category (< 1.5 per hour), was 1.37 (95% confidence interval [CI], 1.03-1.83; P for trend = .005). The corresponding estimate comparing the highest and lowest categories of percentage of sleep time below 90% oxygen saturation (> or = 12% vs < 0.05%) was 1.46 (95% CI, 1.12-1.88; P for trend <.001). In stratified analyses, associations of hypertension with either measure of SDB were seen in both sexes, older and younger ages, all ethnic groups, and among normal-weight and overweight individuals. Weaker and nonsignificant associations were observed for the arousal index or self-reported history of habitual snoring. CONCLUSION: Our findings from the largest cross-sectional study to date indicate that SDB is associated with systemic hypertension in middle-aged and older individuals of different sexes and ethnic backgrounds.

Ambulatory blood pressure and metabolic abnormalities in hypertensive subjects with inappropriately high left ventricular mass.

Appropriateness of left ventricular (LV) mass to cardiac workload can be evaluated by the ratio of observed LV mass to the value predicted for an individual's gender, height(2.7), and stroke work at rest (%PLVM). It is unclear which pathophysiological factors are associated with inappropriately high LV mass in hypertensive subjects. Adequate LV mass was defined by the 90% confidence interval (73% to 128%) of the distribution of %PLVM in 393 normal-weight normotensive subjects. In 185 hypertensive subjects (aged 56+/-11 years; 60% male, 29% black), according to %PLVM, 164 (88%) had adequate LV mass, 16 (9%) had inappropriately high LV mass (%PLVM >128%), and 5 (3%) had %PLVM <73% (low LV mass). Age, gender, smoking habit, proportion of never-treated subjects, total cholesterol, triglycerides, and creatinine levels did not differ significantly between subjects with adequate and inappropriately high LV mass. Body mass index, fasting glucose, and proportion of black subjects were higher (all P<0.05), while HDL cholesterol was lower (P<0.05) in subjects with inappropriately high LV mass. Blood pressure at the echocardiogram was comparable between subjects with adequate and inappropriately high LV mass, but the latter group had higher ambulatory blood pressure (P<0.01). Subjects with inappropriately high LV mass also had higher aortic root dimension and LV relative wall thickness and relatively lower LV systolic performance than those with adequate LV mass (all P<0.001). Larger aortic root diameter and lower systolic function were also found in hypertensive subjects with inappropriate LV hypertrophy compared with those with adequate LV hypertrophy. In an exploratory case-control study that compared subjects with low %PLVM with age-matched counterparts with adequate LV mass, low %PLVM was associated with lower body mass index, more favorable metabolic profile, and higher LV myocardial contractility. Higher body mass index, larger aortic root, and black race were independent correlates of increased %PLVM. Thus, in arterial hypertension, levels of LV mass inappropriately high for gender, cardiac workload, and height(2.7) are associated with higher body mass index, higher ambulatory blood pressure, larger aortic root diameters, and relatively low myocardial contractility.

Job strain and health behaviors: results of a prospective study.

PURPOSE: To assess the association between job demands, job decision latitude, and job strain (defined by Karasek as a combination of high demands and low decision latitude) and cardiovascular disease-related health behaviors such as cigarette smoking, alcohol use, lack of exercise, and overweight. DESIGN: Cross-sectional and prospective. SETTING: Nine New York City public and private sector worksites. SUBJECTS: Two hundred eighty-five male employees, aged 30 to 60, in a wide variety of white-collar and blue-collar job titles. MEASURES: Medical examinations and surveys, which included demographic, health behavior, and job characteristics data. RESULTS: Prospectively, among 189 men, increase in job decision latitude over 3 years was associated with decrease in cigarette smoking, by analysis of covariance, controlling for age, race, education, marital status, and number of children at home (F (8, 180) = 4.37, p = .005). The largest increase in latitude occurred among the 13 men who quit smoking. However, change in job characteristics was not associated with change in overweight or alcohol use. Cross-sectional analyses did not produce consistent associations. CONCLUSIONS: The effectiveness of smoking cessation may be aided by modification of structural features of the work environment, such as job decision latitude. This study is limited by the small number of subjects who were engaged in high risk behaviors.

Is the absence of a normal nocturnal fall in blood pressure (nondipping) associated with cardiovascular target organ damage?

OBJECTIVE: To determine whether the failure to decrease blood pressure normally during sleep is associated with more prominent target organ damage. METHODS: Cardiac and vascular structure and function were characterized in 183 asymptomatic, unmedicated hypertensive patients and compared with their ambulatory blood pressures. RESULTS: The 104 patients with a normal (> 10%) nocturnal fall in systolic blood pressure (dippers) were similar to the 79 patients with an abnormal fall (nondippers) in sex, race, body size, smoking history, and average awake ambulatory blood pressure. Nondippers tended to be older (57 versus 54 years, P = 0.06). The supine blood pressure upon completion of the ultrasound studies was higher in the nondippers (156/93 versus 146/89 mmHg, P < 0.005) as was the variability of the awake diastolic blood pressure. There were no differences between dippers and nondippers in left ventricular mass (170 versus 172 g), mass index (90 versus 91 gm/m2), prevalence of abnormal ventricular geometry, common carotid artery diameter (5.74 versus 5.75 mm), and vascular strain. Although nondippers were more likely to have carotid artery plaque (41 versus 27%, P = 0.053) and an increased intimal-medial thickness (0.84 versus 0.79 mm, P < 0.05), adjustment for age rendered the differences insignificant. There were no differences in the relation of awake and sleeping systolic pressures to the left ventricular mass (r = 0.36 and 0.35, respectively, both P < 0.005) or to the carotid wall thickness (r = 0.28 and 0.29, respectively, both P < 0.005). When the 114 men and 69 women were considered separately, similar findings were obtained. When the 109 whites and 56 blacks (African-Americans and Afro-Caribbeans) were considered separately, there were no differences in left ventricular structure in either group, and differences in vascular structure were confined to the white subgroup. CONCLUSION: The lack of a normal nocturnal fall in blood pressure is not associated with an increase in left ventricular mass or in arterial disease independently of age. Age-related changes in carotid artery wall thickness and plaque among nondippers may reflect a contribution of an altered baroreceptor function to the lack of normal nocturnal and supine blood pressure decreases.

Association of the auscultatory gap with vascular disease in hypertensive patients.

OBJECTIVE: To assess the relation of the auscultatory gap during blood pressure measurement to cardiovascular structure and function. DESIGN: Cross-sectional study. SETTING: A hypertension center in a university hospital. PATIENTS: 168 persons with hypertension who were otherwise healthy and were not receiving medication. MEASUREMENTS: Wideband external pulse recordings and ultrasonographic examination of the left ventricle and extracranial carotid arteries. Vascular stiffness was evaluated using simultaneous carotid pressure waveforms obtained by applanation tonometry of the contralateral carotid artery. RESULTS: Classic auscultatory gaps were present in 21% of patients and were associated with older age (mean age SD, 64 11 years for patients with gaps and 55 13 years for patients without gaps; P < 0.001), female sex (67% of patients with gaps and 44% of patients without gaps were female; P < 0.05), and increased arterial stiffness (arterial stiffness index, 8.5 4.6 in patients with gaps and 5.8 3.2 in patients without gaps; P < 0.005). The prevalence of atherosclerotic plaques was increased more than twofold among patients with gaps compared with patients without gaps (50% compared with 22%; p < 0.002). Patients with and without auscultatory gaps had similar blood pressures, left ventricular structure and function, serum cholesterol levels, and smoking history. Logistic regression analysis indicated that only female sex (P < 0.02), arterial stiffness (P < 0.002), and atherosclerotic plaque (P < 0.02) were independently associated with the presence of an auscultatory gap. CONCLUSIONS: This study provides strong evidence that auscultatory gaps are related to carotid atherosclerosis and to increased arterial stiffness in hypertensive patients, independent of age. Although these observations need to be confirmed prospectively, they suggest that auscultatory gaps may have prognostic relevance.

Factors influencing the awake-sleep difference in ambulatory blood pressure: main effects and sex differences.

The purpose of this study was to assess the biological and behavioural characteristics associated with the variation in the awake-sleep blood pressure (BP) difference in a large series of patients who had ambulatory BP monitoring. The 1186 subjects in the study (689 men and 497 women) each wore an ambulatory BP monitor over one 24 h period. All patients had been off antihypertensive medication for at least 3 weeks prior to the BP monitoring. The extent of the difference in awake-sleep BP was defined by the percentage change to sleep pressure from the average awake value. The results showed that when the average levels of office, awake and sleep pressures are compared across groups defined by this percentage change, there is no statistically significant association between the level of office pressure and the extent of the awake-sleep pressure difference. In accordance with this finding, the relation between ambulatory awake BP and the awake-sleep difference was relatively weak, although significant (P < 0.01). In striking contrast, the ambulatory sleep pressure was a very strong predictor of the awake-sleep difference (P < 0.0001), such that subjects with the lowest sleep pressures had the biggest diurnal change. In examining the factors associated with the awake-sleep change in pressure, the most important predictors were a low sleep pressure and alcohol intake, both of which were associated with bigger diurnal changes of both SBP and DBP in both men and women. A large pulse pressure while awake (that is, isolated systolic hypertension) was also associated with bigger diurnal changes in both sexes. The only other predictive factor which applied in both sexes was a low awake BP variability which was associated with a greater diurnal variation of DBP. Among men but not women, older age, smoking cigarettes, and being overweight were associated with bigger diurnal changes of both SBP and DBP, and a family history of hypertension was also associated with a bigger diurnal change of systolic pressure. Finally, among women but not men, being measured in winter months was associated with a greater awake-sleep difference in diastolic pressure. These results show that there is a general pattern of factors which predict awake-sleep changes in men and women, but there are also contributing behavioural factors which are sex specific. As awake-sleep changes of BP may be of prognostic significance, behavioural factors need to be considered when evaluating this change.

Ambulatory blood pressure monitoring for evaluating the relationships between lifestyle, hypertension and cardiovascular risk.

1. Ambulatory monitoring provides a unique opportunity for studying the temporal relationships between lifestyle factors and blood pressure (BP). These include physical activity, mental activity, environmental stressors, substances ingested for pleasure such as smoking, alcohol and caffeine, and nutrition. 2. Changes in physical activity play a major role in determining the diurnal profile of BP, whereas the influence of mood is small. 3. Environmental stress, in the form of job strain, has been shown to be associated with a sustained increase of BP throughout the day and night in men, and also with an increased left ventricular mass. The effects are most marked in men who drink alcohol regularly. Job strain does not appear to influence BP in women. 4. Although it is recognized that smoking raises BP acutely, its long-term effects have been unclear. Ambulatory monitoring shows that smokers have a larger diurnal swing of BP than non-smokers, because of a higher daytime pressure. Alcohol also increases the diurnal swing of BP. 5. Ambulatory monitoring has been used relatively little for evaluating nutritional factors, but has the possibility of quantifying their effects on BP more reliably than traditional methods, and also elucidating the underlying mechanisms.

Augmentation of calf blood flow by epinephrine infusion during lumbar epidural anesthesia.

Lower rates of deep vein thrombosis after hip surgery performed under epidural anesthesia were noted in patients who received intravenous epinephrine infusion. To determine whether this effect could be mediated by enhanced lower extremity blood flow, 12 patients were studied immediately preoperatively. Calf blood flow increased from 3.7 +/- 1.6 to 5.0 +/- 2.2 mL.100 mL-1.min-1 with an intravenous epinephrine infusion (1.9 +/- 0.5 microgram/min). After epidural anesthesia calf blood flow increased to 6.3 +/- 3.3 mL.100 mL-1.min-1 with epinephrine infusion (2.7 +/- 1.0 micrograms/min) but was reduced to 2.6 +/- 1.5 mL.100 mL-1.min-1 when norepinephrine (0.8 +/- 0.7 microgram/min) was infused. Calf vascular resistance decreased from 27.7 +/- 13.5 to 7.9 +/- 4.6 mmHg.mL-1.100 mL-1.min-1 after epidural anesthesia with epinephrine (2.7 +/- 1.0 micrograms/min) but was unchanged when norepinephrine (0.8 +/- 0.7 microgram/min) was infused. The augmentation of lower extremity blood flow when epinephrine is used in conjunction with epidural anesthesia may in part explain the low frequency of deep vein thrombosis with conduction anesthesia.

Relation between job strain, alcohol, and ambulatory blood pressure.

"Job strain" (defined as high psychological demands and low decision latitude on the job) has been previously reported to be associated with increased risk of hypertension and increased left ventricular mass index (LVMI) in a case-control study of healthy employed men, aged 30-60 years, without evidence of coronary heart disease. We hypothesized that job strain would be associated with increased ambulatory blood pressure (AmBP). A total of 264 men at eight work sites wore an AmBP monitor for 24 hours on a working day. In an analysis of covariance model, job strain was associated with an increase in systolic AmBP of 6.8 mm Hg (p = 0.002) and diastolic AmBP of 2.8 mm Hg at work (p = 0.03) after adjusting for age, race, body mass index, Type A behavior, alcohol behavior, smoking, work site, 24-hour urine sodium, education, and physical demand level of the job. Alcohol use also had a significant effect on AmBP. However, among subjects not in high-strain jobs, alcohol had no apparent effect on AmBP at work. Instead, alcohol use and job strain interacted such that workers in high-strain jobs who drank regularly had significantly higher systolic AmBP at work (p = 0.007). Among the other risk factors, only age, body mass index, and smoking had significant effects on AmBP. Job strain also had significant effects on AmBP at home and during sleep as well as on LVMI.(ABSTRACT TRUNCATED AT 250 WORDS)

Cortisol inactivation overload: a mechanism of mineralocorticoid hypertension in the ectopic adrenocorticotropin syndrome.

The more severe mineralocorticoid manifestations in the ectopic ACTH syndrome compared to pituitary Cushing's disease have been attributed to hypersecretion of 11-deoxycorticosterone. Another difference between the two forms of ACTH-excess, however, is a more severe degree of hypercortisolism in the ectopic syndrome. Cortisol can become a potent mineralocorticoid if its peripheral metabolism is interfered with as occurs in the syndrome of apparent mineralocorticoid excess. This mechanism also occurs in an experimental model of the apparent mineralocorticoid excess syndrome induced by licorice derivatives. We have tested the hypothesis that cortisol is a major mineralocorticoid in the ectopic ACTH syndrome because of two factors, marked hypersecretion and incomplete peripheral metabolism of cortisol as a result of an overload of metabolizing enzymes. Two measures of the peripheral metabolism of cortisol were found to be markedly decreased in two patients with the ectopic ACTH syndrome. The cortisol turnover quotients were 17.2 and 19.6 (normal = 215 +/- 98) and the ring A reduction constants were 11.8 and 13.8 (normal = 101 +/- 23). These values were comparable to that found in the syndrome of apparent mineralocorticoid excess and consistent with the hypothesis that cortisol is a significant functioning mineralocorticoid in the ectopic ACTH syndrome.

Clinic and ambulatory blood pressure measurements for the evaluation of borderline hypertension in smokers and non-smokers.

Hypertension can be diagnosed only by blood pressure measurement, but conventional clinic measurement is subject to two major sources of error, first from the inherent variability of blood pressure, and second from the white coat effect, that is the increase of pressure that occurs in the presence of a physician. Ambulatory monitoring avoids both of these problems. Although smoking has been shown to raise blood pressure acutely, population studies have failed to show a sustained effect. To resolve this paradox, we compared clinic and ambulatory pressures in smokers and non-smokers. Clinic pressures were the same, but smokers had significantly higher daytime ambulatory pressures, than non-smokers, particularly in subjects over the age of 50. No differences in nighttime pressures were observed.

Elevation of ambulatory systolic blood pressure in hypertensive smokers. A case-control study.

Although smoking raises blood pressure, the office blood pressure measurements of smokers are the same as, or lower than, those of nonsmokers. To resolve this paradox, we compared the office and 24-hour ambulatory blood pressures of 59 untreated hypertensive smokers with 118 nonsmoking hypertensives matched for age, sex, and race. The office blood pressures of the smoking and nonsmoking groups were 141/93 and 142/93 mm Hg, respectively. The awake ambulatory systolic blood pressure was significantly higher in the smokers (145 vs 140 mm Hg). This difference was greater among patients over the age of 50 years (153 vs 142 mmHg), and absent among patients under 50 years (140 vs 139 mm Hg). Blood pressures during sleep did not differ between the two groups (121/76 vs 123/77 mm Hg). We conclude that, among white hypertensives above the age of 50 years, smokers maintain a higher daytime ambulatory systolic blood pressure than nonsmokers even though blood pressure measured in the office is similar.

Diagnosis and evaluation of renovascular hypertension. Indications for therapy.

Renovascular hypertension is caused by two distinct conditions with different causes, fibromuscular dysplasia and atheroma. Diagnosis of the former is both simpler and more rewarding, whereas atheromatous lesions of the renal artery may be secondary to essential hypertension. It is therefore important to establish existence of functional renal ischemia as well as an anatomical lesion. Universal screening of all hypertensive patients is not recommended because of the relatively low prevalence of the disease and insufficient accuracy of available screening tests. When renovascular hypertension is clinically suspected, an oral captopril test is the most reliable office screening test. After this, digital subtraction angiography with renal vein renins or captopril renography are appropriate steps. However, the latter procedure, while promising, requires further evaluation. Duplex scanning of the renal arteries also comes into this category. Arteriography is done last, so that if renal ischemia is indicated, angioplasty can be attempted at the same time as arteriography.