Circadian rhythmicity in the occurrence of spontaneous acute dissection and rupture of thoracic aorta.
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Aged↗
Biomedical subjects
F Portaluppi
Publications and source records attributed to F Portaluppi.
Ultrasonographic assessment of ambulatory venous pressure in superficial venous incompetence.
PURPOSE: In spite of its invasiveness, measurement of ambulatory venous pressure (AVP) is widely considered the gold standard measurement of venous function. We studied a technique for noninvasive ultrasonographic AVP determination in superficial venous incompetence. METHODS: A linear relationship between venous pressure (measured by echo-guided venous puncture) and diameter (measured by transverse axis duplex imaging) was preliminarily demonstrated with multiple measurements in different conditions (supine, sitting, standing, and Trendelenburg positions, after exercise with and without cuff occlusion) in a saphenous tract at the thigh of 82 limbs in which reflux had been previously demonstrated. Then AVP was measured in another group of 44 patients who had demonstrated superficial venous incompetence, both with and without proximal occlusion, using again the same invasive method and a new noninvasive technique. The latter technique consisted in the construction of a linear diameter/pressure curve obtained after saphenous diameter (by high-resolution sonography) and noninvasive pressure (using hydrostatic values) determinations in the sitting and standing positions. Further measurement of saphenous diameter after standardized exercise permits extrapolation of the AVP values from the curve. RESULTS: Linear regression analysis demonstrates that (1) beginning from 20 mm Hg, the pressure/diameter relationship of the incompetent greater saphenous vein is linear; and (2) AVP values derived invasively and noninvasively are significantly correlated (r = 0.7347 and p < 0.0001 for AVP derived without occlusion; r = 0.7270 and p < 0.0001 for values recorded with occlusion). CONCLUSIONS: The proposed technique appears able to reliably assess noninvasively AVP values in superficial venous incompetence. In addition, it can be performed with equipment that is widely used for vascular investigations.
Exercise↗
Undiagnosed sleep-disordered breathing among male nondippers with essential hypertension.
OBJECTIVE: A blunting of the nocturnal fall in arterial blood pressure is found in a minority of patients (nondippers) with essential hypertension. We tested whether sleep-disordered breathing (snoring and apnea or hypopnea) might explain such a finding for male patients, among whom its prevalence is much higher. SETTING AND PATIENTS: We studied 100 new cases of hypertension in men, observed consecutively by a local group of general practitioners and diagnosed essential hypertensives in a referral clinic. By using 24 h ambulatory blood pressure monitoring with a SpaceLabs 90207 device, 15 patients were classified initially nondippers (daytime ambulatory blood pressure > or = 136/87 mmHg; night-time decrease by < 10% of the daytime mean), but only 11 were confirmed to be nondippers by continuous blood pressure monitoring with a Finapres device. Ten dippers matched by age, body mass index and mean 24 h blood pressure were used as controls. MAIN OUTCOME MEASURES: Parameters of nocturnal polysomnography. RESULTS: During polysomnography, the nondippers exhibited a blunting of the sleep-related fall in blood pressure and an increased variability in blood pressure associated with sleep-disordered breathing (heavy snoring for all, with an apnea or hypopnea index > 10 in 10 cases). Six of the control patients breathed normally and four snored nonapneically. There was a normal fall in nocturnal blood pressure in all 10 cases. CONCLUSIONS: The nondipper condition appears to be associated with undiagnosed apneic snoring for an unselected population of previously untreated male subjects with a diagnosis of essential hypertension. Ambulatory blood pressure monitoring of such patients is of limited diagnostic value.
Adult↗
Relative influence of menopausal status, age, and body mass index on blood pressure.
The objective of this study was to assess the influence of menopausal status on blood pressure levels in a cross-sectional population study in the setting of a preventive health care program clinically conducted in Ferrara, Italy. The patients were 2397 healthy women 35 to 65 years old (489 in premenopause, 847 in perimenopause, 887 in spontaneous menopause, and 174 in surgical menopause); subgroups were also obtained with increasing duration of menopause (1 to > 5 years) matched with premenopausal and perimenopausal women by chronological age at onset of menopause. Measurements of sphygmomanometric blood pressure, age, age at menopause, duration of menopause, and body mass index were made. Postmenopausal women had higher blood pressure than premenopausal and perimenopausal subjects. After adjustment for body mass index, the blood pressure changes with menopausal status were still significant, but not after correction by age. The increased risk of hypertension of postmenopausal women also lost statistical significance after adjustment for age and body mass index. At multivariate analysis, blood pressure showed no significant relation with the duration of menopause, whereas age was a significant covariant for systolic blood pressure, and body mass index for systolic and diastolic blood pressure. A transient initial rise in blood pressure and body mass index was detected in surgical but not in spontaneous menopause. Blood pressure rises after menopause appear to be due more to increased body mass index and aging than ovarian failure per se.
Adult↗
Seasonal variations in the rupture of abdominal aortic aneurysms.
From 1982 to 1994, 54 patients (47 men; mean age 72 years) were referred to the Hospital of Ferrara, Italy for spontaneous rupture of abdominal aortic aneurysm. Sixteen died in the emergency department and 38 underwent urgent surgery. Day and month of onset of acute symptoms leading to urgent surgery were recorded. A seasonal variation with significant peaks in spring and autumn was found. These findings are likely influenced by local environmental, social and epidemiological factors, but may be relevant for the appropriate timing of the follow-up and therapeutic strategies for abdominal aortic aneurysms.
Aged↗
Alterations of sleep and circadian blood pressure profile.
The organization of sleep activity in stages of different depth is reflected by consistent changes in blood pressure that account for the major part of the day-night blood pressure difference. On the other hand, different mechanisms may underlie dysregulation of nocturnal blood pressure. Cyclic variations in autonomic nervous system activity play an important role in the mediation of the influences of sleep and wakefulness on blood pressure. In addition, several physiologic substances that are knoiwn to induce sleep or arousal are knoiwn to exert actions on blood pressure. Hence, derangements in autonomic nervous system activity, either primitive or secondary to alterations in the circadian rhythm of a variety of neurohumoral factors, are reflected in changes of the circadian blood pressure profile. Important additional influences of sleep on blood pressure may be exerted through respiratory variations, so that sleep-disordered breathing is bound to alter nocturnal blood pressure. Finally, insomnia has to be taken into account as a major cause of sleep-related alteration of the circadian blood pressure profile. The number of medical disorders that can cause insomnia is huge, and includes many if not all of the conditions in which a loss or reversal of the physiologic blood pressure fall at night is found to be prevalent. Unfortunately, objective sleep studies have been performed only in studies of a minority of these disorders, and further studies to assess the pathophysiologic mechanisms actually involved in causing sleep disturbances in each pathologic condition are necessary.
Journal Article↗
The time factor in the treatment of hypertension.
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Antihypertensive Agents↗
The rhythms of blood pressure in humans. Exogenous and endogenous components and implications for diagnosis and treatment.
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Biological Clocks↗
Endocrine mechanisms of blood pressure rhythms.
The temporal organization of blood pressure is mainly controlled by neuroendocrine mechanisms. The monoaminergic systems appear to integrate the major driving factors of temporal variability, but evidence also indicates a role of the hypothalamic-pituitary-adrenal, hypothalamic-pituitary-thyroid, opioid, renin-angiotensin-aldosterone, and endothelial systems as well as other vasoactive peptides. Although their hormonal secretions are typically episodic, the probability of secretory episodes is "gated" by mechanisms that are coupled either to sleep or to an endogenous pacemaker which usually is predominantly (though not only) circadian. Many hormones with established actions on the cardiovascular system (arginine vasopressin, vasoactive intestinal peptide, melatonin, somatotropin, insulin, steroids, serotonin, CRF, ACTH, TRH, endogenous opioids, and prostaglandin E2) are also involved in sleep induction or arousal. Hence, physical, mental, and pathologic stimuli, which may drive activation or inhibition of these neuroendocrine effectors of biologic rhythmicity, may also interfere with the temporal blood pressure structure. On the other hand, the immediate adaptation of the exogenous components of blood pressure rhythms to the demands of the environment are modulated by the circadian-time-dependent responsiveness of the biologic oscillators and their neuroendocrine effectors. These notions may contribute to a better understanding of the pathophysiology and therapeutics of changes in blood pressure.
Animals↗
Relationships of the circadian rhythms of thrombotic, ischemic, hemorrhagic, and arrhythmic events to blood pressure rhythms.
Convincing evidence has recently accumulated that several unfavorable cardiovascular events show a well defined pattern in their occurrence throughout the day. Myocardial angina and infarction, sudden cardiac death, arrhythmias, fatal pulmonary thromboembolism, and ischemic and hemorrhagic cerebrovascular accidents occur more frequently in the morning, after awaking, until noon. Diurnal variations in multiple biologic functions, such as assumption of an upright posture associated with increased platelet aggregability, changes in blood clotting, fibrinolysis, and vascular tone and resistance, may be potentially active triggering factors. Moreover, variations in sympathetic tone, catecholamine secretion, and blood pressure have to be considered. The role of triggering factors and their relationships with blood pressure patterns is discussed in view of an optimized pharmacologic treatment.
Animals↗
Ambulatory blood pressure monitoring. Application to clinical medicine and antihypertension medication trials.
The wide use of ABPM has resulted in greater appreciation of the circadian time structure of BP variability and its clinical relevance. It is now recognized that the day-night change in BP results from an interplay of circadian rhythms in neurohumoral mechanisms coupled with temporal patterns in physical activity and mental load. The composite effect and balance of these endogenous and exogenous cyclic phenomena give rise to elevated BP during diurnal activity and reduced BP during nighttime repose in both normotension and uncomplicated essential hypertension. The balance is frequently disturbed in complicated and secondary forms of hypertension causing gross alteration of the 24-hour BP profile. ABPM also reveals the efficiency of antihypertensive treatment throughout the 24 hours and as a function of drug administration time. The pharmacokinetics and/or pharmacodynamics of antihypertensive medications have been demonstrated to vary with ingestion time. Such time-dependencies arise from circadian rhythms in BP and underlying mechanisms. The effect of antihypertensive medications is not simply superimposed upon endogenous bioperiodicities. Rhythms in neurohumoral mechanisms of BP control may modulate treatment effect. Certain aspects of the shape of the 24-hour BP profile, such as the magnitude of the morning surge and nocturnal decrease, have been implicated as determinants of morbid and mortal cardiovascular events. One large clinical multicenter investigation, known as the CONVINCE (Controlled Onset Verapamil Investigation of Clinical Endpoints) trial, is aimed at assessing the impact (cardiovascular morbidity and mortality) of verapamil chronotherapy over standard diuretic or beta anatagonist treatment in hypertensive patients with at least one risk factor of coronary heart disease. ABPM will help ascertain to what extent depression of the morning surge in BP relates to reduction in cardiac morbidity and mortality in this as well as other such trials. In any event, the importance of ABPM and the indices derived from its application are just beginning to be appreciated and explored.
Antihypertensive Agents↗
Out-of-hospital sudden death referring to an emergency department.
Over an 11-year period, autopsies were performed on 957 of 1038 nontraumatic deaths in the Emergency Department of the Central Hospital in Ferrara, Italy. Of these 957 cases, 732 (76.5%) met criteria for sudden death. In 100 (14%) of these cases, the death could be attributed to pulmonary embolism (55 cases), stroke (17), or rupture of aortic aneurysm (28). Acute myocardial infarction accounted for 403 (55%) of all sudden deaths. Severe coronary artery disease was found in 340 (84%) of these 403 deaths, with plaque fissuring or thrombi in 189 or 151 cases, respectively. Among the 229 sudden deaths for whom no immediate cause could be determined (31% of the total population), all had evidence of heart disease: 147 individuals had severe coronary artery disease, with plaque fissuring or thrombi found in 72 or 43, respectively. The remaining cases with no immediate cause of death had evidence of a cardiomyopathy (61) or valvular disease (21). We conclude that acute myocardial infarction accounts for the majority of cases of nontraumatic sudden death in our Emergency Department. Altogether, 84% of these patients had severe coronary artery disease. In approximately one-third of cases for whom no immediate cause of sudden death could be determined, all had evidence of heart disease, and about two-thirds had severe coronary artery disease.
Cause of Death↗
Circadian and circannual rhythmicity in the occurrence of subarachnoid hemorrhage.
BACKGROUND AND PURPOSE: Inconsistent data are available on the temporal pattern of onset of subarachnoid hemorrhage (SAH). We investigated the possible influence of vascular risk factors. METHODS: Of a consecutive series of 217 cases of SAH, precise determination (within 30 minutes) of the time of symptom onset was possible in 199 (91.7%). Partial Fourier series with up to six harmonics were applied to hourly and monthly data, and the best-fitting curves for circadian and annual rhythmicity were calculated. The amplitude-MESOR (rhythm-adjusted mean over the time period analyzed) ratio was used as a measure of temporal variability. RESULTS: In the total population, a significant circadian pattern of occurrence was demonstrated with major peaks in the morning (approximately 9 AM) and evening (approximately 9 PM) hours and a nocturnal trough (approximately 3 AM). Younger, male, and hypertensive subjects had lower amplitude-MESOR ratios; smokers had no significant rhythmicity. The annual pattern showed a 6-month periodicity with two major peaks in March and September and minor differences in the subgroups studied. CONCLUSIONS: Our study indicates that the temporal distribution in onset of SAH may be influenced by variable combinations of environmental and vascular risk factors.
Age Factors↗
Chronobiologic aspects of ischemic coronary artery disease.
Convincing evidence is now available suggesting that several unfavorable cardiovascular events respect a well-defined diurnal pattern in their occurrence. In particular, ischemic heart disease has been widely investigated, and many data indicate a constellation of underlying risk factors whose temporal coincidence might act as triggering factors in the occurrence of acute events. In this paper, the recent knowledge concerning both epidemiology of ischemic heart disease and potentially favoring factors are reviewed from a chronobiological point of view.
Angina Pectoris↗
Non-invasive blood pressure monitoring in man.
Non-invasive, ambulatory, blood pressure monitoring is now widely used for research and clinical purpose. Its main advantages over the traditional sphygmomanometric method pertain to its ability in providing measures of centrality, but also variability, 24-h profile, and excess over selected limits (load) of BP in the individual subject. Placebo and "white-coat" effects are much less evident when this monitoring technique is used. However, standardization of the procedures, choice of methods of data analysis, definition of normalcy, and particularly prognostic value are still a matter of discussion. Hence, blood pressure monitoring cannot be used as a routine diagnostic technique, except in selected clinical situation of proven advantage over the traditional sphygmomanometric method.
Blood Pressure Determination↗
The relationship between in vitro and in vivo venous compliance measurement.
OBJECTIVE: To assess the relationship between in vitro and in vivo venous compliance measurement. DESIGN: Prospective, blind study. MATERIALS AND METHODS: Patients affected by primary varicose veins and classified in accord with the new CEAP criteria (C2-6/S, Ep, AS1-4/p17-18, PR) underwent blind venous compliance measurements using two different methods. 1) In vivo assessment of the compliance of the greater saphenous vein by duplex scanning, for diameter, and a needle transducer, for venous pressure measurements. 2) In vitro standard compliance assessment of the same vein segment after its excision. RESULTS: The compliance values obtained with the two methods showed a significant degree of correlation, which improved with increasing intravenous pressures. CONCLUSIONS: In vivo compliance assessment of the saphenous vein was validated by the relationship with the standard in vitro measurement.
Elasticity↗
Chronobiological aspects of pulmonary thromboembolism.
A growing body of evidence has recently accumulated suggesting that several unfavorable cardiovascular events, e.g., myocardial angina and infarction, sudden cardiac death, and stroke, present a specific temporal pattern in their occurrence. This has also been shown to be true for fatal pulmonary thromboembolism, with a high frequence peak in winter and in the morning hours. The authors report the circannual and circadian aspects of pulmonary thromboembolism, analysing both the temporal patterns of the underlying favouring or precipitating factors, and the possible therapeutic implications.
Anticoagulants↗
Time-dependent effect of isradipine on the nocturnal hypertension in chronic renal failure.
Nocturnal hypertension is frequently observed in chronic renal failure and contributes to the risk of target organ damages. We assessed whether antihypertensive therapy may restore a nocturnal blood pressure (BP) fall in this condition. A sustained-release oral formulation (SRO) of isradipine was used, and the possible differences in the response to morning nu evening dosing were also investigated. Sixteen hypertensive patients with chronic renal failure due to parenchymal kidney disease were studied after 2 weeks of single-blind placebo runin. According to the double-blind, randomized, cross-over design, they received 5 mg isradipine SRO at 08:00, or at 20:00 for 4 weeks, separated by a single-blind placebo period of 2 weeks. A 24-h BP monitoring at 10-min intervals was carried out at the end of each treatment using a SpaceLabs 90207 instrument. Under placebo, blunt BP profiles were observed, whereas HR showed a mean nocturnal fall of 17.4%, which remained unaltered after isradipine. Both isradipine treatments were equally effective in reducing the mean 24-h BP levels. However, the evening regimen showed a more pronounced effect during the night. The mean nocturnal fall in systolic/diastolic BP represented 4.8/8.7% and 7.5/10.9% of the corresponding daytime mean after morning and evening dosing, respectively. Only the evening administration reset the normal synchronization of the 24-h BP and HR profiles. Our findings demonstrate that antihypertensive treatment may restore a nocturnal BP fall in renal patients. An evening regimen of isradipine SRO seems more apt than a morning regimen to obtain this therapeutic goal.
Antihypertensive Agents↗