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Biomedical subjects

G Piccirillo

Publications and source records attributed to G Piccirillo.

At least 19 recordsLinked to original sources
PubMed2005

The head-up tilt test and the differential diagnosis between epileptic attacks and syncope. Case report.

Often patients who have undergone a false diagnosis of epileptic attack have actually been affected by syncope. One of the most common causes of such misdiagnosis is an abnormal interictal electroencephalographic (EEG) trace. The purpose of this paper is to suggest the usefulness of the head-up tilt test as a differential diagnosis between epileptic attack and syncope. Patients underwent the head-up tilt test, which was considered positive only if the syncopal symptomatology was reproduced. The subjects were patients in a neuropsychiatric clinic. Four patients with a positive anamnesis due to brief episodes of unconsciousness and to falls were assessed. All 4 patients showed an abnormal EEG with focal spikes and sharp-waves. The head-up tilt test produced a syncope in all 4 cases. In the symptomatology evoked by the test the patients and their parents recognized the exact same characteristics of those episodes for which they had sought consultation, so a diagnosis of a vasovagal syncope of 3 different types was made. The head-up tilt test proved appropriate to differentiate syncope from epileptic attacks in patients with symptoms of unconsciousness, falls and interictal EEG spikes or sharp-waves.

Adolescent↗
PubMed2004

Blood pressure variability and cognitive function in older hypertensives.

Several studies have shown that cerebrovascular organ damage can related not only to average blood pressure (BP) levels, but also to BP variability. The aim of this study was to investigate the relationship between 24 hr BP variability and cognitive function in older hypertensives. Forty older, never treated hypertensives were submitted to 24 hr ambulatory BP monitoring (ABPM) and subdivided, according to the variability of the systolic BP (SBP), in two groups: 23 with higher (> PV) and 17 with lower (< PV) SBP variability, defined as the standard deviation (SD) of the mean 24 hr SBP values and as coefficient of variation (CV). They underwent a cognitive assessment by mini mental state examination (MMSE) and a recording of the brain event-related potentials (ERPs). ERPs record neuronal electric activity when the patients are submitted to frequent and rare acoustic stimuli and must recognize and count rare (target) stimuli. The two groups with statistically different 24 hr SBP variability, did not show significant differences in MMSE scores or in N2 and P300 ERP latencies, thus indicating a lack of difference in the cognitive ability between the two groups. Our results show that cognitive function is not related to 24 hr SBP variability in older hypertensives.

Aged↗
PubMed2003

Circadian blood pressure pattern and cognitive function in newly diagnosed older hypertensives.

Hypertensive subjects can be subdivided in two groups, dippers and non-dippers, according to the presence or the lack of a nocturnal fall of blood pressure (BP) of over 10%. Several studies have investigated cardiovascular and cerebrovascular organ damage in the two groups with discordant results, but fewer of them analysed the relationship between circadian BP pattern and cognitive function, and none in the early phases of hypertension. To this purpose, we selected 40 older hypertensives, 23 dippers and 17 non-dippers, with newly diagnosed hypertension, never treated, who underwent to 24-h ambulatory BP monitoring (ABPM), Mini-Mental State Examination (MMSE) and recording of event-related potentials (ERPs). No significant differences between dippers and non-dippers were found in the MMSE scores and P300 latency values, as we expected, and not even in N2 wave latency values, showing that the non-dipping pattern is not associated with lower cognitive function in the early phases of hypertension.

Aged↗
PubMed2001

Neural network analysis in predicting 2-year survival in elderly people: a new statistical-mathematical approach.

We designed this study to test the usefulness of artificial neural networks (ANN) in assessing 2-year survival in elderly persons, and to understand the net's logical functioning, thus determining the relative importance of the single biological and clinical variables which influence survival. ANN are statistical-mathematical tools able to determine the existence of a correlation between series of data and, once 'trained', to predict output data given input data. Although ANN have been applied in various areas of medical research, they have only very recently been applied in geriatrics (Cacciafesta et al., 2000. Arch. Gerontol. Geriatr. 31 (in press)). We built up an ANN to investigate how 17 clinical variables relating to a sample of 159 elderly people affect survival, and the possibility of predicting 2-year survival or non-survival for each single subject. When tested on a sample of 20 elderly people, the trained network gave the correct answer in 85% of the cases. We then extracted the mathematical function that the net used for calculating the output (survival) for each set of input data (clinical variables). Using this formula, we investigated how some clinical variables influence 2-year survival: we found that a low serum cholesterol level is an unfavourable characteristic in relation to survival. We conclude-despite the fact that the sample studied was relatively small-that ANN are useful in predicting 2-year survival in elderly people. The mathematical function we obtained from the net seems useful in determining the relative importance of single variables related to survival.

Journal Article↗
PubMed2001

Influence of aging and other cardiovascular risk factors on baroreflex sensitivity.

OBJECTIVES: To examine the influence of known cardiovascular risk factors (cholesterol, blood glucose levels, arterial pressures, heart rate, and aging) on baroreflex sensitivity. DESIGN: An observational epidemiological study. SETTING: Geriatric Division at the Policlinico Umberto Primo, University of Rome La Sapienza. PARTICIPANTS: Two hundred three subjects whose ages ranged from 9 to 94 years, apparently healthy and free of detectable clinical evidence of atherosclerosis. MEASUREMENTS: All subjects underwent determination of baroreflex sensitivity by phenylephrine infusion (BSphe), and by a noninvasive method derived from spectral analysis of R-R interval and arterial pressure variabilities (alpha index). RESULTS: The population, subdivided into tertiles for each variable studied, had lower BSphe values and lower alpha indexes as a function of age, plasma low-density lipoprotein (LDL) cholesterol, and systolic blood pressure. The alpha index was significantly lower in both groups with elevated LDL cholesterol levels than in those with lower levels (II and III vs I tertile, P <.001), whereas BSphe differed significantly only in the two groups who had extreme levels of LDL (I vs III tertile, P <.001). Multiple regression analysis identified a negative association of the alpha index with age (P <.001), heart rate (P <.01), area under the glucose-response curve (P <.001), and LDL cholesterol (P <.01), but of BSphe only with age (P <.001) and heart rate (P <.01). CONCLUSION: These findings indicate that some risk factors for coronary heart disease adversely influence baroreflex sensitivity.

Adolescent↗
PubMed2001

Influence of aging on cardiac baroreflex sensitivity determined non-invasively by power spectral analysis.

Aging reduces cardiac baroreflex sensitivity. Our primary aim in the present study was to assess the effects of aging on cardiac baroreflex sensitivity, as determined by power spectral analysis (alpha index), in a large population of healthy subjects. We also compared the alpha indexes determined by power spectral analysis with cardiac baroreflex sensitivity measured by the phenylephrine method (BS(phen)). We studied 142 subjects (79 males/63 females; age range 9-94 years), who were subdivided into five groups according to percentiles of age (25, 50, 75 and 95). Power spectral analysis yields three alpha indexes: an alpha low-frequency (LF) index of cardiac baroreflex sensitivity that ranges around 0.1 Hz; an alpha high-frequency (HF) index reflecting cardiac baroreflex sensitivity corresponding to the respiratory rate; and alpha total frequency (alpha TF), a new index whose spectral window includes all power in the range 0.03-0.42 Hz. Spectra were recorded during controlled and uncontrolled respiration. Under both conditions, all three alpha indexes were higher in the youngest age group (< or =34 years old) than in the three oldest groups. Notably, alpha TF was significantly higher in younger subjects than in the three oldest groups [14+/-1 ms/mmHg compared with 9+/-1 (P<0.05), 8.1+/-1 (P<0.001) and 8.1+/-1 (P<0.05) ms/mmHg respectively]. BS(phen) showed a similar pattern [12+/-1 ms/mmHg compared with 8+/-0.5 (P<0.001), 6+/-0.5 (P<0.05) and 6+/-1 (P<0.05) ms/mmHg respectively]. No significant differences were found for cardiac baroreflex sensitivity among the three oldest groups. All alpha indexes were correlated inversely with age. The index yielding the closest correlation with BS(phen) was alpha TF (r=0.81, P<0.001). Cardiac baroreflex sensitivity in normotensive individuals declines with age. It falls predominantly in middle age (from approx. 48 years onwards) and remains substantially unchanged thereafter. The elderly subjects we selected for this study probably had greater resistance to cardiovascular disease that is manifested clinically, with preserved cardiac baroreceptor sensitivity.

Adolescent↗
PubMed2001

Influence of age, the autonomic nervous system and anxiety on QT-interval variability.

As QT variability increases and heart rate variability diminishes, the QT variability index (QTVI) - a non-invasive measure of beat-to-beat fluctuations in QT interval on a single ECG lead - shows a trend towards positive values. Increased QT variability is a risk factor for sudden death. Aging lengthens the QT interval and reduces RR-interval variability. In the present study we investigated the influence of aging and the autonomic nervous system on QT-interval variability in healthy subjects. We studied 143 healthy subjects, and divided them into two age ranges (younger and older than 65 years). For each subject we measured two QTVIs: from the q wave to the end of the T wave (QTeVI) and to the apex of the T wave (QTaVI). Both indexes were calculated at baseline and after sympathetic stress. In 10 non-elderly subjects, both QTVIs were determined after beta-adrenoreceptor blockade induced by intravenous infusion of propranolol or sotalol. The QTVI was higher in elderly than in younger subjects (P<0.001). QTVIs obtained during sympathetic stress remained unchanged in the elderly, but became more negative in the younger group (P<0.05). QTeVI and QTaVI at baseline were correlated positively with age (P<0.01) and anxiety scores (P<0.05), but inversely with the low-frequency spectral power of RR-interval variability (P<0.001). QTVIs were higher in subjects with higher anxiety scores. In younger subjects, sotalol infusion increased both QTVIs significantly, whereas propranolol infusion did not. In conclusion, aging increases QT-interval variability. Whether this change is associated with an increased risk of sudden death remains unclear. The association of abnormal QT-interval variability with anxiety and with reduced low-frequency spectral power of heart rate variability merits specific investigation. In healthy non-elderly subjects, acute sympathetic stress (tilt) decreases the QTVI. beta-Adrenoreceptor blockade inhibits this negative trend, thus showing its sympathetic origin. Because a negative trend in QTVI induced by sympathetic stress increases only in younger subjects, it could represent a protective mechanism that is lost with aging.

Adrenergic beta-Antagonists↗
PubMed2000

A neural network study of the correlation between metabolic-cardiovascular diseases and disability in elderly people.

Numerous studies have affirmed the existence of a correlation between various cardiovascular diseases and functional decline in elderly people. Not much information, however, is available concerning the overall effect of various, possibly coexisting, cardiovascular pathologies, or metabolic conditions notoriously related to them, on determining disability. We wanted to verify if it were possible to assess: (1) The overall importance of various metabolic and cardiovascular diseases which elderly people often suffer from contemporaneously in determining a condition of not self-sufficiency; (2) The possibility of predicting a condition of not self-sufficiency in relation to the above-mentioned pathologies. In order to achieve this aim, we used an artificial neural network: a statistical-mathematical tool able to determine the existence of a correlation between series of data and, once 'trained', to predict output data given the input data. Although artificial neural networks have been applied in various areas of medical research, they have not been previously applied in geriatrics. We have applied this method to a sample of 179 elderly people, demonstrating that seven clinical-biological variables concerning their metabolic and cardiovascular conditions are strictly related, all together, to the presence or otherwise of a functional impairment. When tested on a sample of 20 'unknown' elderly people, the trained network gave the correct answer-self-sufficiency or not self-sufficiency-in 95% of the cases. Despite the fact that the sample studied was relatively small, artificial neural networks are undoubtedly useful in predicting functional impairment in elderly people in relation to the presence of metabolic and cardiovascular diseases.

Journal Article↗
PubMed2000

Autonomic modulation of heart rate and blood pressure in normotensive offspring of hypertensive subjects.

Predominant sympathetic cardiovascular modulation in the hyperkinetic phase of arterial hypertension has been well described. Less information is available on autonomic control in persons with a family history of arterial hypertension. To investigate this question, we selected 61 normotensive subjects (mean age 30.9 +/- 1.8 years) whose mother or father or both had arterial hypertension and 30 normotensive patients (mean age 30.1 +/- 1.4 years) whose parents had not had arterial hypertension (neither mother nor father) to undergo short-term power spectral analysis of RR interval and arterial pressure variabilities. The same recordings were used to determine baroreflex sensitivity or the alpha index by means of the transfer function. Normotensive offspring of hypertensive subjects had higher diastolic blood pressures (P < .05) and left ventricular mass index (P < .05) than did normotensive offspring of non-hypertensive subjects. They also had higher spectral densities of low frequency expressed in normalized units, both for R-R intervals (P < .05) and systolic pressure variabilities (P < .05); they also had a greater ratio of low-frequency to high-frequency powers of R-R interval variability (P < .05). No difference was observed between the two normotensive groups for baroreflex sensitivity. Our spectral data indicate that normotensive persons with a positive family history of arterial hypertension have lower parasympathetic modulation than those with a negative history. In normotensive persons with a family history of arterial hypertension, normal baroreflex sensitivity could be the mechanism that buffers the tendency for pressures to increase. The gradual loss of this regulatory mechanism may favor rising arterial pressures.

Adult↗
PubMed2000

Baroreflex failure syndrome after bilateral excision of carotid body tumors: an underestimated problem.

Carotid body tumors (CBTs) are relatively rare paragangliomas that develop from neural crest cells at the bifurcation of the common carotid artery. They are generally slow growing and benign. Excision is currently considered the treatment of choice, although vascular and especially neural injuries are still relatively frequent in patients with large or bilaterally resected tumors. The baroreflex failure syndrome (BFS) has recently been identified as a severe, rarely recognized, and certainly underestimated complication after the bilateral excision of CBTs. The present report describes a case of a bilateral CBT followed by BFS and reviews the experiences reported in the literature. In light of the low incidence of malignancy of these tumors, their biologic behavior, their very high rate of cranial nerve palsy, and the occurrence of BFS in bilaterally resected paragangliomas, the current practice of bilaterally removing these tumors is questioned.

Baroreflex↗
PubMed1999

QT interval dispersion and autonomic modulation in subjects with anxiety.

This study was designed to assess Q-T interval dispersion as a marker of electrical instability in subjects with anxiety. Recent observations have shown that the presence of anxiety symptoms increases the risk of sudden death. The Kawachi anxiety questionnaire identified 29 subjects (male/female ratio 13:16) who scored 0, 22 subjects (male/female ratio 14:8) who scored 1, and 37 subjects (male/female ratio 13:24) who scored 2 or more. In all subjects we measured electrocardiographic interlead QT dispersion and autonomic function through spectral analysis of R-R interval and blood pressure variabilities and left ventricular mass. Compared with subjects who scored 0, those reporting 2 or more symptoms showed increased heart rate-corrected QT dispersion (54.9+/-1.7 ms vs. 34.9+/-3.2 ms, P<.001), sympathetic modulation (normal logarithm low-frequency power/high-frequency power 0.59+/-0.1 vs. 0.12+/-0.04, P<.05), and left ventricular mass (120.7+/-3.5 g/m2 vs. 97.9+/-2.8 g/m2, P<.001). Probably because it augments sympathetic activity, anxiety causes left ventricular mass to increase and, like hypertension, increases heart rate-corrected Q-T interval dispersion. The consequent electrical instability could be the substrate responsible for inducing fatal ventricular arrhythmias.

Anxiety↗
PubMed1999

Autonomic modulation and QT interval dispersion in hypertensive subjects with anxiety.

Anxiety is associated with an increased risk of sudden death. QT dispersion is a marker of cardiac repolarization instability and is seen in conditions of high risk of sudden death. The purpose of this study was to evaluate autonomic nervous system control and QT dispersion in hypertensive subjects with anxiety symptoms. In a recent preliminary study, we observed that hypertensive individuals reporting high scores on a self-assessment anxiety scale had more marked left ventricular hypertrophy. In 105 hypertensive subjects divided into 3 groups according to severity of anxiety, we evaluated autonomic control by short-term power spectral analysis of RR and arterial pressure variability at rest (baseline) and during sympathetic stress (tilt test), left ventricular mass index, and heart rate-corrected QT (QTc) dispersion. At baseline, hypertensive subjects with higher anxiety symptom scores had significantly lower high-frequency RR values expressed in absolute terms (P<0.05) and in normalized units (P<0.05) than their counterparts without anxiety symptoms. Hypertensive subjects with anxiety also had a higher mean left ventricular mass index (P<0.001) and greater QTc dispersion (P<0.001). Both indexes and high frequency (P<0.05) correlated with severity of anxiety. These findings suggest that anxiety is associated with autonomic imbalance. This condition could favor an increase in left ventricular mass. Myocardial hypertrophy alone or combined with neuroautonomic imbalance may lead to QT dispersion.

Adult↗
PubMed1998

Power spectral analysis of heart rate in subjects over a hundred years old.

Altered autonomic regulation of cardiac function may contribute to the onset of cardiovascular disease and provide a substrate for malignant ventricular arrhythmias. This study was designed to assess cardiovascular neuroautonomic status in healthy subjects with short-term power spectral analysis of heart rate variability, including a group over 100 years of age, to identify a neuroautonomic pattern that could help to protect ultra-centenarians against cardiovascular disease. One hundred and twelve subjects (22 men and 90 women, age range 20 to 107 years) were subdivided into five age groups: <40 years (N=26, mean age 30.6+/-0.9); 41 to 60 years (N=27, mean age 51.9+/-1.2); 61 to 80 years (N=37, mean age 70.3+/-1.1); 81 to 100 (N=10, mean age 85.2+/-0.8) and older than 101 years (N=13, mean age: 103.6+/-0.6). Power spectral analysis with autoregressive algorithm provides two indexes of autonomic activity: a low-frequency component oscillating around 0.10 Hz, mainly reflecting sympathetic activity and a high-frequency component around 0.30 Hz, reflecting parasympathetic activity. Subjects 40 years of age or younger had significantly higher spectral high-frequency power values expressed in logarithmic form than the other age groups (P<0.05), the age group from 41 to 100 years had values similar to those of the other groups. However, the age group over 101 years had significantly higher values than the group from 81 to 100 years (P<0.05). Low-frequency spectral density expressed in logarithmic form and in normalized units decreased with age (P<0.0001). These data confirm an age-related decline in sympathetic activity. Compared with elderly subjects from 81 to 100 years of age ultra-centenarians have significantly higher spectral parasympathetic indexes. Parasympathetic predominance may be the neuroautonomic feature that helps to protect ultra-centenarians against cardiovascular disease.

Adult↗
PubMed1998

Aspirin pretreatment potentiates hyperthermia-induced teratogenesis in the mouse.

OBJECTIVE: Our purpose was to investigate the effect of aspirin pretreatment on hyperthermia-induced teratogenesis. The rationale for the study was based on the growing evidence that prostaglandin pathway may be involved in the cellular response to the thermic injury. STUDY DESIGN: On gestation day 8.5 Swiss mice were treated with 0 or 200 mg/kg of aspirin and 1 hour later exposed to a single 10-minute thermostatic bath treatment at 38 degrees C, 41 degrees C, 42 degrees C, or 43 degrees C. On gestation day 18 uterine contents were evaluated for developmental disorders, including prenatal mortality, intrauterine growth restriction, and external, visceral, and skeletal abnormalities. RESULTS: Consistent with expectations, hyperthermia impaired morphogenesis in a dose-related manner. Although aspirin alone did not reveal embryotoxicity, its administration potentiated hyperthermia-induced teratogenesis. A statistically significant interaction (p < 0.05) was observed at 42 degrees C, where the incidence of fetuses per litter with axial skeletal malformations increased from 20.3% to 55.7%. CONCLUSION: A nonteratogenic dose of aspirin enhanced the teratogenic response to hyperthermia. This result fits the hypothesis that prostaglandins may play a protective role in hyperthermia-induced teratogenesis.

Animals↗
PubMed1998

Heart rate and blood pressure variability in obese normotensive subjects.

OBJECTIVE: To assess autonomic modulation of cardiovascular activity in massively obese subjects. DESIGN: Cross-sectional clinical study. SUBJECTS: 43 age-matched normotensive subjects: 15 moderately obese (body mass index (BMI) < 40); 14 massively obese (BMI > 40) and 14 nonobese controls (BMI < 26). MEASUREMENTS: Using power spectral analysis, heart rate and arterial pressure variability were determined at rest and after sympathetic stress (tilt). Two spectral components were analysed: a low-frequency (LF) component at around 0.1 Hz, predominantly reflecting sympathetic modulation and a high-frequency (HF) component at around 0.26 Hz, reflecting parasympathetic modulation. RESULTS: Spectral data for heart rate showed that the massively obese subjects had lower LF [mean +/- s.e.m.] normalized units (NUs) at rest (35.1 +/- 0.9) and after tilt (56.1 +/- 2.1), than the moderately obese subjects (LF NUs at rest 53.9 +/- 4.2, P < 0.001; LF NUs tilt: 66.8 +/- 5.6, P < 0.001) and nonobese control subjects (LF NUs at rest, 56.6 +/- 3.0, P < 0.001); (LF NUs tilt: 81.7 +/- 1.7, P < 0.001). Data for systolic arterial pressure variability measured at rest exhibited the inverse pattern, the massively obese group having higher mean LF values (LF mm Hg2 rest: 15.0 +/- 1.4; LF mm Hg2 tilt: 15.7 +/- 1.5) than the moderately obese group (LF mm Hg2 rest 3.2 +/- 0.7, P < 0.001; LF mm Hg2 tilt: 7.2 +/- 2.0, P < 0.001) and than the nonobese control subjects (LF mm Hg2 rest 3.5 +/- 0.5, LF mm Hg2 tilt 8.5 +/- 0.8, P < 0.001). Regression detected a significant association between BMI and LF of systolic pressure (beta = 0.364; P = 0.0007), In LF of heart rate (beta = -5.555; P = 0.00001) and very low frequency (VLF) of diastolic pressure (beta = -3.305; P = 0.0020). CONCLUSION: Obesity seems to increase sympathetic modulation of arterial pressure, but diminishes modulation of heart rate. Because our obese subjects had high plasma noradrenaline levels, their low LF power of heart rate could reflect diminished adrenoceptor responsiveness.

Area Under Curve↗
PubMed1998

A nonlinear explanation of aging-induced changes in heartbeat dynamics.

The possibility of computing a cardiac age on the basis of spectral analysis of healthy individual tachograms was confirmed and facilitated by the use of a nonlinear technique: recurrence quantification analysis. The age of 112 subjects was predicted by this technique in terms of a progressive increase in the deterministic character of the heartbeat. This result confirms the "random-walk" character of the heartbeat as predicted by the terminal dynamics paradigm, thus allowing for a simple and comprehensive model of the effect of aging on cardiac dynamics: as age progresses, heart rate dynamics become increasingly predictable (constrained) on a beat-to-beat basis. This implies a basically stochastic nature of heart rate dynamics, probably reflecting the continuous adjustments to an unpredictable internal environment.

Adult↗