Evaluation of the periodontal healing of the second mandibular molar distal site following insertion of PRF in the third molar post extraction alveolus.

The aim of this study was to evaluate the periodontal healing of the distal sites of the mandibular second molars, comparing the extraction therapy of the third molar with and without PRF adjunct into the postextraction alveolus. The study sample was composed by 40 consecutive patients who underwent extraction of mandibular third molars. Patients were divided in two groups: the last 20 participants who have only been subjected to extraction (spontaneous healing group, SHG) and the first 20 patients who had PRF adjunct (PRF group, PG). Healing was evaluated by analyzing the variations in terms of PPD (Probing Pocket Depth), REC (Recession), CAL (Level of Clinical Attachment), BoP (Bleeding on Probing) and GI (Gingival Index) from Baseline to further follow-ups at 1 month and 3 months. The disto-vestibular (DV) and disto-lingual (DL) PPD values of the second mandibular molar were measured at Baseline and after three months in the two groups. Patients of the PG group showed lower PPD values at 1 month and 3 months postoperatively: DV: 3.6±1.09 - DL: 3.5±1.15 and DV: 2.5±0.83 - DL: 2.6±1.09, respectively. Patients belonging to the SHG also showed lower PPD values, reporting respectively the following DV values after 3 months: 2.7±0.86 - DL: 2.75±0. 85. However, there was no statistically significant difference comparing the results obtained in PG and SHG groups at 1 and 3 months (p>0.05). The insertion of PRF inside the post-extraction alveolus of the mandibular third molar leads to limited improvement in terms of periodontal healing, compared to extraction therapy only.

Changes in left ventricular repolarization after short-term testosterone replacement therapy in hypogonadal males.

BACKGROUND AND AIM: Evidences suggest that androgen deficiency is associated with sudden cardiac death (SCD). Our purpose was to analyse some electrocardiographic (ECG) markers of repolarization phase in hypogonadal patients either at baseline or after testosterone replacement therapy (TRT). PATIENTS AND METHODS: Baseline and after 6 months of testosterone replacement therapy, 14 hypogonadal patients and 10 age-matched controls underwent a short-term ECG recordings at rest and immediately after a maximal exercise test. The following ECG parameters have been collected: QTe (the interval between the q wave the end of T wave), QTp (the interval between the q wave and the peak of T wave), and Te (the interval between the peak and the end of T wave). RESULTS: At baseline, in the hypogonadal patients, corrected QTe and QTp values were longer at rest than in the controls at rest (p < 0.05), whereas, during the recovery phase, only the QTp remained significantly longer (p < 0.05). After TRT, hypogonadal patients showed an improvement only in Te (p < 0.05). Conversely, any difference between hypogonadal patients and control subjects was found with respect to the markers of temporal dispersion of repolarization phases, except for a worse QTp → Te coherence (p = 0.001) obtained during the recovery phase. CONCLUSIONS: In conclusion, at rest, hypogonadal patients suffer from a stable increase in the myocardial repolarization phase without an increase in its temporal dispersion and, hence, the SCD risk seems to be low.

Time and Frequency Repolarization Domains in Elderly Candidates to Transcatheter Aortic Valve Replacement.

Background and aim: Aortic valve stenosis (AVS) is a well-known risk factor for sudden cardiac death. Therefore, some non-invasive, electrocardiographic markers are capable to stratify the risk of sudden death at rest and during light mental challenge [mini-mental state examination (MMSE) administration]. Method: We compared short period RR, QT and Te intervals variability in 42 candidates to and 12 age-matched hypertensive control patients at rest and during mental challenge. Results: At rest, AVS patients showed a higher QT standard deviation (sd), QT low frequency power (LF), QT High Frequency (HF), Tpeak-Tend intervals sd (Te sd) and Te HF than the control group. During mental challenge AVS group showed a decrease of RR mean and RR HF, expressed in normalized units (NU), and an increase of RR total power (TP), RR LF, RR LF NU, RR LF, HF ratio (LF/HF). During this same mental test, QT sd, QT LF, QT HF, Te sd, Te LF, Te HF, QT variability index (VI), TeVI, QT normalized variance (VN) were higher in AVS patients than the control group. During mental challenge Te LF (r:0.825, p<0.05) was significantly associated to: serum albumin (ß:-0.473, p<0.001), MMSE (ß:-0.267, p:0.038), diastolic blood pressure (ß:-0.443, p:0.03) and cardiac index (ß:-0.303, p:0.029). Conclusion: AVS patients showed temporal dispersion of ventricular repolarization phase, useful maker to individuate high risk patients. MMSE administration induced a sympathetic sinus activation and vagal deactivation in AVS subjects. Frailty and mental function influenced Te HF and Te LF.

Short-Period Temporal Dispersion Repolarization Markers in Elderly Patients with Decompensated Heart Failure.

Objectives: Aging and chronic heart failure (CHF) are responsible for the temporal inhomogeneity of electrocardiogram (ECG) repolarization phase. In the past, short period repolarization-dispersion parameters were used as makers of mortality risk in different heart diseases, yet. Aim of this work was to evaluate risk of mortality or worsening condition in CHF elderly subjects by mean of these repo-larization variables. Method: An observational, prospective cohort study was performed, collecting 5 minutes ECG recordings to assess the mean and standard deviation (SD) of the following variables: QT end (QTe), QT peak (QTp) and T peak to T end (Te) in 117 decompensated CHF (age range: from 49 to 103 years). 30-day mortality and high levels of NT-pro BNP (<75 percentile) were considered markers of decompensated CHF. Results: A total of 27 patients (23%) died during the 30-day follow-up (overall mortality rate 23%). Te mean (odd ratio (OR): 1.04, 95% confidence limit (Cl 7u): 1.02-1.09, p<0.01), NT-pro BNP (OR: 1.00, 95% cl: 1.00-1.00, p<0.01) and LVMI (OR : 0.98, 95% cl: 0.96-0.10, p<0.05) were associated to risk of mortality at the multivariable logistic analysis. On the contrary, the same statistical analysis selected TeSD (OR: 1.36, 95% cl: 1.16-1.59, p<0.001) and LVEF (OR: 0.91, 95% cl: 0.87-0.95, p<0.001) as marker of decompensated CHF. Conclusion: In decompensated CHF elderly subjects, Te mean seem be associated to mortality and TeSD could be considered a risk factor for CHF worsening and complications. These evidences could provide useful tools for telemonitoring CHF elderly patients, amelio-rating treatments and outcomes.

The GH-IGF system in amyotrophic lateral sclerosis: correlations between pituitary GH secretion capacity, insulin-like growth factors and clinical features.

BACKGROUND AND PURPOSE: The growth hormone (GH) and insulin-like growth factor (IGF) system may be involved in neurodegenerative processes, and some abnormalities have been reported in amyotrophic lateral sclerosis (ALS). Our aim was to investigate the GH-IGF axis in patients with ALS and evaluate correlations between this endocrine system and clinical features. METHODS: Serum levels of GH, IGF-I, IGF-II, insulin, IGF-binding protein 1 (IGF-BP1), and IGF-binding protein 3 (IGF-BP3) were measured in 25 patients with ALS and 25 age-, gender-, and BMI-matched healthy controls. A GHRH plus arginine test was performed in patients and controls. Clinical status of patients was evaluated with the ALS Functional Rating Scale - Revised (ALSFRS-R) and upper motor neuron (UMN) score. RESULTS: GHRH plus arginine test showed GH deficiency (GHD) in 13 (52%) patients with ALS; severe GHD was found in 6 (24%) and partial GHD in 7 (28%) patients. IGF-I levels were significantly higher in patients with ALS than in healthy controls (182.9 +/- 90.8 vs. 139.4 +/- 58.1 ng/ml; P = 0.015). IGF-I levels were higher in patients with ALS with UMN score >10 than those with UMN score <10 (217.8 +/- 100.8 vs. 155.5 +/- 74.6 ng/ml, P = 0.05). IGF-II levels were significantly lower in patients with ALS than in healthy controls (720.9 +/- 215 vs. 1001.9 +/- 475.4 ng/ml; P = 0.03). CONCLUSIONS: The results demonstrate an impairment of the GH-IGFs system in ALS. The degenerative process in ALS might lead to a compensatory increase in IGF-I in an attempt to provide additional support to motor neurons or degenerating muscle fibers. The decrease in IGF-II levels may also be of pathological significance.

Study of cellular toxicity in vitro of two resins for orthodontic use.

OBJECTIVE: The objective of this work is to compare cellular toxicity in vitro of two resins for orthodontic use: an auto-polymerizable composite and a photo-polymerizable composite. MATERIALS AND METHODS: Samples were obtained by joining a couple of steel orthodontic brackets by using auto-polymerizing or photo-polymerizing resin. We used a halogen lamp, a mini LED lamp and a fast LED lamp used for orthodontics cure for 40 seconds. The 3T3 Swiss cellular line of fibroblasts was used. The samples obtained were used to determine the cellular toxicity in vitro using the Neutral Red Up-take (NRU) and the 3-(4,5-dimethylthiazol-2-Yl)-2,5-diphenyltetrazolium bromide (MTT) assay. RESULTS: Toxicity of the extract appraised at a low level at MTT and NRU assays. There were statistically relevant differences between the toxicity induced by the auto-polymerizing material and the toxicity induced by the photo-polymerizing composite material, polymerized with the blue-light lamp (p < 0.001) and with the mini LED lamp (p < 0.05). CONCLUSIONS: From the data collected in this study, we can conclude that both resins show a low level of cytotoxicity that, in the case of photochemical polymerizing resin, depends on the characteristics of the lamp.

Quality of Life of Patients with Mandibular Third Molars and Mild Pericoronitis. A Comparison between Two Different Treatments: Extraction or Periodontal Approach.

Background: The extraction of the mandibular third molar is one of the most frequent intervention in oral surgery. A common indication for wisdom tooth extraction is represented by pericoronitis, which can determine discomfort and pain in patients. The present study aimed to evaluate the impact of patients' quality of life by comparing a surgical approach with a periodontal approach. METHODS: We evaluated 82 patients diagnosed with pericoronitis that occurred at the third molar site. In total, 41 of them received a periodontal treatment and 41 were treated by extraction. The quality of life (QoL) of the patients was assessed by using the Oral Health Impact Profile-14 (OHIP-14) index. RESULTS: A total of 82 patients were included in the study and were followed up for 6 months. Of the patients, 41 received a periodontal treatment and 41 underwent surgical extraction. At the baseline, the OHIP-14 scores of the surgical group were higher (19.71, SD 9.90) than the periodontal group (14.41, SD 8.71). At 1 week, there was a reduction in terms of OHIP-14 in both groups, but the periodontal group showed lower values (12.3, SD 8.11). Long-term follow-up showed a reduction of the OHIP-14 values, with a difference in favor of the surgical group (0.10, SD 0.45). However, there was a reduction in OHIP-14 scores in both groups. CONCLUSION: Although the periodontal treatment offered a rapid improvement in terms of quality of life during the first week after the treatment, after 1 month and 6 months, the extraction of the mandibular third molar extraction remained the best treatment, removing the occurrence of re-inflammation of the site.

Controlled and tuneable drug release from electrospun fibers and a non-invasive approach for cytotoxicity testing.

Electrospinning is an attractive method to generate drug releasing systems. In this work, we encapsulated the cell death-inducing drug Diclofenac (DCF) in an electrospun poly-L-lactide (PLA) scaffold. The scaffold offers a system for a sustained and controlled delivery of the cytotoxic DCF over time making it clinically favourable by achieving a prolonged therapeutic effect. We exposed human dermal fibroblasts (HDFs) to the drug-eluting scaffold and employed multiphoton microscopy and fluorescence lifetime imaging microscopy. These methods were suitable for non-invasive and marker-independent assessment of the cytotoxic effects. Released DCF induced changes in cell morphology and glycolytic activity. Furthermore, we showed that drug release can be influenced by adding dimethyl sulfoxide as a co-solvent for electrospinning. Interestingly, without affecting the drug diffusion mechanism, the resulting PLA scaffolds showed altered fibre morphology and enhanced initial DCF burst release. The here described model could represent an interesting way to control the diffusion of encapsulated bio-active molecules and test them using a marker-independent, non-invasive approach.

Increased QT variability in cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy.

BACKGROUND AND PURPOSE: Although sudden death (SD) accounts for numerous cases of premature mortality in patients with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), the risk factors responsible for this dramatic event remain unclear. We sought possible differences in the QT variability index (QTVI) -- a well-known index of temporal dispersion in myocardial repolarization strongly associated with the risk of SD -- between a group of patients with CADASIL and healthy controls. METHODS: A total of 13 patients with CADASIL and 13 healthy volunteers underwent a 5-min electrocardiogram recording to calculate the QTVI. All the patients also underwent a clinical assessment, including functional status by Rankin score, and a magnetic resonance imaging (MRI) brain scan for quantitative analysis of T2-weighted (T2-W) and T1-weighted (T1-W) lesion volume (LV). RESULTS: Short-term QT-interval analysis showed significantly higher QTVI (P = 0.029) in patients than in controls. In patients, notwithstanding the limitations of the small sample size, QTVI also well correlated with T1-W LV (r = 0.747, P = 0.003) and T2-W LV (r = 0.731, P = 0.005). CONCLUSION: Because patients with CADASIL have increased temporal cardiac repolarization variability as assessed by QTVI, this mechanism could underlie these patients' risk of SD. Whether this easily assessed, non-invasive marker could be used to stratify the risk of malignant ventricular arrhythmias in patients with CADASIL and, possibly, to guide their therapeutic management warrants confirmation from larger prospective studies.

The Marigliano-Cacciafesta polypathology scale (MCPS): a tool for predicting the risk of developing disability.

The purpose of the work was to verify whether our MCPS can be a tool for predicting the risk of developing disabilities. We considered 45 elderly subjects divided into three groups of 15 subjects each. Group 1 consisted of cases with a "moderate-severe" degree of polypathology, with no associated condition of disability evaluated by means of the activities of daily living (ADL). Group 2 contained cases with a "moderate" degree of polypathology (with no associated condition of ADL disability). The Group 3 was the control group with a "mild" degree of polypathology (with no disability associated with ADL). All subjects were re-evaluated after 6 and 12 months. Both Groups 1 and 2 of cases over time developed greater disabilities, compared to the control Group 3; in particular, the subjects with "moderate-severe" polypathology were more disabled after 12 months.

[Syncope: physiopathology, diagnosis and therapy]. / La Sincope: Fisiopatologia, Diagnosi e Terapia

Nowadays, syncope still generates complicated challenges for clinicians for the alarm it arises in patients and, at the same time, for the multiple causes it has determined by. In almost one third of cases, syncope is neuromediated, in young subjects in vasovagal, whereas in elderly is often determinated by carotid sinus hypersensitivity. These two kinds of syncope have two completely different diagnostic approach. In some cases pace-maker implantation will be suggested to avoid new syncope episodes. In a 20% of cases, the underlying cause is arrhythmic, most of all bradiarrhythmia which is treated with pace-maker implantation. In a little number of cases, syncope is caused by ventricular arrhythmias, that require the implantation of a defibrillator device. In this review, we analyze in detail every cause of syncope with its diagnostic and therapeutic approach.

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.

Heart rate and blood pressure variabilities in salt-sensitive hypertension.

In salt-sensitive hypertension, a high sodium intake causes plasma catecholamines to rise and pulmonary baroreceptor plasticity to fall. In salt-sensitive and salt-resistant hypertensive subjects during low and high sodium intakes, we studied autonomic nervous system activity by power spectral analysis of heart rate and arterial pressure variabilities and baroreceptor sensitivity. In all subjects, high sodium intake significantly enhanced the low-frequency power of heart rate and arterial pressures at rest and after sympathetic stress. It also increased heart rate and arterial pressure variabilities. During high sodium intake, salt-sensitive hypertensive subjects had significantly higher low-frequency powers of systolic arterial pressure (7.5 mm Hg2, P < .05) and of heart rate at rest (59.2 +/- 2.4 normalized units [NU], P < .001) than salt-resistant subjects (6.6 +/- 0.3 mm Hg2, 55.0 +/- 3.2 NU) and normotensive control subjects (5.1 +/- 0.5 mm Hg2, 41.6 +/- 2.9 NU). In salt-sensitive subjects, low sodium intake significantly reduced low-frequency normalized units (P < .001) and the ratio of low- to high-power frequency (P < .001). High-sodium intake significantly increased baroreflex sensitivity in control subjects (from 10.0 +/- 0.7 to 17.5 +/- 0.7 ms/mm Hg, P < .001) and salt-resistant subjects (from 6.9 +/- 0.7 to 13.9 +/- 0.9, P < .05) but not in salt-sensitive subjects (7.4 +/- 0.3 to 7.9 +/- 0.4). In conclusion, a high sodium intake markedly enhances cardiac sympathetic activity in salt-sensitive and salt-resistant hypertension. In contrast, although reduced sodium intake lowers arterial pressure and sympathetic activity, it does so only in salt-sensitive subjects. Hence, in salt-resistant subjects, neither arterial pressure nor sympathetic activity depends on salt intake. During a high sodium intake in normotensive subjects and salt-resistant hypertensive subjects, increased sympathetic activity is probably compensated by enhanced baroreflex sensitivity.

Effects of carvedilol on heart rate and blood pressure variability in subjects with chronic heart failure.

In this study we observed that carvedilol administration to patients with heart failure improves hemodynamic function, baroreflex sensitivity, and heart rate variability. These findings contribute to improvement in survival in such patients.

Age-dependent influence on heart rate variability in salt-sensitive hypertensive subjects.

OBJECTIVE: The known association between systemic arterial hypertension in its initial stages and increased sympathetic nervous system drive prompted us to evaluate the influence of age on autonomic nervous system function in subjects with salt-sensitive arterial hypertension. DESIGN: In a randomized study, autonomic nervous system function was assessed by power spectral analysis of heart-rate variability calculated with an autoregressive algorithm in salt-sensitive hypertensives and controls at baseline and under sympathetic stress (passive head-up tilt). For 1 week before the study, all subjects kept to a diet supplying 120 mEq sodium. Sodium sensitivity was assessed by measuring and comparing arterial pressures after a 7-day controlled dietary sodium intake of 20 mEq per day after a 7-day period on 220 mEq sodium/day. SETTING: Geriatric division at the I Medical Clinic of the University of Rome "La Sapienza". PARTICIPANTS: Sixty-five patients with salt-sensitive hypertension (age range 19 to 89 years) and 64 age-matched normotensive controls, divided for data comparison into three age-groups: < 44 years; 44 to 64 years; and > or = 65 years. MEASUREMENTS: With an autoregressive algorithm in a power spectral analysis of heart rate variability, we detected four spectral frequency-domains: total power (0.0033 to 0.40 Hz), high-frequency power (0.16 to 0.40 Hz), low-frequency power (0.04 to 0.15 HZ) and very-low-frequency power (0.0033 to 0.04 Hz). To determine sodium sensitivity, for 1 week before the study all subjects kept to a diet supplying 120 mEq sodium. Sodium sensitivity was assessed by measuring and comparing arterial pressures after a 7-day controlled dietary intake of 20 mEq per day and after a 7-day period of 220 mEq sodium/day. RESULTS: Results were expressed as natural logarithms of power and normalized units. The hypertensive patients of all ages had significantly lower total power of heart rate variability than the normotensive controls (P < .05). At baseline, the youngest hypertensives had lower natural logarithms and low-frequency normalized units than controls (P < .001). After tilt, only their low-frequency normalized units exceeded those of controls (P < .001). The middle-aged hypertensive group had higher low-frequency normalized units than controls at baseline (P < .05) and after tilt (P < .001). At baseline and after tilt, the oldest hypertensives had lower low-frequency natural logarithms than controls (P < .05) and normalized units equal to those of controls. But the hypertensives of all ages were less able than controls (P < .001) to increase low-frequency power after head-up tilt. In the less than 44-year-old hypertensives, diastolic pressure correlated significantly with low-frequency power of heart rate variability, expressed in normalized units, at baseline (P < .05) and after head-tilt (P < .05). A significant inverse correlation was found between age and the natural logarithm of low-frequency power at baseline (r = -.682, P < .001) and after tilt (r = -.800; P < .001). Also, a significant inverse correlation was found to exist in normotensive subjects between the natural logarithm of low-frequency at baseline (r = -.595; P < .001) and after tilt (r = -.391; P < .001). The two regression line coefficients for age correlated significantly (P < .001) with the natural logarithm of low-power frequency after tilt. CONCLUSION: Whereas sodium chloride-sensitive hypertension appears to be associated with sympathetic hyperactivity in young and middle-aged subjects, in older people it is not. Sympathetic activity diminishes with age, declining faster in hypertensive subjects.

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.

Optic nerve involvement in acute lymphoblastic leukemia.

Leukemic infiltration of the optic nerve is rare. We describe the diagnostic assessment and the outcome in two adult patients suffering from acute lymphoblastic leukemia with T phenotype. In both cases the leukemic involvement of the eye was observed as an isolated extramedullary relapse followed after several months by hematological relapse. CT and MRI scans were negative, while an A-scan echography of the eye clarified the diagnosis. Early radiotherapy caused recovery of visual acuity in one case. A-scan echography is the most sensitive investigation for the early recognition of ocular localization in acute leukemias.

Age-adjusted normal confidence intervals for heart rate variability in healthy subjects during head-up tilt.

PURPOSE: Aging leads to a decline in autonomic nervous system function. In this study, designed to assess the influence of age on neuroautonomic regulation of cardiac activity, heart rate variability was measured by power spectral analysis and normal ranges were determined in a population of healthy subjects. PATIENTS AND METHODS: In 83 healthy volunteers (42 men and 41 women; age range 25-85 years) autonomic nervous system function was assessed by autoregressive spectral analysis of heart rate variability in clinostatism and after passive orthostatic load (head-up tilt). The analysis considered two spectral components relevant to the study of the autonomic nervous system--high-frequency power (approximately 0.05 Hz) and low-frequency power (approximately 0.10 Hz)--and the ratio between them. Low-frequency spectral components, in particular the ratio between low- and high-frequency spectra, reflect sympathetic activity; high-frequency components reflect parasympathetic activity. RESULTS: For data comparison, the study group was subdivided into three age groups: 25 subjects (12 men and 13 women) under 44 years of age; 28 (15 men and 13 women) aged 44-64 years; and 30 (15 men and 15 women) over 64 years of age. The natural logarithms and normalized units of low- and high-frequency power, and the low-to-high power ratio were used to calculate 95% confidence intervals. Power spectral analysis at baseline and after postural tilt showed significantly higher low-frequency power of heart rate variability (P < 0.05), natural logarithm of power (P < 0.001) and normalized units (P < 0.001) in the two younger groups than in the oldest group. The two younger age-groups also had significantly increased high-frequency power (P < 0.05) and natural logarithm of power (P < 0.05). The oldest age group had significantly increased high-frequency power analyzed in normalized units (P < 0.001). CONCLUSION: The age-related lowering observed in nearly all the spectral frequency components of heart rate variability confirms in healthy subjects that autonomic nervous system function declines with age.