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Biomedical subjects

F Massari

Publications and source records attributed to F Massari.

At least 37 records · Page 2Linked to original sources
PubMed1998

Beta-blocker effects on respiratory sinus arrhythmia and baroreflex gain in normal subjects.

STUDY OBJECTIVE: The results of studies on the effect of beta-adrenergic blockade on respiratory sinus arrhythmia (RSA) are discordant. The aim of this study was to verify whether chronic beta-adrenergic blockade is capable of increasing RSA, and therefore vagal outflow, and to analyze whether the mechanism of action is central or peripheral. PARTICIPANTS AND DESIGN: Twenty normal subjects (28+/-2 years old) were randomized to receive a hydrophilic (nadolol) beta-blocker, a lipophilic (metoprolol) beta-blocker, and placebo. MEASUREMENTS: After 1 week of therapy, a spectral analysis was made of the variability in heart rate and systolic BP during controlled breathing at 16 breaths/min. The high-frequency component was calculated for the RR interval (measure of RSA) and systolic pressure, and the squared coherence and phase functions were assessed between RR and systolic pressure fluctuations in the respiratory band; a negative phase means that RR changes follow systolic pressure changes. The gain in the relationship between the two signal fluctuations was also calculated. RESULTS: Both beta-blockers increased the mean (+/-SD) RR interval (placebo=808+/-21, nadolol=1,054+/-30, metoprolol=1,031+/-27 ms; p<0.0001), RSA (placebo=542, nadolol=1,177, metoprolol=1,316 ms2; p=0.002), and the gain (placebo=13.6+/-1.5, nadolol=21.9+/-2.8, metoprolol=24.5+/-3.6 ms/mm Hg; p<0.002), and both modified the phase function (placebo=-21.1+/-5.3, nadolol=-1.8+/-4.9, metoprolol=-2.9+/-4.2 degree; p<0.0001). No difference was found between nadolol and metoprolol. CONCLUSIONS: Chronic beta-adrenergic blockade enhanced both RSA and baroreflex gain and reduced the phase between the RR interval and systolic pressure oscillations. Since no difference was found between the hydrophilic and the lipophilic beta-blockers, these changes seem to be due to a peripheral effect.

Adrenergic beta-Antagonists↗
PubMed1998

[Double-blind randomized placebo-controlled study of the effects of slow release and immediate release forms of propafenone in patients ventricular extrasystole symptoms].

This is a multicenter, randomized, double-blind, placebo-controlled, cross-over and double-dummy study aimed at testing the efficacy and tolerability of two slow-release propafenone (Pr SR) preparations and compare them with the effect of instant release propafenone (Pr IR). The study was performed in 83 patients with frequent (> 30 premature ventricular contractions/hour) and stable (< 35% variability in two 24-hour ECG monitoring periods) symptomatic premature ventricular contractions. Patients were preliminarily studied in wash-out from antiarrhythmic drugs. After a period of placebo administration, all patients underwent three consecutive periods during which they received Pr IR at the dosage of 150 mg x 3, Pr SR at the dosage of 225 mg x 2, Pr SR at the dosage of 325 mg x 2. The periods lasted 10-14 days each and the sequence was randomly assigned. Twenty-four-hour ECG monitoring periods were obtained at the end of the placebo as well as at the last day of each treatment period. Treatment efficacy was evaluated by intention to treat analysis in 80 patients and by protocol in 61. Treatment was considered efficacious when premature ventricular contraction reduction > or = 75%, couplet reduction > or = 90% and non sustained ventricular tachycardias were completely suppressed. Pr IR 150 mg x 3 was efficacious in 42% of patients, Pr SR 325 mg x 2 in 45.9% and Pr SR 225 mg x 2 in 32%. Tolerability was considered good in the majority of patients. These results show that among the different types studied, Pr SR 325 mg x 2 should be considered the treatment of choice for premature ventricular contractions.

Adolescent↗
PubMed1997

Dependency of premature ventricular contractions on heart rate.

To identify a method for characterizing the dynamic behavior of ventricular arrhythmias at different heart rates, 201 consecutive patients with frequent premature ventricular contractions (PVCs) underwent two 24-hour electrocardiographic monitoring periods. The percentage of PVCs for each cycle length was calculated and then analyzed by linear regression analysis. On the basis of the significance of the p value, and the positive or negative value of the slope, we identified three trends: a tachycardia-enhanced pattern (p < 0.01, slope negative), a bradycardia-enhanced pattern (p < 0.01, slope positive), and an indifferent pattern (p > 0.01). During the first monitoring period, a tachycardia-enhanced pattern was present in 56 patients (28%), a bradycardia-enhanced pattern was present in 49 patients (24%), and an indifferent pattern was present in 96 patients (48%). This relationship was reproducible in 41 of the patients with a tachycardia-enhanced pattern (73%), in 29 of the patients with a bradycardia-enhanced pattern (59%), and in 70 patients with an indifferent pattern (72%). In conclusion, it is possible to identify a spontaneous trend between the incidence of ventricular arrhythmias and the length of the preceding cardiac cycle that seems to remain stable over time.

Adult↗
PubMed1997

Heart rate dependency of premature ventricular contractions. Correlation between electrocardiographic monitoring and exercise-related patterns.

AIMS: The identification of the response of ventricular arrhythmias to exercise testing could provide important information in the clinical setting but is difficult to obtain as no definite criteria are available. The aim of this study was to evaluate whether analysis of spontaneous heart rate dependency of premature ventricular contractions evaluated by means of 24 h electrocardiographic monitoring is capable of predicting their behaviour during exercise. METHODS AND RESULTS: One hundred and twenty-six patients (49 +/- 16 years) with frequent (> 30 h) premature ventricular contractions underwent 24 h electrocardiographic monitoring in order to evaluate the relationship between arrhythmias and heart rate, and an exercise test in order to evaluate the behaviour of the arrhythmias. On the basis of the incidence of premature ventricular contractions at different cardiac cycle lengths found at electrocardiographic monitoring, three groups of patients were identified: 34 with a tachycardia-enhanced pattern (the shorter the cycle length the higher the incidence of arrhythmias); 32 with a bradycardia-enhanced pattern (the longer the cycle length the higher the incidence of arrhythmias); and 60 patients with an indifferent pattern (no relationship). During the exercise test, the number of premature ventricular contractions/min at maximal effort in comparison with baseline increased in patients with a tachycardia-enhanced pattern (couplets or runs appeared in 10), decreased in those with a bradycardia-enhanced pattern and did not change in those with an indifferent pattern. The positive predictive accuracy of the tachycardia-enhanced pattern in predicting an increase in premature ventricular contractions > 100% at maximal effort was 78%. CONCLUSION: Identification of spontaneous behaviour between the incidence of premature ventricular contractions and the length of the preceding cardiac cycle may predict the behaviour of arrhythmias during exercise.

Adolescent↗
PubMed1997

[The effects of chronic beta-blocker administration on respiratory sinus arrhythmia].

The results of studies on the effect of beta-adrenergic blockade on respiratory sinus arrhythmia (RSA) are discordant. In some studies in which an increased RSA was reported, central vagotonic activity has been proposed. The aim of this study was to verify whether chronic beta-adrenergic blockade is capable of increasing RSA, and therefore vagal outflow, and to analyze whether the mechanism of action is central or peripheral. Twenty normal subjects (mean age 28 +/- 2 years) were randomized to receive a hydrophilic (nadolol, N), a lipophilic (metoprolol, M) beta-blocker and placebo (PL). After 1 week of therapy a spectral analysis was made of the variability in heart rate and systolic blood pressure (SBP) while they controlled their breathing at 16 breaths/min for a period of 5 min. The high frequency component was calculated for the RR interval (HF-RR, RSA measure) and SBP (HF-SBP), and the squared coherence (K2) and phase functions (phi HF) were assessed between RR and SBP fluctuations in the respiratory band (RR-SBP); a negative phi HF means that RR changes follow SBP changes. The alpha HF (an index of the baroreflex gain) was also calculated. Both beta-blockers increased the mean RR interval (PL 808 +/- 21, N 1054 +/- 30, M 1031 +/- 27 ms; p < 0.0001), HF-RR (PL 6.3 +/- 0.3, N 7.1 +/- 0.3, M 7.2 +/- 0.3 ln-ms2; p = 0.002) and alpha HF (PL 13.6 +/- 1.5, N 21.9 +/- 2.8, M 24.5 +/- 3.6 ms/mmHg; p < 0.002), and both modified phi HF (PL -0.23 +/- 0.05, N -0.02 +/- 0.05, M -0.03 +/- 0.04 s; p < 0.0001). No difference was found between N and M. Chronic beta-adrenergic blockade enhanced RSA and baroreflex gain and reduced the phase between the RR interval and SBP oscillations. Since no difference was found between the hydrophilic and the lipophilic beta-blockers, these changes seem to be due to a peripheral effect.

Administration, Oral↗
PubMed1996

Effects of nadolol and its combination with atrial pacing on rate-enhanced ventricular premature complexes.

To explore the role of heart rate in the genesis of ventricular premature complexes whose incidence increases when the length of the preceding cardiac cycle decreases, we analyzed the effect of nadolol alone and together with atrial pacing in 4 patients. Nadolol lengthened the RR cycle and suppressed ventricular premature complexes; atrial pacing, restoring the baseline RR cycle lengths, led to the reappearance of ventricular premature complexes, suggesting the major role of heart rate.

Adult↗
PubMed1996

Short- and long-term reproducibility of time and frequency domain heart rate variability measurements in normal subjects.

OBJECTIVE: To obtain data relating to the reproducibility of the time and frequency domain measurements obtained from 10-min ECG recordings. METHODS: Eighteen normal volunteers underwent evaluations of time and frequency domain heart rate variability 2 weeks and 7 months after baseline analysis. The time domain parameters were mean NN, the standard deviation of NN intervals, the percentage of successive NN intervals > 50 ms and the root mean square successive difference of NN intervals. The frequency domain evaluations (total power, low frequency, and high frequency) were made by means of both the Fast Fourier Transform algorithm (FFT) and the autoregressive method (AR) from 10-min ECG recordings made under three different conditions: rest, controlled respiration, and after a passive head-up tilt test. Reproducibility was evaluated by means of the interclass correlation coefficient (ICC), comparing baseline values with the results obtained at the second week and the seventh month. Time domain evaluation were also made from 10-min ECG. RESULTS: All of the time domain measurements had an ICC > or = 0.75, except for the standard deviation of NN intervals, which had an ICC of 0.57. The frequency domain parameters obtained by means of either FFT or AR showed similar reproducibility. Low frequency was reproducible under all three conditions, total power only at rest, and high frequency only during controlled respiration. CONCLUSION: The reproducibility of frequency domain parameters depends on the analysed condition. These results are of primary importance when the effects of drugs or other interventions on heart rate variability are under investigation.

Adult↗
PubMed1996

Holter-guided identification of premature ventricular contractions susceptible to suppression by beta-blockers.

To evaluate whether the identification of the different types of relations between premature ventricular contractions (PVCs) and the preceding sinus cycle length is capable of predicting the effect of beta-blockers on the PVCs themselves, 55 patients (43 men, 12 women, mean age 52.6 +/- 15.6 years) with different cardiac diseases, and >30 PVCs/hr characterized by stability and the same relation at two Holter monitoring periods were studied. The relation was tachycardia enhanced (the shorter the preceding cycle length, the higher the incidence of PVCs) in 23 patients (group 1); indifferent (no correlation between the preceding cycle length and PVC incidence) in 21 (group 2); and bradycardia enhanced (the longer the preceding cycle length, the higher the incidence of PVCs) in 11 (group 3). A third Holter monitoring was performed 6 days after nadolol administration (80 mg/day) to evaluate its effect on the three types of PVCs. Incidence in all patients (-88;p<0.001). In group 2, it caused a reduction in the majority of patients (-60%;p<0.05) but an increase in five. In group 3, it caused a reduction in only half of the patients (-45%) and a 91% increase in the remainder. The difference in the effect of nadolol in the three groups was highly significant (X2=27.5;p<0.0001). The relation between the incidence of PVCs and the preceding cycle length is a useful means of identifying subsets of patients with PVCs who will benefit from beta-blockers.

Adrenergic beta-Antagonists↗
PubMed1996

Sleep suppression of ventricular arrhythmias: a predictor of beta-blocker efficacy.

It has been reported that the frequency of premature ventricular contractions in some patients tend to decrease during the hours of sleep when modifications in autonomic tone and bradycardia occur. The aim of this study was to evaluate whether the phenomenon of sleep suppression may be a sensitive and specific parameter for predicting the antiarrhythmic effect of beta-blockers on premature ventricular contractions. The presence of sleep suppression was evaluated in 45 patients (mean age 50 +/- 17 years) with frequent premature ventricular contractions at two baseline Holter recordings. Sleep suppression was defined as > 50% reduction in the number of nighttime as opposed to day-time premature ventricular contractions. Three groups of patients were identified: those with sleep suppression at both Holter recordings (group 1); those with sleep suppression at only one Holter recording (group 2); and those without sleep suppression at either Holter recording (group 3). A third Holter was performed 5 days after nadolol administration. In group 1, nadolol led to a mean reduction in the number of premature ventricular contractions of 90% (> 70% in 21/23 patients). In group 2, the mean reduction was 76% (> 70% in three out of six patients). In group 3, there was a mean increase in the number of premature ventricular contractions of 33%. The positive predictive accuracy of sleep suppression in relation to the antiarrhythmic efficacy of nadolol is very high (88%) when sleep suppression is present during two baseline Holter recordings. Sleep suppression is a sensitive parameter for identifying the premature ventricular contractions likely to benefit from beta-blocker administration.

Adolescent↗
PubMed1995

The effect of nadolol on heart rate and the standard deviation of the RR intervals.

The aim of this study was to evaluate the effect of nadolol in modifying the standard deviation of RR intervals (SDRR) and the coefficient of variance (CV) in 47 patients characterized by symptomatic, frequent (> 30 h-1) and reproducible premature ventricular contractions (PVCs). Sixteen patients had suffered a previous myocardial infarction (Group 1), 22 had various non-ischaemic cardiac diseases (Group 2) and nine had no heart disease (Group 3). All patients underwent two 24 h Holter recordings during the washout period, and a third Holter recording was taken 5 days after the administration of nadolol (80 mg.day-1). The RR cycle length (RR), SDRR and CV were evaluated for each 24 h period, as well as for six daytime (1000-1600h) and six night-time hours (0000-0600h). In all three groups, nadolol was highly effective in lengthening RR. However, the effect on SDRR was different in the three groups; 24-h SDRR tended to be reduced in all three groups (but the reduction was significant only in Group 1) due to a certain RR homogeneity. On the other hand, daytime SDRR tended to increase (but the increase was significant only in Group 3). CV is concomitantly affected by heart rate and SDRR, therefore it may be more sensitive in evaluating the effect of beta-blockers. The reduction in CV post-nadolol means that the bradycardia-induced effect is associated with an inadequate increase, or even a reduction in SDRR, whereas the absence of any CV changes (found only in Group 3) is the result of a concomitant increase in both RR cycle length and SDRR.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Turnover of circulating virion RNA and of cell-associated viral DNA reflects active viral replication in human immunodeficiency virus type 1-infected individuals.

A quantitative assessment of human immunodeficiency virus type 1 turnover in patient cell-free virion and infected-cell compartments under the dynamic conditions imposed by an effective antiviral therapy was performed. The turnover was rapid, and following a temporal lag, the extent of viral population replacement was eventually similar in both compartments. Each compartment therefore reflects considerable active virus replication.

Antiviral Agents↗
PubMed1994

Could migraine be a "protective factor" against tumors?

Patients with migraine headaches show significantly lower prevalence of malignant neoplasms when compared with the general control group or the age-matched control group. Conversely, no significant difference concerning the family history for neoplasms has been found between the two groups. Nevertheless, headache and cancer in a family member in migraneous are not coexistent. Although more extensive, epidemiological studies are necessary to confirm our data, it is suggested that some particular biochemical or psychologic aspects involved in the pathogenesis of migraine might represent the presence of a protective factor against neoplasm development.

Adolescent↗
PubMed1994

[Assessment of the autonomic nervous system in the acute phase of myocardial infarction].

The aim of this study was to evaluate how heart rate variability changes during acute myocardial infarction (AMI) and whether this change is different in anterior and inferior AMI. For this purpose 10 patients with anterior (mean age 53 +/- 11 years) and 11 patients with inferior (mean age 55 +/- 11 years) AMI underwent 2 consecutive 24-hour Holter recordings (H1, H2) which started, at most, 6 hours after the onset of symptoms and a further two H at the 10th (H3), and 28th day (H4) of AMI. None of the patients suffered from diabetes or was taking beta-blockers. The standard deviation of the RR intervals (SDRR) for a 24-hour period was evaluated for each H in the group of patients with anterior and inferior AMI. In H1, SDRR was statistically lower in anterior compared to inferior AMI (64 +/- 20 versus 106 +/- 27; p < 0.0001). No statistically significant differences were found in H2 between the anterior and inferior AMI (72 +/- 19 versus 76 +/- 14), due to a reduction in SDRR in inferior AMI: from 106 +/- 27 in H1 to 76 +/- 14 in H2; p < 0.002. No statistically significant changes were present in anterior AMI patients between H1 and H2 (64 +/- 20 versus 72 +/- 19). SDRR recovers at H3 increasing in both groups (anterior: 101 +/- 28, p < 0.001; inferior: 108 +/- 29, p < 0.004). No further significant changes in SDRR were present at H4 for either group (anterior 117 +/- 30; inferior: 118 +/- 31).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Interleukin-1 beta plasma secretion during diurnal spontaneous and induced sleeping in healthy volunteers.

We previously reported nocturnal plasma IL-1 beta (beta) increases during sleep in absence of stress-induced activation of hypothalamic-pituitary-adrenal (HPA) axis. In this paper we evaluate the presence of plasma IL-1 beta secretion in nine healthy volunteers (mean age 31.2 +/- 4.2) during post-prandial naps, after the administration of zolpidem, a benzodiazepine receptorial agonist. Although a significant increase in IL-1 beta plasma levels during spontaneous sleep was present in only four subjects when compared to those obtained during wake and induced-sleep, spontaneous sleep IL-1 beta mean plasma levels appeared slightly higher than both wake and induced-sleep values. Moreover, a negative correlation was present between IL-1 beta and cortisol (F) values obtained during the early afternoon (r = 7; p < 0.05). Our findings are consistent with a possible association of IL-1 beta secretion to physiologic sleep also during daytime spontaneous naps, with the presence of F influence on this phenomenon, and with the lack of IL-1 beta association to daytime naps after sleep-inducer pharmacological agents.

Administration, Oral↗
PubMed1993

Headache and memory impairment. Study on 100 headache patients.

The aim of the present study was to explore the association between memory impairment and primary headache. 100 headache patients (71 females, 29 males, mean age 35.6 +/- 13.8) and 20 healthy subjects (14 females, 6 males, mean age 37.3 +/- 12.1) as control group, were examined: a significant difference between the two groups was found (p < 0.001). The patients were divided into different groups according to the kind of headache, the use of analgesics, the pain side and the illness length: significant differences were found between patients who made a low use of analgesics and the others (p < 0.001); the illness duration also seems to be relevant in the progressive memory impairment, because it strengthens some immunologic and biochemical mechanisms able to favour a progressive mnemonic damage.

Adult↗
PubMed1993

[Postmenopause, plasma lipoproteins, and hormone replacement therapy].

The incidence of coronary heart disease (CHD) rises after menopause. Hormonal replacement therapy (HRT) reduces cardiovascular morbidity and mortality. Plasma lipoproteins are modified by oral estrogen treatment: LDL are lowered while HDL and VLDL are augmented. The cardioprotective effect of oral HRT may be partially due to the reduction in the LDL/HDL ratio. Optimal changes in lipid profile are achieved with doses that usually prevent bone mass loss. Progestogens tend to blunt the increment of HDL induced by estrogens, but this depends on the type of agent and its dose. Unlike oral estrogen, HRT by the transdermal route does not always modify the lipid profile. When it does, changes are similar to those observed under the oral route in that the LDL/HDL ratio is diminished, but VLDL do not rise. Possible explanations for this discrepancy are discussed. At present there is no clear evidence that combined estrogen/progestogen treatment or transdermal estrogen alone could reduce CHD's incidence. Women with an intact uterus should receive a progestogen in addition to estrogen for prevention of endometrial carcinoma. Estrogen alone is preferable for hysterectomized women. When beneficial and adverse effects of HRT are considered simultaneously, the overall result is considered favorable, principally as a consequence of its cardioprotective properties.

Drug Administration Routes↗
PubMed1993

[A critical review of the problem of children at audiological and phoniatric risk in the first year of life].

The "M. L. Marenzi" Centre of Infantile Otophoniatrics, in collaboration with the Department of Neonatal Pathology of the Fatebenefratelli Hospital in Milan, performed longitudinal controls of an audiological and phoniatric type in 252 children. In the present study attention is focused in particular on audiological evaluations made in a group of 71 infants aged from 6-9 months old. During audiological tests the evaluation of auditory capacity and the type of response to acoustic stimulus were taken into account. The behavioural observation of selective attention to sound is a very important index of the maturity of sensorial patterns. The retarded development of response to an acoustic stimulus may indicate future communication disorders. The type of response to acoustic stimulus obtained in 71 infants were compared with those in a further two groups of children: the first comprised 3822 children with no audiological risk, and the second 3755 children at audiological risk according to Feinmeser and Telly's expanded list. This comparison highlighted a significant persistence of an archaic-type response in the group of infants from the Department of Neonatal Pathology. It is therefore essential that these children are examined further from a phoniatric point of view.

Audiometry, Pure-Tone↗