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M V Pitzalis

Publications and source records attributed to M V Pitzalis.

54 records · Page 3Linked to original sources
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

Transvenous defibrillator implantation in patients with persistent left superior vena cava and right superior vena cava atresia.

In this report a transvenous cardioverter defibrillator implantation is described in two patients with a persistent left-sided superior vena cava and right SVC atresia. In the first case, manoeuvring of the guide wire inserted through the left subclavian vein into the SVC proved impossible, revealing a left SVC originating from the left brachiocephalic vein with an acute corner. Changing the side of implantation and inserting a CPI Endotak catheter through the right subclavian vein, the lead was easily advanced through the left SVC into the coronary sinus and then into the right atrium with the tip abutting the lateral atrial wall. Subsequent manoeuvres allowed passage of the tip of the catheter into the right ventricular apex with the proximal defibrillation coil of the Endotak lead in the low left SVC, with its distal limit at the junction with the coronary sinus. A biphasic waveform single pathway RV - > left SVC successfully defibrillated with a stored energy of 5 J. In the second patient, implantation of a transvenous Medtronic system was possible from a left infraclavicular approach. A tripolar RV coil was inserted into the right ventricle via the persistent left SVC and contiguous coronary sinus. Because of the acute angle required to enter the RV in this second case, the RV lead was looped in the right atrium in order to enter the RV in a satisfactory, albeit atypical RV location. This patient was successfully defibrillated with a 5 J monophasic waveform delivered between the RV coil, a CS/left SVC coil, and a subcutaneous patch. In conclusion, both of these patients illustrate the ability to use transvenous ICDs successfully in patients with persistent left superior vena cava although the implantation technique deviates substantially from traditional methods.

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

[Immune evaluations in cancer patients after colorectal resection].

The authors report a protocol of immunomodulation and monitoring of the intestinal function in coloresected patients using fermented milk (yoghurt). Intestinal immunity was evaluated with respect to CD4+ cells armed with secretory intestine-derived IgA, and to CD8+ cells armed with IgG aiming to an additional effect in the host protection against Gram-negative strains, such as Salmonella typhi, whose particularly high incidence in Apulia accounts for an increased immunitary activity. Ten patients (six females, four males), age ranging from 44 to 85 years, who underwent surgery between 1989 and 1992, each of whom had been prescribed a daily ration of 500 gr skimmed yoghurt for one month, were observed. The authors suggest that yoghurt may determine a higher release of gamma-IFN with activation of CD4+ and CD8+ cells. The Lactobacillus stimulation of the B lymphocytes of the Peyer plates seems to induce an increased production of secretory IgA that bind to the CD4+ surface, and of IgG (as an anamnestic response to challenge with yoghurt lactobacilli). Coloresected patients show an immunitary deficiency related to the Gram+ bacterial flora reduction and consequently a decrease in the physiological stimuli. Although these date concern a limited sample, the authors stress the importance of the restoration of bacterial flora in coloresected patients.

Aged↗
PubMed1994

[Report of a case of malignant atrophic papulosis or Degos disease].

The Authors report an exceptional case of Atrophic Malignant Papulosis (P.A.M.) or Degos disease, presenting as acute abdomen with ileal and multiple colic perforations. The disease is due to an occlusive, progressive, thrombotic vascular pathology affecting different parts of the body and may bring to death. Usually this rare disease presents with typical multiple papulous skin lesions, followed by a systemic involvement of the digestive, nervous, and visive tracts. Peritonitis and cerebral infarction are the most frequent causes of death.

Abdomen, Acute↗
PubMed1993

[Acute ileitis due to Ascaris lumbricoides].

The authors report their experience of two cases of acute ileitis with an obstructive complication due to "Ascaris lumbricoides". The distinctive features were, in the first case, the pathogenic mechanism responsible of the occlusion, and in the second one, the need of a long term follow-up. The latter, especially in the "aspecific forms", often allows an etiological diagnosis difficult even at laparotomy. Indicating the most frequent causes of surgical complications found in ileitis, which is a medical disease easily curable by medical and dietetic means, the authors confirm the difficulties of an etiological diagnosis and surgical treatment, increased by the rarity of the disease.

Abdomen, Acute↗
PubMed1993

[Cystosarcoma phyllodes of the breast: clinical cases].

The authors report their experience in the management of 8 cases of cystosarcoma phylloides of the breast observed between January 1979 and December 1986 in the Surgical Department of the University of Bari. This uncommon breast pathology, which stands halfway between benign (adenofibromas) and malignant (carcinomas) tumors presents considerable difficulties in terms of diagnosis particularly problematic for the small-sized lesions. The authors stress the need of a surgical treatment which takes into account women aesthetic desire assuring at the same time a complete exeresis. The latter includes the sacrifice of at least 1 cm thick normal breast tissue to prevent the frequent local relapses.

Aged↗
PubMed1991

Electrophysiologic evaluation of intravenous L-propionylcarnitine in man.

L-propionylcarnitine, a short-chain acylcarnitine, has been shown in experimental studies to induce, during acidic and hypoxic conditions, some electrophysiological changes such as an increase of duration of the action potential and of the effective refractory period. In this study, the acute electrophysiological effects of intravenous L-propionylcarnitine (30 mg/kg in 3 min) were studied in 12 subjects with estimated normal function of the sinus node and normal parameters for atrioventricular conduction. Statistically significant changes were observed 2 min after infusion. The sinus cycle length shortened (866 +/- 138 vs 818 +/- 124 msec, P less than 0.05) while refractory periods of the atrioventricular node increased (effective by 30-50 msec in four cases; functional from 425 +/- 52 to 436 +/- 55 msec, P less than 0.05). Sinuatrial conduction time, atrial refractory periods, infranodal conduction, bundle branch, His-Purkinje system and ventricular refractoriness were unchanged. Systolic and diastolic blood pressure were also unchanged. Because of the limited effects on electrophysiological parameters, L-propionylcarnitine should be used as a metabolic drug even in patients with mild disturbances of conduction.

Blood Pressure↗
PubMed1991

Electrocardiographic patterns during Holter monitoring in patients with first and second degree A-V block due to 'dual A-V nodal pathways'.

The electrocardiographic patterns, observed during 24-h Holter monitoring, of 10 patients (mean age 35 +/- 22 years) with first and second degree A-V block due to dual A-V nodal pathways are reported. Recordings were selected according to the presence of: sudden and persistent prolongation of the PR interval: sudden normalization of the PR interval: 'atypical' Wenckebach sequences showing sudden and pronounced prolongation of any PR interval prior to the blocked P wave. Besides the already recognized pattern, new aspects were identified: (1) Wenckebach sequences in the slow and fast pathways characterized by a progressive increase in the PR interval until a blocked P wave occurred during long and short PR interval periods, respectively; (2) Wenckebach periods first in the slow and then in the fast pathway; (3) 2:1 A-V block with a normal PR interval in the conducted beat after a Wenckebach sequence in the slow pathway; (4) Wenckebach in the fast pathway and, subsequently, in the slow one characterized by a slight prolongation of the PR interval for some beats followed by a sudden and pronounced increase in the PR interval of one beat and a subsequent progressive slight PR prolongation until a blocked P wave occurred; (5) Wenckebach sequence in the fast pathway with subsequent conduction over the slow pathway without a blocked P wave; (6) blocked P waves during both long and short PR interval periods with slight prolongation of the preceding PR interval. The electrophysiological mechanisms involved in these electrocardiographic patterns together with the nature (anatomical or functional) of the intranodal pathways and the clinical significance of this type of block are discussed.

Adolescent↗
PubMed1991

Patterns of atrioventricular conduction during postexercise recovery in patients with atrial fibrillation and Wolff-Parkinson-White syndrome.

The effects of the postexercise recovery phase on the functional anterograde conduction properties of the accessory pathway (AP) were evaluated. Twenty-nine patients with Wolff-Parkinson-White (WPW) syndrome were submitted to supine maximal bicycle exercise testing. In seven patients (group I), in whom sustained atrial fibrillation (AF) could be induced by transesophageal pacing (TP), mean ventricular rate (MVR), the shortest R-R interval (SRR) between preexcited beats, and the observed percentage of preexcited beats were evaluated at rest, after each step of exercise and 2 minutes after the end of exercise. In 22 patients (group II), in whom sustained AF could not be induced, decremental TP was performed to evaluate the shortest atrial cycle length (SCL) with 1:1 conduction over AP at rest, after each step of exercise, and 2 minutes after the end of exercise. In four patients in group I, the protocol was repeated with atropine injected during the last minute of exercise. In 12 patients (three from group I and nine from group II), catecholamine plasma levels were measured at rest, at peak exercise, and during recovery. MVR was 144 +/- 20 beats/min at rest, 186 +/- 21 beats/min at peak exercise (P less than 0.001 vs rest), and 179 +/- 21 beats/min during recovery (P less than 0.001 vs rest; P less than 0.05 vs peak exercise). SRR was 289 +/- 73 msec at rest, 223 +/- 25 msec at peak exercise (P less than 0.05 vs rest), and 227 +/- 29 msec during recovery.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

[Localization of the accessory pathways using surface ECG in Wolff-Parkinson-White syndrome].

During recent years criteria for localization of bypass tracts in the Wolff-Parkinson-White syndrome from the conventional ECG have been acquired utilizing epicardial and endocardial mapping data. The polarity of delta wave and QRS in the frontal and horizontal plane and the morphology of retrograde P waves during orthodromic reciprocating tachycardia, are the most indicative elements. An accurate analysis of QRS complexes during atrial fibrillation confirms the site of pre-excitation and could suggest the presence of 2 or more accessory pathways with sufficient spatial separation. Some criteria for identifying multiple accessory pathways are discussed.

Atrial Fibrillation↗
PubMed1991

[Transesophageal study in the diagnostic evaluation of pre-excitation].

Electrophysiologic non-invasive transesophageal testing is compared to intracardiac study in the management of patients with Wolff-Parkinson-White (WPW) syndrome. Transesophageal study can be reliably used to identify the participation of the accessory pathway in reciprocating supraventricular tachycardia and to determine the anterograde conduction properties of the accessory pathway. Using the shortest pre-excited interval during induced atrial fibrillation, or programmed and continuous atrial transesophageal stimulation can markedly reduce the need of intracardiac evaluation. The greater safety and economy of transesophageal compared to the intracardiac technique justify its wider use in preliminary screening of all WPW patients, unless ablative treatment has been clinically indicated, and in evaluating long-term drug protection against a potential deleterious ventricular response during atrial tachyarrhythmias.

Cardiac Pacing, Artificial↗