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Biomedical subjects

A Puglisi

Publications and source records attributed to A Puglisi.

At least 37 records · Page 2Linked to original sources
PubMed1999

Antiarrhythmic benefits of dual chamber stimulation with rate-response in patients with paroxysmal atrial fibrillation and chronotropic incompetence: a prospective, multicentre study.

BACKGROUND: While the haemodynamic benefits of DDDR pacing compared with DDD pacing in patients with brady-tachy syndrome and chronotropic incompetence (CI) are well demonstrated, the antiarrhythmic advantage is controversial and so far not clearly demonstrated. AIM: We have performed a prospective, randomized, multicentre study to evaluate the efficacy of DDDR and DDD pacing modes in preventing paroxysmal atrial fibrillation (PAF) episodes in patients with brady-tachy syndrome and CI. METHODS AND RESULTS: Seventy-eight patients were included in the study. All patients had a dual chamber pacemaker implanted and were randomly programmed to DDD or DDDR with a cross over (DDD --> DDDR or vice versa) at 3 months. The final evaluation was performed at 6 months by means of two self-administered symptom questionnaires to evaluate activity. Symptoms of palpitations were analysed and scored. The patients were less symptomatic with the DDDR mode. The number of mode-switch activations compared with symptomatic episodes of PAF confirmed the high rate of asymptomatic PAF episodes in patients with brady-tachy syndrome. We conclude that in a small but well defined population of patients affected by sick sinus syndrome with CI and severely symptomatic PAF, DDDR pacing compared with DDD pacing may offer an additional antiarrhythmic benefit and should be considered the primary mode of pacing.

Aged↗
PubMed1999

Kinetic approach to granular gases.

We address the problem of the so-called "granular gases," i.e., gases of massive particles in rapid movement undergoing inelastic collisions. We introduce a class of models of driven granular gases for which the stationary state is the result of the balance between the dissipation and the random forces which inject energies. These models exhibit a genuine thermodynamic limit, i.e., at fixed density the mean values of kinetic energy and dissipated energy per particle are independent of the number N of particles, for large values of N. One has two regimes: when the typical relaxation time tau of the driving Brownian process is small compared with the mean collision time tau(c) the spatial density is nearly homogeneous and the velocity probability distribution is Gaussian. In the opposite limit tau>>tau(c) one has strong spatial clustering, with a fractal distribution of particles, and the velocity probability distribution strongly deviates from the Gaussian one. Simulations performed in one and two dimensions under the Stosszahlansatz Boltzmann approximation confirm the scenario. Furthermore, we analyze the instabilities bringing to the spatial and the velocity clusterization. Firstly, in the framework of a mean-field model, we explain how the existence of the inelasticity can lead to a spatial clusterization; on the other hand, we discuss, in the framework of a Langevin dynamics treating the collisions in a mean-field way, how a non-Gaussian distribution of velocity can arise. The comparison between the numerical and the analytical results exhibits an excellent agreement.

Journal Article↗
PubMed1999

Analysis of heart rate variability five minutes before the onset of paroxysmal atrial fibrillation.

BACKGROUND: Various experimental and clinical observations suggest changes in sympathetic and vagal neural regulatory mechanisms play a critical role in altering cardiac electrical properties and favor the occurrence of arrhythmic events. There is limited information about the influences of the autonomic tone on the development of episodes of paroxysmal atrial fibrillation in patients with no evidence of organic heart disease. The aim of this study was to investigate changes in sympatho-vagal balance 5 minutes before the onset of atrial fibrillation. METHODS: We evaluated 28 patients with no history of heart disease who were not undergoing pharmacological treatment and who had at least one episode of paroxysmal atrial fibrillation recorded during an 24-hour ECG Holter monitoring. We analyzed values of frequency domain heart rate variability parameters 5 minutes before the onset of atrial fibrillation (prefa period) compared to an equivalent period at least 1 hour after from atrial fibrillation (random period). RESULTS: Thirty-six episodes of atrial fibrillation were recorded and our results showed we had two types of episodes. Eighteen were classified as Type A, in which we had an increase of low frequency (LF) (79.15 +/- 10.76 in comparison with 62.64 +/- 19.55) (P = 0.004) and a decrease of high frequency (HF) (20.82 +/- 10.74 in comparison with 37.64 +/- 20.20) (P = 0.004) consistent with an increase of sympathetic tone; and 18 were classified as Type B in which there was a decrease of LF (62.82 +/- 15.38 in comparison with 85.97 +/- 8.48) (P < 0.001), and an increase of HF (36.79 +/- 14.72 compared with 14.01 +/- 8.48) (P < 0.001), consistent with an increase of parasympathetic tone. CONCLUSION: We observed abrupt changes in sympathovagal balance in the last 5 minutes preceding an episode of atrial fibrillation. This can be related to a double behavior in the neurogenic drive: in Type A episodes there is an increase of the LF spectrum, LF:HF ratio, and a decrease of the HF spectrum consistent with an increase of neurogenic sympathetic drive; in Type B episodes there is a reduction of the LF spectrum, LF/HF ratio, and an increase of HF spectrum consistent with an enhancement of the neurogenic parasympathetic drive. In some patients, we found that the two mechanisms operate during different hours of the day and that sometimes there is an increase of sympathetic tone, and in the same instances an increase of parasympathetic tone. Heart-rate variability measures fluctuation in autonomic inputs to the heart rather than the mean level of autonomic impulse; autonomic imbalance is probably more important than the vagal or sympathetic drive alone.

Adult↗
PubMed1999

[Laryngotracheal resection and reconstruction by Grillo's technic for postintubation stenosis].

BACKGROUND: Tracheal resection and reconstruction is the standard treatment for postintubation stenosis. However, when the stenosis extends proximally to the subglottic larynx surgical treatment is particularly difficult. Specific surgical techniques have to be used in order to preserve the recurrent laryngeal nerves. The aim of this study is to evaluate the results obtained at our Department with laryngotracheal resection and reconstruction with the Grillo technique for postintubation stenosis. METHODS: From January 1984 to December 1997, 83 patients with tracheal and laryngotracheal lesions underwent surgical treatment. Eighteen patients had postintubation stenosis of the upper trachea and subglottic larynx and underwent single-stage laryngotracheal resection and reconstruction. Mean stenosis length was 3.5 cm (range 3-5 cm). Twelve patients underwent anterolateral laryngotracheal reconstruction, and 6 patients had a circumferential laryngotracheal reconstruction. A Montgomery suprahyoid laryngeal release was required in 4 cases. RESULTS: There was no surgical mortality. Surgical results were excellent or good in 17 cases and satisfactory in one case. No recurrence of stenosis has been observed. CONCLUSIONS: Cricoid cartilage involvement in postintubation stenosis should not be considered a contraindication to surgical treatment. However, laryngotracheal resection and reconstruction is technically difficult and should be performed only in selected cases.

Adolescent↗
PubMed1998

Multisite pacing as a supplemental treatment of congestive heart failure: preliminary results of the Medtronic Inc. InSync Study.

This report describes the initial results of the "InSync" study, a European and Canadian multicenter trial that examines the safety and efficacy of a multisite pacemaker (Medtronic InSync) and of left ventricular pacing leads (Medtronic 2187 and 2188) implanted via a cardiac vein as a supplemental treatment of refractory congestive heart failure. Over a 10-month period, the system was implanted successfully in 68 of the 81 (84%) patients who had been enrolled in the study. The 68 patients were, on average, 66 +/- 10 years old, had a mean left ventricular ejection fraction (LVEF) = 21% +/- 9%, and 63% were in NYHA functional Class III and 37% were in Class IV. No system implant related complication occurred. During follow-up, 7 of 10 patients who exited the study had died, 4 suddenly. There was a clinical benefit among surviving patients, which was corroborated by a significant improvement in NYHA functional class and in the Minnesota Living with Heart Failure Quality of Life Questionnaire Score (MLS) and by a longer distance covered during a 6-minute walk test. This clinical improvement was associated with a significant narrowing of the paced QRS complex during biventricular pacing, a significant decrease in the interventricular mechanical delay, and a trend towards an increase in the duration of ventricular filling. These encouraging preliminary results confirm the feasibility and reliability of this new multisite pacing system in the management of dilated cardiomyopathy and support the continuation of further evaluations of this complementary treatment of refractory congestive heart failure.

Aged↗
PubMed1998

Cytomegalovirus pneumonia in AIDS patients: value of cytomegalovirus culture from BAL fluid and correlation with lung disease.

OBJECTIVES: To verify the value of cytomegalovirus (CMV) cultures of BAL fluid vs postmortem lung histopathology in detecting CMV pneumonia, and to correlate the BAL viral dose with the number of CMV inclusion bodies (CMV-IB) in the lung tissue of AIDS patients. DESIGN: Retrospective analysis of 434 BALs and 40 autopsies involving 307 AIDS patients; clinical follow-up lasted 10 months. PATIENTS AND METHODS: The 40 patients who died within 20 days of undergoing BAL were divided on the basis of histopathologic findings into subjects with and without CMV-IB in the lung tissue. The relationship between the BAL viral dose and CMV lung infection was evaluated by counting the early antigen (CMV-EA) positive cells/200 microL of BAL and the number of CMV-IB/mm2 of lung tissue. RESULTS: The predictive value of BAL virus isolation for the diagnosis of CMV pneumonia was 61% for positive and 100% for negative results. The patients with the largest number of CMV-IB had CMV-EA counts from 2 to 840; in those with a moderate and small number, the CMV-EA counts were, respectively, from 11 to 700 and 2 to 300. Among the patients surviving up to 10 months after the BAL index sample, the frequency of recurrent extrapulmonary CMV abnormalities was 27% in those with positive and 7% in those with negative cultures. CONCLUSIONS: BAL CMV cultures from AIDS patients have a very high negative and relatively low positive predictive value for CMV pneumonia. The presence and replication of CMV in the lung may lead to systemic dissemination as suggested by the higher probability of CMV extrapulmonary diseases. Viral titers do not seem to be related to the degree of lung damage.

AIDS-Related Opportunistic Infections↗
PubMed1997

Value of automatic processing and reliability of stored data in an implanted pacemaker: initial results in 59 patients.

Stored data in implantable pacemakers have rarely been used as a diagnostic tool because of the complexity. Our group has developed software called AIDA, providing an automatic interpretation of data stored in memories of the Chorus (ELA medical) pacemaker. We compared the results of AIDA analysis to surface ECG Holter interpretation in 59 patients (age 75 +/- 9 years). In 33 cases, neither AIDA nor the Holter found any anomaly. Eleven patients demonstrated episodes of supraventricular tachycardia (SVT), confirmed by AIDA in ten patients; AIDA failure was due to nonsustained episodes of SVT not inducing mode switch. Loss of atrial sensing, pacemaker-mediated tachycardia, and ventricular extrasystoles were detected by AIDA in ten patients. Traditional Holter missed three cases. This initial study confirms that stored pacemaker data, automatically interpreted can provide reliable information over a 24-hour period.

Aged↗
PubMed1997

Steroid-eluting electrodes prevent chronic pacing threshold rise in the atrial chamber after oral propafenone administration.

The aim of the study was to evaluate chronic atrial pacing threshold increase after oral propafenone therapy. Fifty patients affected by advanced AV block and sick sinus syndrome were studied at least 6 months after pacemaker implantation, before and after oral propafenone therapy (450-900 mg/day based on body weight). The patients were subdivided into three groups as to the type of electrode implanted, all three unipolar: group I (20 patients) Medtronic CapSure 4003, group II (13 patients) Medtronic Target Tip 4011, group III (17 patients) Medtronic 4057 screw-in leads. In all cases, Medtronic unipolar pacemakers were implanted with the same noninvasive autothreshold measurement method. Propafenone and 5-OH-propafenone blood levels were measured 3-5 hours after drug administration. The packing autothreshold was measured at 0.8, 1.6, and 2.5 V by reducing the pulse width. After propafenone, groups II and III showed a statistically significant threshold rise (P ranging from < 0.01 to 0.05), whereas no significant difference was found in group I. Propafenone and 5-OH-propafenone blood vessels did not show any significant difference among the three groups. Strength-duration curves were drawn for the three groups before and after propafenone: at baseline the curves shifted to the left with the steep part above the knee, clearly favoring CapSure over the other two groups. After propafenone, the curves shifted to the right, with the flat par progressively more evident in groups II and III. In the atrial chamber, steroid-eluting leads prevented threshold increase after propafenone therapy, in contrast with a significant threshold rise with conventional porous and screw-in leads.

Aged↗
PubMed1997

Long-term haemodynamic and antiarrhythmic benefits of DDIR versus DDI pacing mode in sick sinus syndrome and chronotropic incompetence.

AIMS: The aim of this Italian multicentre study was to evaluate the haemodynamic and antiarrhythmic effects of DDIR versus DDI pacing mode in sick sinus syndrome with chronotropic incompetence. METHODS: Seventy-nine patients were implanted with a dual chamber rate-responsive pacemaker (Medtronic 7075) and centrally randomised to DDI or DDIR pacing mode. After six months, the pacing modality was crossed over. Follow-up included clinical data, rest ECG, echocardiography, Holter monitoring and exercise testing in DDIR. RESULTS: a) Haemodynamic effects. Comparing postimplant exercise testing in DDIR mode with preimplant tests, peak heart rate increased from 96 +/- 17 to 115 +/- 17 bpm (+20%, p < 0.0001), total work capacity from 7.0 +/- 3.5 to 8.8 +/- 4.3 minutes (+26%, p < 0.0001), peak oxygen uptake from 1238 +/- 406 to 1453 +/- 423 ml/min (+17%, p < 0.001) and oxygen uptake at anaerobic threshold from 977 +/- 343 to 1222 +/- 415 ml/min (+25%, p < 0.001). These benefits persisted unchanged during one-year follow-up. b) Antiarrhythmic effects. After six months, paroxysmal atrial fibrillation recurrence significantly decreased in the whole population: group I (DDI) 20.7 vs 48.3%, p < 0.02; group II (DDIR) 21.2 vs 36.4%, p < 0.05; group I + II (DDI + DDIR) 21.0 vs 41.9%, p < 0.001. After one year no significant differences were found between DDI and DDIR. Group I: DDI 23.8 vs DDIR 28.6%, ns; group II: DDI 22.7 vs DDIR 18.2%, ns. CONCLUSION: DDIR vs DDI significantly improves short- and long-term haemodynamic performance. Dual chamber pacing shows a significant reduction of paroxysmal atrial fibrillation recurrence, regardless of rate responsiveness.

Aged↗
PubMed1996

Reliability of a new algorithm for automatic mode switching from DDDR to DDIR pacing mode in sinus node disease patients with chronotropic incompetence and recurrent paroxysmal atrial fibrillation.

To evaluate the safety and efficacy of a new algorithm for automatic mode switching (AMS) from DDD-DDDR to DDIR, 26 patients, 16 females and 10 males, mean age 73 +/- 6 years of age, affected by sinus node disease, chronotropic incompetence, and recurrent paroxysmal atrial fibrillation (PAF) received the Medtronic Thera DR pacemaker. The device continuously calculates, in ms, the running average of the intrinsic atrial rate (MAR) and compares the current atrial interval (CAI) with the stored MAR. When the CAI is greater than the MAR it increases by 8 ms, and when the CAI is less than the MAR, it decreases by 23 ms. When MAR < or = 330 ms (182 beats/min), tachycardia is detected and AMS is activated. All patients had clinical evaluation, 12-lead ECG, Holter monitoring, and exercise testing after implantation and every 3 months for 1 year. The results were compared with the data stored in the pacemaker memory: AMS episodes number; the histogram of the last 14 episodes; and atrial electrogram recording. Twenty-two Holter recordings in 13 patients showed PAF and in all of them AMS occurred simultaneously. AMS lasted between 10 seconds and 20 hours, and MAR ranged from 195-400 beats/min. No episode of PAF and no AMS were recorded in 39 Holter recordings in 22 patients. Appropriate AMS was confirmed in five patients by stored atrial electrogram and in nine by 12-lead ECG and pacemaker event markers. Mean atrial sensing was 2.13 +/- 1.04 mV during PAF and 3.18 +/- 1.46 mV during sinus rhythm. No PAF episode and no AMS were recorded during exercise testing. In conclusion, this new algorithm was very reliable, sensitive, and specific.

Aged↗
PubMed1995

[Blood preservation in thoracic surgery: feasibility and limitations].

The transfusion of homologous blood carries risks associated with reactions to transfusion and the transmission of diseases. Minimizing surgery-related blood use is therefore of utmost importance. However, the application of blood-saving methods in surgery is restricted by a number of factors. Thoracic surgery poses particular problems in this regard due to the type of diseases treated, patients' general status and the use of neoadjuvant chemotherapy protocols. The aim of this study was to analyse the feasibility of a blood conservation program for thoracic surgery. A detailed analysis of blood-sparing techniques was carried out and the factors influencing blood consumption were evaluated in the preoperative, intraoperative and postoperative periods. Although pre-operative autologus blood donation is an extremely important factor, its effect is limited in thoracic surgery since only a few patients are suitable candidates for such a procedure. Our personal experience confirms the difficulty of applying a blood sparing program to thoracic surgery. Nevertheless the risks associated to transfusions, especially those related to the use of homologous blood, can be reduced by optimizing existing blood sparing techniques or developing new hemostatic agents.

Blood Group Incompatibility↗
PubMed1994

Natural history of gallstones in non-insulin-dependent diabetes mellitus. A prospective 5-year follow-up.

This prospective study was undertaken to assess the natural history of gallstones in patients with non-insulin-dependent diabetes. Four hundred forty outpatients with diabetes mellitus were studied; 81 of these had gallstones diagnosed by ultrasound. On the basis of the information they gave, they were divided into two groups: A, asymptomatic; and B, symptomatic (previous episode(s) of biliary pain) at recruitment. Five years after diagnosis, the patients were recalled and questioned about their symptoms. Three of 81 could not be traced and eight had died from diseases not related to gallstones. Seventy were finally evaluated, 47 belonging to group A, 23 to group B. The cumulative percentage of initially asymptomatic patients who presented with biliary pain or complications during the follow-up was 14.9% (4.2% for complications). Of group A patients, 17% underwent cholecystectomy (one prophylactic, six elective and two emergency). One patient (2.1%) died after operation of obstructive jaundice. Of group B patients, 47.8% had biliary symptoms or complications (8.7% cholecystitis); 21.7% were operated (17.4% elective, 4.3% emergency cholecystectomy). Since few patients with asymptomatic gallstones and non-insulin-dependent diabetes mellitus develop pain or complications over time, prophylactic cholecystectomy is probably not advisable.

Adult↗
PubMed1993

Effect of steroid eluting versus conventional electrodes on propafenone induced rise in chronic ventricular pacing threshold.

The aim of this study was to evaluate chronic ventricular pacing threshold increase after oral propafenone therapy. Eighty-three patients affected by advanced atrioventricular block and sick sinus syndrome were studied at least 3 months after pacemaker implantation, before and after oral propafenone therapy (450-900 mg/day based on body weight). The patients were subdivided into three groups according to the type of unipolar electrode that was implanted: group I (41 patients) Medtronic CapSure 4003, group II (30 patients) Medtronic Target Tip 4011, and group III (12 patients) Osypka Vy screw-in lead. In all cases a Medtronic unipolar pacemaker was implanted: 30 Minix, 23 Activitrax, 14 Elite, 12 Legend, and 4 Pasys. Propafenone blood level was measured in 75 patients 3-5 hours after propafenone administration. The pacing autothreshold was measured at 0.8 V, 1.6 V, and 2.5 V by reducing pulse width. At the three different outputs before and after propafenone, threshold increments were significantly lower in group I in comparison with group II and group III (propafenone ranging from < 0.001 to < 0.05). No significant difference was found in pacing impedance or in propafenone plasma concentration in the three groups. Strength-duration curves were drawn for each group at baseline and after propafenone administration. Before propafenone, in group I, the knee was markedly shifted to the left and downward as compared to the classic curve, so that the steep part was predominant; in group II and group III this shift was progressively less evident.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1993

[The prognostic value of the ejection fraction at rest and under stress assessed by nuclear angiography in myocardial infarct patients].

BACKGROUND: The aim of this study was to assess the utility of ejection fraction at rest (rEF) and its change during stress (delta EF) as a predictor of cardiac events during the follow-up of patients (pts) with myocardial infarction. METHODS: 74 pts (44 treated with thrombolytic therapy (TR), and 30 not (noTR)), were studied with 99mTcPYP angiography within 2 +/- 1 months, after AMI. By 20 +/- 10 months, 41 pts had no events (Group A) while 33 pts experienced cardiac events (3 deaths, 16 angina, 12 CABG, and 2 PTCA). RESULTS: rEF was similar in both Groups A and B (A 47 +/- 8 vs B 45 +/- 10 p. ns), 44 +/- 15 vs B-noTR 46 +/- 12 p. ns). delta EF was different between Groups A and B. Group A showed a positive delta EF (3.2 +/- 6), and this result was more evident in thrombolyzed AMI (A-TR 4.4 +/- 4.5 vs A-noTR 1.16 +/- 3.9 p. < 0.01). Group B showed a negative delta EF (-4.4 +/- 5.3), and this result was more evident in non thrombolyzed AMI (B-TR -2 +/- 6.4 vs B-noTR -5.8 +/- 8 p. < 0.01). CONCLUSIONS: A decrease in EF during exercise radionuclide angiography is useful in identifying pts with high risk of cardiac events after AMI. Thrombolytic therapy improves stress EF in both Groups A and B.

Adult↗
PubMed1990

Ventricular cross stimulation in a dual chamber pacing system: phenomenon analysis.

Seven cases of ventricular cross stimulation from a group of 23 patients implanted with DDD devices are presented. In two patients the phenomenon was observed at the moment of DDD programming at nominal values, and in five other patients it was reproduced by increasing the atrial output voltage up to ten volts. In all 23 patients cross stimulation disappeared permanently within 24 hours after implantation. From the onset of cross stimulation to its end, atrial and ventricular threshold voltages were unchanged, while the atrial and ventricular impedances significantly decreased. These results suggest that an important role in the phenomenon occurs by impedance variation at the interface between the pulse generator and body tissue.

Aged↗