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Biomedical subjects

M G Bongiorni

Publications and source records attributed to M G Bongiorni.

At least 19 recordsLinked to original sources
PubMed2006

Management of cardiac device infections: A retrospective survey of a non-surgical approach combining antibiotic therapy with transvenous removal.

Pacemakers (PMs) and implantable cardioverter defibrillators (ICDs) have become life-saving therapeutic tools for patients with cardiac arrhythmia. Complications include thrombosis, embolism and infections at a highly variable rate. Surgical removal of the infected device has been perceived as the only way to guarantee a successful outcome and to reduce the high risk of mortality. Recently, a transvenous extraction method has been developed to remove infected intracardiac leads without sternotomy. This survey was designed to evaluate the outcome of an approach combining antibiotic therapy with non-surgical transvenous complete removal for the management of cardiac device infections (CDIs). We reviewed case-histories of 121 patients (105 with PM and 16 with ICD infections). The aim of our retrospective survey was to ascertain that a non-invasive transvenous complete removal of the infected devices is safe and effective when associated with appropriate antibiotic therapy starting 10 days before the procedure and extending to at least three weeks after. The infected devices were successfully removed in all patients with a non-surgical transvenous technique. The infections were most frequently caused by coagulase-negative staphylococci (70%), Staphylococcus aureus (14%), and Gram-negative rods (12%). Polymicrobial infections were documented in 19 patients and represent 16% of all device-related infections. The removal of the devices was done during antibiotic therapy, administered for a median of 26 days (range 23 to 45 days). Neither fatalities nor relapse of infections were recorded in the patient population during the one-year follow-up visits. According to our experience, CDIs can be treated with antibiotic therapy and non-surgical removal of the entire infected device, thus allowing a successful reimplantation. This procedure prevents recurrent infections and operative mortality.

Anti-Bacterial Agents↗
PubMed2004

Comparative assessment of right, left, and biventricular pacing in patients with permanent atrial fibrillation.

AIMS: Left ventricular (LV) and biventricular (BiV) pacing are potentially superior to right ventricular (RV) apical pacing in patients undergoing atrioventricular (AV) junction ablation and pacing for permanent atrial fibrillation. METHODS AND RESULTS: Prospective randomized, single-blind, 3-month crossover comparison between RV and LV pacing (phase 1) and between RV and BiV pacing (phase 2) performed in 56 patients (70+/-8 years, 34 males) affected by severely symptomatic permanent atrial fibrillation, uncontrolled ventricular rate, or heart failure. Primary endpoints were quality of life and exercise capacity. Compared with RV pacing, the Minnesota Living with Heart Failure Questionnaire (LHFQ) score improved by 2 and 10% with LV and BiV pacing, respectively, the effort dyspnoea item of the Specific Symptom Scale (SSS) changed by 0 and 2%, the Karolinska score by 6 and 14% (P<0.05 for BiV), the New York Heart Association (NYHA) class by 5 and 11% (P<0.05 for BiV), the 6-min walked distance by 12 (+4%) and 4 m (+1%), and the ejection fraction by 5 and 5% (P<0.05 for both). BiV pacing but not LV pacing was slightly better than RV pacing in the subgroup of patients with preserved systolic function and absence of native left bundle branch block. Compared with pre-ablation measures, the Minnesota LHFQ score improved by 37, 39, and 49% during RV, LV, and BiV pacing, respectively, the effort dyspnoea item of the SSS by 25, 25, and 39%, the Karolinska score by 39, 42, and 54%, the NYHA class by 21, 25, and 30%, the 6-min walking distance by 35 (12%), 47 (16%), and 51 m (19%) and the ejection fraction by 5, 10, and 10% (all differences P<0.05). CONCLUSIONS: Rhythm regularization achieved with AV-junction ablation improved quality of life and exercise capacity with all modes of pacing. LV and BiV pacing provided modest or no additional favourable effect compared with RV pacing.

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PubMed2002

An evaluation of the strategy of maintenance of sinus rhythm by antiarrhythmic drug therapy after ablation and pacing therapy in patients with paroxysmal atrial fibrillation.

AIMS: Permanent atrial fibrillation develops in many patients after ablation and pacing therapy. We compared a strategy that initially allowed patients to remain in atrial fibrillation with a strategy that initially attempted to restore and maintain sinus rhythm. METHODS AND RESULTS: In this multicentre randomized controlled trial, 68 patients affected by severely symptomatic paroxysmal atrial fibrillation were assigned, after successful atrioventricular junction ablation and pacing treatment, to antiarrhythmic drug therapy with amiodarone, propafenone, flecainide or sotalol and were compared with 69 patients assigned, after successful AV junction ablation and pacing treatment, to no antiarrhythmic drug therapy. The patients were followed-up for 12 to 24 months (mean 16+/-4). The drug arm patients had a 57% reduction in the risk of developing permanent atrial fibrillation (21% vs 37%, P=0.02). Evaluation after 12 months revealed similar quality of life scores and echocardiographic parameters in the two groups, but the drug arm patients had more episodes of heart failure and hospitalizations (P=0.05). The outcome was similar between the 40 patients who developed permanent atrial fibrillation and the 97 who did not. CONCLUSION: Conventional antiarrhythmic therapy reduces the risk of development of permanent atrial fibrillation after ablation and pacing therapy. The present data do not support the concept that the development of permanent atrial fibrillation is related to an adverse outcome when a perfect control of heart rate is obtained by ablation and pacing.

Aged↗
PubMed1999

Which strategy is "best" after myocardial infarction? The Beta-blocker Strategy plus Implantable Cardioverter Defibrillator Trial: rationale and study design.

The Beta-blocker Strategy plus Implantable Cardioverter Defibrillator (BEST-ICD) Trial is a multicenter prospective randomized trial that started in June 1998, in 95 centers in Italy and Germany. The trial will test the hypothesis whether, in high-risk post myocardial infarction (MI) patients already treated with beta blockers, electrophysiologic study (EPS)-guided therapy (including the prophylactic implantation of implantable cardioverter defibrillator [ICD] in inducible patients) will improve survival compared with conventional therapy. Patients eligible for the study are survivors of recent MI (> or = 5 and < or = 21 days), aged < or = 80 years, with left ventricular ejection fraction < or = 35% and > or = 1 of the following additional risk factors: (1) ventricular premature beats > or = 10/hour; (2) decreased heart rate variability (standard deviation of unusual RR intervals < 70 msec); and (3) presence of ventricular late potentials. Furthermore, all enrolled patients must be able to tolerate at least 25 mg of metoprolol per day. These patients constitute about 9% of all patients with recent MI and are expected to have a 2-year all-cause mortality > 25% of which 50% is anticipated to be from sudden death. The main criteria of exclusion from the study are (1) a history of sustained ventricular arrhythmia; (2) documentation of nonsustained ventricular tachycardia during the screening phase; and (3) the need for myocardial revascularization and contraindications or intolerance to beta-blocker therapy. Eligible patients will be randomized to 2 different therapeutic strategies: conventional strategy or EPS/ICD strategy. Patients allocated to the EPS/ICD strategy will undergo further risk stratification, and electrophysiologically inducible patients (approximately 35%) will receive prophylactic ICDs, in addition to the conventional therapy, whereas noninducible patients will be only conventionally treated. The primary endpoint of the study will be death from all causes. By hypothesizing a 30% reduction in the 2-year mortality (from 20% to 14%) in the EPS/ICD group compared with conventionally treated patients, 1,200 patients will have to be included. A triangular, 2-sided sequential design with preset boundaries, for a 5% significance level and 90% power to detect a reduction in 2-year mortality from 20% to 14%, will be used to permit early termination of the trial if the strategy is found to be efficacious, no difference, or inefficacious.

Adrenergic beta-Antagonists↗
PubMed1999

Prospective, randomized study of atrioventricular ablation and mode-switching, dual chamber pacemaker implantation versus medical therapy in drug-resistant paroxysmal atrial fibrillation. The PAF study. Paroxysmal Atrial Fibrillation.

We performed a prospective randomized 6-month evaluation of the clinical effects of atrioventricular junctional ablation together with placement of a DDDR mode-switching pacemaker vs pharmacological treatment in 43 patients with intolerable paroxysmal atrial fibrillation not controlled with antiarrhythmic drugs. Ablation and pacemaker treatment were highly effective and superior to drug therapy in controlling symptoms and improving quality of life. However, discontinuation of drug therapy exposed patients to further recurrences of paroxysmal atrial fibrillation and the risk of developing permanent atrial fibrillation.

Anti-Arrhythmia Agents↗
PubMed1999

Incessant nonreentrant atrioventricular nodal tachycardia due to multiple nodal pathways treated by radiofrequency ablation of the slow pathways.

In patients with dual AV nodal physiology, simultaneous anterograde fast and slow pathway conduction resulting in an unusual form of nonreentrant AV nodal tachycardia has been observed. We describe the case of a young patient with an incessant form of complex supraventricular tachycardia who underwent electrophysiologic evaluation, which showed simultaneous conduction via multiple AV nodal pathways that caused a unique form of incessant nonreentrant AV nodal tachycardia. Radiofrequency ablation of the spatially closed intermediate and slow pathways effectively treated the tachycardia. The electrophysiologic determinants of simultaneous conduction through the multiple nodal pathways and the apparently different behavior of the fast pathway before and after ablation are discussed.

Adolescent↗
PubMed1998

Radiographic assessment of atrial dipole position in single pass lead VDD and DDD pacing. The Multicenter Study Group.

Atrial electrode position was determined by radiographic analysis in 160 patients paced in single-lead VDD for second- or third-degree A-V block, implanted > 1 year with Phymos single pass leads and Phymos 3D pacemakers. The packing lead features an atrial dipole with a 30-mm electrode interspace. In 44% of patients, the upper atrial electrode was positioned within a band of 20 mm centered at the level of the superior vena caval insertion (junctional area) and was in the inferior vena cava or in the atrium in 35% and 21% of cases, respectively. In spite of these different dipole locations, all patients had stable atrium-driven pacing at routine follow-up visits. With the electrode in the junctional area, unipolar stimulation of up to 5 V for 1 ms resulted in stable atrial capture in 63% and 59% of the patients in supine and upright positions, respectively. With the electrode in the atrium, corresponding success rates were 45% and 54%. In the atrium, however, the prevalence of diaphragmatic stimulation was significantly lower than at the junction (10% vs 42% in supine position; 21% vs 47% upright). Though atrial sensing function proved adequate in a wide range of positions, these results suggest that the Phymos lead atrial dipole should be positioned within the atrium, as close as possible to the atrial wall, to maximize the number of VDD patients who might benefit from single-lead DDD pacing.

Cardiac Pacing, Artificial↗
PubMed1997

Assessment of atrioventricular junction ablation and DDDR mode-switching pacemaker versus pharmacological treatment in patients with severely symptomatic paroxysmal atrial fibrillation: a randomized controlled study.

BACKGROUND: The purpose of the study was to evaluate the effect of AV junction ablation and pacemaker implantation on quality of life and specific symptoms in patients with paroxysmal atrial fibrillation (AF) not controlled by drugs. METHODS AND RESULTS: We performed a multicenter, randomized, 6-month evaluation of the clinical effects of AV junction ablation and DDDR mode-switching pacemaker (Abl+Pm) versus pharmacological treatment in 43 patients with intolerable, recurrent paroxysmal AF of three or more episodes in the previous 6 months not controlled with three or more antiarrhythmic drugs. Before completion of the study, 3 patients in the drug group withdrew because of the severity of their symptoms and 1 patient assigned to the Abl+Pm group in whom the ablation procedure failed. At the end of the 6 months, the 21 patients of the Abl+Pm group who completed the study showed, in comparison with the 18 of the drug group, lower scores in the Living with Heart Failure Questionnaire (-51%, P=.0006), palpitations (-71%, P=.0000), effort dyspnea (-36%, P=.04), exercise intolerance score (-46%, P=.001), and easy fatigue (-51%, P=.02). The scores for rest dyspnea, chest discomfort, and NYHA functional classification were also lower (-56%, -50%, and -17%, respectively) in the Abl+Pm group, although not significantly. At the end of the study, palpitations were no longer present in 81% of the Abl+Pm group and in 11% of the drug group (P=.0000). AF was documented in 31 of 122 visits (25%) in the Abl+Pm group and in 9 of 107 examinations (8%) in the drug group (P=.0005); chronic AF developed in 5 (24%) and 0 (0%) in the two groups, respectively (P=.04). CONCLUSIONS: In patients with paroxysmal AF not controlled by pharmacological therapy, Abl+Pm treatment is highly effective and superior to drug therapy in controlling symptoms and improving quality of life. The discontinuation of drug therapy exposes patients to further recurrences of paroxysmal AF and the risk of developing permanent AF.

Aged↗
PubMed1996

Is local myocardial contractility related to endocardial acceleration signals detected by a transvenous pacing lead?

The availability of sensors monitoring cardiac function parameters may offer many interesting new applications in cardiac pacing. A microaccelerometer sensor (BEST, Biomechanical Endocardial Sorin Transducer) located at the tip of a pacing lead (PL) has been developed by Sorin Biomedica. The signal detected by the accelerometer, peak endocardial acceleration (PEA), was shown to reflect cardiac contractility and to be related to the dP/dt signal. Whether the PEA detected by the BEST sensor in different cardiac locations is the expression of local acceleration forces or reflects the whole heart contractility has not yet been demonstrated in humans. Endocardial acceleration and PEA were evaluated in five patients (4 males, 1 female, mean age 68 years) who underwent cardiac catheterization. Sinus rhythm was present in four patients and chronic atrial fibrillation was present in one. The BEST PL was introduced through the left subclavian vein and PEA signals were recorded: (1) at the apex of the right ventricle (RV), (2) within the coronary sinus (CS), (3) at the right atrial appendage (RAA), and (4) floating in the right atrium. The PEA signals were recorded simultaneously with surface ECG, intracardiac electrograms, and RV pressure. At each recording site, PEA signals with significant amplitude were always recorded during the preejection period, during the isovolumic contraction phase, independently of the recording site and cardiac rhythm. The PEA amplitude was higher in the RV (mean value 1.32 g) and it decreased in the RAA and CS (0.75 and 0.45 g, respectively). The same behavior of PEA was observed during sinus rhythm or atrial fibrillation. The amplitude and the timing of the PEA signals detected by the BEST accelerometer were independent of the recording site and atrial rhythm; they appeared to be strictly related to the global ventricular contractility. These results suggest that the BEST could be used either as an effective sensor in closed loop pacing systems, or primarily as a diagnostic hemodynamic sensor.

Acceleration↗
PubMed1996

Transvalvular impedance (TVI) recording under electrical and pharmocological cardiac stimulation.

The cardiac electric impedance was recorded between right atrium and ventricle, throughout the cardiac cycle, by means of a tripolar single pass lead for VDD pacing. The transvalvular impedance signal (TVI) is a sharp periodic wave, with high signal-to-noise ratio, that is detected exclusively in the presence of cardiac mechanical activity. The minimum TVI value is attained during the atrial systole, the maximum at the end of ventricular systole. Different parameters of TVI waveform are affected by changes in the inotropic state, and could therefore be proposed as potential signals for new rate responsive algorithms based on the correlation between inotropic and chronotropic regulation. The signal might be used, moreover, for pacing and sensing validation in autoregulating pacemakers and for fibrillation recognition in ICDs.

Adrenergic Agonists↗
PubMed1992

Histologic evidence of myocardial damage in apparently healthy subjects with ventricular arrhythmias and myocardial dysfunction.

The association of ventricular arrhythmias and myocardial dysfunction could be considered an early step toward cardiomyopathy; therefore, we studied 28 patients in NYHA class I and II, characterized by complex ventricular arrhythmias (VA) on 24-h Holter monitoring and volumetric and/or contractile abnormalities on a standard two-dimensional echocardiogram (2-D echo). All patients underwent radioisotopic angiography, 20 patients complete hemodynamic study, and 15 patients endomyocardial biopsy. Ambulatory ECG monitoring showed the presence of frequent premature ventricular contractions in 14 patients (50%) and episodes of ventricular tachycardia in 16 patients (57%). 2-D echo showed mono- or biventricular enlargement and dyssynergies in 25 patients (89%) (left ventricle in 6, right ventricle in 11, both in 8). Two patients showed only left ventricle enlargement and one patient isolated left ventricular dyssynergies. Radioisotopic angiography showed mono- or biventricular ejection fraction reduction in 24 patients (85%) and regional dyssynergies in 24 patients (85%) in accordance with 2-D echo. Hemodynamic study showed in all patients normal coronary arteries, and right and left angiography confirmed enlargement and/or regional dyssynergies. Endomyocardial biopsy was abnormal in 11 of 15 patients: various degrees of hypertrophy, parcellar fibrosis, and adipogenic infiltration were found. Our preliminary data suggest that the simultaneous occurrence of ventricular arrhythmias and ventricular dyssynergies and/or enlargement in patients without apparent clinical heart disease may represent an early stage of dilated cardiomyopathy.

Adolescent↗
PubMed1992

Multicenter clinical evaluation of a new SSIR pacemaker.

A multicenter clinical evaluation of Sorin Swing 100, a new SSIR pacemaker with a gravimetric sensor, was performed by seven different centers enrolling a total of 89 patients, 56 men and 33 women, mean age 73.1 years, for pacemaker implantation (73 patients) or pacemaker replacement (16 patients). Pacing mode was VVIR in 73 patients and AAIR in 16. The behavior of pacing rate was evaluated 3 months after the implant by performing a 24-hour Holter monitor, an exercise stress test, and tests for the assessment of mechanical external interference (MEI). A physiological behavior of the paced rate was always observed during Holter monitoring. In 52 completely paced patients mean diurnal, nocturnal, and maximal heart rate were, respectively, 74.9 +/- 5.7 ppm, 58.1 +/- 5.8 ppm, and 113.4 +/- 12.7 ppm; a paced rate exceeding 100 ppm was reached on the average 5.6 times/Holter monitor. In all but two patients the sleep rate (55 ppm) was reached during the night or long resting time. During exercise stress test a direct correlation between the increase in pacing rate and the increase in workload was observed; the mean maximal heart rate reached in 49 completely paced patients was, respectively, 102.8 +/- 9 ppm in 17 patients who accomplished stage 1, 116.2 +/- 13.6 ppm in 28 patients who accomplished stage 2, and 133 +/- 6.7 ppm in 10 patients who accomplished stage 3 of the Bruce protocol. MEI testing never increased the pacing rate over the noise rate (10 ppm over the basic rate). In only seven patients the results obtained suggested to change the nominal set up of the pacemaker.(ABSTRACT TRUNCATED AT 250 WORDS)

Acceleration↗
PubMed1992

Atrial stimulation by means of floating electrodes: a multicenter experience. The Multicenter Study Group.

It is well established that single lead VDD pacing is a physiological, reliable, and easy to use mode of pacing. The major limitation of VDD pacing is the need of a normal sinus node function, confirming its indication to patients with isolated atrioventricular conduction disturbances. The Phymos 830 pacing lead was originally designed for VDD pacing in association with the Phymos MPS pulse generator; it has a floating atrial dipole with an interelectrode distance of 3 cm; the distal electrode is 11, 13, or 15 cm proximal to the tip. As a result of the incidental observation of atrial captures occurring at very low pulse amplitudes delivered from the floating dipole of this lead, a 13-center Italian study was initiated to test the systematic feasibility of this type of atrial pacing. Pacing parameters were set and strength-duration curves were acquired with the PSA Master 470 external device. The investigation was performed at pacemaker implant in 114 patients in the supine position. The tip of the electrode was positioned at the right ventricular apex and the atrial dipole at the site of the highest endocavitary signal. Atrial bipolar pacing was performed with the proximal electrode as the cathode. Stable atrial capture was obtained in 108 of 114 patients (94.7%); pacing threshold was < 3.5 V with a pulse width of 1 msec in 85 of 108 patients. Results of voltage threshold were: 2.99 +/- 1.25 and 2.59 +/- 1.13 V at pulse widths of 0.5 and 1 msec, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗