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Biomedical subjects

G Benedini

Publications and source records attributed to G Benedini.

At least 19 recordsLinked to original sources
PubMed2000

Clinical feasibility of low energy internal atrial cardioversion with a three-electrode configuration in patients with unsuccessful conventional configurations.

Low energy internal cardioversion is a safe and highly effective method for atrial fibrillation termination. We will describe 6 patients in whom the conventional 2-electrode systems with the defibrillation leads positioned in the right atrium and in the coronary sinus or left pulmonary artery failed to terminate the arrhythmia despite the use of maximal available energies. A 3-electrode configuration including right atrium, coronary sinus and left pulmonary artery was used in order to encompass as much atrial mass as possible between the cathode and the anode. The atrial fibrillation was successfully interrupted in 4 out of 6 patients. The creation of a 3-electrode configuration may be a further technical expedient in order to increase the success rate of internal cardioversion when usual manoeuvres like lead repositioning, reversion of polarity, or addition of antiarrhythmic drugs are ineffective.

Aged↗
PubMed1998

Blind extrathoracic subclavian venipuncture for pacemaker implant: a 3-year experience in 250 patients.

We report our 3-year experience using a modification of the percutaneous technique for extrathoracic subclavian venipuncture proposed by Magney and colleagues for permanent pacing lead placement. Before surgery bony landmarks were marked on the skin according to Magney's description to identify the needle entry point and the target point corresponding to the ideal location of the extrathoracic portion of the subclavian vein. Then the venipuncture was accomplished by inserting the needle through a standard infraclavicular pacemaker pocket. Two hundred fifty patients undergoing primary pacemaker implant (231 patients) or reimplant or change of mode of pacing (19 patients) were included in the study. The technique was successful in 245 (98%) cases. Inadvertent puncture of the subclavian artery occurred in 5 (2%) patients but in no case did it jeopardize the success of the implant procedure. No major complications were observed. Seven (2.9%) patients experienced early complications unrelated to the venous approach: 2 subclavian vein thrombosis, 5 lead dislodgment in 4 patients, and 1 pocket hematoma. During a mean follow-up of 15.2 months (range 4-40) no lead or patient related complications occurred. In the present study the blind approach to the extrathoracic portion of the subclavian vein proved to be safe and effective for pacing lead insertion. Further observations are required to establish whether this method extends the lead survival.

Aged↗
PubMed1998

Worsening of head-up tilt test response during chronic beta-blocker therapy in patients treated for neurally mediated syncope.

The prognosis of patients with neurally mediated syncope and asystolic response at tilt test is controversial and there is no consensus regarding their management. Many patients seem to benefit from beta-blockers and their effectiveness has been assessed with repeated tilt tests in asystolic patients as well. However, little is known about the long-term effects of beta-blockers. Preliminary data and isolated reports suggest that in some cases, these agents may actually worsen the clinical outcome or the tilt test response. Three patients are described who experienced worsening of tilt test response with prolonged asystole (19.9, 9 and 5.5 sec respectively) during chronic treatment with beta-blockers in the absence of spontaneous symptoms. At discharge, one patient received a dual-chamber pace-maker combined with metoprolol, another one continued to take metoprolol and enalapril. The third patient refused any further medication. During follow-up (8, 11, 13 months respectively), they were symptom-free. The clinical and prognostic significance of this response is not clear and needs further investigation.

Adrenergic beta-Antagonists↗
PubMed1997

[Cardiomyopathy induced by tachycardia: description of a typical clinical case].

Different chronic tachyarrhythmias may cause a form of reversible myocardial dysfunction and left ventricular enlargement known as tachycardia-induced cardiomyopathy. Many authors in recent years observed that the control of heart rate or interruption of the arrhythmia were frequently associated with a significant improvement in ventricular function and a reduction of cardiac dimensions. We report a case of tachycardia-induced cardiomyopathy secondary to atrial fibrillation of unknown duration which occurred in a young patient with structurally normal heart. The regression of left ventricular enlargement and the recovery of left ventricular systolic function were complete few months after the restoration of sinus rhythm.

Adult↗
PubMed1996

Torsade de pointes occurring early during oral amiodarone treatment.

Amiodarone is reported to have a low incidence of proarrhythmic effects. They generally occur during chronic treatment in association with increase in amiodarone dosage, electrolyte disorders, or concomitant therapy with class IA antiarrhythmic drugs. We describe a case of amiodarone-induced torsade de pointes early after initiation of low-dose oral therapy, in absence of other predisposing factors.

Amiodarone↗
PubMed1995

Implantable defibrillation and thromboembolic events.

In ICD patients thromboembolic events (TEEs) are described as possible complications at implant or during the follow-up. We report four cases of TEEs (two peripheral and two cerebral; 6.5% of patients) that occurred in our series during a mean follow-up of 19.4 months. The patients had chronic postinfarction LV aneurysm (3) and idiopathic dilated cardiomyopathy (1). None had previous embolisms nor evidence of left atrial or LV clots at standard preoperative transthoracic echocardiography. No paroxysms of atrial fibrillation were documented prior or after ICD implant. We discuss the possible causes of embolization and the suitability of anticoagulant therapy in ICD patients.

Aged↗
PubMed1991

[The prognosis of the patient with heart failure: an analysis of the most significant clinical and instrumental parameters].

Despite the progress of the medical and surgical therapy of cardiac failure, the prognosis of this syndrome remains severe. We studied in a group of cardiac failure patients (n = 203; 18-74 years old) admitted in our division from 1982 to 1987 the most significant clinical and instrumental parameters of prognostic importance. The clinical parameters considered were: age, sex, heart rate, blood pressure, NYHA class, presence of mitral insufficiency, episodes of acute heart failure. The instrumental parameters were: presence of complete left bundle branch block (LBBB), atrial fibrillation, episodes of ventricular tachycardia, cardiothoracic index (C/T), end-diastolic and end-systolic diameters, ejection fraction (EF). Statistical analysis was performed in order to correlate single parameters with mortality. The total survival at 5 years was 50%, being higher in patients with coronary artery disease than in patients with primary dilated cardiomyopathy. The parameters worsening the prognosis were: mitral insufficiency, III-IV NYHA class, occurrence of repeated episodes of acute heart failure in the last year, complete LBBB, C/T greater than 0.55 and EF less than 20%. In conclusion, considering instrumental parameters high risk patients are detected with a precision of 80%.

Adolescent↗
PubMed1991

[Malignant ventricular arrhythmias: nonpharmacological therapies].

In these last few years the indications for non pharmacological options in the therapy of malignant ventricular arrhythmias have been extended. Some of these approaches (antiarrhythmic surgery, cardiac transplant, automatic implantable cardioverter defibrillator) have an exact clinical collocation, some others are still experimental. Our personal experience and the recent literature have been analysed to explain the state of the art of these therapies. We undoubtedly think that these options are a valid alternative to drugs in non responder patients. The choice needs an accurate evaluation. The clinical picture, not only arrhythmic, and the specific aim of each procedure should be carefully considered.

Adolescent↗
PubMed1990

[Comparative effects of atrial and ventricular stimulation on morbidity and mortality in patients with sinus node disease].

In patients with sinus node disease (SND) the VVI pacing seems an inappropriate mode of cardiac stimulation because of its potential hemodynamic and arrhythmic adverse effects. The AAI-DDD pacing, preferred because of a lower morbidity, might also determine higher survival. We examined retrospectively 2 groups of patients with SND respectively stimulated with VVI pacing (Group I:57 patients) and AAI (Group II:53 patients). The mean follow-up was 43 months for Group I and 50 for Group II: 10 (17.5%) patients in VVI group and 5 (9.4%) in AAI group died. During the follow-up in the VVI group 3 patients developed congestive heart failure and 10 chronic atrial fibrillation whereas 1 case of heart failure and 2 of atrial fibrillation have been recorded in AAI group. Moreover, 4 patients had embolic complications in Group I; 5 (9.4%) patients with VVI pacing were converted into sequential pacing owing to occurrence of II degree heart block. The statistical analysis was performed by chi 2 test for the comparison among the proportions of events (atrial fibrillation, congestive heart failure, embolic accidents) in the 2 groups: a significative higher morbidity (p less than 0.01) was recorded in VVI group. Survival also is higher in AAI patients but the survival rate difference, calculated with Mantel-Cox method, is not statistically significant. The findings of this study show that in SND the superiority of AAI pacing over VVI is statistically significant as regards morbidity and we have also noticed an evident but not statistically significant superiority as regards mortality.

Aged↗
PubMed1989

Electrophysiological evaluation of the sinus node in patients with atrioventricular and/or intraventricular conduction defects.

The authors evaluated retrospectively sinoatrial conduction time (SACT), sinus node recovery time (SNRT), and corrected sinus node recovery time (CSNRT) in 272 patients with atrioventricular and/or intraventricular conduction defects without evidence of overt sinus node dysfunction. The study was designed to determine the prevalence of electrophysiologic sinus node abnormalities in patients with overt atrioventricular and/or intraventricular conduction defects. One or more sinus node electrophysiological abnormalities were observed in 133 cases (48.9%). There was a significant prevalence of electrophysiologic sinus node abnormalities only in patients older than 71 years of age. The data suggest that the involvement of the specialized conduction system is much more diffuse than one might expect simply observing the single recorded ECG defect and that the prevalence of associated defects of the conduction system increases with increasing age of patients.

Adolescent↗
PubMed1989

Survival rates after pacemaker implantation: a study of patients paced for sick sinus syndrome and atrioventricular block.

It is still a matter of controversy as to whether the patients paced for atrioventricular block (AVB) have different prognosis and survival rates than those paced for Sick Sinus Syndrome (SSS). We have compared the survival rates of 962 AVB patients (group A) with that of 283 SSS patients (group B) who underwent pacemaker implantation during the period January 1968 to December 1986. The survival rate graphs of the examined groups were calculated using the actuarial method and the differences in the survival rates between the groups were evaluated using the Logrank test. Our results show that SSS patients have a higher survival rate than AV block with a difference on the rate of survival between the two groups reaching the borderline of statistical significance. Multivariate discriminant analysis was then used to assess that of the parameters (i.e., age at the time of implantation, sex, electrophysiological indication to pacing, etiology or pacing mode) could have had the main influence upon mortality and the different pattern of the survival rate graph within the two groups of patients. Our data show that survival is mostly related to age, pacing mode and, although more slightly, to underlying heart disease; the electrophysiological indication to pacing, instead, does not significantly influence it.

Age Factors↗
PubMed1989

[Arrhythmia related to a dual chamber DDD pacemaker: a study using intra-atrial dynamic electrocardiographic monitoring].

The intra-atrial Holter monitoring (IAHM) has been recently suggested to accurately analyze atrial activity in some complex arrhythmias. We have used this new method to examine DDD pacing-related tachyarrhythmias (DDD/TAs). Fifteen patients underwent IAHM (24 hours) early after DDD pacemaker (PM) implantation. The intra-atrial ECGs were obtained through a multipolar electrode catheter; simultaneously a chest wall lead (CM5) was recorded. A standard Holter equipment was used. When DDD/TAs were observed, a second 24-hours recording was performed after a suitable PM re-programming. In 9 patients (60%) 1 or more DDD/TAs were observed, due to the following mechanisms: PM re-entry, oversensing of extra atrial potentials, fast ventricular stimulation triggered by spontaneous atrial tachyarrhythmias. Whereas the diagnostic accuracy of the IAHM was manifest, the DDD/TAs were often misdiagnosed on the basis of the CM5 lead data. At last, a right DDD PM re-programming, based on IAHM results, was able to solve or minimize the referred arrhythmic problems. In conclusion, the IAHM can be an useful method to understand the electrogenetic causes of the DDD/TAs and to optimally program the dual chamber PM. However, on account of the invasivity of the procedure, the IAHM must be used only when the noninvasive techniques fail to detect the mechanisms of the DDD/TAs.

Adult↗
PubMed1989

[Combination use of an automatic anti-tachycardia pacemaker and an automatic implantable cardioverter-defibrillator in sustained recurrent ventricular tachycardia resistant to drugs].

We used the combination of an antitachycardia automatic ventricular pacemaker with the automatic implantable cardioverter-defibrillator in two patients with sustained, recurrent, drug-resistant ventricular tachycardias in whom a surgical ablation was not indicated. The indications for the combined use of the two systems were the possibility to control: a) the ventricular tachycardias with ventricular programmed stimulation; b) the arrhythmias which might eventually degenerate into ventricular flutter or fibrillation (as a result of anti-tachycardia pacing) with the defibrillator. To avoid any possible interference between the two systems we used the following protocol: a) endocardial bipolar pacing; b) the sensing electrodes of the defibrillator were placed as far as possible from the endocardial one; c) a suitable programming of the pacemaker output; d) a careful selection of the anti-tachycardia pacing programme (burst rate inferior to the cut-off rate of the cardioverter-defibrillator and/or a duration of the burst pacing inferior to the arrhythmia sensing time of the defibrillator); e) use of cardioverter-defibrillators with a high cut-off rate. We never observed, during the follow-up (11 and 4 months, respectively), interference between the two systems. Both patients had ventricular tachycardia recurrences (51 and 3 episodes, respectively). The arrhythmias were correctly detected and interrupted by the pacemaker without the intervention of the defibrillator. These data confirm the feasibility of the combined use of the two systems in patients with ventricular tachycardias and, in selected cases, this approach is preferable. The anti-tachycardia pacemaker counteracts some limitations of the defibrillators available at present. It offers a protection against bradyarrhythmias and allows a more precise storage of arrhythmic events. The anti-tachycardia pacemaker often controls ventricular tachycardias without the intervention of the defibrillator, thus giving the same a longer life-span and allowing patients to avoid the shock.

Aged↗
PubMed1986

Inhibitory effect of acute and chronic administration of digitalis on the sick sinus node.

We have determined the effects of the acute administration of intravenous (i.v.) digitalis administration (0.8 mg of digoxin in 5-10 min) on the electrophysiological variables of 12 normal subjects (group 1), 12 patients with asymptomatic sinus node bradycardia (group 2) and 34 patients with symptomatic sinus node dysfunction (SSS) (group 3). The injection of digitalis induced: an increase of sinus node cycle length (SNCL) in all groups; a 10% increase of sinus node recovery time (SNRT) in group 1, no changes in group 2 and a 25% increase in group 3; a tendency to increase, without reaching statistical significance, of corrected sinus node recovery time (CSNRT) and sino-atrial conduction time (SACT) in all groups. In 16 patients of group 3 the effects of oral chronic treatment with digoxin (0.25 mg daily for 7 days) was also determined. The results show that chronic treatment did not further affect SNCL, SNRT or CSNRT, but caused a greater increase of SACT than did the acute i.v. administration. Chronic treatment significantly reduced the sinus rate and increased the number of premature supraventricular and ventricular beats, measured by means of 24 hour-Holter monitoring. These data suggest that digitalis should be used with great caution in patients with SSS.

Administration, Oral↗