Biomedical subjects

L Sallusti

Publications and source records attributed to L Sallusti.

4 recordsLinked to original sources

PubMed2001

A semi-automatic algorithm for reducing the time spent on routine follow-up of cardioverter defibrillators.

BACKGROUND: The routine follow-up of cardioverter defibrillators (CD) is a time-consuming procedure. AIM of the STUDY and METHODS: The present study was a prospective randomized cross-over evaluation on the clinical usefulness of a specific semi-automatic software algorithm (Quick Check) for CD follow-up, available in CPI Guidant systems (CD and programmer). Time-saving, while ensuring all the required data and patient safety, was evaluated in a large group of patients (105), recruited in different centers. In the same session and under a physician's supervision all patients underwent a follow-up with the aid of Quick Check or a standard follow-up, in a randomized sequence. Each patient served as his own control. RESULTS: In the overall population of 105 patients, the time spent for follow-up was reduced by Quick Check from 186+/-105 sec to 106+/-67 sec (p<0.0001) (43% reduction). The reduction in time spent for follow-up with Quick Check was the same (43% reduction) in patients with detected episodes (n=38) (from 241+/-144 sec to 138+/-95 sec (p<0.0001)) and in patients without detected episodes (n=67) (from 154+/-52 sec to 88+/-34 sec (p<0. 0001)). No adverse events or deletion of potentially useful data was detected by the supervising physician. CONCLUSIONS: Use of a specific software algorithm for routine follow-up of implanted CDs allows a significant shortening of the time spent on routine follow-up, thus reducing costs. The supervision of a physician is a guarantee of patient safety.

Algorithms↗

PubMed2001

Comparison of defibrillation thresholds using monodirectional electrical vector versus bidirectional electrical vector.

BACKGROUND: Currently, two main lead configurations are used for implantable cardioverter-defibrillators (ICD). One generates a monodirectional electrical vector by using the can surface as an active part (hot can) together with a right ventricular defibrillation coil. The other one (TRIAD) produces a bidirectional electrical vector by adding a proximal defibrillation electrode on the same lead. The purpose of this prospective study was to determine whether there is a difference between these configurations in terms of the acute defibrillation threshold (DFT). The secondary objective was to evaluate the possible sequential effect of successive arrhythmia induction and defibrillation shocks on the final DFT value. METHODS: In 44 patients (37 males, 7 females, mean age 59.18 +/- 12.05 years; mean ejection fraction 35.21 +/- 11.69%), a Hot Can Ventak family ICD (Guidant, St. Paul, MN, USA) was implanted in a left pectoral pocket. During the implant procedure, step-down to failure DFT testing was performed twice in each patient using the two different above-mentioned configurations: the bidirectional and the monodirectional. The first configuration to be tested was determined by a 1:1 randomization by center. RESULTS: The step-down DFT protocol was followed in 35 patients. The average DFT was 8.6 +/- 4.0 J for TRIAD and 10.4 +/- 4.3 J for the monodirectional (p = 0.009) lead configuration; this represents a 16.3% decrease in the DFT using a bidirectional configuration. Furthermore, no relationship between the final DFT and the number of ventricular fibrillation inductions and shocks received was observed, confirming the secondary objective. CONCLUSIONS: Compared to the monodirectional electrical vector, the bidirectional electrical vector is clearly more beneficial for the patient.

Adult↗

PubMed2000

Cardiac pacing in heart failure patients with left bundle branch block: impact of pacing site for optimizing left ventricular resynchronization.

BACKGROUND: Acute left ventricular pacing has been associated with hemodynamic improvement in patients with congestive heart failure and wide QRS complex. We hypothesized that pacing two left ventricular sites simultaneously would produce faster activation and better systolic function than single-site pacing. METHODS: We selected 14 heart failure patients (NYHA functional class III or IV) in normal sinus rhythm with left bundle branch block and QRS > 150 ms. An 8F dual micromanometer catheter was placed in the aorta for measuring +dP/dt (mmHg/s), aortic pulse pressure (mmHg), and end-diastolic pressure (mmHg). Pacing leads were positioned via coronary veins at the posterior base and lateral wall. Patients were acutely paced VDD at the posterior base, lateral wall, and both sites (dual-site) with 5 atrioventricular delays (from 8 ms to PR -30 ms). Pacing sequences were executed in randomized order using a custom external computer (FlexStim, Guidant CRM). RESULTS: Dual-site pacing increased peak +dP/dt significantly more than posterior base and lateral wall pacing. Dual-site and posterior base pacing raised aortic pulse pressure significantly more than lateral wall pacing. Dual-site pacing shortened QRS duration by 22 %, whereas posterior base and lateral wall pacing increased it by 2 and 12%, respectively (p = 0.006). CONCLUSIONS: In heart failure patients with left bundle branch block, dual-site pacing improves systolic function more than single-site stimulation. Improved ventricular activation synchrony, expressed by paced QRS narrowing, may account for the additional benefit of dual- vs single-site pacing in enhancing contractility. This novel approach deserves consideration for future heart failure pacing studies.

Adult↗

PubMed1998

Clinical experience with downsized lower energy output implantable cardioverter defibrillators. Ventak Mini II Clinical Investigators.

BACKGROUND AND STUDY OBJECTIVE: Technical improvements in cardioverter defibrillators technology has resulted in decrease in can size coupled with improved electrodes technology. A decrease in maximum energy output allows further decrease in device size. The aim of this study was to evaluate the feasibility of a single lead transvenous implant employing a downsized cardioverter-defibrillator (volume 59 cm3), with a related decrease in maximum energy output (29-31 joules as stored energy and 25-27 joules as delivered energy). METHODS AND RESULTS: Fifty-five patients with ventricular tachyarrhythmias were enrolled in 17 European institutions for implantation. At implantation step-down defibrillation threshold (DFT) was determined and the device was implanted only if a safety margin > or =10 joules was maintained between DFT and maximum programmable output. Implantation was performed in 54 of the 55 referred patients (98%) in a single electrode-device configuration. Step-down DFT testing was performed in 44 patients (43 finally implanted) and DFT was 7.77+/-4.41 joules (range 3-20). In 20 of the tested patients (45%) DFT was < or =5 joules, in 26 patients (59%) was < or =8 joules and in 34 patients (77%) it was < or =10 joules. No differences were found in DFT comparing patients with left ventricular ejection fraction < or = or >40% or patients treated or not with antiarrhythmic drugs or beta-blockers. Mean implant duration was 85+/-34 min. CONCLUSIONS: Employing a downsized cardioverter defibrillator, successful transvenous implantation can be achieved in 98% of the patients, with maintenance of adequate defibrillation safety margins despite a reduction in stored energy to 29 joules.

Adult↗