P. Festa - Academia.edu (original) (raw)

Papers by P. Festa

European Heart Journal Supplements

Introduction Adults with repaired tetralogy of Fallot (rToF) experience episodes of atrial tachyc... more Introduction Adults with repaired tetralogy of Fallot (rToF) experience episodes of atrial tachycardia (AT) and radiofrequency catheter ablation (RFCA) is often required but systematic evaluation of the mechanisms and recurrences is lacking. Methods Between January 2013 and October 2021, 20 rToF patients with AT referred for catheter ablation were enrolled. Electrophysiologic study with 3D electroanatomic mapping with multi–electrode mapping catheters was done, with right atrial bipolar voltage and activation mapping of the AT. Three mechanisms were searched: intra–atrial re–entrant tachycardias (IART), focal (FAT), other. Critical isthmus (CI) for IART was identified with activation mapping. FATs were localized according to the earliest uni/bipolar signal. All induced AT were treated. RFCA was aimed at the earliest activation point for FAT and at the critical isthmus for IART, anchoring lesion to fixed obstacles (valve annuli or scar). Written informed consent was provided. Results...

2017 19th International Conference on Transparent Optical Networks (ICTON)

The introduction of new services requiring large and dynamic bitrate connectivity can cause chang... more The introduction of new services requiring large and dynamic bitrate connectivity can cause changes in the direction of the traffic in metro and even core network segments along the day. This leads to large overprovisioning in statically managed virtual network topologies (VNT), designed to cope with the traffic forecast. To reduce expenses while ensuring the required grade of service, in this paper we propose the VNT reconfiguration approach based on current and near-future traffic matrices (VENTURE) to regularly adapt the topology to both, the current and future traffic volume and direction. The problem is formally stated and a heuristic algorithm is proposed to solve it.

European Heart Journal - Cardiovascular Imaging, 2020

Introduction Congenital heart diseases (CHD) are detected in 1% of children, often usually the fi... more Introduction Congenital heart diseases (CHD) are detected in 1% of children, often usually the first year of life; however, many defects are diagnosed later or remain undiagnosed. Both congenital and acquired disorders could affect the left ventricle (LV). First-line assessment includes echocardiography; nonetheless, because of intrinsic or technical limitations and artefacts, further investigation may be required. Cardiac Magnetic Resonance (CMR) is capable of providing anatomical and functional information without many of limitations and drawbacks of echocardiography. We describe CMR findings of misdiagnosed cases of two rare congenital LV abnormalities: isolated LV apical hypoplasia (ILVAH) and double-chambered LV (DCLV). Case report 1 (image A,B,D) An 18 yrs girl diagnosed with dilated cardiomyopathy (DCM) was submitted to our CMR Lab for a functional assessment. After birth, deep Q waves in the inferior leads were noted on the ecg, and an echocardiographic examination showed a ...

European Heart Journal – Cardiovascular Imaging, 2016

Background: Impaired right ventricular (RV) systolic function after acute ST-segment elevation my... more Background: Impaired right ventricular (RV) systolic function after acute ST-segment elevation myocardial infarction (STEMI) is associated with poor clinical outcomes. CMR feature tracking technique enables quantification of myocardial deformation and becomes promising method. The aim of this study was to evaluate longitudinal and transverse strain and strain rate of RV free wall in patients with acute isolated left ventricular STEMI using CMR feature tracking. Methods: A total of 38 participants (mean age 59 + 10.8 years; 60% male) were recruited into the study and underwent CMR at 1.5 Tesla (Siemens Magnetom Aera). TomTec 2D Cardiac Performance Analysis software was used to analyze mean and segmental longitudinal and transverse strain and strain rate of the RV free wall. Patients with RV myocardial infarction (LGE of RV myocardium) were excluded. Results: RV free wall longitudinal strain and strain rate parameters did not reach statistical significance. Patients with acute STEMI demonstrated lower mean RV free wall transverse strain (12.40 + 8.10% vs 21.70 + 7.32%, p ¼ 0.0001) and strain rate (1.08 + 0.33 s-1 vs 1.51 + 0.38 s-1, p ¼ 0.001) than controls. We also performed segmental analysis. Transverse strain was significantly impaired in the basal (15.52 + 8.81% vs 24.52 + 11.29%, p ¼ 0.03), mid (11.16 + 8.34% vs 18,21 + 7.57%, p ¼ 0.02) and apical (10.52 + 11.53% vs 22.37 + 10.33%, p ¼ 0.001) segments of RV free wall in patients with STEMI comparing with controls. Transverse strain rate was lower in the basal (0.97 + 0.44 s-1 vs 1.51 + 0.43 s-1, p ¼ 0.001) and mid (0.91 + 0.31 s-1 vs 1.36 + 0.41 s-1, p ¼ 0.01) segments in STEMI group. There was no difference between groups for apical transverse strain rate of RV free wall. Conclusions: This study demonstrates that transverse strain and strain rate of RV free wall are impaired in patients with acute isolated left ventricular STEMI while longitudinal RV systolic function remains normal.

Springer Proceedings in Mathematics & Statistics, 2014

This paper describes the far from most string problem, one of the computationally hardest string ... more This paper describes the far from most string problem, one of the computationally hardest string selection problems that has found its way into numerous practical applications, especially in computational biology and bioinformatics, where one is interested in computing distance/proximity among biological sequences, creating diagnostic probes for bacterial infections, and/or discovering potential drug targets.With special emphasis on the optimization and operational research perspective, this paper studies the intrinsic properties of the problem and overviews the most popular solution techniques, including some recently proposed heuristic and metaheuristic approaches. Future directions are discussed in the last section.

Studies in Computational Intelligence, 2009

Experience has shown that a crafted combination of concepts of different metaheuristics can resul... more Experience has shown that a crafted combination of concepts of different metaheuristics can result in robust combinatorial optimization schemes and produce higher solution quality than the individual metaheuristics themselves, especially when solving difficult real-world combinatorial optimization problems. This chapter gives an overview of different ways to hybridize GRASP (Greedy Randomized Adaptive Search Procedures) to create new and more effective metaheuristics. Several types of hybridizations are considered, involving different constructive procedures, enhanced local search algorithms, and memory structures.

Lecture Notes in Economics and Mathematical Systems

Ad hoc networks have been used in the last few years to provide communications means among agents... more Ad hoc networks have been used in the last few years to provide communications means among agents that need to accomplish common goals. Due to the importance of communication for the success of such missions, we study the problem of maximizing communication among a set of agents. As a practical tool to solve such problems, we introduce a one-pass randomized algorithm that maximizes the total communication, as measured by the proposed objective function. Agents in this problem are routed along the edges of a graph, connecting their individual starting nodes to their respective destination nodes. This problem, known as the Cooperative Communication Problem in Mobile Ad Hoc Networks, is known to be NP-hard. We present a new heuristic and motivate the need for more advanced methods for the solution of this problem. In particular, we describe 1) a construction algorithm and 2) a local improvement method for maximizing communication. Computational results for the proposed approach are provided, showing that instances of realistic size can be efficiently solved by the algorithm.

Journal of Cardiovascular Medicine, 2015

On the behalf of the working group 'Applicazioni della Risonanza Magnetica' of the Italian Societ... more On the behalf of the working group 'Applicazioni della Risonanza Magnetica' of the Italian Society of Cardiology Cardiac magnetic resonance (CMR) is considered the gold-standard noninvasive technique for the quantification of ventricular volumes by cine-imaging and of vascular flows by velocity-encoded phase contrast (VENC). In routine CMR scans, it is common to found clinical conditions, as valve regurgitations and cardiac shunts, producing a volume overload and significant mismatch between the right and left ventricular stroke volumes (RSV and LSV). In the presence of a valve regurgitation, the volume overload involves the respective ventricular chamber, whereas in cardiac shunts, the location of the volume overload depends on the site of the anatomic defect. Moreover, when a cardiac shunt is present, pulmonary and systemic cardiac outputs are different (Qp/Qs < 1 or Qp/Qs > 1), whereas in the presence of valve regurgitation, Qp/Qs U 1. Therefore, by combining the cine-imaging with the VENC technique, it is possible to investigate the cardiac physiology underlying different pathological conditions producing volume overload, and to quantify this overload (the regurgitant volume and/or shunt volume). In this report, we discussed the technical, theoretical and methodological aspects of this sort of 'virtual catheterization' by CMR, providing a simple algorithm to make the correct diagnosis.

Lecture Notes in Computer Science, 2010

GRASP with path-relinking (GRASP+PR) is a metaheuristic for finding optimal or near-optimal solut... more GRASP with path-relinking (GRASP+PR) is a metaheuristic for finding optimal or near-optimal solutions of combinatorial optimization problems. This paper proposes a new automatic parameter tuning procedure for GRASP+PR heuristics based on a biased random-key genetic algorithm (BRKGA). Given a GRASP+PR heuristic with n input parameters, the tuning procedure makes use of a BRKGA in a first phase to explore the parameter space and set the parameters with which the GRASP+PR heuristic will run in a second phase. The procedure is illustrated with a GRASP+PR for the generalized quadratic assignment problem with n = 30 parameters. Computational results show that the resulting hybrid heuristic is robust.

Lecture Notes in Computer Science, 2011

This paper presents a new approach to solve the NP-complete minimum branch vertices problem (MBV)... more This paper presents a new approach to solve the NP-complete minimum branch vertices problem (MBV) introduced by Gargano et. al[1]. In spite of being a recently proposed problem in the network optimization literature, there are some heuristics to solve it [3]. The main contribution of this paper consists in a new heuristic based on the iterative refinement approach proposed by Deo and Kumar [2]. The experimental results suggest that this approach is capable of finding solutions that are better than the best known in the literature. In this work, for instance, the proposed heuristic found better solutions for 78% of the instances tested. The heuristic looks very promising for the solution of problems related with constrained spanning trees.

Pediatric Cardiology, 2007

To evaluate the relationship between plasma concentration of amino-terminal fragment of pro-brain... more To evaluate the relationship between plasma concentration of amino-terminal fragment of pro-brain natriuretic peptide (NT-proBNP), functional capacity, and right ventricular overload in survivors of tetralogy of Fallot (TOF) repair, we prospectively studied 70 operated TOF patients (44 males, 21 ± 1 years old; mean ± SEM) who underwent, during the same day, echocardiography, cardiac magnetic resonance imaging, neurohormonal characterization (plasma NT-proBNP, catecholamines, plasma renin activity, and aldosterone assay), and cardiopulmonary exercise testing. Forty-eight age-and sex-matched healthy volunteers served as the control group. Compared to controls, maximal workload and peak oxygen consumption (VO 2 /kg) were lower in operated TOF patients (p < 0.001), whereas NT-proBNP concentration was elevated (p < 0.001). No difference was found among the other neurohormones. In operated TOF patients, NT-proBNP showed a significant positive correlation with right ventricular (RV) end systolic and end diastolic volumes and RV systolic pressure, and it showed a negative correlation with peak VO 2 /kg and RV ejection fraction. From multivariable analysis, NT-proBNP concentration was found to be an independent predictor of peak VO 2 /kg, RV end systolic volume, and RV systolic pressure. These results show an association among RV overload, decrease in functional capacity, and cardiac natriuretic peptide expression in operated TOF patients. NT-proBNP plasma assay may be a useful tool for diagnostic purposes and for decision making in this setting.

Optimization Letters, 2013

This paper presents a new edge-swap heuristic for generating spanning trees with a minimum number... more This paper presents a new edge-swap heuristic for generating spanning trees with a minimum number of branch vertices, i.e. vertices of degree greater than two. This problem was introduced in Gargano et al. (Lect Notes Comput Sci 2380:355-365, 2002) and has been called the minimum branch vertices problem by Cerulli et al. (Comput Optim Appl 42:353-370, 2009). The heuristic starts with a random spanning tree and iteratively reduces the number of branch vertices by swapping tree edges with edges not currently in the tree. It can be easily implemented as a multi-start heuristic. We report on extensive computational experiments comparing single-start

Journal of Biomechanics, 2006

European Heart Journal, 2012

Cardiology in the Young, 2005

The recent developments in imaging techniques have created new opportunities to give an accurate ... more The recent developments in imaging techniques have created new opportunities to give an accurate description of the three-dimensional morphology of vessels. Such three-dimensional reconstruction of anatomical structures from medical images has achieved importance in several applications, such as the reconstruction of human bones, spine portions, and vascular districts.

Cooperative Networks: Control and Optimization, Jan 2, 2007

ABSTRACT. Ad-hoc networks are a new paradigm for communications systems in which wireless nodes c... more ABSTRACT. Ad-hoc networks are a new paradigm for communications systems in which wireless nodes can freely connect to each other without the need of a pre-specified structure. Difficult combinatorial optimization problems are associated with the design and operation of these networks. In this paper, we consider the problem of maximizing the connection time between a set of mobile agents in an ad-hoc network. Given a network and a set of wireless agents with starting nodes and target nodes, the objective is to find a set ...

Journal of Optimization Theory and Applications, Apr 1, 2001

Computing the chromatic number of a graph is an NP-hard problem. For random graphs and some other... more Computing the chromatic number of a graph is an NP-hard problem. For random graphs and some other classes of graphs, estimators of the expected chromatic number have been well studied. In this paper, a new 0–1 integer programming formulation for the graph coloring problem is presented. The proposed new formulation is used to develop a method that generates graphs of known chromatic number by using the KKT optimality conditions of a related continuous nonlinear program.

Extended Abstracts of the Fourth Metaheuristics International Conference, Jul 1, 2001

The Max-Cut problem can be stated as follows: Given an undirected graph G=(V, E) and nonnegative ... more The Max-Cut problem can be stated as follows: Given an undirected graph G=(V, E) and nonnegative weights wij on the edges (i, j)∈ E, i, j∈ V, find a subset of vertices S that maximizes the sum of the edge weights in the cut (S, S), ie the sum of the weights of the edges with one endpoint in S and the other in S. The weight of a cut (S, S) will be denoted in the following by w (S, S)=