Permanent cardiac pacing in a 2.5 month-old infant with severe cyanotic breath-holding spells and prolonged asystole

We report the case of a 2.5 month-old infant with cyanotic breath-holding spells, loss of consciousness and seizures. Prolonged asystole up to 70 s despite cardiopulmonary resuscitation was documented by 24 hour Holter monitoring. An epicardial pacemaker was implanted followed by no further loss of consciousness and seizures during spells in a six month follow-up period. (Cardiol J 2011; 18, 6: 704–706

Left ventricular non-compaction in children and adolescents: Clinical features, treatment and follow-up

Background: Left ventricular non-compaction (LVNC) is a specific cardiomyopathy that occurs following a disruption of endomyocardial morphogenesis. This study presents clinical findings, diagnostic features, treatment and follow-up of pediatric patients diagnosed with LVNC. Methods: Patients with LVNC who were followed from January 2006 to March 2010 were included in this study. Diagnosis was made with the use of characteristic findings of magnetic resonance imaging and echocardiography. Holter electrocardiography and metabolic screening tests were also performed in all patients. Results: A total of 24 patients were studied (18 male, six female). Patient age at diagnosis was 50 ± 60 months (eight days to 15 years). Average follow-up period was 22 ± 12 months (four months to four years). Findings at diagnosis were as follows: eight (33%) patients had heart failure, five (20%) had rhythm abnormalities, five (20%) had cardiomegaly, two had murmurs, two had cyanosis, and two presented with fatigue. Ten (41%) patients had been followed previously with other diagnoses. In 21 (87.5%) patients, electrocardiographic abnormalities were noted, especially left ventricular hypertrophy and ST-T changes. Patients had an average ejection fraction of 46% (18-73%) and three of them had additional congenital heart disease (patent ductus arteriosus, aortopulmonary window and complex cyanotic heart disease). Scanning for metabolic diseases revealed fatty acid oxidation disorder in one patient, and mitochondrial disease in another. During follow-up, a permanent pacemaker was implanted in a patient with severe bradycardia and ventricular dysfunction, and three patients died. Conclusion: LVNC can be diagnosed at any age from newborn to adolescent and has a variable clinical course. Closer study of patients with cardiomegaly and heart failure can reduce delays in diagnosis of LVNC. (Cardiol J 2011; 18, 2: 176-184

Evaluation of coronary artery abnormalities in Williams syndrome patients using myocardial perfusion scintigraphy and CT angiography

Background: Sudden death risk in Williams syndrome (WS) patients has been shown to be 25–100 times higher than in the general population. This study aims to detect coronary artery anomalies and myocardial perfusion defects in WS patients using noninvasive diagnostic methods. Methods: This study features 38 patients diagnosed with WS. In addition to physical examination, electrocardiography, and echocardiography, computed tomography (CT) angiography and rest/dipyridamole stress technetium-99m sestamibi (99mTc-sestamibi) single photon emission computed tomography (SPECT) myocardial perfusion scintigraphy (MPS) were performed. Results: Twenty-one (55%) patients were male; 17 (45%) were female. The average patient age was 12 ± 5 years (2.5–26 years); the average follow-up period was 7.2 ± 4.2 years (6 months–18 years). Cardiovascular abnormalities were found in 89% of patients, the most common one being supravalvar aortic stenosis (SVAS). CT angiography revealed coronary anomalies in 10 (26%) patients, the most common ones being ectasia of the left main coronary artery and proximal right coronary artery as well as myocardial bridging. SVAS was present in 80% of patients with coronary artery anomalies. 99mTc-sestamibi SPECT MPS revealed findings possibly consistent with myocardial ischemia in 29% of patients, and ischemia in 7 out of 10 patients (70%) with coronary anomalies shown on CT angiography (p = 0.03). Conclusions: Coronary artery abnormalities are relatively common in WS patients and are often accompanied by SVAS. CT angiography and dipyridamole 99mTc-sestamibi SPECT MPS seem to be less invasive methods of detecting coronary artery anomalies and myocardial perfusion defects in WS patients

A Full Wave Conductor Modeling Using Augmented Electric Field Integral Equation

A numerical full wave solver is proposed to solve conductor problems in electromagnetics. This method is an extension of the dielectric augmented electric field integral equation (D-AEFIE). Using this method, conductors, from lowly lossy to highly lossy, can be rigorously modeled to capture the conductive losses. Broadband stability can be achieved, thanks to the introduction of the augmentation technique. This paper demonstrates the formulation of this method. A simple and effective preconditioner is introduced to accelerate the convergence. A novel integration scheme is adopted to accurately capture the losses inside the conductor. Finally some numerical examples are shown to support the capability of this method to solve real-world circuit problems

Novel Fast Algorithms for Time Domain Integral Equation Analysis of Antennas and Circuits

182 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2002.This dissertation focuses on the development of state-of-the-art TDIE-based methods for analyzing electromagnetic transients in broadband antenna systems and circuits. This is achieved by (i) constructing efficient marching-on-in-time solvers suitable for analysis of scattering and radiation from perfect electrically conducting surface-wire and penetrable dielectric structures, (ii) tailoring the currently existing PWTD schemes to complement these solvers, (iii) extending the PWTD technology for fast analysis of structures with highly varying length scales, and (iv) applying the resulting algorithms to the analysis of nonlinear devices and systems by developing a hybrid circuit-electromagnetic solver. The proposed effort expands the applicability of PWTD-augmented TDIE solvers to the realm of electromagnetic compatibility and electromagnetic interference analysis of electronic and electromagnetic circuits.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD

Impact of Fiber Weaves on 56 Gbps SerDes Interface in Glass Epoxy Packages

Some package substrates are composed of glass fiber bundles and epoxy resin which have different electrical properties. These differences result in variations in characteristic impedance and propagation speeds, which may be detrimental at high data rates. The insertion loss (IL), within pair skew and differential to common mode conversion ratio of transmission lines may drastically increase due to the fiber weave effect. Consequently, the link budget of high speed communication channels may be significantly hindered. This paper addresses the problems due to the fiber weave effect and provides mitigation techniques at the package level, particularly for 56 Gbps Serializer/Deserializer (SerDes) interface

Fiber Weave Impact on Crosstalk of High Speed Communication Channels in Glass Epoxy Packages

Some packaging technologies utilize glass epoxy substrates that are composed of glass fiber bundles and epoxy resin. Because of the different electrical properties of glass and resin, the signal traces can have some variability, depending on their position with respect to the weaves. One of the parameters that are affected by the inhomogeneity of the substrate is the far end crosstalk. Crosstalk may significantly increase, hindering the link budget of high speed communication channels, especially in the dense routing areas. This paper addresses the crosstalk variations, in the frequency and time domains, due to the fiber weave effect (FIVE). Analytical and numerical results are presented to provide a physical insight into the phenomenon, followed by a mitigation technique to minimize the impact

Design of Low-loss Transmission Lines with Common Mode Suppression for Packages

Increasing data rates of high speed serial interfaces forces the insertion loss and common mode (CM) noise requirements to be tighter. This paper addresses both of these challenges by introducing a new low-loss transmission line design with simultaneous common mode filtering property. The line is composed of periodical repetitions of narrow and wide sections, which generates a CM impedance contrast to filter out the CM noise, while differential impedance is kept constant by locally voiding the planes below and above the wide trace sections. As a result of the wider sections, the loss is also smaller