Sivakumar Radhakrishnan

Intel 870: a building block for cost-effective, scalable servers

Architects based the Intel 870 system architecture on the scalability port, a coherent system interconnect. The systems building-block approach lets a single chip set support a wide range of server segments.

The Blackford Northbridge Chipset for the Intel 5000

The Intel 5000 is a shared-memory, symmetric dual-processor system based on the energy-efficient, high-performance Intel core 2 dual- and quad-core processors. A key component is the northbridge, which interconnects processor, memory, and I/O interfaces. The Blackford northbridge chipset provides multicore processor support and platform-level features and technologies. In this article, we describe the Intel 5000 component architecture, focusing on the BNB chipset and its main interfaces. We also describe the chipsets key innovations, which help define new standards of function, performance, and feature set in the dual-processor segment.

Nonsurgical Management of a Congenital Aortocaval Fistula from Right Subclavian Artery to Superior Vena Cava Along with SVC Obstruction

Congenital arteriovenous malformations between the subclavian artery and the superior vena cava (SVC) is a very rare anomaly scantily described in the literature. We describe this anomaly in a 4-month-old infant who presented with congestive heart failure. He was diagnosed to have a right subclavian artery to SVC fistula associated with SVC stenosis .The child successfully underwent device (vascular plug) closure of the fistula and SVC stenting. Six months postprocedure, child is doing well, with complete resolution of symptoms.

Methemoglobinemia: Arterial blood gas as a diagnostic tool

Methemoglobinemia is an important differential diagnosis of a case of cyanosis with no underlying structural heart disease. We report 2 cases of this rare disorder who were referred to our hospital with cyanosis.

Long-term results of percutaneous balloon valvuloplasty of congenital aortic stenosis in adolescents and young adults

Balloon aortic valvuloplasty (BAV) is a well accepted modality of treatment in congenital aortic stenosis in all age groups. Although in infants and children it is the modality of choice, in adolescents and young adults, it is of debatable efficacy. Aim To evaluate long-term results of aortic valvuloplasty particularly in adolescent and adults (>12 years) and compare the outcome in other age groups that are <1 year and between 1 are 11 years. Setting Tertiary referral center. Patients 165 consecutive patients treated at the median age of 9 years (1 day to 64 years). The follow-up was up to 14 years (median 3 years). The whole cohort was divided into 3 age-based subgroups: Group A (<1 year) n = 45, Group B (1 year–11 years) n = 52, and Group C (>12 years) n = 68. The characteristics of each subgroup were mutually compared. Intervention Percutaneous balloon valvuloplasty with mean (SD) balloon to annulus ratio of 0.93. Main outcome measures were repeat BAV, significant aortic regurgitation (AR), and aortic valve replacement/repair. Results The incidence of significant AR from the whole cohort was 9.9% (8% moderate, 1.9% severe); n = 16. Group A = significant AR 9.5% (7.1% moderate, 2.4% severe), Group B = significant AR 11.3% (9.4% moderate, 1.9% severe), and Group C = significant AR 9% (7.5% moderate, 1.5% severe); p value = 0.99 (Group C vs Group A) and 0.92 (Group C vs Group B). Repeat BAV rate was 13.3% (n = 22 out of 165 patients). Group A – n = 5 (11.9%), Group B – n = 10 (18.2%), and Group C – n = 7 (10.3%). p Value = 0.78 (C vs A) and 0.19 (C vs B). Surgery in follow-up was needed in n = 4 (2.4%), none in Group A, 2 patients in Group B (3.6%), and 2 patients in group C (2.9%). Patients were followed up for a period of 14 years; Group A = up to 8 years, Group B = up to 13 years, and Group C = up to 14 years. Mean survival probability after the procedure was 8 years (Group A = 6.5 years, Group B = 8.1 years, and Group C = 9.9 years), and p value = 0.49 (A vs B), 0.23 (B vs C), and 0.4 (A vs C). Conclusion There is no statistical difference in the long-term outcome in the adults and adolescents as compared to the children; thus BAV remains an obvious treatment of choice with good long-term outcome.

Lutembacher Syndrome With Unroofed Left Superior Vena Cava: A Diagnostic Dilemma

Lutembacher syndrome involving the association of congenital atrial septal defect (ASD), usually of the ostium secundum variety, and mitral valve disease is a well-known entity. Its association with a coronary sinus, ASD, and a persistent left superior vena cava (LSVC) draining into the left atrium (LA) (Raghib syndrome) is rarely described in the literature. This association in a 15-year-old boy erroneously deemed to be inoperable before referral to the authors’ hospital due to cyanosis in the presence of atrial septal defect (ASD) and mitral stenosis is described in this report. Evaluation by echocardiography followed by cine angiography confirmed the cause of cyanosis to be drainage of the LSVC into the LA together with an ASD and rheumatic mitral stenosis, a combination of Raghib and Lutembacher syndromes. The boy underwent successful surgical correction. The authors believe this is the second such case to be reported in the English literature and the first of its kind to be managed by surgical intervention.

Anatomically Corrected Malposition of the Great Arteries {S, D, L} With Left Juxtaposition of the Atrial Appendages in DORV: Influence on Surgical Approach

The case of an infant with double outlet right ventricle with anatomically corrected malposition of the great arteries, bilateral infundibulum, and an echocardiographically routable ventricular septal defect (VSD) is presented. After numerous efforts to visualize the margins of the VSD, the best surgical exposure of the VSD was through the aorta. We believe this to be the first report of this phenomenon, which results from the left-sided position of the aorta and the presence of left juxtaposition of the atrial appendages.

Anatomically Corrected Malposition

At the outset, we would like to thank Professor Robert Anderson about having appreciated the article and really cherish his comments, which are always very informative. What the present case highlights is a case that would otherwise classify itself as anatomically corrected malposition of great arteries with fS,D,Lg morphology. As Professor Anderson emphasizes, the entity would classically hold itself in the presence of concordant ventriculoarterial connection. The reason of our using the terminology of double outlet right ventricle (DORV) in the present case was essentially because of the presence of aortomitral discontinuity and this arising out of the presence of the left-sided conal tissue (and hence the presence of bilateral conus tissue). We found it rather suitable to follow Professor Anderson’s suggestions (given in many of his earlier communications) that we rather elaborated the lesions in the case report and hence forth classified it further into the two abovementioned modalities. We are aware of the fact that the two existent morphological schools of thought, that of Professor Anderson and that of Dr Richard Van Praagh, would look at this particular lesion in different descriptive subsets. With the presence of the bilateral conus, the latter would rather classify the lesion into DORV (as we used intermittently), though we reemphasize that we would rather put the lesion as a fS,D,Lg morphology (as emphasized by the usage of the terminology both in the text and also in the heading of the topic). To further emphasize upon the anatomy, let me highlight a few surgical features of the case. Intraoperatively, it was observed that main pulmonary artery arose completely from the right ventricle (RV). The ascending aorta arose externally from RV. Looking through the transected aorta, the inferior border of the ventricular septum could be seen to have position with about 70% of the aorta overlying the RV and rest over the left ventricle. There was a muscular ridge separating the mitral valve from the aortic valve (conus tissue that was seen in echo too). Moreover, the final anterior sutures of the ventricular septal defect (VSD) were interrupted mattress sutures taken with the loop placed on the patch and tied on the anterior wall of the RV, as that was the site where the anterior ascending aorta was attached. We would also like to highlight that the purpose of having presented the present case is not only to highlight the morphology observed rather the presence of associated juxtaposed right atrial appendage that hampered the visualization of the VSD in this particular case.

Dual Right Coronary Arteries in Transposition of Great Arteries

A 37-day-old full-term male neonate weighing 3.5 kg presented with mild tachypnea and cyanosis observed since birth. The boy was observed to have transposition of great arteries (TGA) with malpositioned great vessels. He had a nonrestricted perimembranous ventricular septal defect (VSD) and an additional small mid-muscular VSD. The boy had a 2.3-mm PDA that shunted left to right. His coronary profile showed a large branch arising from the left facing sinus, giving rise to the left anterior descending artery and the right coronary artery (RCA) [1, 4, 5]. This RCA supplied the anterior aspect of the right ventricular free wall (Figs. 1, 2). An additional coronary artery, which traveled in the right atrioventricular groove (smaller than the RCA from the left facing sinus), supplied the remainder of the right ventricular aspect (Fig. 3). The left circumflex artery originated from the RCA arising from right facing sinus (Fig. 4). The boy underwent successful coronary artery translocation, VSD closure, and the Lecomptes maneuver with an arterial switch operation. The coronary artery anatomy was confirmed during surgery with successful translocation of the coronary buttons.

Stepwise evaluation of left to right shunts by echocardiography

Echocardiography has revolutionized the practice of pediatric cardiology. The addition of Doppler and color flow mapping also gives physiological information about flow and pressures and enables the pediatric cardiologist to refer patients for surgical treatment without cardiac catheterization, especially in neonate and infants. In this communication echocardiographic findings of common shunt lesions are discussed.