The QT interval: standardization, limits and interpretation

Despite clinical importance of ventricular repolarisation, it remains difficult to analyse. Conventionally, quantification of the electrocardiographic ventricular repolarization is usually performed with reference to axis of the T wave and QT interval duration. A variety of factors can prolong the QT interval, such as drug effects, electrolyte imbalances, and myocardial ischemia. The biggest risk with prolongation of the QT interval is the development of torsades de pointes. Commonly accepted reference ranges for the electrocardiogram (ECG) have been in use, with little change, for many years. Populations throughout the world present several differences: age, ethnic compositions, and are exposed to different environmental factors. Recent studies have reported reference data for QT interval in healthy population and have evaluated the influence of age, gender, QRS duration and heart rate on this interval. In this review, we address several issues relative to the measurement, and interpretation of QT interval and its adjustment for rate, age, gender and QRS duration.     

Hypertension and aortorenal disease in Alagille syndrome

Alagille syndrome is a rare congenital multisystem disorder that may involve heart disease and pulmonary or peripheral artery stenosis. We report the clinical and radiological presentation of five adult patients with Alagille syndrome, hypertension and renal artery stenosis. All had systolic hypertension and a narrowing of the abdominal aorta, corresponding to a secondary midaortic syndrome. Renovascular disease progressed during follow-up, with increases in blood pressure, decreases in glomerular filtration rate and/or kidney atrophy. A literature review identified several anecdotal reports of Alagille syndrome associated with hypertension, renal artery stenosis and/or midaortic syndrome. We discuss this condition, focusing on diagnosis, differential diagnosis, associated conditions and management. Cardiologists, nephrologists and radiologists should be aware of this rare cause of renovascular hypertension and of the need for clinical, biological and echographic follow-up.     

Extrahepatic metastases occur in a minority of hepatocellular carcinoma patients treated with locoregional therapies: analyzing patterns of progression in 285 patients

Although most cancers are considered predominantly systemic processes, this may not hold true for hepatocellular carcinoma (HCC). The literature regarding patterns of progression of HCC (local versus systemic) has been relatively sparse. Our objectives were to: (1) analyze patterns of progression in HCC patients presenting with intrahepatic disease from initial treatment until death, and (2) identify clinically relevant risk factors for the development of metastases. Over a 9-year period, 285 patients treated with transarterial locoregional therapies underwent scheduled imaging follow-up from treatment until death and were categorized by pattern of progression: (i) intrahepatic (increased tumor enhancement/size, development/progression of vascular invasion, new hepatic lesions) progression or (ii) extrahepatic (adrenal/bone/lung/lymph node) metastases. Uni/multivariate analyses assessing the risk factors for the development of metastases were performed. The median time from last scan to death was 2.4 months (interquartile range: 1.3-4.8 months). The time to development of metastases, vascular invasion, and/or new lesions was 13.8 months (confidence interval: 11.3-17.7 months). Of the 209 patients followed until death, only 50 developed extrahepatic metastases (24%). Multivariate analyses identified age <65 years (P = 0.038), alpha-fetoprotein >200 ng/mL (P = 0.04), and vascular invasion (P = 0.017) as significant predictors of metastases development. CONCLUSION: Knowledge of the risk factors associated with the development of metastases may help guide assessment of patient prognosis. Because 76% of patients presenting with local disease treated with locoregional therapies die without developing extrahepatic metastases, the notion of HCC as a systemic disease, as detected by imaging, may be reconsidered.     

High-fat diet induced an oxidative stress in white adipose tissue and disturbed plasma transition metals in rat: prevention by grape seed and skin extract

Obesity is a public health problem characterized by increased accumulation of fat into adipose tissues leading to oxidative stress, dyslipidemia, and chronic inflammatory status. We used an experimental model of high-fat diet-induced obesity to analyze the link between dyslipidemia, oxidative stress, and fat accumulation into adipose tissue of rats, as well as the involvement of intracellular mediators such as transition metals on signal transduction. We also looked at the ability of a grape seed and skin extract (GSSE) from a Tunisian cultivar to prevent fat-induced disturbances. Data showed that a high-fat diet (HFD) provoked dyslipidemia into plasma which is linked to an oxidative stress, an accumulation of transition metals such as manganese, copper, and zinc and a depletion of iron. GSSE prevented dyslipidemia by modulating lipase activity, together with increased antioxidant capacity and depletion of transition metals as well as of free radicals such as O₂ ^? and OH. These data indicated that GSSE has important preventive effects on HFD-induced obesity and oxidative stress whose transduction seems to involve transition metals. GSSE should be used as a safe anti-obesity agent that could find potential applications in metabolic disorders involving transition metals dyshomeostasis.     

Long-term results after endoscopic drainage and necrosectomy of symptomatic pancreatic fluid collections

Aims: To determine the immediate and long‐term results of endoscopic drainage and necrosectomy for symptomatic pancreatic fluid collections. Methods: The data of 80 patients with symptomatic pancreatic fluid collections (mean diameter: 11.7 cm, range 3–20; pseudocysts: 24/80, abscess: 20/80, infected walled‐off necrosis: 36/80) referred for endoscopic management from October 1997 to March 2008 were analyzed retrospectively. Results: Endoscopic drainage techniques included endoscopic ultrasound (EUS)‐guided aspiration (2/80), EUS‐guided transenteric drainage (70/80) and non‐EUS‐guided drainage across a spontaneous transenteric fistula (8/80). Endoscopic necrosectomy was carried out in 49/80 (abscesses: 14/20; infected necrosis: 35/36). Procedural complications were bleeding (12/80), perforation (7/80), portal air embolism (1/80) and Ogilvie Syndrome (1/80). Initial technical success was achieved in 78/80 (97.5%) and clinical resolution of the collections was achieved endoscopically in 67/80 (83.8%), with surgery required in 13/80 (perforation: four; endoscopically inaccessible areas: two; inadequate drainage: seven). Within 6 months five patients required surgery due to recurrent fluid collections; over a mean follow up of 31 months, surgery was required in four more patients due to recurrent collections as a consequence of underlying pancreatic duct abnormalities that could not be treated endoscopically. The long‐term success of endoscopic treatment was 58/80 (72.5%). Conclusions: Endoscopic drainage of symptomatic pancreatic fluid collections is safe and effective, with excellent immediate and long‐term results. Endoscopic necrosectomy has a risk of serious complications. The underlying pancreatic duct abnormalities must be addressed to prevent recurrence of fluid collections.     

Computer-assisted fluoroscopic navigation of percutaneous spinal interventions

Purpose

Percutaneous spine procedures may occasionally be difficult and subject to complications. Navigation using a dynamic reference base (DRB) may ease the procedure. Yet, besides other shortcomings, its fixation demands additional incisions and thereby defies the percutaneous character of the procedure.

Methods

A new concept of atraumatic referencing was invented including a special epiDRB. The accuracy of navigated needle placement in soft tissue and bone was experimentally scrutinised. Axial and pin-point deviations from the planned trajectory were investigated with a CT-based 3D computer system. Clinical evaluation in a series of ten patients was also done.

Results

The new epiDRB proved convenient and reliable. Its fixation to the skin with adhesive foil provided a stable reference for navigation that improves the workflow of percutaneous interventions, reduces radiation exposure and helps avoid complications.

Conclusions

Percutaneous spine interventions can be safely and accurately navigated using epiDRB with minimal trauma or radiation exposure and without additional skin incisions.     

Histologically Unstable Asymptomatic Carotid Plaques Have Altered Expression of Genes Involved in Chemokine Signalling Leading to Localised Plaque Inflammation and Rupture

BackgroundMany studies have evaluated histological and gene expression profiles in TIA/stroke patients after onset of symptoms, but there is limited understanding as to how these plaque related features interact before symptom onset. In particular, no studies have evaluated differential gene expression in histologically unstable (vs stable plaques) in neurologically asymptomatic patients.MethodsNine asymptomatic patients had their plaques scored blindly by two independent Histopathologists using the AHA plaque scoring system. RNA extracted from the plaques was hybridised onto a whole genome microarray. Analysis was performed using GenomeStudio (v1.0) and the DAVID bioinformatics resource (v6.7).ResultsThree plaques were histologically unstable (Grade 2/3), while six were stable (Grade 0/1). 346 differentially expressed genes (>1.3 fold, P < 0.05) were identified (293 down-regulated and 53 up-regulated) between stable and unstable plaques. Genes related to chemokine and protein signalling (pro-inflammatory/pro-apoptotic) were identified to have high enrichment scores (>1.3) and were significantly up-regulated in unstable (asymptomatic) plaques.ConclusionThe findings confirm the intuitively held belief that changes in chemokine and protein signalling may be associated with acute plaque disruption and precede the onset of symptoms. Once validated, these genes could therefore become targets for innovative medical treatments in the future or could help identify asymptomatic patients with histologically unstable plaques that would benefit from surgical intervention.