New cardiology guidelines

The 2006 Guidelines for Management of Patients with Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death (SCD) were released by the American College of Cardiology (ACC), American Heart Association (AHA), and the European Society of Cardiology (ESC) in collaboration with the European Heart Rhythm Association (EHRA) and the Heart Rhythm Society (HRS).

The purpose of this document is to update and combine the previously published recommendations into one source approved by the major cardiology organizations in the United States and Europe.

The new ACC/AHA/ESC Guidelines outline recommendations on the evaluation and treatment of patients who have or may be at risk for ventricular arrhythmias. Evaluation includes noninvasive and invasive techniques such as electrocardiography and electrophysiological testing. Possible therapies include pharmacological (drugs), devices, ablation (destrucworldwide tion of the affected area), surgery and revascularization.

Acute and chronic therapies are addressed. Prognosis and management are individualised according to symptom burden and severity of underlying heart disease in addition to clinical presentation. In addition to recommendations in patients with specific pathology, cardiomyopathy and heart failure, specific populations are also covered, such as athletes, pregnant women, the elderly and paediatric patients.

One of the key updates in the 2006 document is that the implantation of devices now has a range of ejection fractions. The executive summary will be published in the 5 September 2006 issues of the Journal of the American College of Cardiology, and Circulation: Journal of the American Heart Association, and the first September issue of the European Heart Journal (Eur Heart J 2006;27:2099- 2140).

The full-text guideline is published in Europace and e-published in the same issue of the journals noted above, as well as posted on the ACC (www.acc.org), AHA (www.americanheart.org), and ESC (www.escardio.org) sites.

3-D PET /CT Stanford University researchers have demonstrated for the first time the ability to create 3-D positron emission tomography (PET)/computed tomography (CT) images for ‘fly-through’ and ‘flyaround viewing’ of cancer in the lungs and colon, according to a study in the July issue of the Journal of Nuclear Medicine. This powerful ability to meld functional data with accurate anatomical information of possible cancerous tumours from inside the body provides a visual navigation of organs often portrayed on television crime shows like CSI.

Such visualisation “may be used to detect and characterise cancer, spare someone from more invasive medical procedures, lead to better disease detection rates of colon cancer, provide surgical guidance and detect which tumours may be easier to biopsy,” explained Andrew Quon, Stanford’s Clinical Assistant Professor of Radiology/ Diagnostic Radiology.

“Three-dimensional fusion provides unique views of the body that internal organs typically impede,” said Quon. “Our new imaging and processing protocol can peel away the organs, highlight tumours and detect cancerous ‘hot spots’, providing an omnipotent perspective of the body.”

Stanford’s 3-D fusion imaging “appears to have potential for presurgical visualisation, particularly in guiding biopsies,” explained the co-author of ‘Flying Through’ and ‘Flying Around a PET/CT Scan: Pilot Study and Development of 3-D Integrated 18F-FDG PET/CT for Virtual Bronchoscopy and Colonoscopy’.

This imaging technique “may add important diagnostic information that could herald new applications for the use of PET/CT,” he noted. In addition, its diagnostic value was demonstrated in a case in which it revealed a cancer lesion that had not been detected by PET, CT or PET/CT imaging.

“This one case shows the potential synergistic enhancement of both PET and CT when rendered into three dimensions,” said Quon. It should be noted that researchers proved the concept rather than validated the technique.

Future validation studies will be conducted and software tools need additional development, said Quon. Links to videos of Stanford University’s ‘fly through’ and ‘flying around’ PET/CT scans may be viewed at http://jnm.snm journals.org/cgi/content/full/4 7/7/1081/DC3



Cure for blindness

Pioneering work to tackle two of the most common forms of blindness is being undertaken by Glasgow University scientists.

By employing technology similar to that in digital cameras, Dr Keith Mathieson hopes to produce an electronic implant for eyes that will help blind people to regain their vision. Dr Mathieson said: “Blindness is often caused by the light cells at the back of the eye dying off.

By implanting a microelectronic device into the eye, we hope to be able to fool the brain into believing the retina, which converts light into signals that are sent to the brain, is still in working order.

“Advances in microelectronics have allowed us to develop a retinal prosthesis – a small device to be implanted on the retina itself. The device would contain an imaging detector with hundreds of pixels coupled to an array of microscopic stimulating electrodes.

If light forms an image on the detector, then the result will be electrical stimulation of the retina in the shape of this image. The stimulated cells then send the information, via the optic nerve, to the brain.”

The implant prototype has 100 pixels but the team hope that number will increase significantly as their work progresses, as around 500 pixels would allow people to walk down the street and recognise faces. Dr Mathieson cautioned patience with the development, stating: “We are between five and 10 years from first human implants.”



Cardiac diet

The ‘Mediterranean diet’ may half the risks of heart attack and cardiovascular disease according to what’s being hailed as one of the world’s largest and longest dietary intervention studies.

In an article entitled ‘Effects of a Mediterranean- Style Diet on Cardiovascular Risk Factors,’ reported in the 4 July issue of the Annals of Internal Medicine, the researchers note that highrisk participants who improved their diet with vegetables, legumes, olive oil or nuts (especially walnuts), showed lower blood pressure, improved lipid profiles, decreased insulin resistance and reduced concentrations of inflammatory molecules compared with those allocated to a low-fat diet.




Microscopic skin scaffolding

A revolutionary, dissolvable scaffold for growing new areas of skin could provide a safer, more effective way of treating burns, diabetic ulcers and similar injuries.

This ultra-fine, 3-D scaffold, which is made from specially developed polymers, looks similar to tissue paper but has fibres 100 times finer.

Before it is placed over a wound, the patient’s skin cells (obtained via a biopsy) are introduced and attach themselves to the scaffold, multiplying until they eventually grow over it. When placed over the wound, the scaffold dissolves harmlessly over six to eight weeks, leaving the patient’s skin cells behind.

This new approach to skin reconstruction has been developed by a team of chemists, materials scientists and tissue engineers at the University of Sheffield, UK, with funding from the Engineering and Physical Sciences Research Council.

It is designed primarily for cases involving extensive burns where surgeons are unable to take enough skin grafts from elsewhere on the body to cover the damaged areas. Currently, bovine collagen or skin from human donors is used in these cases, but these approaches have potential health and rejection risks. “Simplicity is the key,” said team leader Professor Tony Ryan.

“Previous attempts to find better ways of encouraging skin cell growth have used chemical additives and other elaborate techniques to produce scaffolds, but their success has been limited. We’ve found that skin cells are actually very ‘smart’ - it’s in their DNA to sort themselves into the right arrangement. They just need a comparatively uncomplicated scaffold to help them grow in a safe, natural way.”

The process for making the scaffolds is based on electrospinning. However, the team has made a key advance by developing a new method of making aligned-fibre ‘mats’ from the same biodegradable polymers, for potential use in promoting nerve or tendon growth. This method is currently being patented.



Chemo harm underrated

Young breast cancer patients who receive chemotherapy may have a higher number of serious side effects than reported in clinical trials. According to a new study in the 18 August issue of the Journal of the National Cancer Institute, they may have higher health care expenditures than previously estimated.

Drug-related side effects account for an estimated 6.5% of all hospitalisations in the United States and 100,000 deaths per year. Some researchers believe that these effects are not adequately reported in clinical trials.

Michael Hassett, MD, of the Dana-Farber Cancer Institute in Boston, and colleagues identified 12,239 breast cancer patients age 63 and under through a database of medical claims made through employer-sponsored health insurance plans. They narrowed the pool to 7,052 patients who had made claims during hospitalisations and emergency room visits for side effects from chemotherapy and healthcare expenditures.

Half received chemotherapy and half did not. The authors observed that women who received chemotherapy were more likely to be hospitalised for side effects than those who did not. Chemotherapy recipients, on average, incurred $1,271 more per year in costs for medical expenses related to side effects and $17,617 more per year in costs for ambulatory care than women who did not receive chemotherapy.

The authors write: “Our results suggest that breast cancer chemotherapy may cause more patient suffering and higher healthcare costs than previously estimated. “Healthcare providers must carefully decide whether trial results can be applied to routine clinical practice.”

In an accompanying editorial, John K Erban, MD, and Joseph Lau, MD, of Tufts New England Medical Center and Tufts University School of Medicine in Boston, suggest that the study’s methodology may have excluded under-represented populations and racial and ethnic minorities but note that the results are “important and intriguing”.

They write: “As new drugs of increasing efficacy and few acute toxicities emerge, the tendency will be to push them to market, and there will be few incentives for longer term toxicity studies. “Without careful longterm tracking of late adverse effects, there is a risk that very important toxicity events will occur unnoticed.”



Chronic pain switch

Chronic pain affects millions of people worldwide and current medications are either largely ineffective or have serious side effects.

However, researchers from Columbia University Medical Center (CUMC) in the United States have discovered a protein in nerve cells that acts as a switch for chronic pain, and have applied for a patent to develop a new class of drugs that will block chronic pain by turning this switch off.

The discovery is published on the website of the journal Neuroscience, and was due to appear in the publication’s August issue. Most prior attempts at alleviating chronic pain have focused on the “second order” neurons in the spinal cord that relay pain messages to the brain. It’s difficult to inhibit the activity of these neurons with drugs, though, because the drugs need to overcome the blood-brain barrier.

Instead, the CUMC researchers have focused on the more accessible “first order” neurons in the periphery of our body that send messages to the spinal cord. Pain becomes chronic when the activity of first and second order neurons persists after damaged neuron heals or the tissue inflammation subsides. It’s been known for years that for chronic pain to persist, a master switch must be turned on inside the peripheral neurons, though until now the identity of this switch remained a mystery.

Richard Ambron, PhD, professor of cell biology, and Ying-Ju Sung, PhD, assistant professor, both in the department of Anatomy and Cell Biology, have now discovered that the switch is an enzyme called protein kinase G (PKG). “We’re very optimistic that this discovery and our continued research will ultimately lead to a novel approach to pain relief for the millions suffering from chronic pain,” said Dr Ambron.

The researchers found that upon injury or inflammation, the PKG is turned on and activated. Once activated, these molecules set off other processes that generate the pain messages. As long as the PKG remains on, the pain persists. Conversely, turning the PKG off relieves the pain, making PKG an excellent target for therapy. Dr Ambron and Dr Sung have applied for a patent for the pathway that turns on the PKG, as well as several molecules that inhibit it. The worldwide painkiller market was worth US$50 billion in 2005 and is expected to increase to $75 billion by 2010 and $105 billion by 2015. But none of the existing drugs on the market are adequate to deal with chronic pain. Cox-2 inhibitors carry severe risk of side effects, opioids are highly addictive, Tylenol is ineffective for chronic pain, and other pain drugs cause significant drowsiness.



Global smoking study

A major Canadian-led global study has found all forms of tobacco exposure, whether that be smoking, chewing or inhaling second hand smoke, increase the risk of heart attack. The INTERHEART study, published in the 14 August issue of The Lancet included data from more than 27,000 people in 52 countries. The researchers found that tobacco use in any form, including sheesha smoking, popular in the Middle East, and beedie smoking, common in South Asia, was harmful. Compared to people who had never smoked, smokers had a three-fold increased risk of a heart attack.

Even those with relatively low levels of exposure of eight to 10 cigarettes a day doubled their risk of heart attack. Each cigarette smoked per day, increased the risk by 5.6%. However, the researchers did find that the risk of heart attack decreased with time after stopping smoking. Light smokers, those who consume fewer than 10 cigarettes a day, benefit the most. They have no excess risk three to five years after quitting. By contrast, moderate and heavy smokers of 20 or more cigarettes a day still had an excess risk of around 22%, 20 years after quitting.

The team also found that exposure to second hand smoke increased the risk of heart attack in both former and non-smokers. The findings suggest that individuals with the highest levels of exposure to second hand smoke of 22 hours or more per week may increase their risk of heart attack by around 45%.

Professor Salim Yusuf of the Michael G DeGroote School of Medicine at McMaster University and Hamilton Health Sciences in Hamilton, Canada, said: “Since the risks of heart attack associated with smoking dissipate substantially after smoking cessation, public-health efforts to prevent people from starting the habit, and promote quitting in current smokers, will have a large impact in prevention of heart attack worldwide.”



Circumcision pain

One of the first things many little boys experience is something they’ll never remember – circumcision – but that doesn’t mean it isn’t a painful experience.

The debate over whether infants feel pain has ended – they do. This conclusion is catching up with obstetrical, paediatric and family physician training programmes in the United States, 97% of which now learn effective pain relief techniques for circumcision.

Just 10 years ago, only 71% learned how to ease pain during the brief surgical procedure. The study, published in the 20 July issue of Ambulatory Pediatrics, says the two most effective and most commonly used pain relief techniques are the dorsal penile nerve block and the subcutaneous ring block.

Both techniques involve the injection of the painkiller lidocaine at the base of the penis which decreases pain sensation prior to circumcision. Topical anaesthetic creams are less effective but they are safe and do provide some pain relief. Any of these techniques can be used in combination with the Mogen clamp, the Gomco clamp and the Pastibell method, the three most common surgical methods of circumcision.



TV kills pain for kids

TV really does act like a painkiller when it comes to kids, reveals a small study published ahead of print in the Archives of Disease in Childhood.

The research team assessed 69 children between the ages of 7 and 12, who were randomly divided into three groups to have a blood sample taken. One group was given no distraction while the sample was being taken. In the second group mothers attempted to actively distract their children by talking to them, soothing, and/or caressing them.

And in the third group, the children were allowed to watch TV cartoons while the procedure was being carried out. None of the children was given any form of anaesthesia, and after the samples had been taken, all the children and their mothers then rated their pain scores. The children recording the highest pain scores were in the group for whom no distraction had been provided.

These scores were around three times as high as those recorded by children allowed to watch the TV cartoons. Middling scores were recorded by those children whose mothers had attempted to actively distract them while the sample was taken.

Although on average, the mothers rated pain scores higher than their children had done, and particularly for their own attempts at distracting their offspring, they nevertheless recorded the lowest pain scores for children who had been allowed to watch TV cartoons. Pain is stressful for children, even when relatively minor procedures are involved, say the authors, who conclude that the passive distraction of TV is a more effective analgesic than active distraction. Watching TV also seems to increase children’s pain tolerance, they add.



 

                                  
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