31 May 08
Posted in Arrhythmia, Cardiac arrest/Resuscitation at 16:26 by Laci
By M Haïssaguerre, N Derval, F Sacher, L Jesel, I Deisenhofer, L de Roy, J-L Pasquié, A Nogami et al
N Engl J Med 2008;358:2016-2023
Early repolarization is a common electrocardiographic finding that is generally considered to be benign. Its potential to cause cardiac arrhythmias has been hypothesized from experimental studies, but it is not known whether there is a clinical association with sudden cardiac arrest.
Method
We reviewed data from 206 case subjects at 22 centers who were resuscitated after cardiac arrest due to idiopathic ventricular fibrillation and assessed the prevalence of electrocardiographic early repolarization. The latter was defined as an elevation of the QRS–ST junction of at least 0.1 mV from baseline in the inferior or lateral lead, manifested as QRS slurring or notching. The control group comprised 412 subjects without heart disease who were matched for age, sex, race, and level of physical activity. Follow-up data that included the results of monitoring with an implantable defibrillator were obtained for all case subjects.
Result
Early repolarization was more frequent in case subjects with idiopathic ventricular fibrillation than in control subjects (31% vs. 5%, P<0.001). Among case subjects, those with early repolarization were more likely to be male and to have a history of syncope or sudden cardiac arrest during sleep than those without early repolarization. In eight subjects, the origin of ectopy that initiated ventricular arrhythmias was mapped to sites concordant with the localization of repolarization abnormalities. During a mean (±SD) follow-up of 61±50 months, defibrillator monitoring showed a higher incidence of recurrent ventricular fibrillation in case subjects with a repolarization abnormality than in those without such an abnormality (hazard ratio, 2.1; 95% confidence interval, 1.2 to 3.5; P=0.008).
Conclusions
Among patients with a history of idiopathic ventricular fibrillation, there is an increased prevalence of early repolarization.
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15 May 08
Posted in Anesthesia, Pre-operatie evaluation at 18:42 by Laci
By L A Fleisher, D Poldermans for the POISE Study Group
Lancet 2008 May 13 – early online publication
Trials of β blockers in patients undergoing non-cardiac surgery have reported conflicting results. This randomised controlled trial, done in 190 hospitals in 23 countries, was designed to investigate the effects of perioperative β blockers.
Methods
We randomly assigned 8351 patients with, or at risk of, atherosclerotic disease who were undergoing non-cardiac surgery to receive extended-release metoprolol succinate (n=4174) or placebo (n=4177), by a computerised randomisation phone service. Study treatment was started 2–4 h before surgery and continued for 30 days. Patients, health-care providers, data collectors, and outcome adjudicators were masked to treatment allocation. The primary endpoint was a composite of cardiovascular death, non-fatal myocardial infarction, and non-fatal cardiac arrest. Analyses were by intention to treat.
Findings
All 8351 patients were included in analyses; 8331 (99·8%) patients completed the 30-day follow-up. Fewer patients in the metoprolol group than in the placebo group reached the primary endpoint (244 [5·8%] patients in the metoprolol group vs 290 [6·9%] in the placebo group; hazard ratio 0·84, 95% CI 0·70–0·99; p=0·0399). Fewer patients in the metoprolol group than in the placebo group had a myocardial infarction (176 [4·2%] vs 239 [5·7%] patients; 0·73, 0·60–0·89; p=0·0017). However, there were more deaths in the metoprolol group than in the placebo group (129 [3·1%] vs 97 [2·3%] patients; 1·33, 1·03–1·74; p=0·0317). More patients in the metoprolol group than in the placebo group had a stroke (41 [1·0%] vs 19 [0·5%] patients; 2·17, 1·26–3·74; p=0·0053).
Interpretation
Our results highlight the risk in assuming a perioperative β-blocker regimen has benefit without substantial harm, and the importance and need for large randomised trials in the perioperative setting. Patients are unlikely to accept the risks associated with perioperative extended-release metoprolol.
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07 May 08
Posted in Mechanical ventilation at 16:19 by Laci
By K Ojiako, H Shingala, C Schorr, D R Gerber
American Journal of Critical Care. 2008;17: 142-147
Mechanical ventilation increases risk for bleeding in the upper part of the gastrointestinal tract. Proton pump inhibitors, although they are more potent and longer acting inhibitors of gastric acid production than are histamine2 antagonists, also are generally more expensive. data comparing the 2 types of agents for preventing gastrointestinal bleeding in critically ill patients are limited.
Objectives
To compare the effectiveness of famotidine (a histamine2 antagonist) and pantoprazole (a proton pump inhibitor) in preventing stress ulcers in critically ill patients receiving mechanical ventilation.
Methods
Data were collected from the Project Impact database. All patients who received mechanical ventilation for more than 48 hours from November 2002 to June 2006 and were treated with either drug were included. Patients receiving other drugs or with known bleeding in the upper part of the gastrointestinal tract, thrombocytopenia, or coagulopathy were excluded.
Results
A total of 522 patients who received famotidine and 95 who received pantoprazole were included. Bleeding in the upper part of the gastrointestinal tract was more common in patients receiving pantoprazole than in patients receiving famotidine (0.38% vs 3.2%, P= .03). Although scores on the Acute Physiology and Chronic Health Evaluation II were higher in patients who received pantoprazole (P= .01), other outcome measures did not differ significantly between groups. Bleeding in the upper part of the gastrointestinal tract was more frequent among dialysis patients receiving pantoprazole than among those receiving famotidine.
Conclusions
Famotidine and pantoprazole are similarly effective for preventing bleeding in the upper part of the gastrointestinal tract in patients receiving mechanical ventilation.
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