Predictive value of local and core laboratory echocardiographic assessment of cardiac function in patients with chronic stable angina: The ACTION study.

AIMS: To evaluate the relationship between echocardiographic cardiac function and outcome in patients with stable symptomatic angina. METHODS: Baseline echo left ventricular ejection fraction and volume data measured in a central laboratory was available for 7016 patients (92% of the total) participating in the ACTION trial (A Coronary disease Trial Investigating Outcome with Nifedipine GITS). Ejection fraction was also measured by investigators. Evaluation of the different echocardiographic variables was based on adjusted hazard ratios comparing the unfavourable limit of the 90% range of the variable concerned to the favourable limit. RESULTS: The centrally measured ejection fraction was the most powerful predictor of all-cause death (adjusted hazard ratio=2.5), myocardial infarction, any stroke or transient ischaemic attack and overt heart failure (adjusted hazard ratio=4.5). The addition of either end systolic volume or end diastolic volume to ejection fraction did not materially affect the power of prediction. Compared to the central ejection fraction measurement, the investigator-measured ejection fraction was a less powerful predictor for all outcomes considered. CONCLUSION: Routine echocardiography carefully analysed by standardised methods provides useful prognostic information in patients with stable angina, including for total mortality.     

REPERFUSION FOLLOWING MYOCARDIAL ISCHAEMIA ENHANCES INOSITOL PHOSPHATE RELEASE IN THE ISOLATED PERFUSED RAT HEART

1. Global myocariial ischaemia (MI) for periods greater tan 5 min caused an inhibition of phosphatidylinositol specific phospholipase C (PtdIns-PLC) activity. 2. Two min reperfusion following a 20 min MI period, a time point associated with reperfusion-induced arrhythmias, resulted in an activation of PtdIns-PLC activity, dependent on endogenous noradrenaline and mediated via al-adrenoceptors. 3. This 2 min reperfusion response, in contrast to healthy myocardium, resulted in: (i) enhanced PtdIns-PLC activity; (ii) increased sensitivity to endogenous noradrenaline; (iii) rapid increases in inositol(1,4,5)trisphosphate (Ins(1,4,5)P3); and (iv) PLC hydrolysis primarily of PtdIns(4,5)P₂, such that the majority of InsP isomers derive from Ins(1,4,5)P₃. 4. Together, these data suggest a functional role for Ins(1,4,5)P3 under postischaemic reperfusion conditions, and provide a possible link between al-adrenoceptor stimulation of the PtdIns turnover pathway and reperfusion injury.     

T wave amplitude as a quantitative index of regional myocardial sympathetic responsiveness

Alterations in T wave morphology have been quantitated in seven open chest anesthetized dogs by simultaneous recording of electrograms from 10 epicardial sites across the anterior left ventricular wall under basal conditions, following left sympathetic stimulation (LSS) at 2, 4, 8, 12, and 16 Hz and during noradrenaline infusions (NAI) of 0.125, 0.25, 0.50, and 1.0 micrograms/kg/min. Overdrive atrial pacing at 175 beats/min was employed and rate of rise of left ventricular pressure (dP/dt) monitored. Linear log dose-response relationships were found between both peak T amplitude and left ventricular dP/dt for NAI between 0.125 and 0.50 micrograms/kg/min (peak T wave amplitude 4.0 +/- 0.9 to 1.4 +/- 0.7 mV). Following LSS, T wave amplitude responses were highly variable both between animals and between electrode sites in individual studies. A linear log dose-response relationship was found at stimulation frequencies between 8 and 16 Hz (T amplitude 3.9 +/- 1.4 to 1.8 +/- 1.2 mV). Changes in QT interval were minor and inconsistent. It is concluded that changes in peak T wave amplitude may provide a useful index of regional myocardial sympathetic responsiveness following NAI, but are more variable following LSS.     

Common bile duct calculi: updated experience with dissolution with methyl tertiary butyl ether

The authors describe their experience with methyl tertiary butyl ether (MTBE) in a larger series of patients than previously reported in order to acquaint physicians with both its effectiveness for dissolution of common bile duct calculi and the limitations of its use. Ten patients with 13 biliary calculi underwent percutaneous stone dissolution treatment with the experimental cholesterol solvent, MTBE. Three stones completely dissolved within 30 minutes, seven were reduced in size, and three were visibly unaffected. All stones not completely dissolved were easily extracted by means of a stone basket except for one in a patient taken to surgery. Although MTBE perfusion is an effective technique for management of biliary calculi, practitioners should be aware that its use is quite time consuming and its odor difficult to control.     

Clinical MR imaging with a Helmholtz-type surface coil

Limited-field-of-view radio-frequency receiver antennas provide improved near-field sensitivity for magnetic resonance imaging by decreasing the antenna volume. The Helmholtz-type surface coil, consisting of two flat rings, is an organ-encompassing antenna that takes advantage of this principle to yield an improved signal-to-noise ratio (S/N). The coil was tested in a group of 50 patients and 16 healthy volunteers. Images obtained with the Helmholtz coil demonstrated quantitatively superior S/N of 2.2-fold or greater than that of comparison body coil images, as well as qualitatively superior anatomic resolution.     

The effects of paracetamol (acetaminophen) on hepatic tests in patients who chronically abuse alcohol – a randomized study

Aliment Pharmacol Ther 2010; 32: 478–486

Summary

Background Retrospective accounts suggest that therapeutic doses of paracetamol can produce severe hepatic injury in patients with putative high‐risk conditions, including alcoholism and infectious hepatitis. Metabolism of paracetamol to its hepatotoxic metabolite is enhanced in patients who abuse alcohol, who also have compromised liver defences from depressed hepatic glutathione. Aim To determine the effect of paracetamol on serum liver tests of newly abstinent subjects who abuse alcohol, including subjects with hepatitis C infection. Methods A randomized, double‐blind, placebo‐controlled study. Adult alcohol abusers with a current drinking episode longer than 7 days received either placebo or paracetamol 4 g/day for 5 days. Results Of 142 subjects enrolled, 74 received paracetamol and 68 received placebo. Mean ALT activity during treatment increased from 48 to 62 IU/L in the paracetamol group and from 47 to 49 IU/L in the placebo group. Maximum ALT was 238 and 249 IU/L in the paracetamol and control groups respectively. The INR remained unchanged and serum bilirubin decreased in both groups. Subgroup analyses for subjects with alcoholic hepatitis, hepatitis C virus antibody and other subgroups showed no statistical difference between groups. Conclusion Administration of paracetamol 4 g/day appears safe in newly abstinent patients who abuse alcohol.