Consumer behaviour survey for assessing exposure from consumer products: a feasibility study.

Evaluating chemical exposures from consumer products is an essential part of chemical safety assessments under REACH and may also be important to demonstrate compliance with consumer product legislation. Modelling of consumer exposure needs input information on the substance (e.g.

[Non-Q-wave-electrocardiograms. Signs of earlier myocardial infarction].

An increasing number of elderly people and diabetes patients with myocardial infarction go unrecognized because of painless ischemia and regression of major Q-waves over time. An increased awareness of diagnostic electrocardiogram (ECG) abnormalities other than Q-waves should allow physicians to optimize patient management. Particularly emphasized is the R-peak delay in V6, i.

Left ventricular function-conduction impairment as reflected by the ECG in chronic aortic regurgitation.

The study was conducted to ascertain that the ECG assists in the assessment of systolic dysfunction in chronic aortic regurgitation. Five variables were reviewed in 146 adults without bundle branch block who underwent angiocardiography: total 12-lead QRS amplitude, QRS duration, maximum R peak time in I, V5 or V6, maximum R peak time relative to S peak time of the maximum S in V1, V2 or V3, and maximum T wave amplitude and polarity in I, V6 or aVF. In order to define which of them could differentiate left ventricular ejection fraction (EF) ≥50% (n = 101) from EF <50% (n = 45) they were subjected to stepwise linear discriminant analysis.

[Cardiac memory of the ECG following ventricular pacing].

During abnormal pacemaker depolarization, abnormal repolarization occurs and persists in normal QRS beats often seen in alternation with paced beats. The T-wave direction of normal beats is typically similar to the direction of the QRS complex during pacing, hence the term cardiac memory. The normal nonpaced beats have shown a sensitivity of 92% and a specificity of 100% for cardiac memory in the presence of T-wave inversions (TWI) in the precordial and inferior (II, III and aVF) leads with a positive T wave in aVL, a positive or isoelectric T wave in lead I, and the maximal precordial TWI being greater than the TWI of lead III, discriminating it from ischemic precordial TWI.

R peak time prolongation and R peak delay in leads I, V5, or V6. Diagnostic values as signs of myocardial dysfunction in chronic mitral incompetence.

On the assumption that maximum R peak time prolongation in the left-sided leads I, V5, or V6 and its time relationship to the S peak time of the maximum S amplitude in leads V1, V2, or V3 (representing dorsally directed forces of ventricular depolarization) could indicate the extent of left ventricular volume overloading and possibly left ventricular systolic function, these variables and the preoperative findings of angiocardiography were compared between patients with chronic mitral incompetence who, late after corrective valve surgery, had either well-preserved radionuclide left ventricular ejection fraction (group 1, n = 36) or radionuclide left ventricular ejection fraction below 50% (group 2, n = 30). Before surgery, group 2 patients had a highly significant lower mean left ventricular ejection fraction, a highly significant greater mean end-systolic volume index, a significantly greater mean end-diastolic volume index, a significantly greater mean maximum R peak time in leads I, V5, or V6, and a significantly greater prolongation of the maximum R peak time above the S peak time in the right precordial leads, as compared with group 1. R peak times greater than 50 ms or the presence of R peak delay (maximum R peak time greater than the S peak time of the maximum right precordial S amplitude) yields less sensitive but highly reliable results in predicting radionuclide left ventricular ejection fraction below 50% with both specificity and positive predictive values of 100%.