Demonstration of muscular activity in the human aorta. Effects of trinitrin

The human thoracic aorta is usually considered to be a purely elastic vessel. Transoesophageal echo-cardiography (TEE) provides a new approach to study the mechanical properties of the descending aorta. The aim of the study was to evaluate the reproducibility and accuracy of M mode recordings of the human descending thoracic aorta and to appreciate the changes produced by an infusion of glyceryl trinitrate (GTN). The reproducibility of M mode recordings was studied in vitro on plexiglass tubes of different calibre, and also in vivo, the inter and intra-observer error was estimated to 0.6% in vitro and 1% in vivo. The accuracy of the method was evaluated in vitro by comparing the measured values (MV) with the actual diameters of the plexiglass tubes (T): MV = 1.012T + 0.9; r = 0.99; SE = 0.8 mm. The systolic and diastolic diameters of the descending thoracic aorta were measured in 8 healthy volunteers by TEE, before and during continuous intravenous infusion of GTN at a rate of 0.9 mg/hr and then 1.35 mg/hr after a 10 minutes interval. Systolic and diastolic blood pressures were recorded automatically every minute. The results showed a very significant increase in the systolic (from 20.3 +/- 0.7 to 20.9 +/- 1.3 and 22.1 +/- 2.2 mm) and diastolic diameters of the aorta (from 18.3 +/- 0.7 to 19.1 +/- 1.4 and 20.1 +/- 2.4 mm) despite a fall in systolic blood pressure (from 121.3 +/- 7.7 to 114.5 +/- 6.6 and 108.4 +/- 5.4 mmHg). This study shows that TEE is a reliable and reproducible method of measuring the diameter of the human descending thoracic aorta.(ABSTRACT TRUNCATED AT 250 WORDS)     

A new definition for myocardial infarction: what difference does it make?

AIMS: As a response to changing diagnostic tools of myocardial infarction (MI), new case definitions for acute coronary events were published in 2003 as the American Heart Association Scientific Statement. We assessed the new definition in hospitalized patients in a large population-based MI register study. METHODS AND RESULTS: We identified all suspected acute coronary syndromes with data either on troponin T or on troponin I and at least one of the enzymatic markers of myocardial injury (n=6104). The 2003 definition with the use of troponins identified 83% more definite MIs than the WHO MONICA definition using cardiac enzymes. The additional patients were older, had more often diabetes, and received less often thrombolysis and revascularization than those having MI by both definitions. Adjusting for age, sex, study area, and study year, the additional patients with their first MI aged 25-74 had a higher risk of cardiovascular death within 1 year than patients having definite MI by both definitions (hazard ratio 1.6, 95% CI 1.1-2.2). CONCLUSION: The changing diagnostic criteria present a considerable challenge for the assessment of long-term trends in MI events in the community as well as for longitudinal studies of the natural history of MI. The 2003 definition, when applied using troponins, identified a sizable new group of MI patients, among persons with suspected acute coronary syndrome, at high risk of a recurrent event.     

Effect of amiloride on digitalis-induced electrocardiographic changes.

In 10 out of the 13 healthy subjects a single oral dose of 1.25 mg of digoxin induced S-T-J depression and T wave flattening in the exercise ECG. Treatment with potassium-sparing diuretic, amiloride, at a dose of 5 mg twice daily for one week reversed the digoxin-induced S-T-J depression but had no effect on the T wave changes.     

Fiches techniques : aide à l’analyse des effets indésirables receveurs

In order to help the analysis of adverse effects of transfusion, factsheets have been written by working groups of the French agency for the safety of health products ANSM. Each factsheet deals with a blood transfusion side effect and is composed of five parts, including pathophysiological mechanisms, diagnostic criteria, management recommendations, etiologic investigations and rules for filing the notification form to ANSM. Since 2006, 11 factsheets have been published on the French haemovigilance network website. The major characteristics of the two last sheets published “post-transfusion purpura” and “non erythrocyte incompatibility reaction” are presented, followed by the updated card for “allergy”. These factsheets give relevant guidelines allowing better evaluation of recipients’ adverse reactions, particularly their diagnosis, severity and accountability. They also could initiate studies among European and international haemovigilance networks.     

Infantile Blount's disease treated by hemiplateau elevation and epiphyseal distraction using a specific external fixator: preliminary report

The treatment of infantile Blount's disease remains controversial. The progressive development of epiphysiodesis of the medial tibial physis induced a complex deformity of the lower limb such as severe genu varum, joint incongruity, torsion instability and leg length discrepancy with major functional consequences. Nine knees on eight children (average age was 7 years and 2 months) were treated by a one-time procedure using a specific external fixator that combined elevation of the medial tibial plateau, axial correction in the valgus, complete sterilization of the upper tibial growth cartilage, leg lengthening anticipation and de-rotation if necessary. Magnetic resonance imaging was useful to describe the deformity and to prepare for surgery. Corrections were progressively obtained through the physis plan by means of short incisions and the use of a specific external fixator. The primary results at an average of 24 months were good with a low rate of complications but final evaluation will be conducted at the end of the children's growth period.