Assessment of LVEF using a new 16-segment wall motion score in echocardiography.

BACKGROUND: Simpson biplane method and 3D by transthoracic echocardiography (TTE), radionuclide angiography (RNA) and cardiac magnetic resonance imaging (CMR) are the most accepted techniques for left ventricular ejection fraction (LVEF) assessment. Wall motion score index (WMSI) by TTE is an accepted complement. However, the conversion from WMSI to LVEF is obtained through a regression equation, which may limit its use. In this retrospective study, we aimed to validate a new method to derive LVEF from the wall motion score in 95 patients. METHODS: The new score consisted of attributing a segmental EF to each LV segment based on the wall motion score and averaging all 16 segmental EF into a global LVEF. This segmental EF score was calculated on TTE in 95 patients, and RNA was used as the reference LVEF method. LVEF using the new segmental EF 15-40-65 score on TTE was compared to the reference methods using linear regression and Bland-Altman analyses. RESULTS: The median LVEF was 45% (interquartile range 32-53%; range from 15 to 65%). Our new segmental EF 15-40-65 score derived on TTE correlated strongly with RNA-LVEF (r = 0.97). Overall, the new score resulted in good agreement of LVEF compared to RNA (mean bias 0.61%). The standard deviations (s.d.s) of the distributions of inter-method difference for the comparison of the new score with RNA were 6.2%, indicating good precision. CONCLUSION: LVEF assessment using segmental EF derived from the wall motion score applied to each of the 16 LV segments has excellent correlation and agreement with a reference method.

Traumatic brain injury is not associated with significant myocardial dysfunction: an observational pilot study.

BACKGROUND: Myocardial dysfunction has been well described with catastrophic neurological events, such as subarachnoid hemorrhage and brain death. There is very limited data describing myocardial function in the context of traumatic brain injury (TBI), as no prospective study has yet examined this association. The objective of our study was to evaluate cardiac function using echocardiography in patients with clinically important TBI. METHODS: We conducted a prospective observational study of consecutive TBI patients admitted to the intensive care unit. All patients older than 16 years with moderate to severe TBI according to the Glascow Coma Scale (GCS) were eligible for the study. Only patients with a prior history of heart disease or cardiomyopathy or evidence of brain death on admission were excluded. A complete transthoracic echocardiogram was performed within 4 days of admission. RESULTS: Forty-nine patients (67% males, median age 34 years) were included in the study. Forty-one patients had severe TBI (84%) with a median GCS of six, 44 patients (90%) required mechanical ventilation and 36 (74%) intracranial pressure monitoring. Hospital mortality was 18%. No patients had global left ventricular dysfunction as defined by a left ventricular ejection fraction (LVEF) below 50% (95% CI, 0-0.07). Average LVEF was 65 +/- 4%. Four patients (8%) had regional wall motion abnormalities with preserved LVEF. DISCUSSION: The main finding of this study is the absence of clinically significant myocardial dysfunction in patients with moderate or severe TBI. Although myocardial dysfunction has been well described in a variety of neurological settings, it is possible that the young age of TBI patients and the absence of cardiovascular risk factors are protective against significant myocardial injury from catecholamine excess. CONCLUSIONS: In a group of patients with clinically important TBI, we did not identify any significant cardiac dysfunction.

Left ventricular ejection fraction assessment by non-cardiologists from transverse views using a simplified wall motion score index.

For the non-cardiologist emergency physician and intensivist, performing an accurate estimation of left ventricular ejection fraction (LVEF) is essential for the management of critically ill patients, such as patients presenting with shock, severe respiratory distress or chest pain. Our objective was to develop a semi-quantitative method to improve visual LVEF evaluation. A group of 12 sets of transthoracic echocardiograms with LVEF in the range of 18-64% were interpreted by 17 experienced observers (PRO) and 103 untrained observers or novices (NOV), without previous training in echocardiography. They were asked to assess LVEF by two different methods: i) visual estimation (VIS) by analysing the three classical left ventricle (LV) short-axis views (basal, midventricular and apical short-axis LV section) and ii) semi-quantitative evaluation (base, mid and apex (BMA)) of the same three short-axis views. The results for each of these two methods for both groups (PRO and NOV) were compared with LVEF obtained by radionuclide angiography. The semi-quantitative method (BMA) improved estimation of LVEF by PRO for moderate LV dysfunction (LVEF 30-49%) and normal LVEF. The visual estimate was better for lower LVEF (<30%). In the NOV group, the semi-quantitative method was better than than the visual one in the normal group and in half of the subjects in the moderate LV dysfunction (LVEF 30-49%) group. The visual estimate was better for the lower LVEF (ejection fraction <30%) group. In conclusion, semi-quantitative evaluation of LVEF gives an overall better assessment than VIS for PRO and untrained observers.

Safety and effectiveness of enoxaparin following fibrinolytic therapy: Results of the Acute Myocardial Infarction (AMI)-QUEBEC registry.

BACKGROUND: Previous randomized controlled trials and meta-analyses demonstrated the superior efficacy of enoxaparin (ENOX) over unfractionated heparin (UFH) in patients with ST segment elevation myocardial infarction (STEMI). The external validity of randomized controlled trials may be limited by selective inclusion of patients who are younger and healthier than the 'real-life' population. OBJECTIVE: To evaluate the safety and effectiveness of ENOX compared with UFH in unselected STEMI patients. METHODS: The safety and effectiveness of ENOX and UFH were compared in STEMI patients who received fibrinolytic therapy at 17 Quebec hospitals in 2003. RESULTS: A total of 498 STEMI patients received systemic anticoagulation, with ENOX and UFH administered in 114 and 384 patients, respectively. There were no differences in baseline characteristics between the two patient groups. The rates of in-hospital major adverse cardiac or cerebral events were 11.4% in the ENOX group compared with 14.0% in the UFH group (P=0.51). In-hospital death or nonfatal reinfarction occurred in 7.9% of patients who received ENOX compared with 9.9% of patients who received UFH (P=0.52). Major bleeding occurred in 4.4% of patients who received ENOX versus 6.0% in patients who received UFH (P=0.51). INTERPRETATION: There was no significant difference in the rates of in-hospital adverse events in the ENOX group compared with the UFH group, when used in the real-life context. Larger observational studies may further confirm the safety, effectiveness and optimal duration of the administration of ENOX in unselected STEMI patients treated with fibrinolysis.

HISTORIQUE : Des essais aléatoires et contrôlés et des méta-analyses passés ont démontré l'efficacité supérieure de l'enoxaparine (ENOX) par rapport à l'héparine non fractionnée (HNF) chez les patients ayant un infarctus du myocarde avec élévation du segment ST (IMÉST). La validité externe des essais aléatoires et contrôlés peut être limitée par l'inclusion sélective de patients qui sont plus jeunes et en meilleure santé qu'au sein de la « véritable ¼ population. OBJECTIF : Évaluer l'innocuité et l'efficacité de l'ENOX par rapport à l'HNF chez des patients non sélectionnés ayant eu un IMÉST. MÉTHODOLOGIE : Les chercheurs ont comparé l'innocuité et l'efficacité de l'ENOX et de l'HNF chez des patients qui ont subi un IMÉST et ont reçu des fibrinolytiques dans 17 hôpitaux québécois en 2003. RÉSULTATS : Au total, 498 patients ayant subi un IMÉST ont reçu des anticoagulants systémiques, l'ENOX et l'HNF ayant été administrés chez 114 et 384 patients, respectivement. On ne constatait aucune différence à l'égard des caractéristiques de base des deux groupes de patients. Le taux d'événements cardiaques ou cérébraux négatifs majeurs en milieu hospitalier s'élevait à 11,4 % au sein du groupe prenant de l'ENOX, par rapport à 14,0 % dans celui prenant de l'HNF (P=0,51). Un décès en milieu hospitalier ou un infarctus non fatal s'est produit chez 7,9 % des patients qui avaient reçu de l'ENOX par rapport à 9,9 % de ceux qui avaient reçu de l'HNF (P=0,52). Des saignements majeurs se sont produits chez 4,4 % des patients qui avaient reçu de l'ENOX et 6,0 % de ceux qui avaient reçu de l'HNF (P=0,51). INTERPRÉTATION : En milieu réel, on ne remarquait aucune différence significative dans les taux de réactions néfastes en milieu hospitalier au sein du groupe prenant de l'ENOX par rapport à celui prenant de l'HNF. De plus vastes études d'observation pourraient mieux confirmer l'innocuité, l'efficacité et la durée optimale de l'administration d'ENOX chez des patients non sélectionnés ayant eu un IMÉST et étant traités par fibrinolyse.