[Comparison of four formulas of adjusting QT interval for the heart rate in young elite athletes]. / Intervalle QT chez les athlètes : comparaison de quatre formules de correction dans une population de jeunes sportifs de haut niveau.

PURPOSE: Sudden cardiac death in young athlete is always tragic. Some international guidelines recommend the realization of an electrocardiogram before practicing competitive sports to carry out the risk of sudden cardiac death due to genetic cardiopathy like QT long syndrome. Unfortunately, the diagnosis can be difficult because intensive sport can increase the QT interval over normal recognized values for sedentary people. Using a QT correction formula free of heart rate appears essential. PATIENTS AND METHODS: Four hundred and forty-six young athletes (aged 10 to 18) had an electrocardiogram. QT intervals were measured and four methods were used to correct the QT interval for heart rate. RESULTS: The Bazett formula performed the worst in terms of rate adjustment success. Hodges and Fridericia formulas are the best both in males and females, independently of age. Female had longer QTc intervals than males. CONCLUSION: The most widely used Bazett formula should be surrendered whereas Hodges and Fridericia formulas should be preferred, particularly in young athletes.

[Evaluation of anterior knee laxity on MRI]. / Évaluation de la laxité antérieure du genou en IRM: la laxi-IRM.

PURPOSE: Evaluation of the ACL and anterior knee laxity on MR during anterior tibial translation. PATIENTS AND METHODS: Three groups were identified based on clinical and arthrometric (KT-1000) data: normal ACL (n=12), complete tear (n=10) and partial tear (n=20). MRI was performed without and with anterior tibial translation (pneumatic device) with morphological and laximetric analysis: drawer tests and dynamic evaluation of ligamentous tension. RESULTS: Intra- and inter-observer reproducibility was excellent, correlated to arthrometric data and clinical tests (Lachman, pivot shift). The difference between the drawer signs of normal subjects and patients with ACL tear was significant for a threshold value of 1,1mm for the anterior drawer (sensitivity: 93.33%, specificity: 91.7%) and 2.8 mm for the posterior drawer (sensitivity: 86.7%, specificity: 100%). Dynamic evaluation of ligamentous tension was also reproducible, statistically correlated to the MR drawer tests and reliable for the diagnosis of ACL lesions. In this preliminary study, the distinction between complete and partial ACL tears could not be detected. CONCLUSION: Anterior cruciate ligament function can be demonstrated on MR. The predictive value of this morphological and functional association should be determined in the management of patients with partial tears.