[Effect of frontal electrodes location on the electrocardiogram quality of obese subjects: Roots versus limb of extremities]. / Effet de l'emplacement des électrodes frontales sur la qualité de l'électrocardiogramme du sujet obèse : racines versus extrémités des membres.

ABSTRACT

INTRODUCTION: In obese patients, standard recording of electrocardiogram seems to have specific electrical modifications related to obesity. These modifications could be minimized by the use of alternative recording techniques. The aim of this study is to evaluate the effect of the recording technique (standard versus Lund) on the electrocardiogram quality in healthy obese patients. METHOD: This is an observational and descriptive study carried out in emergency medical services during a two years period. Healthy subjects with an age over 18 years and a body mass index (BMI)≥30kg/m2 were included. Each participant had an electrocardiogram according to Lund's technique immediately followed by a standard recording. Deflections amplitude and their respective axes were compared between the two techniques. The primary endpoint was the frequency of microvoltage. The secondary endpoints were the flat T wave at the inferior and the left axial deviations. RESULTS: Fifty obese patients were included. The average BMI was 36.8±6.6kg/m2. The average age was 45±13 years with a sex ratio of 0.52. The standard technique was associated with a higher incidence of microvoltage (40% versus 20%, P=0.029) and flattening of the T wave (40% versus 18%, P=0.015). Analysis of the variance of the P, QRS and T wave axes did not find any difference between the two techniques. CONCLUSION: The Lund technique reduces the incidence of electrical abnormalities in the electrocardiogram of healthy obese patients.