Letter on 'sodium-dependent modulation of systemic and urinary renalase expression and activity in the rat remnant kidney'.

M aunganidze et al. [1] are to be commended for a thorough and accurate investigation of the diagnostic performance of several ECG criteria of left ventricular hypertrophy in a large community sample of black African ancestry. In their study, the accuracy of all examined criteria was poorer in obese than in nonobese individuals, as shown by a lower area under the receiver operating characteristics curve, and a weaker correlation with echocardiographic left ventricular mass index. The main conclusion of this article [1], and of the fine accompanying editorial comment by Cuspidi et al. [2], is that no current left ventricular hypertrophy criterion is recommended for use in obesity. Although it is generally agreed that obesity reduces ECG sensitivity because of the attenuation of QRS voltages, we believe that ethnicity and the choice of diagnostic criterion may have an impact on the ability of ECG to detect left ventricular hypertrophy in obesity. Sokolow-Lyon voltage [3,4] and the Framingham criterion [5] have a poorer diagnostic performance in obese individuals. In contrast, the Cornell voltage criterion [3,4] and the voltage-independent Romhilt-Estes point score [4] may not be influenced by the effect of obesity in predominantly white populations. Similarly, in an ethnically diverse Brazilian population [6], Cornell voltage and voltage-duration criteria and the multifactorial Perugia criterion [7] did not show differences in diagnostic performance between obese and nonobese individuals. In a group of 95 white individuals with morbid obesity prior to scheduled bariatric surgery [8], the best diagnostic performance was obtained with the Romhilt-Estes point score, with an area under the receiver operating characteristics curve of 0.662. We suggest that the conclusions of a ‘mission impossible’ [1,2] for an accurate ECG detection of left ventricular hypertrophy in obese individuals might not necessarily be extended from black people of African ancestry to other ethnicities, and multifactorial criteria based on a composition of voltage and nonvoltage criteria including left ventricular strain, left atrial enlargement and the duration of intrinsicoid deflection, such as the RomhiltEstes point score and the Perugia criterion, may still have a place for detecting left ventricular hypertrophy in obese individuals.