LAUSR

The following editorial was focused on the most relevant points of the article by Malik et al.: firstly, normal cut-off values of phase analysis parameters and different variables that influence in the ventricular synchrony analysis; secondly, the impact of the duration of type II diabetes mellitus on left ventricular mechanical synchrony analysis; thirdly, the repercussions on the cardiac function of the diseases associated with diabetes mellitus (DM), and its complications; and fourthly, a normal gated SPECT definition. In the last 13 years, we have a new tool in the area of nuclear cardiology called analysis of left ventricle synchrony. Since 2005, several articles have been published in relation to the normal cut-off values (Table 1), and diagnosis and prognosis (Table 2). From a physiological point of view, the study of the mechanical synchronization of the ventricles is very complex. Among the different publications, there is a general agreement between the average values and the cut-off values normality obtained; however, in spite of that they are not exactly concordant. This is due to the fact that these cut-off values depend on multiple variables, which are difficult to control in the statistical analysis (Figure 1). Until now, all the information provided by different groups of researchers have taught us that these influential variables can be grouped into four main categories (Figure 1): type of software, type of statistical methodology to find the appropriate cut-off values, the moment that images are acquired, and clinical patient data. But probably, as experimental studies show, the most complex thing to control is the effect of the intrinsic myocardial properties on ventricular synchrony, which are specific to each patient. Through different mechanisms, patients with DM have high cardiovascular morbidity and mortality. The left ventricular diastolic dysfunction, systolic dysfunction, and left ventricular mechanical dyssynchrony (LVMD) are frequent. In this issue of Journal of Nuclear Cardiology, Malik et al. evaluated retrospectively 146 consecutive patients with normal gated SPECT-MPI. LVMD was determined by the cut-off values (mean ? 2 SD) observed for phase standard deviation (SD) and phase bandwidth (BW) from the control subjects. LVMD was detected in 24 (28%) DM patients with the pre-defined cut-off values for SD ([ 10.8) and BW ([ 35.6) derived from the controls. Hyperlipidemia, overweight/obesity, duration of DM, and its long-term complications were independently associated with LVMD, with long-term complications being the highest risk factor (OR 28.00; p\ 0.001). The authors concluded that the evolution time of the patients with type II DM affects the left ventricular mechanical synchrony. In this study, long-term type II diabetes complications (nephropathy, neuropathy, neuropathy, and/or retinopathy) were present in 27.9% (24/86) of patients, and 18 of them (18/24, 75%) had LVMD. Therefore, the cause and the degree of LVMD is not only due to the Reprint requests: Guillermo Romero-Farina MD, PhD, FESC, FASNC, Cardiology Department, Hospital Universitari Vall d’Hebron, Institut de Recerca (VHIR), Universitat Autònoma de Barcelona, Paseo Vall d’Hebron 119-129, 08035, Barcelona, Spain; [email protected], [email protected] J Nucl Cardiol 2019;26:1659–66. 1071-3581/$34.00 Copyright 2018 American Society of Nuclear Cardiology.