Agreement between manual and automated measurements of simple QRS/T angle

Abstract

<jats:title>Abstract</jats:title><jats:p>The spatial QRS/T angle (QRS/T) has been identified as a strong and independent predictor of adverse cardiac events. QRS/T can be determined from the electrocardiogram (ECG) by matrix transformation methods or formula which uses a combination of net QRS and T-wave amplitudes (QRS/Tsimple). Amplitudes can be measured automatically by using dedicated software (QRS/Tauto) or can be manually measured on a computer screen (QRS/Tmanual). This latter method allows analysis of QRS/T, when digital ECGs are not available. The aim of the study was to determine the agreement in the measurements between automatically derived QRS and T amplitudes and manually measured on the computer screen amplitudes. The relative error of the QRS/T between the two methods was estimated in 73 patients. In the case of QRS/Tmanual the inter-observer as well as intra-observer variability was estimated. The relative error between QRS/Tauto vs. QRS/Tmanual was 3.51%. Inter-observer and intra-observer variability of the QRS/Tmanual was 1.19% and 1.18% respectively. Manual measurement of the QRS/T is reliable, however, the predictive value of this parameter should be tested in clinical trials, before QRS/Tmanual can be considered a useful tool in clinical practice or retrospective studies.</jats:p>

The bidirectional relationship between chronic kidney disease and atrial fibrillation does not occur in elderly female outpatients

“…The study on nearly 25,000 subjects aged above 55 years (the percentage of CKD and diabetes or hypertension comorbidity was smaller than in our examined population) performed by Sandhu et al also did not show a significant correlation between AF and CKD [17]. Also, a study performed on 234 Polish patients aged over 75 years old showed no difference in prevalence of AF depending on renal function (eGFR ≥ 60 ml/ min/1.73 m² vs. eGFR < 60 ml/min/1.73 m²) [19].…”

“…However, the relationship between CKD and AF was inadequately evaluated in elderly patients, especially females, because not only are males burdened with higher risk of CVD [16][17][18][19][20], such as AF, but also they comprise the majority of most of the examined groups. Some side results of performed studies referring to the AF-CKD dependence suggest that this relationship may differ in this group of patients [15][16][17][18][19]. Given that the population of elderly women is constantly increasing, it is important to establish the AF-CKD relationship in this group, because it may suggest the need to adjust diagnostic and therapeutic options within it.…”

An Electrocardiogram-Based Risk Equation for Incident Cardiovascular Disease From the National Health and Nutrition Examination Survey

“…43 Finally, clinical use of the ECG score is limited to settings in which computerized ECG machines are available; with a trained ECG reader, however, manual measures of these data may be derived as well. 44 …”