Journal of electrocardiology
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QT interval measured in the electrocardiogram (ECG) varies with RR interval challenging the calculation of corrected QT (QTc) in Atrial fibrillation (AF). ⋯ BF in commercial software is not ideal for measurement of QTc in AF, Fridericia Formula in lead II from the average RR from automated ECG measurement maybe utilized for the calculation of QTc.
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Comparative Study
A deep neural network learning algorithm outperforms a conventional algorithm for emergency department electrocardiogram interpretation.
Cardiologs® has developed the first electrocardiogram (ECG) algorithm that uses a deep neural network (DNN) for full 12‑lead ECG analysis, including rhythm, QRS and ST-T-U waves. We compared the accuracy of the first version of Cardiologs® DNN algorithm to the Mortara/Veritas® conventional algorithm in emergency department (ED) ECGs. ⋯ Cardiologs' DNN was more accurate and specific in identifying ECGs with at least one major abnormal group. It had a significantly higher rate of accurate ECG interpretation, with similar sensitivity and higher PPV.
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The role of left AV nodal (SVN) connections in the genesis of "left-variant" atypical atrioventricular nodal reentrant tachycardia (AVNRT) and those with multiple retrograde pathways remain unclear. We describe an unusual case of "left-variant" atypical AVNRT, where change in the retrograde earliest atrial activation site (REAAS) at the coronary sinus (CS) following radiofrequency catheter ablation (RFCA) was observed. Our observation suggests that the REAAS, that is, the left AVN connections, could participate in the formation of the reentrant circuit of "left-variant" atypical AVNRT. Furthermore, its atrial breakthroughs involved as a circuit of SVT could be (functionally) multiple.
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A combined aVR criterion is described as the presence of a pseudo r' wave in aVR during tachycardia in patients without r' wave in aVR in sinus rhythm and/or a ≥50% increase in r' wave amplitude compared to sinus rhythm in patients with r' wave in the basal aVR lead. We aimed to investigate the use of combined aVR criterion in differential diagnosis of atrioventricular nodal reentrant tachycardia (AVNRT) and atrioventricular reciprocating tachycardia (AVRT). ⋯ In the differential diagnosis of patients with SVT, the combined aVR criterion identifies the presence of AVNRT with an independent and acceptable diagnostic value. In addition to classical ECG criteria for AVNRT, it is necessary to evaluate the combined aVR criterion in daily practice.
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Criteria for electrocardiographic detection of acute myocardial ischemia recommended by the Consensus Document of ESC/ACCF/AHA/WHF consist of two parts: The ST elevation myocardial infarction (STEMI) criteria based on ST elevation (ST↑) in 10 pairs of contiguous leads and the other on ST depression (ST↓) in the same 10 contiguous pairs. Our aim was to assess sensitivity (SE) and specificity (SP) of these criteria-and to seek their possible improvements-in three databases of 12‑lead ECGs. ⋯ Current recommended criteria for detecting acute myocardial ischemia, involving ST↓, boost SE of widely-used STEMI criteria, at the cost of SP. To keep the SP high, we propose either the adjustment of threshold for the added ST↓ criteria or a selective use of ST↓ only in contiguous leads V2 and V3 plus ST↑ in lead pairs (aVL, -III) and (III, -aVL).