Premature Atrial Contraction (PAC) and Premature Ventricular Contraction (PVC) are two types of E... more Premature Atrial Contraction (PAC) and Premature Ventricular Contraction (PVC) are two types of ECG arrhythmias that are identified for presenting anomalies in the normal cardiac rhythm, generating alterations in the heart rate that disrupts his mechanic and electric heart activity due to these delayed contractions (premature). Also when a delayed contraction occurs (i.e. PVC or PAC), it generates alterations in heart rate that can produce ventricular tachycardia and eventually sudden cardiac arrest. Piece Wise Linear Algorithm (PLA) is a widely used segmentation process that represents each signal as linear segments with different scopes. In this work we are presenting an evaluation of PLA and the optimal number of segments when this type of segmentation is applied on normal ECG traces and when these ECG traces present PAC or PVC. We established that optimal number of segments is related with the coefficient of determination (R2), before and after the reconstruction of an ECG trace. Results show that number of segments taken on normal ECG traces differs radically compared when this method was applied on traces with PVC and PAC events.
Page 1. Ventricular Late Potentials (VLPs) are important indicators of sudden cardiac death (SCD)... more Page 1. Ventricular Late Potentials (VLPs) are important indicators of sudden cardiac death (SCD) in people with a history of heart attack. Many algorithms for VLPs detection are based on quantifying increases in the QRS complex ...
Ventricular Late Potentials make QRS complexes larger, that is why many algorithms are based on q... more Ventricular Late Potentials make QRS complexes larger, that is why many algorithms are based on quantifying increases in the QRS complex duration. These elongations generate misalignments in the QRS, resulting in practice; the averaged algorithm considers the ECG components, including those VLPs, as well as random variables. We recorded High Resolution ECGs (HRECGs) from 50 subjects in resting position with
Ventricular late potentials (VLPs) are small-amplitude waves with a short duration that appear at... more Ventricular late potentials (VLPs) are small-amplitude waves with a short duration that appear at the end part of the QRS complex, making a QRS complex duration larger. The signal-averaged electrocardiography (ECG) technique enhances VLPs and beats, assuming noise as the only random variable. However, ECG signals are not completely stationary and different elongations appear in both time and amplitude in each beat. This research proposes to use piecewise linear approximation to segment each beat and performs the alignment of the beats using the technique known as derivative dynamic time-warping to have beats better aligned and consequently enhance the presence of VLPs. We recorded high-resolution ECGs (HRECGs) from 50 subjects in supine position with no heart-stroke antecedents. VLPs were created synthetically and added to the HRECGs. Two cases were evaluated: (i) duration of the QRS complexes with VLPs without beats alignment, and (ii) duration of QRS complexes with VLPs using beats alignment in time and amplitude. Considering QRS duration as an indicative of VLP presence, results show that when using beats alignment in time and amplitude it is possible to reach a sensitivity of 0.96 and a specificity of 0.52, as opposed to 0.72 and 0.40, respectively, when using only averaging without beats alignment in time and amplitude.
Premature Atrial Contraction (PAC) and Premature Ventricular Contraction (PVC) are two types of E... more Premature Atrial Contraction (PAC) and Premature Ventricular Contraction (PVC) are two types of ECG arrhythmias that are identified for presenting anomalies in the normal cardiac rhythm, generating alterations in the heart rate that disrupts his mechanic and electric heart activity due to these delayed contractions (premature). Also when a delayed contraction occurs (i.e. PVC or PAC), it generates alterations in heart rate that can produce ventricular tachycardia and eventually sudden cardiac arrest. Piece Wise Linear Algorithm (PLA) is a widely used segmentation process that represents each signal as linear segments with different scopes. In this work we are presenting an evaluation of PLA and the optimal number of segments when this type of segmentation is applied on normal ECG traces and when these ECG traces present PAC or PVC. We established that optimal number of segments is related with the coefficient of determination (R2), before and after the reconstruction of an ECG trace. Results show that number of segments taken on normal ECG traces differs radically compared when this method was applied on traces with PVC and PAC events.
Page 1. Ventricular Late Potentials (VLPs) are important indicators of sudden cardiac death (SCD)... more Page 1. Ventricular Late Potentials (VLPs) are important indicators of sudden cardiac death (SCD) in people with a history of heart attack. Many algorithms for VLPs detection are based on quantifying increases in the QRS complex ...
Ventricular Late Potentials make QRS complexes larger, that is why many algorithms are based on q... more Ventricular Late Potentials make QRS complexes larger, that is why many algorithms are based on quantifying increases in the QRS complex duration. These elongations generate misalignments in the QRS, resulting in practice; the averaged algorithm considers the ECG components, including those VLPs, as well as random variables. We recorded High Resolution ECGs (HRECGs) from 50 subjects in resting position with
Ventricular late potentials (VLPs) are small-amplitude waves with a short duration that appear at... more Ventricular late potentials (VLPs) are small-amplitude waves with a short duration that appear at the end part of the QRS complex, making a QRS complex duration larger. The signal-averaged electrocardiography (ECG) technique enhances VLPs and beats, assuming noise as the only random variable. However, ECG signals are not completely stationary and different elongations appear in both time and amplitude in each beat. This research proposes to use piecewise linear approximation to segment each beat and performs the alignment of the beats using the technique known as derivative dynamic time-warping to have beats better aligned and consequently enhance the presence of VLPs. We recorded high-resolution ECGs (HRECGs) from 50 subjects in supine position with no heart-stroke antecedents. VLPs were created synthetically and added to the HRECGs. Two cases were evaluated: (i) duration of the QRS complexes with VLPs without beats alignment, and (ii) duration of QRS complexes with VLPs using beats alignment in time and amplitude. Considering QRS duration as an indicative of VLP presence, results show that when using beats alignment in time and amplitude it is possible to reach a sensitivity of 0.96 and a specificity of 0.52, as opposed to 0.72 and 0.40, respectively, when using only averaging without beats alignment in time and amplitude.
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Papers by Lucio Cetto