The signal-averaged electrocardiogram and late potentials. A comparative analysis of commercial devices
R Henkin1, E B Caref, G J Kelen
1Department of Medicine, State University of New York Health Science Center.
Abstract:
The authors used two separate protocols to compare four commercially available devices for recording of the signal-averaged electrocardiogram and "late potentials" to assess their degree of concordance in identifying abnormalities. In one protocol, studies were performed using each system. In 19% of recordings the results from one system were discordant in at least one numeric parameter. In the second protocol identical averaged data files were used to identify discordancies due solely to differences in analysis algorithms used for QRS offset determination by the various devices. This disclosed 23% discordant findings, mostly in the root mean square amplitude of the terminal 40-msec segment resulting from small differences in the estimate of QRS offset point. To improve concordance between commercial systems, there is an urgent need for adoption of a rigorously standardized algorithm for analysis of baseline noise and QRS offset.
Related Concept Videos
01:30Pulse rhythm
Conversely, an irregular pulse pattern is termed dysrhythmia, stemming from disruptions in cardiac muscle...
01:29Electrocardiogram
Three major waveforms are present in a typical ECG recording: the P wave, the QRS complex, and the T...
01:25Correlation between ECG and Cardiac Cycle
A cardiac action potential originates in the SA node and spreads throughout the atria and the AV node in approximately 0.03 seconds. This results in the P wave in an ECG and triggers atrial contraction. The action potential is then briefly slowed at the AV node, allowing the atria to contract and fill the ventricles with blood before...
01:30Cardiac Action Potential
The cardiac action potential process involves a series of phases characterized by the movement of ions across the cardiac cell membranes, leading to the depolarization and repolarization of the cardiac myocytes.
Ionic Basis of Cardiac Action Potentials
01:28Electrocardiogram Fundamentals
An electrocardiogram (ECG) is a diagnostic tool for identifying cardiac conditions such as arrhythmias, conduction abnormalities, and myocardial ischemia.
Definition
An electrocardiogram (ECG) visualizes the heart's electrical activity by tracing the electrical movement associated with each heartbeat on a graph or monitor. As the heart beats, an electrical wave passes through it, correlating with the cardiac cycle events.
Parts of an ECG
An ECG utilizes electrodes on the skin to...
01:24ECG Interpretation of Rhythms
Components of the Electrocardiogram
The primary components of a normal ECG waveform in Normal sinus rhythm(NSR) include the P wave, PR interval, QRS complex, ST segment, T wave, and occasionally a U wave.
ECG waveforms are divided by vertical and horizontal lines at standard intervals.
The horizontal axis measures time and rate, and the vertical axis measures amplitude or voltage. When...