The triangular wave test for electrocardiographic devices: a historical perspective
1Center of Information Technology, National Institutes of Health, Bethesda, MD 20892-5620, USA.
Abstract:
Baseline wander makes interpretation ECG recordings difficult, especially the assessment of ST deviation. Eliminating baseline wander without distorting the ST segment is a problem. The traditional high pass filter with a 0.5 Hz low frequency cutoff effectively suppresses baseline but introduces considerable distortion in the level of the ST segment. This distortion results from phase nonlinearities that occur when frequency content and wave amplitude change abruptly, as occurs where the end of the QRS complex meets the ST segment. Since the 1980s nonlinear, digital filters have been designed that can increase the low frequency cutoff without the introduction of phase distortion. The triangular wave test, first described in the 1990 AHA Recommendations, is an objective method for measuring the ability to suppress baseline wander without affecting the ST segment. This methodology was adopted in 3 American National Standards.
Related Concept Videos
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...
01:30Dysrhythmias V: Evaluating Dysrhythmias