signal-averaged electrocardiogram

(redirected from Late potentials)

signal-averaged electrocardiogram

Abbreviation: SAECG
An electrocardiographic study, usually performed on patients with unexplained loss of consciousness or suspected dysrhythmias, in which hundreds of QRS complexes are collected, filtered, and analyzed to discover the presence or absence of certain abnormalities in the conducting system of the ventricle. These abnormalities, called late potentials, point to an increased risk of ventricular tachycardia or ventricular fibrillation. The signal-averaging technique allows late potentials to be examined free from random electrical discharges (“noise”), which often are present when only a small number of QRS complexes are evaluated.
References in periodicals archive ?
Objective: To determine the association of ventricular late potentials with left ventricular hypertrophy in patients with systemic arterial hypertension.
Radiofrequency lesions were placed at the new scar site and extended to the sites of late potentials in order to consolidate the lesions.
It is of great importance to develop the apparatus "high-resolution ECG", which allows recording cardiac signals in order to detect their low-amplitude potentials: ventricular late potentials (VLP) and atrial late potentials (ALP).
High-resolution electrocardiography (HRECG) is a noninvasive method which allows detection of arrhythmogenic substrates by identification of late potentials defined as high-frequency, low-amplitude delayed electrical signals which are present in the terminal portion of the QRS complex and extend into the ST segment (SANTANGELI et al.
Further division of these patients was made in two separate subgroups according to the presence of late potentials (SAECG) with noise interval between 0.
Ventricular late potentials and heart rate variability in patients with mitral valve prolapsed [unpublished thesis].
Depolarisation/conduction abnormalities Major Minor * Epsilon wave (reproducible * Late potentials by SAECG in low-amplitude signals between end of [greater than or equal to]1 of QRS complex to onset of the T wave) 3 parameters in the absence of in the right precordial leads (V1 to a QRS duration of [greater than V3) or equal to]110 ms on the standard ECG * Filtered QRS duration (fQRS)[greater than or equal to]114 ms * Duration of terminal QRS <40[mu]V (low-ampplitude signal duration) [greater than or equal to]38ms * Root-mean-square voltage of terminal 40 ms [less than or equal to]20[micro]V * Terminal activation duration of QRS [greater than or equal to]55ms measured from the nadir of the S wave to the end of the QRS, including R', in V1, V2, or V3, in the absence of complete RBBB V.
15) showed that the presence of late potentials was positively correlated with an ECG score based on R and Q wave duration and R/S ratio in 211 myocardial infarction patients with or without a history of sustained ventricular tachycardia.
Late potentials on signal averaged electrocardiogram were not present in RVOT VT patients but were present in 78 per cent of the patients with ARVD/C.
Arrhythmic evaluation by 24 h Holter ECG, measurement of ventricular late potentials and heart rate variability have been suggested for risk stratification and programmed ventricular electrophysiological stimulation has a relatively high predictive value for spontaneous ventricular tachyarrhythmias in selected groups of patients with myocarditis (12).
Late potentials were not present at signal averaged ECG recording.
Late potentials are abnormal bioelectric bursts that have been associated with ventricular tachyarrhythmia and sudden death.