Improved quantification of left ventricular function by applying signal averaging to echocardiographic acoustic quantification

Mor‐Avi, Victor; Gillesberg, Inger E.; Korcarz, Claudia E.; Sandelski, Joanne; Lang, Roberto M.

doi:10.1016/s0894-7317(05)80382-7

Cited by 28 publications

(6 citation statements)

References 17 publications

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“…All 45 seconds of LA waveform data were signal averaged resulting in a single composite waveform. Signal averaging reduces noise and variability of the AQ waveforms 11. From this signal averaged waveform the first derivative of LA area was computed.…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Effects of aging on left atrial reservoir, conduit, and booster pump function: a multi-institution acoustic quantification study

Spencer¹,

Mor‐Avi²,

Gorcsan³

et al. 2001

Heart

188

126

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Objective-To assess the feasibility of measuring left atrial (LA) function with acoustic quantification (AQ) and then assess the eVects of age and sex on LA reservoir, conduit, and booster pump function. Patients and setting-165 subjects without cardiovascular disease, 3-79 years old, were enrolled by six tertiary hospital centres. Interventions-Continuous LA AQ area data were acquired and signal averaged to form composite waveforms which were analysed oV-line. Main outcome measures-Parameters of LA performance according to age and sex. Results-Signal averaged LA waveforms were suYciently stable and detailed to allow automated analysis in all cases. An age related increase in LA area was noted. LA reservoir function did not vary with age or sex. All parameters of LA passive and active emptying revealed a significant age dependency. Overall, the passive emptying phase accounted for 66% of total LA emptying ranging from 76% in the youngest to 44% in the oldest decade. LA contraction accounted for 34% of atrial emptying in all subjects combined with the older subjects being more dependent on atrial booster pump function. When adjusted for atrial size, there were no sex related diVerences in LA function. Conclusions-LA reservoir, conduit, and booster pump function can be assessed with automated analysis of signal averaged LA area waveforms. As LA performance varies with age, establishment of normal values should enhance the evaluation of pathologic states in which LA function is important. (Heart 2001;85:272-277) Keywords: aging; atrium; echocardiography Left atrial (LA) performance is complex and includes functioning as a reservoir, conduit, and booster pump at diVerent stages of the cardiac cycle. Abnormalities of LA performance are clinically important and found in a wide variety of common clinical conditions such as atrial fibrillation, dilated cardiomyopathy, diastolic dysfunction, and valvar heart disease.1-5 Detailed evaluation of LA function has been performed using a variety of invasive methods which combine LA pressure with volume measurement to generate pressuredimension loops.6 7 This approach is limited by the need for direct LA pressure recordings which precludes routine clinical use.The most commonly used non-invasive technique to evaluate LA performance is Doppler echocardiography. However, Doppler echocardiography is limited since it provides no information about LA size and, although the use of this technique to evaluate LA booster pump function has been described, it is not suitable for the assessment of the reservoir and conduit phases of LA function. Measurement of LA size at diVerent phases of the cardiac cycle has proven to be useful for evaluating LA performance. However, the assessment of LA volume by two dimensional (cross sectional) echocardiography requires tedious hand tracing of endocardial borders.Acoustic quantification (AQ), an automated border detection technique, provides on-line continuous cardiac chamber area or volume over time and has been used extensively to study t...

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Section: Methodsmentioning

confidence: 99%

“…Individual AQ waveforms can be noisy due to random and physiologic variations, but the use of signal averaging of AQ waveforms reduces this variation 11. Initial studies applying AQ to the LA chamber have not used signal averaging and additionally have been limited by the need to identify manually the different cardiac phases which is tedious and subjective 4…”

mentioning

confidence: 99%

Effects of aging on left atrial reservoir, conduit, and booster pump function: a multi-institution acoustic quantification study

Spencer¹,

Mor‐Avi²,

Gorcsan³

et al. 2001

Heart

188

126

View full text Add to dashboard Cite

show abstract

“…Therefore, in order to enhance the accuracy of measurements of LV function indexes, their inter-beat variability is usually considered a factor to be minimized. As a result, the automatic on-line analysis of the LV volume signal is based on an average of values corresponding to a few beats, while the post-processing analysis is usually based on template matching techniques (Mor-Avi et al 1995, Caiani et al 1998a. Starting from a different approach, we focused our attention onto the beat-to-beat variability of LV function parameters, to obtain information about the influence of respiration on LV function.…”

Section: Discussionmentioning

confidence: 99%

Characterization of Hydrogen-Treated Pentacene Organic Thin Film Transistors

Yang

Suen

Whang

2004

Jpn. J. Appl. Phys.

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This study was designed to assess, using the echocardiographic acoustic quantification technique, the influence of respiration on left ventricular (LV) function and its modifications connected with the ageing process, quantifying in a non-invasive way the respiratory contribution to the LV volume variability. An automated algorithm is applied to extract the beat-to-beat measurements of LV function parameters from the LV volume signal, obtained from recordings lasting a few minutes. Mean values, amount of variability and spectral content were studied in a population of 17 normal young (mean age 25 ± 1 years) and 12 normal old (mean age 64 ± 2 years) subjects. Mean values of the beat-to-beat measurements of LV function parameters were able to point out alterations connected with the ageing process in peak filling rate, peak atrial filling rate and peak ejection rate. Spectral analysis, applied to the extracted variability series, displayed a predominance of the high-frequency (HF) component corresponding to respiration in all LV function parameters; moreover, age related changes of HF variability were observed in peak ejection rate. The HF power spectrum component of beat-to-beat series extracted from the LV signal can provide a non-invasive assessment of the fluctuations in ventricular parameters associated with respiration.

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“…The diastolic portion of the LV AQ waveform can be used to assess the diastolic properties of the LV 8–18 . We have found that the reliability of AQ for the assessment of LV diastolic function is improved by signal averaging of the continuous data to generate a single averaged waveform 19 . Signal averaging circumvents beat‐to‐beat variability and allows for the computation of a more reliable derivative waveform with accurate identification of the phases of the cardiac cycle.…”

Section: Assessment Of Diastolic Function Using Acoustic Quantificationmentioning

confidence: 99%

Assessment of Global and Regional Left Ventricular Diastolic Function in Hypertensive Heart Disease Using Automated Border Detection Techniques

et al. 2003

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Acoustic quantification (AQ) and color kinesis (CK) are techniques that involve automated detection and tracking of endocardial borders. These methods are useful for the evaluation of global and regional left ventricular (LV) systolic function and more recently have been applied to evaluating LV diastolic performance. Assessment of diastolic dysfunction in hypertensive heart disease is a relevant clinical issue in which these techniques have proven useful. The diastolic portion of left atrium and LV AQ area waveforms are frequently abnormal in patients with left ventricular hypertrophy (LVH). Left ventricular AQ curves consistently demonstrate reduced rapid filling fraction (RFF) and peak rapid filling rate (PRFR), elevated atrial filling fraction (AFF), peak atrial filling rate (PAFR), and reductions in the ratio PRFR/PAFR. Acoustic quantification complements traditional Doppler echocardiographic evaluation of global diastolic function. Many patients with significant LVH and normal Doppler diastolic parameters can be identified as having diastolic dysfunction with AQ. In addition, CK has allowed the evaluation of regional diastolic performance in hypertensive patients. Regional filling curves obtained from CK have demonstrated that endocardial diastolic motion is commonly delayed and heterogeneous in patients with LVH.

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Improved quantification of left ventricular function by applying signal averaging to echocardiographic acoustic quantification

Cited by 28 publications

References 17 publications

Effects of aging on left atrial reservoir, conduit, and booster pump function: a multi-institution acoustic quantification study

Effects of aging on left atrial reservoir, conduit, and booster pump function: a multi-institution acoustic quantification study

Characterization of Hydrogen-Treated Pentacene Organic Thin Film Transistors

Assessment of Global and Regional Left Ventricular Diastolic Function in Hypertensive Heart Disease Using Automated Border Detection Techniques

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