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Variability in frame by frame analysis of left ventricular wall motion from contrast angiograms
H Hosokawa1, F H Sheehan, T Suzuki
1National Toyohashi Higashi Hospital, Japan.
Insights
Manual tracing of left ventricular (LV) borders on contrast angiograms shows variability in wall motion and timing measurements. This variability impacts derived functional parameters, but analysis of LV wall motion synchrony is reproducible.
Area of Science:
- Cardiology
- Medical Imaging
- Biomedical Engineering
Background:
- Accurate measurement of left ventricular (LV) function requires precise endocardial border delineation from contrast angiograms.
- Variability in manual tracing can affect assessments of LV wall motion, asynchrony, and diastolic function.
Purpose of the Study:
- To quantify intraobserver and interobserver variability in manual LV border tracing.
- To assess the impact of this variability on derived functional parameters.
Main Methods:
- Contrast ventriculograms from 25 patients were analyzed by two observers twice.
- LV wall motion and timing were measured using the centerline method.
- Variability was calculated for wall motion, asynchrony, and timing of contraction and filling.
Main Results:
- Intraobserver and interobserver variability in wall motion were similar and varied by cardiac cycle phase and LV location.
- Variability was highest at end systole (8% of mean wall motion).
- Timing variability was highest at peak contraction, with asynchrony variability averaging 18 msec.
Conclusions:
- Reproducibility of LV wall motion analysis from contrast ventriculograms is comparable to end-systolic measurements.
- Manual border tracing introduces variability impacting functional parameter assessment.
Background:
Measurement of the timing of left ventricular (LV) wall motion, of asynchrony, and of diastolic function from contrast angiograms requires delineation of the endocardial border frame by frame through the cardiac cycle. This study was performed to determine the magnitude of intraobserver and interobserver variability in manual border tracing, and to measure the impact of this variability on the derived functional parameters.
Methods:
The contrast ventriculograms of 25 patients with coronary artery disease (CAD) or with normal coronary arteries were analyzed frame by frame, by two observers or twice by the same observer. Motion was measured using the centerline method at each twelfth of systole and of diastole. Variability was calculated as the absolute difference between repeated measurements of: wall motion, asynchrony, and the time at which each region of the LV reached 10%, 50%, and 100% of peak contraction, and 50% of filling.
Results:
Intraobserver and interobserver variability in wall motion were similar, and varied with time in the cycle, and with location on the LV contour. Variability was highest at end systole, when it averaged 8% of the normal mean for wall motion. Variability in timing was highest at peak contraction; however, the variability in measuring asynchrony averaged only 18 msec.
Conclusion:
Analysis of the magnitude and synchrony of regional LV wall motion through the cardiac cycle from contrast ventriculograms can be performed with reproducibility comparable to that at end systole.