Background: Visual evaluation of wall motion is subjective and may be difficult in patients with impaired left ventricular function. Current algorithms used to analyze wall motion usually neglect motion asynchrony that may be profoundly altered in coronary artery disease. This study was to investigate whether the extent of left ventricular asynergy can be used to quantify the severity of regional myocardial dysfunction by the use of Fourier phase imaging.
Methods: Echocardiographic cine loops of 21 patients with ischemic cardiomyopathy (EF < or = 40%) were mathematically transformed using a first-harmonic Fourier algorithm displaying the sequence of wall motion as phase angles in parametric images and regional phase histograms. Segmental fractional area shortening (FAC) and qualitative assessment of regional wall motion based on visual inspection served as reference method.
Results: There was an inverse linear relationship between FAC and phase angles (r = -0.75, p < 0.01). Normal endocardial motion yielded low phase angles (mean 16 +/- 15 degrees SD). With an increase in wall motion abnormalities, phase angles were progressively delayed by 56 +/- 38 degrees in hypokinetic, by 88 +/- 38 degrees in akinetic, and by 143 +/- 33 degrees (p < 0.001) in dyskinetic segments.
Conclusions: These results demonstrate that left ventricular asynchrony is an indicator of regional myocardial dysfunction in coronary artery disease. Echocardiographic Fourier phase imaging can be used to quantify wall motion displaying contraction sequence in a simple and objective format.