Anatomical M-mode: A novel technique for the quantitative evaluation of regional wall motion analysis during dobutamine echocardiography

Recognition of abnormal wall motion during dobutamine echocardiography requ ires an expert observer. Anatomical M-mode echocardiography may offer a nov el quantitative approach to interpretation, amenable to less expert readers . We studied the application of this new modality to 124 patients (80 with known coronary anatomy and 44 patients at low probability of coronary disea se) who underwent dobutamine echocardiography, using a standard protocol. W all motion was interpreted by an experienced reader, using digitally stored 2-dimensional echocardiographic images at rest and peak stress. Percentage of systolic thickening was measured offline using anatomical M-mode echoca rdiography in the basal and mid segments at rest and peak dose, and compare d with wall motion scores and coronary angiography. Of 729 segments, wall m otion was identified as normal in 449, ischemic or viable in 171 and showed resting WM abnormalities only in 109 segments. After exclusion of the apex , anatomical M-mode measurements were feasible in 729 of 960 possible basal - and mid-zone segments (76%). Measurement of systolic thickening at peak d ose was reproducible within (r(2) = 0.83) and between observers (r(2) = 0.9 3). Systolic thickening was significantly greater in segments with normal w all motion (37 +/- 2%) compared with ischemic or viable segments (30 +/- 2% , p < 0.001), and scar segments (23 +/- 3%, p < 0.001). There was an increm ent of thickening from rest to stress in normal and viable segments, no cha nge in scar, and a decrement in ischemic segments. Significant coronary art ery disease (defined by stenoses > 70% diameter) was present in 59 patients . Systolic thickening showed significant variation between segments interpr eted by wall motion scoring and angiography as true and false positive and true and false negative (p < 0.05). Measurement of systolic thickening usin g anatomical M-mode echocardiography offers an objective method to quantify systolic thickening at dobutamine echocardiography but has limited clinica l feasibility.