title: Quantitative assessment of short axis wall motion using myocardial strain rate imaging.
abstract: Although left ventricular wall motion has been usually assessed with four-point scale (1 = normal; 2 = hypokinesis; 3 = akinesis; 4 = dyskinesis) based on the visual assessment, this method is only qualitative and subjective. Recently, a new echocardiographic system that enables calculation of myocardial strain rate based on tissue Doppler information has been developed. We investigated whether myocardial strain rate could quantify regional myocardial contraction in 17 patients with and without wall motion abnormalities including 6 patients undergoing dobutamine stress echocardiography. Left ventricular short-axis wall motion was assessed with standard two-dimensional echocardiography at basal, mid-ventricular, and apical levels. The same levels were imaged with tissue Doppler method to determine regional myocardial strain rate. Sixty-four segments were judged normokinesis, 53 segments hypokinesis, and 18 segments akinesis at rest; 16 segments were judged normokinesis and 6 segments hypokinesis at stress. No segments characterized dyskinesis. Strain rates of normokinetic, hypokinetic, and akinetic wall segments at rest were significantly different each other (-2.0 +/- 0.6 for normokinesis,-0.6 +/- 0.5 for hypokinesis,P < 0.0001 vs. normokinesis, and-0.008 +/- 0.3 for akinesis, P < 0.0001 vs. normokinesis and hypokinesis). Further, strain rates well reflected the change in wall motion induced by dobutamine challenge: strain rates in the 15 segments revealing augmented wall motion changed from -2.0 +/- 0.7 to -4.7 +/- 1.7 (1/sec) (P < 0.0001) and those in the 7 segments revealing deteriorated or unchanged wall motion changed from -2.1 +/- 1.0 to -1.7 +/- 0.8 (1/sec) (P < 0.05). In conclusion, strain rate agreed well with assessed wall motion. Strain rate imaging may be a new powerful tool to quantify regional wall contraction.
authors.affiliation: Cardiology Division of Medicine, National Cardiovascular Center, 5-7-1 Fujishiro-dai, Suita, Osaka 565-8565, Japan. nakatas@hsp.ncvc.go.jp
authors.forename: Satoshi
authors.initials: S
authors.lastname: Nakatani
authors.forename: Marie
authors.initials: M
authors.lastname: Stugaard
authors.forename: Akihisa
authors.initials: A
authors.lastname: Hanatani
authors.forename: Keiko
authors.initials: K
authors.lastname: Katsuki
authors.forename: Hideaki
authors.initials: H
authors.lastname: Kanzaki
authors.forename: Masakazu
authors.initials: M
authors.lastname: Yamagishi
authors.forename: Masafumi
authors.initials: M
authors.lastname: Kitakaze
authors.forename: Kunio
authors.initials: K
authors.lastname: Miyatake
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D009202:Cardiomyopathies / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D015331:Cohort Studies; D004280:Dobutamine; D018618:Echocardiography, Doppler, Color / Q000379:methods*; D005080:Exercise Test; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction / Q000502:physiology*; D009206:Myocardium / Q000473:pathology*; D015588:Observer Variation; D011336:Probability; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index
chemical_list: D004280:Dobutamine