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Publications (3)28.17 Total impact

  • Motoyoshi Maenaka
    Journal of The American College of Cardiology - J AMER COLL CARDIOL. 01/2010; 55(10).
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    ABSTRACT: This study was designed to characterize both regional left ventricular (LV) systolic and diastolic function after percutaneous coronary intervention by using strain imaging (SI) derived from 2-dimensional speckle-tracking echocardiography. Ischemic insult after coronary occlusion affects not only regional LV systolic but also diastolic function. Regional LV transverse peak strain and strain changes during the first one-third of diastole duration (strain imaging diastolic index [SI-DI]) were monitored in at-risk segments after percutaneous coronary intervention in 30 patients with coronary artery disease. The segments were divided into proximal and distal. Strain data in the at-risk segments were compared with values derived from remote nonischemic segments. Coronary occlusion induced a marked reduction in the systolic strain in both proximal and distal at-risk segments (from 36.9 +/- 6.0% to 12.0 +/- 3.9% and from 31.9 +/- 5.6% to 6.2 +/- 3.3%, respectively, p < 0.0001). Concomitantly, SI-DI values decreased (from 76.6 +/- 5.3% to -21.2 +/- 9.1% and from 72.5 +/- 5.9% to -48.7 +/- 20.8%, respectively, p < 0.0001). Upon reperfusion, systolic deformation parameters returned to near-normal pre-occlusion values. However, SI-DI values in the both proximal and distal at-risk segments decreased (43.2 +/- 9.5%, p < 0.01, and -17.3 +/- 11.1%, p < 0.0001, respectively) 30 min after reperfusion and were still lower (51.5 +/- 9.9%, p < 0.01) in the distal at-risk segment 24 h after reperfusion. SI analysis provides detailed mechanical characterization of regions with myocardial ischemic insult and can demonstrate post-ischemic diastolic stunning despite complete systolic functional recovery after reperfusion.
    Journal of the American College of Cardiology 10/2009; 54(17):1589-97. · 14.09 Impact Factor
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    ABSTRACT: The aim of this study was to determine whether post-ischemic left ventricular (LV) delayed relaxation could be detected by using strain imaging (SI) derived from 2-dimensional speckle-tracking echocardiography in patients with stable effort angina. Regional LV delayed relaxation during early diastole is a sensitive sign of acute myocardial ischemia and may persist beyond recovery of exercise-induced ischemia. Regional LV transverse strain changes during the first one-third of diastole duration (strain imaging diastolic index [SI-DI]) were determined at baseline and 5 and 10 min after the exercise test in 162 patients with stable effort angina. The ratio of SI-DI before and after exercise (SI-DI ratio) was used to identify regional LV delayed relaxation. A total of 117 patients had significant (> or =50% of luminal diameter) coronary stenoses. The mean SI-DI decreased from 78.0 +/- 9.7% to 27.6 +/- 16.0% (p < 0.0001) in 191 territories perfused by coronary arteries with significant stenoses 5 min after the treadmill exercise, whereas it remained unchanged in 280 territories perfused by arteries with nonsignificant stenoses. Ten minutes after exercise, regional delayed relaxation was still observed in 85% of territories perfused by stenotic coronary arteries. An SI-DI ratio with a cutoff value of 0.74 had a sensitivity of 97% and a specificity of 93% to detect significant coronary stenosis in the receiver-operator characteristic curve. Detection of post-ischemic regional LV delayed relaxation or diastolic stunning after treadmill exercise using SI is a sensitive and reliable method for the detection of coronary artery disease.
    Journal of the American College of Cardiology 03/2009; 53(8):698-705. · 14.09 Impact Factor