Abstract 14787: Improvement of the Diagnostic Accuracy for Ischemic Memory by a Combination of Intraventricular Activation Time Index and Post-Systolic Shortening
Background: Post-systolic shortening (PSS), subtle myocardial shortening in isovolumic relaxation time, is induced by myocardial ischemia and remains for a while after its resolution. Therefore, PSS is considered a marker of ischemic memory. However, the fact that PSS can also be seen in the normal myocardium hampers its routine clinical use. We found that a novel intraventricular activation time index (T30%), time from end-diastole to 30% value of peak strain, prolonged during ischemia showing it another promising index of myocardial ischemia. We hypothesized that the prolongation of T30% persisted after brief ischemia, and investigated whether the diagnostic accuracy of ischemic memory was improved by a combination of T30% and PSS.
Methods: In 9 open-chest dogs, the left anterior descending coronary artery was occluded for 2 minutes. Left ventricular short-axis images were acquired with speckle tracking echocardiography (118 fps, Toshiba Aplio) at baseline and after reperfusion (10, 20 and 30 min). Circumferential strain profiles were analyzed in the anterior segment (risk area). Post-systolic index (PSI) as a parameter of PSS, and T30% (corrected by R-R duration) were calculated. The diagnostic accuracy for detecting ischemic memory was assessed by receiver operating characteristic (ROC) curve using single and multiple logistic regression analysis.
Results: In 10 and 20 min after reperfusion, PSI and T30% significantly higher than that of baseline (PSI: 0.01±0.03 vs. 0.09±0.07; T30%: 0.22±0.07 vs. 0.32±0.06, both for baseline vs. 20 min, p<0.05). The AUCs of PSI and T30% at 20 min after reperfusion were similar and significantly larger than that of the line of no information. The AUC exceeded 0.9 by a combination of PSI and T30% (Figure).
Conclusion: The prolongation of T30% persisted after brief ischemia suggesting its feasibility as a marker of ischemic memory. The diagnostic accuracy for ischemic memory was improved by a combination of T30% and PSS.
Author Disclosures: H. Adachi: None. T. Asanuma: None. K. Masuda: None. T. Kamimukai: None. Y. Sakakibara: None. D. Sakurai: None. S. Nakatani: Honoraria; Significant; Edwards Lifesciences Inc..
- © 2016 by American Heart Association, Inc.