Myocardial perfusion imaging detects mechanical dyssynchrony in left ventricular infarcted and noninfarcted areas early after acute myocardial infarction in a porcine model. Issue 2 (February 2019)

• Record Type: Journal Article
• Authors: Zhang, Feifei; Tian, Yi; Yang, Wei; Shao, Xiaoliang; Wang, Jianfeng; Fan, Shengdeng; Li, Xiaoxia; Yan, Hui; Wang, Xiaosong; Wang, Yuetao
• Is Part Of: Nuclear medicine communications. Volume 40:Issue 2(2019:Feb.)
• Publication Date: 2019-02
• Subjects: acute myocardial infarction -- dyssynchrony -- myocardial perfusion imaging -- noninfarcted -- phase analysis -- regional -- wall motion -- wall thickening; Nuclear medicine -- Periodicals; 616.07575
• DOI: 10.1097/MNM.0000000000000945
• Languages: English
• ISSNs: 0143-3636

Abstract

Abstract : Background: Left ventricular mechanical dyssynchrony (LVMD) is closely associated with left ventricular dysfunction and poor prognosis in patients with acute myocardial infarction (AMI). However, whether mechanical dyssynchrony is present in the noninfarcted areas remains controversial. This research aimed to quantitatively evaluate the global and regional mechanical dyssynchrony early after AMI by phase analysis of single-photon emission computed tomography (SPECT) gated myocardial perfusion imaging (GMPI) and to further explore the related influencing factors. Materials and methods: Of 11 Bama suckling pigs, eight animals were successfully subjected to left anterior descending artery occlusion by balloon to generate porcine AMI models and completed the study. SPECT GMPI was performed before AMI and at 1 day, 1 week, and 4 weeks after AMI. The global bandwidth (BW), SD, entropy, total perfusion deficit, summed rest score, regional BW, regional summed motion score, and regional summed thickening score were measured by SPECT GMPI. Results: The global BW, SD, and entropy values significantly increased after AMI and showed no significant change among the three time points after AMI. The BW in the infarcted area (left anterior descending artery-dominated area) at 1 day, 1 week, and 4 weeks after AMI was significantly higher than that before AMI, as was the BW in the noninfarcted areas (left circumflex artery-dominated and right coronary artery-dominated areas), which revealed that there was less dyssynchrony in the noninfarcted areas than in the infarcted area at the three time points after AMI. The global BW was positively correlated with the scar burden measured by summed rest score ( r =0.709–0.832, all P <0.05), whereas the regional BW in the noninfarcted areas after AMI showed moderate to good correlation with regional summed motion score ( r =0.733–0.875, all P <0.05) and regional summed thickening score ( r =0.713–0.889, all P <0.05). Conclusion: LVMD occurs early on the first day after AMI, with no significant worsening over the next 4 weeks. Mechanical dyssynchrony was present in both the infarcted and noninfarcted areas. The global LVMD is mainly influenced by the scar burden, and the regional mechanical dyssynchrony in the noninfarcted areas is closely associated with the abnormal regional wall thickening and motion, which are indicative of reduced myocardial contractility.