经标记磁共振成像显示，再灌注急性心肌梗死后尽管收缩功能完全恢复，但仍存在持续性舒张功能障碍。

Persistent diastolic dysfunction despite complete systolic functional recovery after reperfused acute myocardial infarction demonstrated by tagged magnetic resonance imaging.

作者信息

Azevedo Clerio F, Amado Luciano C, Kraitchman Dara L, Gerber Bernhard L, Osman Nael F, Rochitte Carlos E, Edvardsen Thor, Lima Joao A C

机构信息

Department of Medicine, Division of Cardiology, Johns Hopkins Hospital, 600 N Wolfe Street/Blalock 524, Baltimore, MD 21287-0409, USA.

出版信息

Eur Heart J. 2004 Aug;25(16):1419-27. doi: 10.1016/j.ehj.2004.06.024.

DOI:10.1016/j.ehj.2004.06.024

PMID:15321700

Abstract

AIMS

This study was designed to characterise both the systolic and diastolic mechanical properties of regions with different degrees of myocardial ischaemic injury after reperfused acute myocardial infarction (AMI).

METHODS AND RESULTS

Fourteen dogs underwent 90-min coronary artery occlusion followed by reperfusion. Image acquisition was performed 24 h after reperfusion using three techniques: tagged, first-pass perfusion and delayed-enhancement magnetic resonance imaging (MRI). Systolic circumferential strain and both systolic and diastolic strain rates were calculated in 30 segments/animal. Transmural AMI segments displayed reduced systolic contractility when compared to subendocardial AMI segments (systolic strain = -2.5 +/- 0.5% versus -6.0 +/- 0.9%, P < 0.01 and systolic strain rate = -0.11 +/- 0.12 versus -0.82 +/- 0.16 s(-1), P < 0.01), and both exhibited significant systolic and diastolic dysfunction compared to remote. Moreover, AMI segments presenting with microvascular obstruction ("no-reflow") displayed further compromise of systolic and diastolic regional function (P < 0.05 for both). Importantly, risk region segments only exhibited diastolic impairment (diastolic strain rate = 1.62 +/- 0.14 versus 2.99 +/- 0.13 s(-1), P < 0.001), but not systolic dysfunction compared to remote 24 h after reperfusion.

CONCLUSION

Reversibly injured regions can demonstrate persistent diastolic dysfunction despite complete systolic functional recovery after reperfused AMI. Moreover, the presence of no-reflow entails profound systolic and diastolic dysfunction. Finally, tagged magnetic resonance imaging (MRI) strain rate analysis provides detailed mechanical characterisation of regions with different degrees of myocardial ischaemic injury.

摘要

目的

本研究旨在对再灌注急性心肌梗死（AMI）后不同程度心肌缺血损伤区域的收缩期和舒张期力学特性进行表征。

方法与结果

14只犬接受90分钟冠状动脉闭塞后再灌注。再灌注24小时后使用三种技术进行图像采集：标记成像、首过灌注和延迟强化磁共振成像（MRI）。每只动物在30个节段计算收缩期圆周应变以及收缩期和舒张期应变率。与心内膜下AMI节段相比，透壁AMI节段的收缩期收缩性降低（收缩期应变=-2.5±0.5%对-6.0±0.9%，P<0.01；收缩期应变率=-0.11±0.12对-0.82±0.16 s⁻¹，P<0.01），并且与远隔节段相比，二者均表现出显著的收缩期和舒张期功能障碍。此外，出现微血管阻塞（“无复流”）的AMI节段的收缩期和舒张期局部功能进一步受损（二者P均<0.05）。重要的是，与再灌注24小时后的远隔节段相比，危险区域节段仅表现出舒张功能受损（舒张期应变率=1.62±0.14对2.99±0.13 s⁻¹，P<0.001），但无收缩期功能障碍。