Contractile reserve and contrast uptake pattern by magnetic resonance imaging and functional recovery after reperfused myocardial infarction
Christopher M. Kramer, MD, FACC*,
Walter J. Rogers, Jr., MS ,
Sunil Mankad, MD, FACC,
Therese M. Theobald, MPH,
Diana L. Pakstis, RN and
Yong-Lin Hu, PhD
* Departments of Medicine and Radiology, University of Virginia Health System, Charlottesville, Virginia, USA
Department of Medicine, Allegheny General Hospital, Pittsburgh, Pennsylvania, USA
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Figure 1 Left panel: End-systolic apical magnetic resonance tagged short-axis image in a patient on day 3 after anterior myocardial infarction treated with percutaneous transluminal coronary angioplasty and stenting of the left anterior descending coronary artery. The septum lies between the arrows, from 7 o’clock to 12 o’clock on the image. Note the reduced deformation of the tag stripes in this region compared with that in the anterolateral wall (12 o’clock to 4 o’clock) and inferoposterior wall (4 o’clock to 7 o’clock). Percent intramyocardial circumferential shortening (%S) was 4% in the septal subendocardium and 3% in the septal subepicardium. Center panel: End-systolic apical magnetic resonance tagged short-axis image in the same patient at the end of the 10 µg/kg/min dobutamine stage. Qualitatively, shortening increased significantly in the anterolateral and inferoposterior regions, whereas no improvement is seen in the septum (between the arrows). Quantitatively, %S was 5% in the septal subendocardium and 1% in the septal subepicardium, neither of which constitutes improvement. Right panel: End-systolic apical magnetic resonance tagged short-axis image in the same patient at nine weeks after myocardial infarction. Function did not improve in the septum (between the arrows), either qualitatively or quantitatively, whereas deformation of the tag stripes remains normal in the anterolateral and inferoposterior regions. Percent shortening is 7% in the septal subendocardium and 2% in the septal subepicardium—still significantly depressed. %S = percent intramyocardial circumferential shortening.
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Figure 2 Left panel: Short-axis inversion recovery Turboflash image during first pass of gadolinium-diethylenetriaminepenta-acetic acid through the myocardium in the same patient and the same apical short-axis plane as in Figure 1 with the LV and RV as marked. Note the region of hypoenhancement or reduced signal intensity between the arrows in the septum. Right panel: Short-axis inversion recovery Turboflash image 5 min after bolus infusion of gadoteridol in same plane as panel A with the LV and RV apex as marked. Note the hyperenhancement or increased signal intensity of the septum between the arrows. The pattern demonstrated in the two panels of this figure is consistent with that of the COMB pattern (first pass hypoenhancement and delayed hyperenhancement). LV = left ventricle; RV = right ventricle.
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Figure 3 Plot of linear regression analysis for %S at nine weeks after myocardial infarction (follow-up) on the y-axis and at peak dobutamine at day 3 after myocardial infarction for all 168 segments. A significant correlation is demonstrated (y = 0.68x + 4, r = 0.62, p < 0.0001). %S = percent intramyocardial circumferential shortening.
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