Evaluation of experimental myocardial infarction models via electromechanical mapping and magnetic resonance imaging

2013 ◽  
Vol 91 (8) ◽  
pp. 617-624 ◽  
Author(s):  
Edit Lukács ◽  
Balázs Magyari ◽  
Levente Tóth ◽  
Örs Petneházy ◽  
Zsolt Petrási ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Myocardial Infarction ◽  
Magnetic Resonance ◽  
Late Enhancement ◽  
Left Ventricular ◽  
Resonance Imaging ◽  
Characteristic Analysis ◽  
Diagnostic Features ◽  
Electromechanical Mapping ◽  
Diagnostic Characteristics

The diagnostic characteristics of electromechanical mapping (EMM) were evaluated in porcine myocardial infarction (MI) models with the parallel application of cardiac magnetic resonance imaging (cMRI) from the aspect of different pathophysiology and localization. Balloon occlusion in the left anterior descending coronary artery (LAD balloon group) or coil deployment in the LAD (LAD coil group) or circumflex artery (Cx coil group) was applied percutaneously in 16 domestic pigs. Regional left ventricular viability data were captured via cMRI and EMM. The unipolar voltage (UV) value was significantly decreased in segments containing transmural and subendocardial late enhancement compared with viable segments in the LAD balloon, LAD coil, and Cx coil groups. Receiver operating characteristic analysis revealed area under the curve values of 0.809 and 0.691 in the LAD infarct territory, and 0.864 and 0.855 in the Cx infarct territory for the UV compared with cMRI viability results as transmural late enhancement or viable tissue and subendocardial late enhancement or viable tissue, respectively. In conclusion, the UV value detected the presence of scar tissue with differential transmural extent and which represented proper diagnostic features both in the reperfused and nonreperfused models. This data could provide additional benefit in the clinical use of EMM for diagnostic purposes.

Abstract 1975: Detection Of Left Ventricular Thrombus With Cardiac Magnetic Resonance Imaging In Patients With Acute St-segment Elevation Myocardial Infarction (stemi)

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Ingo Eitel ◽  
Kathrin Schindler ◽  
Josef Friedenberger ◽  
Georg Fuernau ◽  
Gerhard Schuler ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Myocardial Infarction ◽  
Cardiac Magnetic Resonance ◽  
Magnetic Resonance ◽  
Cardiac Magnetic Resonance Imaging ◽  
Late Enhancement ◽  
Left Ventricular ◽  
Resonance Imaging ◽  
Ventricular Thrombus ◽  
Left Ventricular Thrombi

Introduction Previously published studies showed differences regarding the prevalence of intraventricular thrombi in patients with acute myocardial infarction (MI) (4–56%). Until now there are no exact results about the occurrence of left ventricular thrombi in acute STEMI. Recognition of LV thrombus is important because the related risk of systemic embolization is high. Methods To investigate the extent of myocardial infarction we examined 225 consecutive patients undergoing primary percutaneous coronar intervention (PCI) in acute STEMI within 12 h after symptom onset by cardiac magnetic resonance imaging within 2– 4 days. Routinely all patients were examined with transthoracic echocardiography (TTE) or transesophageal echocardiography (TEE). All images were analyzed for the presence of intraventricular thrombi. Results In 18 patients (8.0%) we detected left ventricular thrombi, but none of these were seen in TTE or TEE. In two cases an intraventricular thrombus was detected by TEE and TTE, but in the subsequently performed MRI no thrombus was found. In all cases the left ventricular thrombi could be detected in the late enhancement sequence, 8 (44.4%) of them were missed in the cine SSFP sequences. Left ventricular thrombi were more frequently diagnosed in patients with moderate to severe impairment of the left ventricular systolic function (13/18 [72,2%]). Remarkable was also that 14 (77.8%) of the 18 patients with left ventricular thrombus in MRI had an anterior MI, whereas only 2 (11.1%) had an inferior MI, 1 (5,6%) a septal MI and 1 patient (5,6%) a lateral MI. Conclusion In our study TEE and TTE missed left ventricular thrombi in all 18 patients as compared to MRI. There were two false-positive results in TEE and TTE as compared to MRI. Patients with impaired left ventricular function and acute anterior MI have a higher risk of developing left ventricular thrombi than in other infarct-locations. Therefore it could be potentially important to screen in particular high-risk patients (with anterior MI and impaired left ventricular function) with cardiac magnetic resonance imaging to exclude left ventricular thrombi and to lower the risk of embolic events. In particular late enhancement sequences are suitable to detect intraventricular thrombi.

Abstract 9634: As Compared With Cardiac Magnetic Resonance Imaging, Transthoracic Echocardiography Has an Excellent Accuracy in Diagnosing a Left Ventricular Thrombus After an Anterior Myocardial Infarction Complicated With Left Ventricular Dysfunction: Results of a Prospective Multicentric Study

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Philippe Meurin ◽  
Virginie Brandao Carreira ◽  
Raphaelle D Dumaine ◽  
Alain Shqueir ◽  
Olivier Milleron ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Myocardial Infarction ◽  
Cardiac Magnetic Resonance ◽  
Magnetic Resonance ◽  
Cardiac Magnetic Resonance Imaging ◽  
Antiplatelet Therapy ◽  
Transthoracic Echocardiography ◽  
Dual Antiplatelet Therapy ◽  
Left Ventricular ◽  
Resonance Imaging

Introduction: The generalization of reperfusion techniques to treat acute myocardial infarction (MI) has allowed for markedly reduced incidence in left ventricular (LV) thrombi because of the reduced myocardial damage. LV thrombi are estimated to complicate 5% to 10% of unselected anterior-wall MI (Ant-MI). However, the incidence and evolution of LV thrombi in high-risk patients with Ant-MI complicated by LV systolic dysfunction is not well known. Cardiac magnetic resonance imaging with contrast delayed enhancement (CMR-DE) is the gold standard in assessing LV thrombus, but comparisons of transthoracic echocardiography (TTE) and CMR-DE are scarce. Hypothesis: We assessed whether LV thrombi are still frequent after major Ant-MI, despite systematic dual antiplatelet therapy, and whether focused TTE has a good accuracy for detection as compared with CMR-DE. Methods: From 2011 to 2013, from 7 centers, we prospectively included patients with LV ejection fraction (LVEF) < 45% at a first TTE performed < 7 days after Ant-MI. A second evaluation including TTE and CMR-DE (analyzed by blinded examiners) was performed at 30 days. A third TTE and assessment of clinical status and adverse events were performed between months 6 and 12. Results: We included 100 consecutive patients (71% males; mean age 59.1 ± 12.1 years; LVEF 33.5 ± 6.0%) at a mean of 4.8 ± 1.9 days after Ant-MI; 88% had undergone primary coronary angioplasty. In total, 26 patients had LV thrombi detected at a mean of 23.2 ± 34.8 days after MI (6 during the first week after the MI, 16 from days 8 to 30, 4 after day 30). As compared with CMR-DE, TTE sensitivity and specificity were 94.7% and 98.5%, respectively. For 24 patients (92.3%), the LV thrombi disappeared with triple antithrombotic therapy including dual antiplatelet therapy and a vitamin K antagonist. One patient died from a recurrent subdural haematoma and another had a peripheral embolism. Conclusions: In this prospective multicenter study, LV thrombus occurred in 26% of patients after Ant-MI complicated by LV dysfunction. Focused TTE has a high accuracy for detection. CMR-DE should be performed only when the apex is not clearly seen.

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