HIGH-RESOLUTION END-SYSTOLIC MYOCARDIAL PERFUSION MRI ENABLES RELIABLE DETECTION OF SUBENDOCARDIAL ISCHEMIA IN THE ABSENCE OF OBSTRUCTIVE CORONARY DISEASE

Patients suspected of having epicardial coronary disease are often investigated with noninvasive myocardial ischemia tests to establish a diagnosis and guide management. However, the relationship between myocardial ischemia and coronary stenoses is affected by multiple factors, and there is marked biological variation between patients. The ischemic cascade represents the temporal sequence of pathophysiological events that occur after interruption of myocardial oxygen delivery. The earliest part of the cascade is examined via perfusion imaging, and fractional flow reserve (FFR) is a corresponding index which is specific to the coronary artery. Whereas FFR has come to be regarded a clinical reference standard against which other newer invasive and noninvasive tests are validated, the diagnostic FFR threshold for detecting ischemia was established against a combination of noninvasive ischemia tests that assessed different stages of the ischemic cascade. Moreover, the validity of invasive pressure-derived indices of stenosis severity are contingent on the assumption that pressure is proportional to flow if microvascular resistance is constant, a condition induced by pharmacological intervention or by examining specific segments of the cardiac cycle. Furthermore, myocardial perfusion reserve depends on dynamic modulation of microvascular resistance, and dysfunction of the microvasculature can lead to ischemia even in the absence of epicardial coronary disease.

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The real-time reliable detection of the horizon line on high-resolution maritime images for unmanned surface-vehicle

2020 International Conference on Cyberworlds (CW) ◽

10.1109/cw49994.2020.9247845 ◽

2020 ◽

Author(s):

Uuganbayar Ganbold ◽

Takuya Akashi

Keyword(s):

High Resolution ◽

Real Time ◽

Unmanned Surface Vehicle ◽

The Real ◽

Reliable Detection ◽

Horizon Line

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High resolution impedance cardiography for the detection of coronary disease during stress testing

Journal of the American College of Cardiology ◽

10.1016/0735-1097(90)91903-8 ◽

1990 ◽

Vol 15 (2) ◽

pp. A46

Author(s):

Steve M. Teaque ◽

Paul N. Kizakevich ◽

Warren Jochem ◽

Romain Niclou ◽

Mukesh K. Sharma

Keyword(s):

High Resolution ◽

Coronary Disease ◽

Impedance Cardiography ◽

Stress Testing

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Abstract 1681: Evaluation of Quantitative Myocardial Perfusion MRI and TIMI myocardial blush grade (Blush score)

Circulation ◽

10.1161/circ.116.suppl_16.ii_353-a ◽

2007 ◽

Vol 116 (suppl_16) ◽

Author(s):

Hiroshi Nakajima ◽

Shinya Okamoto ◽

Hajime Sakuma ◽

Tairo Kurita ◽

Motonori Nagata ◽

...

Keyword(s):

Coronary Angiography ◽

Myocardial Perfusion ◽

Area Under The Curve ◽

Primary Angioplasty ◽

Perfusion Mri ◽

St Segment Elevation ◽

Quantitative Perfusion ◽

Timi Grade ◽

Significant Difference ◽

Myocardial Blush Grade

Background: The TIMI myocardial blush grade (MBG) has been shown to be a strong angiographic predictor of mortality in patients with TIMI 3 flow after primary angioplasty. This study was conducted to evaluate the relationship between regional myocardial perfusion quantified by cardiac magnetic resonance and angiographic reperfusion score defined by MBG. Methods: We studied 29 consecutive patients (25 men, age 63±13 years) with ST-segment elevation acute myocardial infarction (LAD lesion: 12, RCA lesion: 16, LCx lesion: 2) who underwent primary angioplasty within 6 hours from the onset and showed TIMI grade 3. MBG was determined on angiography at the end of angioplasty. All patients underwent rest myocardial perfusion MRI during initial hospitalization, and regional MBF (ml/min/g) was quantified by using a Patlak plot method. Myocardial perfusion (MP) ratio was calculated from quantitative perfusion MRI, as MBF in infarction area/MBF in normal area. The optimal cut-off value of MP ratio that can predict MBG 3 on coronary angiography was determined by using a receiver-operating characteristic (ROC) analysis. Results: In 29 patients with TIMI 3 flow after angioplasty, 4 patients had MBG 0–1, 7 had MBG 2 and 18 had MBG 3. The MP ratio in MBG 3 group calculated from quantitative perfusion MRI was significantly higher than the MP ratios in MBG 0 –1 group and MBG 2 group (0.96±0.18 vs. 0.48±0.25, P<0.001; 0.96±0.18 vs. 0.66±0.19, P=0.003, respectively). There was no significant difference between the MP ratios in MBG 0 –1 group and MBG 2 group. The ROC curve revealed that MP ratio of 0.74 is an optimal threshold to distinguish MBG 3 from MBG 0 –2, with a high area under the curve of 0.90. Conclusions: The result of this study demonstrates that MP ratio quantified from rest perfusion MRI correlated well with MBG on coronary angiography.

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