Presentation
Acute chest pain and dyspnoea, known CAD with a coronary stent in LAD. ST elevation in II, III, aVF on ECG; akinetic inferior wall, EF ~30% on echo.
Patient Data
Invasive coronary angiography (ICA):
occlusion of the medial RCA, high-grade stenosis of the distal RCA and stenosis PDA
significant high-grade in-stent restenosis of the high-proximal LAD
significant high-grade stenosis of the ramus intermedius artery
significant, long high-grade stenosis of the obtuse marginal branch
Percutaneous coronary intervention (PCI):
initial recanalisation with balloon angioplasty of the medial RCA stenosis and subsequent placement of a drug-eluting stent (DES)
direct coronary stent (DES) placement into the distal RCA stenosis
Image courtesy: Dr Frank-Peter Held (cardiologist)
Heart rate: 63 bpm
Image quality: mild to moderate respiratory artifacts, otherwise no limitations
Morphology and functional analysis (endo-volume):
LV-EDVI: 95 mL/m²
LV-ESVI: 53 mL/m²
LV-SVI: 42 mL/m²
LV-EF: 45%
cardiac output: 5.8 L/min
cardiac index: 2.6 L/min/m²
LV-ED wall mas index (without papillary muscles): 64 g/cm
septum and inferior wall thickness: 12 and 7 mm
Findings:
Hypokinetic myocardium in basal inferoseptal to inferolateral, midventricular inferior and inferoseptal and apical inferior segments with corresponding late gadolinium enhancement (transmural infarct extent 75-100%) including a part of the inferior right ventricular wall a small part of the inferior papillary muscle and a subendocardial no-reflow zone with associated perfusion defect.
Associated massive myocardial oedema of the inferior left and right ventricular wall.
Associated increased extracellular volume as well as elevated T1 and T2 mapping values in the infarcted myocardium and marginal T2 values
T1 mapping native: >1250 ms (infarcted myocardium); 1040-1130 (remaining myocardium)
extracellular volume (ECV): >50% (infarcted myocardium); 28-32% (remaining myocardium)
T2 mapping: 82 +/-10 ms (infarcted myocardium); 55-57 +/-6 ms (remaining myocardium)
Normal reference ranges based on local data:
-
native T1: 940-1060 ms; ECV: >32%; T2: 44-56 ms
No intracavitary thrombi.
Mild mitral valve insufficiency.
Visually normal atrial size.
No pericardial effusion.
Mild right pleural effusion.
Impression:
Cardiac MRI findings are consistent with an acute inferior wall myocardial infarction with associated microvascular obstruction and right ventricular involvement.
Mildly reduced left ventricular function.
The whole anterior wall is viable but also displays elevated T1 values and marginally elevated T2 values.
Exam courtesy: Diana Buchardt & Tobias Jahn (radiographers)
Case Discussion
A case of ischaemic cardiomyopathy due to an inferior wall myocardial infarction with signs of microvascular obstruction and right ventricular involvement in a patient with multivessel coronary artery disease, who admittedly waited quite some time at home before eventually calling the ambulance. The myocardial infarction was due to a long occlusion of the right coronary artery, which was successfully revascularised through cardiac catheterisation and coronary stent placement immediately after hospital admission.
The cardiac MRI beautifully shows the whole extent of the inferior wall myocardial infarction, which also involves the inferior wall of the right ventricle on late gadolinium enhancement as well as the "no-reflow zone" indicating microvascular obstruction. The latter might be due to the patient's long waiting time or a result of reperfusion injury, microembolisation or a combination of those. The STIR images also nicely depict intense myocardial oedema in the infarcted myocardium but not the mild myocardial oedema in the anterior wall, which was only detected by myocardial mapping, which in the context of the stenoses of the branches of the left coronary artery might indicate that also that area is at risk.
Concerning the in-stent restenosis and the high-grade stenosis of the obtuse marginal branch the patient received an urgent appointment for coronary bypass surgery.
Co-author: Dr Frank-Peter Held (cardiologist)
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