Number 10-05: Dobutamine inducible ischaemia- Case 2
Case from: P McParland, B Shepherd, S Harden, J Shambrook and C Peebles.
From the Department of Cardiothoracic Radiology, Southampton University Hospital Trust, Southampton, UK.
*** this is the second case of a series on dobutamine CMR. See also Case 10-02.
Clinical history: An 48 year old male was admitted to hospital with 6 hours of crushing central chest pain. He had inferolateral ST elevation on ECG therefore thrombolysis was performed. The ST segments resolved with no Q wave formation. During the remaining course of his admission he complained of continuing mild central chest pain which was not associated with ST segment changes. He had previously undergone PCI to RCA in 2007. He underwent coronary angiography which demonstrated extensive left coronary disease. The RCA was patent. A dobutamine stress CMR was requested to target appropriate revascularisation.
Dobutamine Stress CMRI images: Short axis images of the basal and mid left ventricle are shown at rest and with selected dobutamine concentrations of 5, 20, and 40 mcg/kg/min (Movie 1). The inferolateral wall is thinned and hypokinetic and shows no response to dobutamine challenge suggesting infarct with non-viability. The lateral wall is hypokinetic at rest and demonstrates a biphasic response to dobutamine stress. At low dose dobutamine, there is improvement in function but at higher doses the function deteriorates thus indicating viable myocardium with inducible ischemia of the lateral wall. The anterolateral wall shows normal function at rest and an inducible wall motion abnormality at peak stress indicating ischemia.
GRE first pass perfusion: Four short axis cine images of the left ventricle during perfusion at maximum dobutamine stress (Movie 2). There is an extensive perfusion defect of the anterolateral, lateral and inferior walls. The anterolateral wall shows normal function at rest and an inducible wall motion abnormality at peak stress indicating ischemia.
Movie 1 Movie 2
Image 1 Image 2
Late gadolinium enhancement: Short axis and four chamber images demonstrate a full thickness infarct of the inferolateral wall and only subendocardial infarct within the anterolateral and lateral walls with significant viable myocardium subtending these territories (Image 1&2).
Coronary Angiogram: RAO projection shows subtotal occlusion of the distal circumflex and OM1 branches as well as significant disease in the LAD and D1 (Image 3).
Perspective: This case demonstrates the clinical utility of dobutamine stress CMR to identify viability and myocardial ischemia. The inferolateral wall is predominantly non viable (distal circumflex territory) due to full thickness infarct. There is clear inducible ischemia over the viable lateral wall extending onto the anterolateral wall (OM1 and Diagonal territories). The OM1 and Diagonal lesions were not felt to be attractive for PCI and the patient refused CABG and so the patient was managed medically.
1. Sensky PR, Jivan A, Hudson NM, et al. Coronary artery disease: combined stress MR imaging protocol-one-stop evaluation of myocardial perfusion and function. Radiology. 2000 May; 215(2):608-14.