Limited type A aortic dissection (LTAAD) is a rare subtype of dissection that is confined within a well-defined border of the ascending aorta. These dissections may occur in the remaining native portion of the aortic root following aortic root replacement and can be complicated by malperfusion syndrome—a syndrome where dissections compromise the aortic branches and lead to end-organ ischemia. Because LTAAD is confined within the ascending aorta, malperfusion syndrome may preferentially affect the coronary arteries resulting in coronary malperfusion, myocardial infarction, and increased mortality. We report a case of LTAAD and malperfusion syndrome of the left main coronary artery which resulted in inadequate contrast opacification of the aorta and failure of the dissection protocol to trigger on computed tomography (CT). Upon further evaluation of the situation, the radiologist oversaw the manual triggering of CT acquisitions which yielded an actionable CT at 6 minutes post-contrast and real-time visualization of the patient’s developing cardiac ischemia.