Acute Myocardial Infarction Caused by "Malignant" Anomalous Right Coronary Artery Detected by Multidetector Row Computed Tomography

Minoru Ichikawa, Sei Komatsu, Hiroshi Asanuma, Akio Iwata, Tamayo Ishiko, Atsushi Hirayama, Young-Jae Lim, Kazuhisa Kodama, Masayoshi Mishima
2005 Circulation Journal  
he incidence of coronary artery anomalies is reported to be about 1% in patients undergoing angiography. 1 Origination of the right coronary artery (RCA) from the left sinus of Valsalva is a rare anomaly with an incidence of 0.05-0.10% among all patients having coronary angiography (CAG) 2,3 and it has been suggested that such an anomaly with the RCA coursing between the ascending aorta and the pulmonary trunk could be a cause of ischemia or sudden death. 4 There are some previous reports of
more » ... vious reports of incidentally detecting coronary anomalies during multidetector row computed tomography (MDCT), 5-7 but acute coronary syndrome (ACS) associated with "malignant" anomalies has not been reported. We describe a patient with anomalous origin of the RCA in whom ACS occurred. We evaluated the plaque texture using a plaque analyzing system ("Plaque Map"), and compared the results with those from intravascular ultrasound (IVUS). Case Report A 47-year-old man with no prior history of cardiac disease developed severe chest pain that persisted for 2 h while he was drinking alcohol. His cardiovascular risk factors included current smoking. The 12-lead electrocardiogram showed ST segment elevation in leads II, III and aVF, so emergency cardiac catheterization was performed. Multiple attempts to catheterize the RCA were unsuccessful, so the possibility of anomalous origin of the RCA was suspected, but aortography failed to reveal the ostium (Fig 1) . The left coronary artery (LCA) showed no signifi-cant stenosis, and there were no collaterals to the RCA. The patient was treated with recombinant tissue plasminogen activator (1,600,000 IU of Monteplase). His peak creatine kinase level was 5,480 IU/L and the clinical course was uneventful. To confirm the anomalous origin and course of the RCA, MDCT was performed using a 16-slice scanner (LightSpeed 16, GE Systems, USA) at 2 weeks after admission. The patient was pretreated with metoprolol (20 mg po) 1 h before scanning and with sublingual nitroglycerin 10 min before the procedure. For determination of the circulation time, 15 ml of contrast medium (Optiray 320; Tyco Healthcare Co, Ltd, Japan) was administered into an antecubital vein at 3.5 ml/s and 80 ml of contrast medium was used for MDCT at 3.5 ml/s. The slice thickness was 0.625 mm, pitch 0.3:1, rotation time 0.5 s, temporal resolution 125 ms and the trigger point was 70-80% (R-R). Reconstruction was done by the snapshot burst reconstruction method (retrogating reconstruction). Cross-sectional images of the coronary arteries were obtained by applying the curved multiplanar reformation technique at intervals of 5 mm and these were analyzed by Plaque Map. 8 Axial images showed the RCA originating from the left sinus of Valsalva, anterior to the origin of the LCA. Volume-rendered images that were reconstructed on an Advantage Workstation 4.2 (GE Healthcare, WI, USA) showed an anomalous RCA arising from the left sinus of Valsalva and coursing between the aortic root and the pulmonary trunk (Fig 2) . The anomalous RCA did not show any kinks or sharp bends and it branched from the aorta at angle of 33°. There was significant stenosis at the midpoint of the RCA. Three weeks after admission, invasive CAG was attempted again based on the information obtained by MDCT. CAG confirmed that the RCA arose from the left sinus of Valsalva and was contiguous anterior with the LCA ostium (Fig 3A) . The culprit lesion showed 75% stenosis. There was Thrombolysis in Myocardial Infarction Circ J 2005; 69: 1564 -1567 Anomalous coronary arteries are usually identified incidentally by angiography or autopsy, but some "malignant" coronary anomalies are associated with a high incidence of syncope, arrhythmia, myocardial infarction, and sudden death. So far, the pathogenesis of the coronary events in such cases has only been revealed by autopsy. In the present case report, a patient with anomalous origin of the right coronary artery from the left sinus of Valsalva developed acute myocardial infarction, and visualization of the anomaly and assessment of the culprit plaque in the artery were done by multidetector row computed tomography and intravascular ultrasound. (Circ J 2005; 69: 1564 -1567
doi:10.1253/circj.69.1564 pmid:16308510 fatcat:2d4f5yiulnelzntduix246mmye