History
A 70-year-old female patient, suffering from intermittent pain in the interscapular dorsal region, occasionally associated with dyspnea, over the past year, came to the cardiology clinic. Her medical history included an infiltrating ductal breast cancer 7 years ago and a melanoma on her right hand 2 years ago – both had been surgically treated. Physical examination revealed a systolic murmur in the aortic focus. An echocardiogram revealed a moderate aortic valve stenosis. A performed coronary angiography could not catheterize the right coronary artery (RCA), however, revealed a retrograde filling from the left anterior descending artery (LAD) to the RCA, with contrast reflux from the RCA ostium to the pulmonary artery, suspicious of an abnormality of the origin or a fistula of the RCA. A coronary CT angiography (cCTA) was requested for further evaluation.
Diagnosis
cCTA images revealed an RCA dominant system. The RCA was diffusely dilated with an anomalous origin off the pulmonary trunk (ARCAPA). It came off at an angulation of less than 45 degrees and ran a proximal trajectory towards the right atrioventricular groove with a sharp turn. The left main coronary artery (LM), the left anterior descending artery (LAD) and the circumflex (Cx) were also diffusely dilated, with normal origins and courses. Collaterals between the RCA and the LAD were shown, consistent with retrograde filling seen previously in the coronary angiogram. The diffuse dilation of the coronary arteries was presumably caused by the left-to-right shunt flow. A tri-leaflet aortic valve was seen with calcification in the leaflets causing moderate stenosis, confirming the previous finding of the echocardiogram. A surgical correction was recommended but was refused by the patient.
Courtesy of Clínica IMAT Oncomedica, Montería, Córdoba, Colombia.
Fig. 1: cVRT images (Fig. 1a, 1b, and 1d) and a thin MIP image (Fig. 1b) show a diffusely dilated RCA with an ARCAPA (arrows) at an angulation of less than 45 degrees and a proximal trajectory towards the right atrioventricular groove making a sharp turn. The LM, LAD, and Cx were also diffusely dilated, with normal origins and courses. Collaterals between the RCA and the LAD are seen.
Comments
ARCAPA syndrome is infrequent, corresponding to only 0.002% of all congenital heart diseases. Most patients are asymptomatic and the anomaly is incidentally detected in adulthood. [1] Occasionally, ARCAPA may lead to myocardial ischemia and/ or sudden cardiac arrest. In most patients, surgical correction, aiming at eliminating the left-to-right shunt and establishing dual coronary circulation to prevent the potential risk of myocardial ischemia from coronary steal, is recommended. [2] Surgical techniques available include simple ligation of the RCA, ligation of the RCA with saphenous vein bypass grafting and reimplantation of the RCA into the aorta. The location of the ostium of the RCA in the pulmonary artery will influence the technique used for surgical repair. cCTA imaging allows for optimal visualization of the anomalies with detailed anatomic information of the origins, courses and collaterals, providing important information for surgical planning as well as for post-surgery follow-up. In this case, a retrospective ECG gated spiral scan mode is applied to acquire image data which can be reconstructed in different cardiac phases. The best systolic and the best diastolic phases are identified by the system automatically. Images are visualized in three dimensions using cinematic volume rendering technique (cVRT) facilitating a lifelike demonstration and an easier communication with all parties involved.
Examination Protocol