Quick Fire Cases
Danish Vaiyani, MD
Cardiologist
Children's Hospital of Philadelphia
Kevin K. Whitehead, MD, PhD
Cardiologist
Children's Hospital of Philadelphia
David M. Biko, MD, MBA, FSCMR, FAHA
Chief, Body imaging
Children's Hospital of Philadelphia
Sara Partington, MD
Associate Professor of Pediatrics
Children's Hospital of Philadelphia
Mark A. Fogel, MD, FACC, FAHA, MSCMR, FNASCI, FAAP
Professor
University of Pennsylvania
Matthew A. Harris, MD
Associate Director, Cardiac MRI
Children's Hospital of Philadelphia
An 8-month-old male presented to clinic after being referred for a murmur heard by his pediatrician. There was no history of heart failure. An echocardiogram demonstrated an aorto-ventricular tunnel with severe insufficiency, moderate left ventricular dilation and low normal ejection fraction; however the coronary artery origins as they related to the tunnel were unclear.
Diagnostic Techniques and Their Most Important Findings:
The patient presented the following week for a sedated cardiac MRI using ferumoxytol as the contrast agent. Contrast enhanced angiography was performed consisting of inversion recovery gradient echo imaging as well as Four-dimensional Multiphase Steady-State MRI (MUSIC). The combination of these two imaging sequences allowed complete visualization of the tunnel, aortic valve, coronary arteries and their spatial relationships to one another.
The tunnel was seen to originate below the left sinus of Valsalva and extend leftward over the aortic valve and terminate in the right sinus of Valsalva. The right coronary artery origin was located at the level of the sinotubular junction (STJ) just rightward of the tunnel. The left coronary artery origin was also at the level of the STJ with normal proximal course and branching. The total insufficiency was estimated at 33% with nearly all of this coming from the tunnel; the aortic valve itself had only trivial insufficiency.
The patient underwent surgical repair at 10 months of life. The right coronary artery os was noted to be distant from the tunnel and he underwent autologous pericardial patch closure of the tunnel at the aortic end. Post-operative transesophageal echocardiogram showed normal function, no residual shunting via the tunnel and no aortic insufficiency. At his 2 year follow up, he was doing well with trivial aortic insufficiency, no residual tunnel communication seen and normal left ventricular function.
Learning Points from this Case:
Aorto-ventricular tunnel is a rare congenital paravalvar communication between the aorta and the left ventricle that presents in early infancy with heart failure. While the diagnosis can readily be made with echocardiography, delineating the coronary artery anatomy can be challenging. This is important as coronary artery anomalies can rarely be present.
In our case, cross sectional imaging consisting of ferumoxytol-enhanced cardiac MRI was obtained to delineate the coronary artery anatomy, the relation of the coronary arteries to the tunnel and the orientation of the tunnel. Ferumoxytol is an iron-based contrast agent that been shown to be both safe and effective in acquiring high resolution imaging.
Surgical correction, consisting of patch closure of the tunnel, is the treatment of choice and has good outcomes.
Rarely, transcatheter closure has also been successfully completed. Following repair, clinicians should be vigilant for complications such as aortic insufficiency. In cases where the coronary artery anatomy is difficult to identify by echocardiogram, cross sectional imaging is useful for surgical planning.
