Martin Hosking

Feasibility of Optical Coherence Tomography in Children with Kawasaki Disease and Pediatric Heart Transplant Recipients

Background—Optical coherence tomography (OCT) is a high-resolution intravascular imaging technique used in adults. We tested the hypothesis that OCT could identify coronary abnormalities not seen by angiography in children with a history of Kawasaki disease (KD) and pediatric heart transplant (TX) recipients. Methods and Results—Patients with KD and TX recipients were evaluated between December 2012 and October 2013 with angiography and OCT (Ilumien System, LightLabs, St Jude Medical, Westford, MA). Modifications were made to the adult OCT protocol to adapt this technique for children. Serial cross-sectional area measurements of the lumen, intima, and media were made. Entire imaging data were analyzed for the presence of qualitative changes. Seventeen children were evaluated (5 patients with KD; 12 TX recipients). In patients with KD, angiography was normal. However, OCT imaging revealed that significant vessel wall abnormalities were present in all children including intimal thickening (intima/lumen cross-sectional area ratio>0.4), loss of the normal layered structure of the vessel wall, white thrombus, calcification, and neovascularization. There was extensive destruction of the internal elastic lamina. In TX recipients, angiography was normal; however, intimal thickening (intima/media cross-sectional area ratio>1) was seen in 9 of 12 patients. The median intima/media cross-sectional area ratio was 1.18. Conclusions—In this initial experience with OCT in children, we have identified significant coronary abnormalities with OCT that are angiographically silent in children with a history of coronary aneurysms because of KD and in pediatric TX recipients.

Coronary Arteriovenous Fistula: Direct Connection of the Proximal Circumflex Artery to the Coronary Sinus

There exists an extensive literature describing the clinical and morphologic characteristics of coronary artery fistulas [1, 2]. The angiographic and echocardiographic appearances of the two cases in the reports that follow highlight the confusion in the current literature with regard to differentiating coronary arteriovenous fistulas and the entity known as the aorto-right atrial tunnel [3, 4]. The aorto-right atrial tunnel is a very rare anatomic condition in which the communication arises directly from the aorta, with dilation of the corresponding sinus of Valsalva [4]. The ‘‘tunnel’’ consists of a dilated and tortuous vessel originating from either the left, or noncoronary, sinus with variable entry to the right atrium. The coronary arteries arise independently of the aorto-right atrial tunnel, and no branching vessels (coronary artery) arise from the tunnel itself. Two-dimensional echo cardiography can differentiate a coronary arteriovenous fistula by visualizing both coronary origins separately away from the tunnel. They manifest as a dilated main coronary artery with proximal and distal branches that distribute into the myocardium [4, 5]. The sinus of Valsalva has normal morphology.

Congenital right atrial diverticulum, atrial septal defect within the oval fossa, and complex pulmonary valvar obstruction in an infant with chromosome 8(p23.1) deletion

We describe an unusual right atrial aneurysm, occurring with progressive obstruction of the right ventricular outflow tract and increasing cyanosis, in a nine-month-old boy with chromosome 8(p23.1) deletion. Surgical resection of the diverticulum, and relief of the right ventricular obstruction, was successful, although impairment of right ventricular compliance persists after 19 months follow-up.

Optical coherence tomography for the evaluation of asymmetric cardiac allograft vasculopathy in a child

We present an unusual case of CAV in a child with isolated disease in the LAD coronary artery. Initial progression of the disease appeared to have been halted by the use of sirolimus, but the assessment of disease in other vessels (particularly the RCA) was of particular importance in deciding whether or not to relist this patient for transplantation. Due to the known limitations of coronary angiography, we used OCT to assess for angiographically silent CAV. The normal intravascular appearance of the RCA by OCT was reassuring, and the child was not relisted for transplantation. OCT offers multiple advantages for the assessment of CAV in children.

Left Ventricle Pseudoaneurysm After Aortic Valvuloplasty

Acquired left ventricular aneurysm is extremely rare in children. This report describes an infant with acquired left ventricular aneurysm after percutaneous aortic balloon valvuloplasty for critical aortic stenosis. The potential risk factors for myocardial injury during cardiac catheterization and potential complications are discussed.

Persistent fever in an infant: incomplete Kawasaki disease

A four-month-old white girl presented to her local hospital when her parents noticed that her left upper extremity had turned blue from her midforearm to her fingertips. When she was nine weeks old, a persistent fever had developed associated with a patchy macular rash extending over her trunk and

Acute respiratory distress secondary to severe compression of the left main bronchus by the ductus arteriosus.

Two newborn infants presented with acute respiratory distress. In both cases, the left lung was opaque, hyperinflated, and associated with a rightward shift of the mediastinum. A diagnosis of retained fetal fluid secondary to vascular compression of the left bronchus by the ductus arteriosus was made by combining various imaging methods including chest radiograph, computed tomography (CT), and echocardiography. Although the initial chest radiographs were similar, the mechanisms of obstruction were different. The imaging emphasizes the importance of CT angiography to understanding the three-dimensional relationships resulting in bronchial compression.

Device Closure of a Secundum Atrial Septal Defect in a 4-Month-Old Infant with a Marginal Left Ventricle Following Coarctation Repair

A male infant presented at birth with severe coarctation of the aorta and marginal left ventricular and mitral valve dimensions associated with a large secundum atrial septal defect. Following successful arch repair, the left ventricle remained small with preferential left-to-right atrial shunting and a dilated right ventricle. Clinically, the infant continued with tachypnea, poor feeding, and failure to thrive. At 4 months of age, the defect was closed with an Amplatzer Atrial Septal Occluder which resulted in immediate left ventricular cavity enlargement and clinical improvement.

Jellyfish-Like Accessory Mitral Valve Tissue Causing Near-Collapse in a Young Child.

Accessory mitral valve tissue (AMVT) causing left ventricular outflow tract obstruction (LVOTO) is rare. We report a case of AMVT causing severe LVOTO resulting in acutely progressive symptoms of near-collapse. Urgent surgical resection eliminated the patient’s life-threatening symptoms. AMVT should be considered among potential LVOTO diagnoses, and early surgical intervention may be required.

Intimal thickening at coronary bifurcations in pediatric heart transplant recipients

Heart transplant recipients are at increased risk for atherosclerosis and cardiac allograft vasculopathy, both initially presenting as intimal thickening. We aimed to determine the presence, extent, and anatomical characteristics of intimal thickness at coronary bifurcations in children using OCT. We measured the intimal thickness of coronary arteries in pediatric transplant recipients using OCT during routine cardiac catheterization. Intimal thickening was defined as (i) a percent change in contralateral intimal thickness greater than 50% when comparing the thickness at the bifurcation to the baseline thickness, and (ii) greater than 0.1 mm. We evaluated 153 unique coronary bifurcations in 31 children (58% boys, median 12.7 years). Intimal thickening was almost exclusively observed in the left coronary system (22 of 67 bifurcations) and rare in the right coronary system (2 of 86 bifurcations; P < .001). There was a positive association between the relative size of the side branch and contralateral intimal thickening at coronary bifurcations (P = .009). Intimal thickening at coronary bifurcations is already present in the left coronary system in many pediatric transplant recipients. The correlation between intimal thickening and side branch size suggests that low shear stress and oscillating shear stress may have an important role in the development of intimal thickening at coronary bifurcations.