Christopher R. Mart

Echocardiographic Methods, Quality Review, and Measurement Accuracy in a Randomized Multicenter Clinical Trial of Marfan Syndrome

BACKGROUND The Pediatric Heart Network is conducting a large international randomized trial to compare aortic root growth and other cardiovascular outcomes in 608 subjects with Marfan syndrome randomized to receive atenolol or losartan for 3 years. The authors report here the echocardiographic methods and baseline echocardiographic characteristics of the randomized subjects, describe the interobserver agreement of aortic measurements, and identify factors influencing agreement. METHODS Individuals aged 6 months to 25 years who met the original Ghent criteria and had body surface area-adjusted maximum aortic root diameter (ROOTmax) Z scores > 3 were eligible for inclusion. The primary outcome measure for the trial is the change over time in ROOTmaxZ score. A detailed echocardiographic protocol was established and implemented across 22 centers, with an extensive training and quality review process. RESULTS Interobserver agreement for the aortic measurements was excellent, with intraclass correlation coefficients ranging from 0.921 to 0.989. Lower interobserver percentage error in ROOTmax measurements was independently associated (model R(2) = 0.15) with better image quality (P = .002) and later study reading date (P < .001). Echocardiographic characteristics of the randomized subjects did not differ by treatment arm. Subjects with ROOTmaxZ scores ≥ 4.5 (36%) were more likely to have mitral valve prolapse and dilation of the main pulmonary artery and left ventricle, but there were no differences in aortic regurgitation, aortic stiffness indices, mitral regurgitation, or left ventricular function compared with subjects with ROOTmaxZ scores < 4.5. CONCLUSIONS The echocardiographic methodology, training, and quality review process resulted in a robust evaluation of aortic root dimensions, with excellent reproducibility.

Extracorporeal membrane oxygenation as a bridge to surgical treatment of flail tricuspid valve in a neonate

A term infant rapidly developed profound cyanosis and metabolic acidosis shortly after an uncomplicated vaginal delivery. Echocardiography identified a flail antero-superior leaflet of the tricuspid valve, which was producing severe tricuspid insufficiency. The clinical state deteriorated despite maximal medical management, and the patient was placed on venoarterial extracorporeal membrane oxygenation. Within twenty-four hours, the metabolic acidosis corrected, inotropic support was discontinued, and the patient was weaned to minimal ventilator settings. Successful repair of the tricuspid valve was performed two days later.

Safety and efficacy of sedation with propofol for transoesophageal echocardiography in children in an outpatient setting

BACKGROUND Transoesophageal echocardiography has become a powerful tool in the diagnosis and management of children with congenital cardiac malformations. Unlike adults, children will not tolerate transoesophageal echocardiography under light sedation. This study was undertaken, therefore, to evaluate the safety and efficacy of deep sedation with propofol for transoesophageal echocardiography in children examined in an outpatient setting. METHODS This is a retrospective study of patients undergoing transoesophageal echocardiography with propofol given in bolus aliquots to achieve a level of sedation adequate to insert the transoesophageal echocardiographic probe and maintain sedation throughout the procedure. RESULTS We included a total of 118 patients, 57% being male, with a mean age of 12.9 years. Adequate sedation was achieved using a mean propofol dose of 8.3 milligrams per kilogram, with the dose per kilogram decreasing concomitant with increasing weight of the patient. Patients less than two years of age were intubated for the procedure. There were no clinically significant changes in cardiac function or haemodynamics. Non-intubated patients received supplemental oxygen prior to, or just after, the onset of sedation, with transient hypoxaemia observed in one-fifth. Complications were rare, with minor problems occurring in 7.6%, and major ones in 4%. CONCLUSIONS Transoesophageal echocardiography can be performed on an outpatient basis in children with a wide spectrum of congenital cardiac malformations, and propofol is an ideal sedative agent in this setting. Although not common, preparations must be made for significant haemodynamic and respiratory complications. In our study, we intubated all the children under 2 years of age.

Shape of the dilated aorta in children with bicuspid aortic valve.

Background: The dilated aorta in adults with bicuspid aortic valve has been shown to have different shapes, but it is not known if this occurs in children. This observational study was performed to determine if there are different shapes of the dilated aorta in children with bicuspid aortic valve and their association with age, gender, hemodynamic alterations, and degree of aortic enlargement. Methods: One hundred and eighty-seven echocardiograms done on pediatric patients (0 – 18 years) for bicuspid aortic valve, during 2008, were reviewed. Aortic valve morphology, shape/size of the aorta, and pertinent hemodynamic alterations were documented. Aortic dilation was felt to be present when at least one aortic segment had a z-score > 2.0; global aortic enlargement was determined by summing the aortic segment z-scores. The aortic shape was assessed by age, gender, valve morphology, and hemodynamic alterations. Results: Aortic dilation was present in 104/187 patients. The aorta had six different shapes designated from S1 through S6. There was no association between the aortic shape and gender, aortic valve morphology, or hemodynamic abnormalities. S3 was the most common after the age of six years and was associated with the most significant degree of global aortic enlargement. Conclusions: The shape of the dilated aorta in children with bicuspid aortic valve does not occur in a uniform manner and multiple shapes are seen. S2 and S3 are most commonly seen. As aortic dilation becomes more significant, a single shape (S3) becomes the dominant pattern.

A systematic method for using 3D echocardiography to evaluate tricuspid valve insufficiency in hypoplastic left heart syndrome

With surgical palliation of hypoplastic left heart syndrome (HLHS), the tricuspid valve (TV) becomes the systemic atrioventricular valve and moderate/severe TV insufficiency (TVI), an adverse risk factor for survival to Fontan, has been reported in up to 35% of patients prior to stage I palliation. Precise echocardiographic identification of the mechanism of TVI cannot be determined by two-dimensional echocardiography. Three-dimensional echocardiography (3DE) can provide significant insight into the mechanisms of TVI. It is the intent of this report to propose a systematic method on how to evaluate and display 3DE images of the TV in HLHS which has not been done previously. TV anatomy, function, and the known mechanisms of insufficiency are reviewed. We defined three regions of the TV (anterior, posterior, septal) that can help define valve “leaflets” that incorporates the many variations of TV anatomy. To determine how the surgeon views the TV, a picture of a pathologic specimen of the TV was placed on a computer screen and rotated until it was oriented as it appears during surgery, the “surgeons view.” We have proposed a systematic method for evaluating and displaying the TV using 3DE which can provide significant insight into the mechanisms causing TVI in HLHS. This has the potential to improve both the surgical approach to repairing the valve and, ultimately, patient outcomes.

Abnormal location of umbilical venous catheter due to Scimitar syndrome.

Scimitar syndrome is a rare congenital anomaly where the right pulmonary veins return to the inferior vena cava (IVC) just below the diaphragm. On chest X-ray (CXR), an IVC catheter will be in a bizarre location outside the heart if it inadvertently passes into the scimitar vein rather than into the right atrium.

Endocarditis After Pectus Excavatum Repair A Case Report

Pectus excavatum is a common congenital musculoskeletal disease occurring in approximately 1 in 800 births.1 Indications for surgical repair include pain, exercise intolerance, abnormal pulmonary function, right ventricular (RV) dysfunction, tricuspid valve compression, and cosmetic enhancement.2 We present an unusual case of endocarditis after pectus repair. A 14-year-old girl presented to the emergency room with a 2-week history of intermittent fever, chills, and pain in the lower parasternum 2 months after pectus excavatum repair. The modified Ravitch technique was used, inserting an 18-cm vitallium strut for stabilization. Physical examination revealed a 3/6 holosystolic midfrequency murmur heard throughout the precordium and an early, short diastolic murmur. Initial laboratory studies demonstrated a mild left shift and elevated inflammatory markers. Chest radiograph demonstrated a normal cardiac silhouette with inferior and posterior displacement of the pectus bar at the level of the …