Richard E. Hawker

Right ventricular dysfunction in congenitally corrected transposition of the great arteries

Although right ventricular (RV) dysfunction is an important complication in subjects with congenitally corrected transposition of the great arteries, its pathogenesis is poorly understood. We assessed the role of RV myocardial perfusion and found perfusion defects at rest in all 20 patients, involving 4.6 +/- 2.3 of a total of 12 segments; the extent of the resting perfusion defects correlated inversely with the RV ejection fraction.

Generalized arterial calcification of infancy: Three case reports, including spontaneous regression with long-term survival

Generalized arterial calcification in infancy is a rare disorder in which death usually occurs in infancy, the diagnosis generally being made at autopsy. Three patients are reported. The diagnosis was made during life in two, enabling new information to be collected. Cardiac catheterization in one provided evidence suggesting stiffness of pulmonary and systemic arterial walls. Another is a long-term survivor with spontaneous regression of calcification. The third case, diagnosed at necropsy, was associated with endocardial fibroelastosis.

Outcomes following surgery for congenital heart disease in low-birthweight infants

Aim:  To describe cardiac surgery, survival and outcomes for low‐birthweight (≤2500 g) infants undergoing surgery for congenital heart disease.

Evaluation of the Extracardiac Conduit Modification of the Fontan Operation for Thrombus Formation using Magnetic Resonance Imaging

BACKGROUND The prevalence of thrombosis after the Fontan procedure depends upon the surgical technique used and the method of detection employed. Current investigations for thrombosis lack sensitivity and specificity or, in the paediatric population, require a general anaesthetic. We undertook a study to examine the feasibility of using magnetic resonance imaging (MRI) to detect thrombosis within the conduit, cardiac chambers and pulmonary arteries after the extracardiac conduit modification of the Fontan procedure. METHODS Of the 50 children who had undergone this procedure at our institution between 1997 and 2002, 26 were eligible for, and 13 underwent, MRI study. The mean age was 10.2 years (range 8.2-16.8 years, median 9.5 years) and the average time from operation was 63 months (range 29-79 months, median 68 months). The mean age at Fontan operation was 4.9 years (range 2.1-10.5 years). Ten were on low dose aspirin, two were on warfarin and one was not anti-coagulated. In all cases, satisfactory imaging of the venous pathways and pulmonary arteries was obtained and there were no thrombi detected. CONCLUSIONS We conclude that MRI is a potentially useful tool for the detection of thrombus in patients who have undergone the Fontan operation.

Anomalous Systemic Arterial Supply to Normal Basal Segment of the Left Lung

BACKGROUND Anomalous systemic arterial supply to normal segments of the lung is an unusual anomaly. It represents part of a spectrum of bronchovascular abnormalities which have various anatomical and clinical manifestations. METHODS We retrospectively analysed cases from January 2007 to April 2010 from two institutions diagnosed with an anomalous systemic arterial supply to a normal lung segment. RESULTS Three infants were found to have anomalous systemic arterial supply to normal segments of the lung. One patient was from The Childrens Hospital at Westmead, Australia and two cases from Amrita Institute of Medical Sciences, Kochi, India. The mean age at diagnosis was 65 days (range 30-120 days) and mean weight was 3.05 kg (range 1.9-4.4 kg). All babies presented with tachypnoea. The diagnosis was suspected on echocardiography and confirmed by computerised tomography scan (CT scan) in one and by angiography in two cases. The preterm baby underwent ligation of the anomalous vessel by thoracotomy and other two infants had transcatheter occlusion of the collateral. There was no residual flow on echocardiography in any of the three cases and all have done well on follow up. CONCLUSION Anomalous systemic arterial supply to normal lung segments is a very rare anomaly. A high index of suspicion is needed to expedite diagnosis. Transcatheter embolisation or surgical ligation of the collateral proved effective therapeutic approaches in young infants without a need for surgical lobectomy.

CHANGES IN PRESSURE WAVE TRANSMISSION ALONG HUMAN AORTA WITH AGE AND ARTERIAL DISEASE

Previous studies have shown that in children the amplitude of pressure waves increases progressively along the aorta and a diastolic wave appears in peripheral arteries. These alterations become less with age or arterial disease so that the wave is transmitted virtually unchanged in older patients (pts.) with arterial degenerative disease. Pressures were measured in aortic root, aortic arch, and either iliac or brachial arteries during diagnostic catheterization in 198 pts., aged 1 day to 70 yrs. There was no significant difference in amplification for pts. with normal arteries and normal aortic valves (81), aortic stenosis (48), or aortic insufficiency (9). Amplification averaged 1.56±.26 for normal pts. aged 0-19 yrs., 1.23±.19 between 20-39, and 1.17±.13 over 40. For each age range, pts. with arterial disease had a lower mean amplification, but with considerable overlap after 40 yrs. Slightly improved separation of normal and abnormal was obtained using catheter-tip manometers, Fourier analysis and amplification of individual harmonic terms. Pulsewave velocity, using foot-to-foot transmission time and measured catheter lengths from aortic arch, averaged 455±78 cm/sec in 50 normals, 464±82 in 39 with aortic stenosis, and 622±245 in 18 with arterial disease.(Supported by NIH-HL14207-03).