Faculty Bibliography

BACKGROUND: The incidence of congenital coronary anomalies is mainly derived from autopsy series and pre-participation exams in athletes. Limited data exist regarding the spectrum of coronary anomalies that can be detected in asymptomatic patients. We sought to describe echocardiographically detected congenital coronary artery anomalies in asymptomatic children after implementing a screening protocol mandating identification of coronary artery origin and proximal course in all initial studies. METHODS: Our database was searched from 1/1/1993 to 3/31/2006 and all echocardiograms coded for coronary anomalies were identified. Clinically "silent" congenital coronary anomalies were culled from that group. RESULTS: Of the 168 "silent" coronary anomalies detected, 111 were anomalies of aortic origin, including 59 patients with "high coronary takeoff" and 30 patients with "wrong sinus" origin of either the left or right coronary artery. Small coronary fistulas were seen in 57. Associated congenital heart defects were found in 53% of individuals with coronary anomalies. CONCLUSIONS: This study comprises the largest group of echocardiographically detected, "silent" but potentially clinically significant, congenital coronary anomalies in children. Prospective echocardiographic diagnosis of "high coronary takeoff", a risk factor for injury during cardio-pulmonary bypass, and asymptomatic intraseptal coronary stenosis are described for the first time.

This study evaluated the quality of the visualization of extracardiac thoracic vessels by magnetic resonance angiography (MRA) in young infants with congenital heart disease. Echocardiography is often sufficient in evaluating CHD in young infants. Cardiac catheterization is needed in some instances to evaluate extracardiac thoracic vessels. Extracardiac thoracic vessels can be accurately evaluated using MRA in adults and older children, but image quality in small infants may be limited. Twenty-nine magnetic resonance angiographic scans were performed at a single institution on 28 infants aged <3 months (median 6 days, range 1 to 90 days) with complex CHD in whom imaging was inconclusive by echocardiography. A blinded observer at a different institution graded (from 0 to 3) the quality of the visualization of the main, branch, lobar, and second-generation pulmonary arteries; lobar pulmonary veins; aortopulmonary collaterals; vena cavae; thoracic aorta and its branches; patent ductus arteriosus; and visceral sidedness. The results of MRA were compared with those of x-ray angiography and surgical inspection, when available. The mean image quality grade was >2 for all structures except the second-generation pulmonary arterial branches, for which it was 2. The median total scan duration was 9 minutes (range 3 to 46). Findings were concordant with surgical inspection (n = 25) and cardiac catheterization (n = 8) in all subjects. There were no complications. In conclusion, MRA is excellent for the visualization of extracardiac thoracic vessels in young infants with CHD and can be used as an alternative to cardiac catheterization when echocardiography is inconclusive.

Cardiac magnetic resonance imaging (CMR) has become integrated into the routine care of individuals with congenital heart disease. Its strengths and limitations are being refined and CMR derived variables predictive of clinically important outcomes are being evaluated. This manuscript will focus on several congenital heart diseases commonly referred for CMR evaluation and review their clinical aspects, goals of the MRI evaluation, imaging protocol and current literature

The physiology of isolated partially anomalous pulmonary venous connection of a single pulmonary vein has yet to be fully characterized. This study assessed the magnitude of the left-to-right shunt and right ventricular (RV) dilation from a single anomalous pulmonary vein using cardiac magnetic resonance imaging. Subjects with >1 anomalous pulmonary vein or associated lesions, including atrial septal defects, were excluded. In the 6 subjects identified, the median pulmonary-to-systemic flow ratio was 1.55 (range 1.3 to 1.6). The mean RV end-diastolic volume indexed to body surface area in the subjects was significantly larger than in a normal reference cohort (108 +/- 16 vs 78 +/- 18 cm(3)/m(2), p = 0.0009) and greater than the upper limit of normal in all 6 subjects. Older age did not correlate with increased magnitude of shunting (r = 0.3, p = 0.5), but increased age did correlate with RV end-diastolic volume indexed to body surface area (r = 0.96, p = 0.01). Isolated partially anomalous pulmonary venous connection with only 1 vein connecting anomalously results in a modest left-to-right shunt and mild RV dilation.

Survivors of tetralogy of Fallot (TOF) repair constitute a large and growing population of patients. Although postsurgical outcome is generally favorable, as these patients move into adulthood, late morbidity is becoming more prevalent and the notion that TOF has been "definitively repaired" is increasingly being challenged. Recent evidence suggests that adverse long-term postsurgical outcome is related to chronic pulmonary regurgitation, right ventricular dilatation, and deteriorating ventricular function. Cardiac magnetic resonance (MR) imaging has been established as an accurate technique for quantifying ventricular size, ejection fraction, and valvular regurgitation. Cardiac MR imaging does not expose the patient to ionizing radiation and is therefore ideal for serial postsurgical follow-up. Familiarity with the anatomic basis of TOF, the surgical approaches to repair, and postrepair sequelae is essential for performing and interpreting cardiac MR imaging examinations. For example, awareness of the complications and sequelae that can occur will assist in determining when to intervene to preserve ventricular function and will improve long-term outcome. Technical facility is necessary to tailor the examination to the individual patient (eg, familiarity with non-breath-hold modifications that allow evaluation of young and less compliant patients). The radiologist can play an essential role in the treatment of patients with repaired TOF by providing noninvasive anatomic and physiologic cardiac MR imaging data. Further technologic advances in cardiac MR imaging are likely to bring about new applications, better normative data, and more examinations that are operator independent.

OBJECTIVE: We sought to explore the relationship of color Doppler tissue imaging-derived systolic indices of tricuspid valve annular motion and magnetic resonance imaging-derived right ventricular (RV) ejection fraction in patients with congenital heart disease. METHODS: Patients with congenital heart disease who underwent echocardiography and magnetic resonance imaging on the same day were included. The tricuspid valve annular color Doppler tissue imaging-derived parameters of peak velocity during isovolumic contraction, myocardial acceleration during isovolumic contraction, peak systolic velocity, and Tei index were compared with magnetic resonance imaging-derived RV ejection fraction. RESULTS: Peak systolic velocity and myocardial acceleration during isovolumic contraction correlated well with RV ejection fraction after adjusting for age, RV dilation, and pressure overload (r = 0.65 and 0.73, respectively). Interobserver and intraobserver reliability were excellent for peak systolic velocity (r = 0.95 and 0.97, respectively) and very good for myocardial acceleration during isovolumic contraction (r = 0.93 and 0.85, respectively). CONCLUSIONS: Color Doppler tissue imaging indices of tricuspid valve annular motion are reproducible and provide a potentially useful complementary tool for assessment of RV systolic function in patients with congenital heart disease.

BACKGROUND: MRI is increasingly used for anatomic assessment of aortic coarctation (CoA), but its ability to predict the transcatheter pressure gradient, considered the reference standard for hemodynamic severity, has not been studied in detail. This study evaluated the ability of MRI to distinguish between mild versus moderate and severe CoA as determined by cardiac catheterization. METHODS AND RESULTS: The clinical, MRI, and catheterization data of 31 subjects referred for assessment of native or recurrent CoA were reviewed retrospectively. Patients were divided into 2 groups on the basis of peak coarctation gradient by catheterization: <20 mm Hg (n=12) and > or =20 mm Hg (n=19). Patients with cardiac index <2.2 L x min(-1) x m(-2) by catheterization were excluded. By logistic regression analysis, the following variables simultaneously predicted coarctation gradient > or =20 mm Hg: (1) smallest aortic cross-sectional area (adjusted for body surface area) measured by planimetry from gadolinium-enhanced 3D magnetic resonance angiography (OR 1.71 for 10 mm2/m2 decrease, P=0.005) and (2) heart rate-corrected mean flow deceleration in the descending aorta measured by phase-velocity cine MRI (OR 1.68 for 100 mL/s(1.5) increase, P=0.018). For the combination of these variables, a predicted probability >0.38 had 95% sensitivity, 82% specificity, 90% positive and negative predictive values, and an area under the receiver-operator characteristics curve of 0.938. In a subsequent validation study, the prediction model correctly classified 9 of 10 patients, with no false-negatives. CONCLUSIONS: The combination of anatomic and flow data obtained by MRI provides a sensitive and specific test for predicting catheterization gradient > or =20 mm Hg.