Biomedical subjects

Edward N Marcus

Publications and source records attributed to Edward N Marcus.

5 recordsLinked to original sources

PubMed2006

Fetal aortic valve stenosis and the evolution of hypoplastic left heart syndrome: patient selection for fetal intervention.

BACKGROUND: Fetal aortic valvuloplasty may prevent progression of aortic stenosis (AS) to hypoplastic left heart syndrome (HLHS). Predicting which fetuses with AS will develop HLHS is essential to optimize patient selection for fetal intervention. The aim of this study was to define echocardiographic features associated with progression of midgestation fetal AS to HLHS. METHODS AND RESULTS: Fetal echocardiograms were reviewed from 43 fetuses diagnosed with AS and normal left ventricular (LV) length at < or =30 weeks' gestation. Of 23 live-born patients with available follow-up data, 17 had HLHS and 6 had a biventricular circulation. At the time of diagnosis, LV length, mitral valve, aortic valve, and ascending aortic diameter Z-scores did not differ between fetuses that ultimately developed HLHS and those that maintained a biventricular circulation postnatally. However, all of the fetuses that progressed to HLHS had retrograde flow in the transverse aortic arch (TAA), 88% had left-to-right flow across the foramen ovale, 91% had monophasic mitral inflow, and 94% had significant LV dysfunction. In contrast, all 6 fetuses with a biventricular circulation postnatally had antegrade flow in the TAA, biphasic mitral inflow, and normal LV function. With advancing gestation, growth arrest of left heart structures became evident in fetuses developing HLHS. CONCLUSIONS: In midgestation fetuses with AS and normal LV length, reversed flow in the TAA and foramen ovale, monophasic mitral inflow, and LV dysfunction are predictive of progression to HLHS. These physiological features may help refine patient selection for fetal intervention to prevent the progression of AS to HLHS.

Abortion, Therapeutic↗

PubMed2006

Faster flow quantification using sensitivity encoding for velocity-encoded cine magnetic resonance imaging: in vitro and in vivo validation.

PURPOSE: To test the agreement between conventional and sensitivity-encoded (SENSE) velocity encoded cine (VEC) MRI in a flow phantom and in subjects with congenital and acquired heart disease. MATERIALS AND METHODS: Flow measurements were performed in a 1.5 T scanner using a segmented k-space VEC MRI sequence and then repeated with a SENSE factor of 2. The flow phantom used a piston pump to generate physiologic arterial waveforms (0.5-4.9 L/min). In the subjects, flow measurements were performed in the ascending aorta (N = 33) and/or the main pulmonary artery (N = 24). RESULTS: Utilization of SENSE reduced the scan time by 50%. In the phantom, measurements without and with SENSE agreed closely with a mean difference of 0.01 +/- 0.08 L/min or 0.12% +/- 3.8% (P = 0.68). In the subjects, measurements without and with SENSE also agreed closely with a mean difference of 0.08 +/- 0.36 L/min or 1.3% +/- 7.2% (P = 0.08). Compared with standard imaging, the use of SENSE reduced the signal-to-noise ratio (SNR) by 28% in the phantom (N = 10) and 27% in vivo (N = 22). CONCLUSION: VEC MRI flow measurements with a SENSE factor of 2 were twice as fast and agreed closely with the conventional technique in vitro and in vivo. VEC MRI with SENSE can be used for rapid and reliable quantification of blood flow.

Adolescent↗

PubMed2005

Improving outcomes in fetuses and neonates with congenital displacement (Ebstein's malformation) or dysplasia of the tricuspid valve.

From 1984 to 2004, 66 patients were diagnosed with Ebstein's malformation (n = 61) or congenital tricuspid valve (TV) dysplasia (n = 5) in utero or during the first month of life. Of these, 33 were diagnosed by fetal echocardiography at a median gestational age of 22 weeks, and 33 were diagnosed postnatally at a median age of 1 day (range 1 to 27). In 8 of the 33 prenatally diagnosed patients (24%), the pregnancies were terminated; in 9 (27%), the fetuses died in utero, and in 16 (49%), the fetuses survived to birth. Seven prenatally diagnosed patients survived beyond the neonatal period (21% of 33). Of the 49 neonates, 35 (71%) survived to hospital discharge and beyond 1 month of age. Independent predictors of death by multivariable logistic regression analysis included right atrial area index >1, the absence of anterograde flow across the pulmonary valve, and diagnosis before 1997. Although outcomes in fetuses and neonates with congenital anomalies of the TV have improved in more recent experience, survival in patients at the severe end of the spectrum remains poor. To improve outcomes in this group of high-risk patients, novel approaches to management may be indicated.

Adult↗

PubMed2005

Magnetic resonance imaging predictors of coarctation severity.

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.

Adolescent↗

PubMed2002

Echocardiographic assessment of the right ventricular response to hypertension in neonates on the basis of average-shaped contraction models.

BACKGROUND AND METHOD: We evaluated a new method of shape analysis in defining right ventricle (RV) response to pressure overload. Twenty-five neonatal patients (13 with RV hypertension, 12 without) underwent echocardiographic imaging and reconstruction of RV regional chamber volumes over 1 cardiac cycle. Group tracing data in coronal, sagittal, and transverse echocardiography planes were then shape-averaged to construct normal- and hypertensive-average-shape contraction models. Each patient's RV was classified as more similar to the normal- or hypertensive-average-shape model on the basis of the median tangent-angle difference, a quantitative technique of shape comparison. RESULTS: Ejection fraction, time of end systole, and ejection rate demonstrated significant regional differences between normotensive and hypertensive contractions. The normal-average-shape contraction model correctly diagnosed all patients who were normotensive (specificity 100%) and the hypertensive-average-shape model identified 11 of 13 patients who were hypertensive (sensitivity 85%). CONCLUSION: Reconstructed-shape contraction models throughout 1 cardiac cycle identify altered patterns of RV contraction in the presence of pulmonary hypertension.

Echocardiography↗