Early diagnosis and treatment of atrioventricular block in the fetus exposed to maternal anti-SSA/Ro-SSB/La antibodies: a prospective, observational, fetal kinetocardiogram-based study.

BACKGROUND: A fetus exposed to maternal anti-SSA/Ro or anti-SSB/La antibodies (or both) may develop complete atrioventricular block (AVB), which results in high prenatal and postnatal morbidity and mortality. Until recently, only high-grade AVB could be diagnosed in utero. The tissue velocity-based fetal kinetocardiogram (FKCG) enables accurate measurement of AV conduction time and diagnosis of low-grade AVB. In the present multicenter observational study, we used FKCG to detect first-degree AVB in fetuses at risk. METHODS AND RESULTS: FKCG was performed in 70 fetuses of 56 mothers who were positive for anti-SSA/Ro and/or anti-SSB/La. Fetuses were monitored with weekly FKCG from 13 to 24 weeks' gestation, followed by monthly assessments until delivery in unaffected fetuses and weekly assessments in affected fetuses. AV conduction in 70 at-risk and 109 normal fetuses was compared. FKCG was obtained readily in all fetuses; 6 showed first-degree AVB (AV conduction time >2 z scores above normal mean) at 21 to 34 gestational weeks. Immediate maternal treatment with dexamethasone resulted in normalization of AV conduction in all affected fetuses within 3 to 14 days. AV conduction time in the remaining 64 untreated fetuses remained normal throughout gestation. The ECG PR interval immediately after birth was normal in all affected newborns. No child developed AVB or cardiomyopathy in the subsequent 1- to 6-year (median 4-year) follow-up. CONCLUSIONS: The present findings suggest that an FKCG can detect first-degree AVB in the fetus exposed to maternal anti-SSA/Ro or anti-SSB/La antibodies (or both). Dexamethasone given on detection was associated with normalized AV conduction in fetuses with first-degree AVB. No fetus in the present study developed complete prenatal or postnatal AVB.

NT-proBNP as a marker for persistent cardiac disease in children with history of dilated cardiomyopathy and myocarditis.

Children with myocarditis and dilated cardiomyopathy may recover clinically and echocardiographically. Plasma levels of the N-terminal segment of B-type natriuretic peptide prohormone (NT-proBNP), a sensitive marker for cardiac dysfunction, may reflect residual cardiac damage in these patients. The purpose of this study was to evaluate NT-proBNP status in pediatric patients with a history of myocarditis and dilated cardiomyopathy. Cardiac evaluation was performed and the levels of NT-proBNP were measured in 23 children who had a history of myocarditis or dilated cardiomyopathy. NT-proBNP levels were also measured in 56 age-matched control children. Nine of the 23 patients had evidence of left ventricular dysfunction (DCM group), whereas 14 had none (recovery). NT-proBNP levels were higher in the DCM group (3154 +/- 2858 pg/ml) than in the recovery group (122 +/- 75 pg/ml, p < 0.001) and the control group (113 +/- 96 pg/ml, p < 0.001). There was no difference between the recovery and the control groups (p = 0.45), and none of the recovered patients had a NT-proBNP level higher than the upper limit of normal. The area under the receiver operating characteristics curve for the diagnosis of persistent left ventricular dysfunction was 0.984. NT-proBNP levels correlated with echocardiographically derived shortening fraction and with clinical score. NT-proBNP is a good marker for persistent left ventricular dysfunction in children who have had myocarditis or cardiomyopathy. In this group of patients, NT-proBNP levels are normal in children who recover echocardiographically, suggesting no residual hemodynamic abnormalities.

Tetralogy of Fallot with pulmonic atresia with cyclic occlusion of an associated aortic sinus of Valsalva-pulmonary artery window.

A first case of an unusual aortopulmonary window with tetralogy of Fallot associated with pulmonary atresia is presented. The aortopulmonary window was at the aortic sinus of Valsalva. The left aortic leaflet prevented pulmonary hypertension by occluding the window in systole.

N-terminal pro-B-type natriuretic peptide: reference plasma levels from birth to adolescence. Elevated levels at birth and in infants and children with heart diseases.

AIM: Determination of plasma levels of N-terminal pro-B-type natriuretic peptide (N-BNP) in infants and children with and without heart diseases. METHODS: Plasma N-BNP was measured in 78 infants and children without heart disease and in 55 infants and children with heart disease causing volume and pressure overload. Heart diseases included chronic dilated cardiomyopathy, acute left ventricular dysfunction, and congenital cardiac anomalies resulting in left and right ventricular volume or pressure overload. The Mann-Whitney rank-sum test and the ANOVA for ranks test were used to compare two or more groups, respectively. RESULTS: N-BNP levels were elevated in the first days of life but were not significantly different in children from 4 mo to 15 y old. The upper limit in children older than 4 mo with no heart disease was 349 pg/ml. In patients with heart disease, N-BNP levels were significantly higher than in control children (p < 0.0001). CONCLUSION: N-BNP levels are elevated in the first days of life and are stable from age 4 mo to adolescence. Elevated N-BNP levels reflect cardiac dysfunction in infants and children.

Use of tissue velocity imaging in the diagnosis of fetal cardiac arrhythmias.

BACKGROUND: Precise diagnosis of cardiac arrhythmias in the fetus is crucial for a managed therapeutic approach. However, many technical, positional, and gestational age-related limitations may render conventional methods, such as M-mode and Doppler flow methodologies, or newer techniques, such as fetal electrocardiography or magnetocardiography, difficult to apply, or these techniques may be unsuitable for the diagnosis of fetal arrhythmias. METHODS AND RESULTS: In this prospective study, we describe a novel method based on raw scan-line tissue velocity data acquisition and analysis. The raw data are available from high-frame-rate 2D tissue velocity images and allow simultaneous sampling of right and left atrial and ventricular wall velocities to yield precise temporal analysis of atrial and ventricular events. Using this timing data, a ladder diagram-like "fetal kinetocardiogram" was developed to diagram and diagnose arrhythmias and to provide true intervals. This technique was feasible and fast, yielding diagnostic results in all 31 fetuses from 18 to 38 weeks of gestation. Analysis of various supraventricular and ventricular arrhythmias was readily obtained, including arrhythmias that conventional methods fail to diagnose. CONCLUSIONS: The fetal kinetocardiogram opens a new window to aid in the diagnosis and understanding of fetal arrhythmias, and it provides a tool for studying the action of antiarrhythmic drugs and their effects on electrophysiological conduction in the fetal heart.

Atrioventricular block in a toxic child: do not forget diphtheria.

We describe a 4.5-year-old girl who presented with severe febrile throat infection and who, after a few days, developed ventricular tachycardia followed by atrioventricular block. Although a pacemaker was inserted, she died of cardiogenic shock. Throat cultures were positive for Corynebacterium diphtheriae.

Echocardiographic sign for cerebral ischemia.

We describe a newborn who underwent balloon dilatation of critical aortic stenosis and surgical correction of coarctation of the aorta. Postoperative Doppler echocardiogram revealed diastolic retrograde flow in the distal aortic arch and increased systolic flow as well as diastolic forward flow in the left common carotid artery. Cranial computed tomography suggested increased left middle cerebral artery flow and a subacute infarction with luxury perfusion and damage to the blood brain barrier. Therefore, in the absence of another reason for diastolic "run-off" in the distal aortic arch, this flow pattern may represent the echocardiographic sign for cerebral hyperemia associated with subacute ischemia.