Lindsey D. Allan

Prospective diagnosis of 1,006 consecutive cases of congenital heart disease in the fetus.

OBJECTIVE This report describes our experience with fetal congenital heart disease since 1980. BACKGROUND Knowledge and expertise in the diagnosis, management and natural history of fetal congenital heart disease is increasingly demanded by both obstetricians and parents. The analysis of a large series should help the pediatric cardiologist to provide this service. METHODS The notes of 1,006 patients, where a prospective diagnosis of fetal congenital heart disease was made, were reviewed. The reason for referral, the diagnosis made, the accuracy of diagnosis, the fetal karyotype and the outcome of the pregnancy were noted. The cases were grouped into malformation categories, and the spectrum of disease seen was compared with that found in infants. RESULTS Most fetal cardiac anomalies are now suspected by the ultrasonographer during obstetric scanning. A different incidence of abnormalities is seen compared with that expected in infants. Chromosomal anomalies were more frequent in the fetus than in live births. The accuracy of diagnosis was good. The survival rate after diagnosis was poor because of frequent parental choice to interrupt pregnancy and the complexity of disease. CONCLUSIONS A large experience with fetal congenital heart disease allows the spectrum of disease to be described with accuracy and compared with that in infancy. Knowledge of the natural history of heart malformations when they present in the fetus allows accurate counseling to be offered to the parents. If the trend in parental decisions found in this series continues, a smaller number of infants and children with complex cardiac lesions will present in postnatal life.

Ebstein's anomaly: Presentation and outcome from fetus to adult

OBJECTIVES This study was conducted to investigate the presentation and outcome of patients with Ebsteins anomaly of the tricuspid valve. BACKGROUND Ebstins anomaly may present at any age and has a highly variable clinical course. Previous natural history studies have been based on clinical and angiographic diagnosis and have included mainly older children and adults. Echocardiography, however, has facilitated fetal and neonatal diagnosis so that the natural history needs to be redefined. METHODS We reviewed 220 cases of Ebsteins anomaly presenting from fetal to adult life between 1958 and 1991, with 1 to 34 years of follow-up. RESULTS The most common presentation in each age group was abnormal routine prenatal scan for fetuses (86%), cyanosis for neonates (74%), heart failure for infants (43%), incidental murmur for children (63%) and arrhythmia for adolescents and adults (42%). Early presentation was frequently associated with other cardiac lesions, usually pulmonary stenosis or atresia. Surgery was undertaken at some stage in 86 (39%) of the 220 patients. Actuarial survival for all liveborn patients was 67% at 1 year and 59% at 10 years. There were 58 deaths, including 26 from heart failure, 19 perioperative and 8 sudden. Predictors of death included echocardiographic grade of severity at presentation (relative risk 2.7 for each increase in grade, 95% confidence limits 1.6 to 4.6), fetal presentation (6.9, confidence limits 1.6 to 16.5) and right ventricular outflow tract obstruction (2.1, confidence limits 1.1 to 4.4). Morbidity was mainly related to arrhythmias and late hemodynamic deterioration. Of 155 survivors, 129 (83%) were in functional class 1 and 104 (67%) were receiving no medical therapy. CONCLUSIONS In Ebsteins anomaly, fetal and neonatal presentation is associated with a poor outcome and can be predicted by the echocardiographic appearance and presence of associated lesions. In older children and adults, incidental findings and arrhythmia are common and the long-term outcome is superior.

Balloon dilatation of the aortic valve in the fetus: a report of two cases.

Because they had irreversible damage to the left ventricular myocardium none of 12 patients with critical aortic stenosis diagnosed prenatally survived after postnatal treatment. This experience prompted three attempts at intrauterine balloon dilatation of the aortic valve in two fetuses with this condition. On each attempt the balloon catheter was successfully delivered to the left ventricle. In the first fetus the aortic valve was not crossed and the fetus died the next day. In the second fetus the balloon was correctly positioned across the aortic valve and inflated in the valve ring. After delivery, a further balloon angioplasty was performed; this relieved the stenosis but the patient died five weeks later from persisting left ventricular dysfunction related to endocardial fibroelastosis. Balloon angioplasty is feasible in fetal life but the prognosis depends on the ability of the relief of stenosis to limit, prevent, or allow regression of left ventricular damage before delivery.

Prenatal screening for congenital heart disease

Routine ultrasound examination of the fetus is already established in most obstetric units in Britain. A simple method was devised to evaluate one section of the fetal heart systematically. Examination of this section, the four chamber view, may readily be incorporated into routine obstetric screening. Severe cardiac abnormalities detectable in this view occur in two per 1000 pregnancies. For six years the department of paediatric cardiology at Guys Hospital, London, served as a referral centre for fetal echocardiography. As teaching became more widespread an increasing proportion of cases of cardiac anomaly were referred because the obstetrician suspected abnormality on examination of the four chamber view. Currently 80% of detected abnormalities are referred for this reason. Further extension and organisation of teaching might result in most severe cardiac malformations being detected in early prenatal life.

Screening for congenital heart disease prenatally. Results of a 2½‐year study in the South East Thames Region

Objective To assess the efficacy of four chamber view examination, during routine obstetric scanning, in the prenatal detection of fetuses with congenital heart disease.

M-mode echocardiography in the developing human fetus.

The M-mode echocardiogram can be obtained in the developing human fetus from around the 16th week of gestation until term. Errors in interpretation of the M-mode echocardiogram can be avoided by concurrent two dimensional fetal cardiac examination. The pattern of motion of the mitral, tricuspid, aortic, and pulmonary valves and ventricular wall motion can be studied. Motion of the foramen ovale flap, which is characteristic in fetal life, can also be observed. Using the M-mode tracing, measurement data for six variables were made and growth charts constructed. The variables recorded were septal and left ventricular wall thickness, right and left ventricular internal dimension in diastole, aortic root dimension, and left atrial internal dimension. The measurements were made in normal pregnancies where the fetal heart was structurally normal. Confidence limits for each measurement were derived for gestational ages between 16 and 39 weeks.

Outcome of isolated congenital complete heart block diagnosed in utero.

OBJECTIVE: To establish identifiable prenatal factors in fetal heart block which might predict death in utero, the need for intervention, or the probability of pacemaker requirement. SETTING: Tertiary referral unit for fetal echocardiography. SUBJECTS: 36 fetuses with congenital complete heart block and structurally normal hearts identified between 1980 and 1993. METHODS: Maternal anti-Ro antibody status was documented. Prenatal variables examined included absolute heart (ventricular) rate, change in rate, and development of hydrops fetalis. Postnatally, heart rate, need for pacing, and the indications for pacing were detailed. RESULTS: Of the total of 36 patients, there are 24 survivors; 11 are paced. Of those fetuses which died, two were electively aborted for severe hydrops, seven died in utero, two were immediate postnatal deaths, and one was an unrelated infant death. The trend was for the heart rate to decrease during fetal life and postnatally. Fetuses with deteriorating cardiac function did not always show the lowest heart rates. Bradycardia of less than 55 beats/min in early pregnancy or rapid decrease in heart rate prenatally were poor prognostic signs. Hydrops was also associated with bad outcome, 10 out of the 12 hydropic fetuses dying (83%). Of 10 fetuses presenting with a heart rate above 60/min, nine survived of whom three required pacing. Of seven presenting with heart rates of 50/min or less, only three survived and two of these required pacing. Of the two fetuses with negative maternal anti-Ro antibody status one died in utero and one required heart transplantation after pacemaker insertion. CONCLUSIONS: Isolated complete heart block identified in fetal life does not always have a good prognosis. An individual heart rate does not accurately predict the outcome in utero or the need for postnatal pacing. Regular, careful monitoring during pregnancy is required in order to optimise care and timing of any interventions.

Evidence of redistribution of cardiac output in asymmetrical growth retardation

Summary. Thirty‐one fetuses with growth retardation were studied by Doppler estimation of the cardiac output from each side of the fetal heart. Asymmetrical growth retardation was diagnosed in 16 fetuses by a head to abdominal circumference ratio above the 95th centile. In the 15 fetuses with symmetrical growth retardation, the distribution of cardiac output was normal. The mean and maximum velocity of blood flow in the pulmonary artery and aorta were similar to values in normal fetuses, and there was a greater calculated output from the right heart than from the left. The right heart flow expressed as a percentage of the combined cardiac output was not statistically significantly different from that in normal fetuses. In contrast, all 16 fetuses with asymmetrical growth retardation had a higher mean and maximum velocity in the aorta than in the pulmonary artery. The calculated volume flow from each side of the heart showed a greater output from the left than the right heart in 15. The right heart flow expressed as a percentage of the combined cardiac output was statistically different from the value in normal fetuses. These findings are consistent with theories of the redistribution of fetal blood flow, where cerebral blood flow is preferentially ‘spared’.

Evaluation of fetal arrhythmias by echocardiography.

The normal fetal heart shows variation in rate and rhythm. Twenty three cases that fell outside the normal patterns of variation of heart rate and rhythm were evaluated by echocardiography. Ten showed atrial or ventricular extrasystoles and these were not associated with perinatal morbidity or mortality. Seven cases showed complete heart block, two in association with structural cardiac abnormality. Six cases were of supraventricular tachycardia, five of which were successfully treated and one was delivered prematurely. It was possible to diagnose accurately the type of arrhythmia using the M-mode echocardiogram to compare the relation between atrial and ventricular contraction. Cross-sectional echocardiography allowed identification of associated structural abnormalities. Recognition that an arrhythmia is present and appropriate prenatal treatment if this is indicated will avoid unnecessary operative or premature deliveries.

Flecainide in the treatment of fetal tachycardias.

Fourteen mothers were treated with flecainide for fetal atrial tachycardias associated with intrauterine cardiac failure. Twelve of the 14 fetuses responded by conversion to sinus rhythm. One of the 12 fetuses subsequently died in utero. The remaining fetuses suffered no morbidity and were alive and well 3 months to 2 years after delivery. The two fetuses in whom atrial tachycardia did not convert with flecainide were successfully treated with digoxin. These results compare favourably with previous forms of antiarrhythmic treatment. After recent reports of the side effects of flecainide treatment, however, it has been advised that this drug should be confined to high risk patients and those with life threatening arrhythmias. The use of flecainide for fetal arrhythmias should be limited to patients with severe fetal hydrops and supraventricular tachycardias. It should not be the first drug of choice in atrial flutter.