Sotalol in the treatment of fetal dysrhythmias.

BACKGROUND: Fetal tachycardia may cause hydrops fetalis and lead to fetal death. No unanimity of opinion exists regarding the optimum treatment. This study evaluates our experience with transplacental sotalol therapy to treat fetal tachycardias in terms of safety and efficacy. METHODS AND RESULTS: The charts of 21 patients who were treated with sotalol for fetal tachycardia were reviewed. Ten fetuses had atrial flutter (AF), 10 had supraventricular tachycardia (SVT), and 1 had VT. Hydrops fetalis was present in 9 fetuses. Drug treatment was successful in establishing sinus rhythm in 8 of 10 fetuses with AF and in 6 of 10 fetuses with SVT. The mortality rate in this study was 19% (4 of 21 fetuses; 3 had SVT and 1 had AF); 3 deaths occurred just days after the initiation of sotalol therapy, and 1 occurred after a dosage increase. At birth, tachycardia was present in 6 infants. Two patients who converted to sinus rhythm in utero suffered from neurologic pathology postnatally. CONCLUSIONS: Fetal tachycardia is a serious condition in which treatment should be initiated, especially in the presence of hydrops fetalis. The high success rate in fetuses with AF suggests that sotalol should be considered a drug of first choice to treat fetal AF. The low conversion rate and the fact that 3 of the 4 deaths in this study occurred in fetuses with SVT indicate that the risks of sotalol therapy outweigh the benefits in this group and that sotalol should, therefore, be limited in the treatment of fetal SVT.

Ultrasonic assessment of cardiac function in the intact human fetus.

Echocardiography may provide information concerning the structural development of the fetal human heart. The information available from such studies, when interpreted in light of existing knowledge of developmental cardiac physiology, may give insight concerning in utero cardiac pump function. The quantitation of cardiac structural growth in utero has been used to provide growth curves for the chambers of the fetal heart. Disparity in the ratio of right ventricular/left ventricular size (normally 1.0 to 1.2) may suggest acute ventricular failure and dilation. Electromechanical analysis using M-mode techniques may be used to analyze and monitor the treatment of fetal cardiac arrhythmias and provide systolic time interval analysis. Doppler waveform analysis provides information concerning directional flow and vascular impedance and Doppler flowmetry has promise for the measurement of fetal aortic and umbilical venous blood flows. Such studies have increased our understanding of fetal circulatory function and have practical implications for the establishment of fetal cardiac diagnosis and treatment programs.

Atrial dissociation: an electrophysiologic finding in a patient with transposition of the great arteries.

Complete interatrial block with two independent atrial rhythms is demonstrated by intracardiac electrograms in a patient with transposition of the great arteries who had undergone a Mustard operation. The atrial conduction abnormalities produced by the Mustard procedure with subsequent baffle revision are related to damaged anatomic interatrial connections and are similar to conduction abnormalities produced in experimental models of interatrial block.

Antenatal diagnosis of coarctation of the aorta: a multicenter experience.

OBJECTIVES: The purpose of this study was to test observations that might aid prenatal prediction of the presence of coarctation of the aorta in newborn infants with and without other forms of heart disease. BACKGROUND: Previous reports have suggested that abnormal growth of the aortic arch in utero may be identifiable as a marker for the diagnosis of coarctation. METHODS: We reviewed the prenatal echocardiograms and postnatal outcome of 20 infants (gestational age at initial study 18 to 36 weeks) with coarctation of the aorta established postnatally, to identify echocardiographic findings that would most facilitate the prenatal diagnosis of coarctation. Associated cardiac lesions included double-inlet left ventricle anatomy (n = 5), double-outlet right ventricle (n = 4), abnormal aortic valve (n = 5), unbalanced atrioventricular canal (n = 3), and membranous ventricular septal defect (n = 1). Chromosomal abnormalities included XO karyotype (n = 1), trisomy 18 (n = 1), and trisomy 21 (n = 1). RESULTS: Hypoplasia determined by measurement of the distal aortic arch was the most frequently observed finding among the fetuses with coarctation. In 12 of 15 fetuses with a well visualized transverse arch at initial prenatal study, the diameter of the transverse arch was < or = 3rd percentile for gestational age as compared with that in a normal group of fetuses. Ten of 10 fetuses with adequate images of the isthmus had isthmus hypoplasia at prenatal study with a diameter < or = 3rd percentile for gestational age. On serial study in six of seven, including three fetuses with normal distal arch measurements at initial study, the distal arch became progressively more hypoplastic for gestational age. In three there was no growth of the transverse arch or isthmus on serial study, and in three there was reversal of flow from antegrade to retrograde through the distal arch. CONCLUSIONS: In our study, quantitative hypoplasia of the isthmus and transverse arch was the most consistent observation and therefore the most definitive antenatal sign of postnatal coarctation. The potential for progression of distal arch hypoplasia necessitates serial study in fetuses with associated cardiac and noncardiac lesions.

Tricuspid valve disease with significant tricuspid insufficiency in the fetus: diagnosis and outcome.

The echocardiographic studies and clinical course of 27 fetuses (mean gestational age 26.9 weeks) diagnosed in utero with tricuspid valve disease and significant tricuspid regurgitation were reviewed. The diagnosis of Ebstein's anomaly was made in 17 of the fetuses, 7 had tricuspid valve dysplasia with poorly developed but normally attached leaflets and 2 had an unguarded tricuspid valve orifice with little or no identifiable tricuspid tissue. One fetus was excluded from data analysis because a more complex heart lesion was documented at autopsy. All fetuses had massive right atrial dilation and most who were serially studied had progressive right-sided cardiomegaly. Hydrops fetalis was found in six cases and atrial flutter in five. Associated cardiac lesions included pulmonary stenosis in five cases and pulmonary atresia in six. Four fetuses with normal forward pulmonary artery flow at the initial examination were found at subsequent study to have retrograde pulmonary artery and ductal flow in association with the development of pulmonary stenosis (n = 1) and pulmonary atresia (n = 3). On review of the clinical course of the 23 fetuses (excluding 3 with elective abortion), 48% of the fetuses died in utero and 35% who were liveborn died despite vigorous medical and, when necessary, surgical management, many of whom had severe congestive heart failure. Of the four infants who survived the neonatal period, three had a benign neonatal course, all of whom were diagnosed with mild to moderate Ebstein's anomaly; only one had pulmonary outflow obstruction. An additional finding at autopsy was significant lung hypoplasia documented in 10 of 19 autopsy reports.(ABSTRACT TRUNCATED AT 250 WORDS)

Perinatal outcome of fetal complete atrioventricular block: a multicenter experience.

The clinical course and outcome of 55 fetuses with complete atrioventricular (AV) block detected prenatally were studied to identify factors that affect the natural history of this lesion. In 29 fetuses (53%) complete AV block was associated with complex structural heart defects, usually left atrial isomerism (n = 17) or discordant AV connection (n = 7). The other 26 fetuses had normal cardiac anatomy; in 19 cases the mother had connective tissue disease or tested positive for antinuclear antibodies. Six fetuses showed progression from sinus rhythm or second degree block to complete AV block. Of the 55 pregnancies, 5 were terminated and 24 fetuses or neonates died; at the end of the neonatal period 26 fetuses were still alive. Fetal or neonatal death correlated significantly with the presence of structural heart defects (4 of 29 surviving, p less than 0.001), hydrops (0 of 22 surviving, p less than 0.001), an atrial rate less than or equal to 120 beats/min (1 of 12 surviving, p less than 0.005) or a ventricular rate less than or equal to 55 beats/min (3 of 21 surviving, p less than 0.001). Mean atrial and ventricular rates were higher in surviving than in nonsurviving fetuses (142 +/- 8 vs. 127 +/- 21 beats/min, p less than 0.002; 64 +/- 8 vs. 52 +/- 8 beats/min, p less than 0.001, respectively). A slow atrial rate, however, was frequently associated with left atrial isomerism.(ABSTRACT TRUNCATED AT 250 WORDS)

Diagnosis and management of fetal cardiac tumors: a multicenter experience and review of published reports.

OBJECTIVES: We sought to determine the prevalence and natural history of cardiac tumors in patients referred for fetal echocardiography. BACKGROUND: Cardiac tumors are rare; the prevalence, reported from autopsy studies of patients of all ages, varies from 0.0017% to 0.28%. Despite many case reports, the prevalence and natural history of fetal cardiac tumors are unclear. METHODS: Fourteen thousand fetal echocardiograms recorded over an 8-year period in seven centers were available for retrospective review. Medical records and echocardiograms were studied to determine the reason for referral, family history of tuberous sclerosis, prenatal and postnatal course and tumor description and type. RESULTS: Cardiac tumors were present in 19 pregnancies (0.14%). Gestational age at diagnosis ranged from 21 to 38 weeks. The most common indication for referral was a mass on an obstetric ultrasound study. The tumors were singular in 10 patients and multiple in 9. Tumor size ranged from 0.4 x 0.4 to 3.5 x 4 cm, and the majority of tumors were not hemodynamically significant. There were 17 patients with rhabdomyomas, 1 with a fibroma and 1 with an atrial hemangioma. Tuberous sclerosis complex was diagnosed in 10 patients. Partial or complete tumor regression was seen in eight patients; tumors were unchanged in five; and three required operation. CONCLUSIONS: Fetal cardiac tumors, a rare condition, are often benign. The majority of tumors are rhabdomyomas, but not all fetuses with rhabdomyoma have tuberous sclerosis.

Management outcome and follow-up of fetal tachycardia.

OBJECTIVES: The aim of this study was to evaluate fetal tachycardia and the efficacy of maternally administered antiarrhythmic agents and the effect of this therapy on delivery and postpartum management. BACKGROUND: Sustained fetal tachycardia is a potentially life-threatening condition in which pharmacologic therapy is reported to be effective. There is ongoing discussion about optimal management. METHODS: A group of 51 patients with M-mode echocardiographically documented fetal tachycardia was studied retrospectively. RESULTS: Thirty-three fetuses had supraventricular tachycardia; 15 had atrial flutter; 1 had two episodes of both; and 2 had ventricular tachycardia. Fetal hydrops was seen in 22 patients. Thirty-four fetuses received maternal therapy with either digoxin or flecainide as the first administered drug (additional drugs were given in 12). Drug treatment was successful in establishing acceptable rhythm control in 82% (84% without, 80% with hydrops). In the latter group the median number of drugs and number of days to conversion were higher. Three patients with fetal hydrops died. In 50% of cases, tachycardia reappeared at delivery: 9 neonates presented with atrial flutter, 14 with supraventricular tachycardia and 1 with ventricular tachycardia. Seventy-eight percent of the group had pharmacologic therapy by 1 month of age and 14% by 3 years. CONCLUSIONS: Fetal tachycardia can be treated adequately in the majority of patients, even in the presence of hydrops, and therefore emergency delivery might not be indicated. Digoxin and flecainide were drugs of first choice and produced no serious adverse effects in this series of patients. The majority of patients do not require prolonged therapy.

Atrial flutter in the perinatal age group: diagnosis, management and outcome.

OBJECTIVES: The aim of this retrospective study was to evaluate perinatal atrial flutter (AF) and the efficacy of maternally administered antiarrhythmic agents, postpartum management and outcome. BACKGROUND: Perinatal AF is a potentially lethal arrhythmia, and management of this disorder is difficult and controversial. METHODS: Forty-five patients with documented AF were studied retrospectively. RESULTS: Atrial flutter was diagnosed prenatally in 44 fetuses and immediately postnatally in 1 neonate. Fetal hydrops was seen in 20 patients; 17 received maternal therapy, 2 were delivered and 1 was not treated because it had a severe nontreatable cardiac malformation. In the nonhydropic group of 24 patients, 18 were treated and the remaining 6 were delivered immediately. In the hydropic group, 10 received single-drug therapy (digoxin or sotalol) and 7 received multidrug therapy. In the nonhydropic group, 13 received a single drug (digoxin or sotalol) and 5 received multiple drugs. One patient with rapid 1:1 atrioventricular conduction (heart rate 480 beats/min) died in utero and another died due to a combination of severe hydrops because of the AF, sotalol medication, stenosis of the venous duct and hypoplastic placenta. Of the 43 live-born infants, 12 were in AF at birth. Electrical cardioversion was successful in eight of nine patients. No recurrences in AF have occurred beyond the neonatal period. Four patients with fetal flutter and hydrops showed significant neurological pathology immediately after birth. CONCLUSIONS: Fetal AF is a serious and threatening rhythm disorder, particularly when it causes hydrops, it may be associated with fetal death or neurological damage. Treatment is required and primarily aimed at reaching an adequate ventricular rate and preferably conversion to sinus rhythm. Digoxin failed in prevention of recurrence at time of delivery in a quarter of our patients, whereas with sotalol no recurrence of AF has been reported, suggesting that class III agents may be the future therapy. Once fetuses with AF survive without neurological pathology, their future is good and prophylaxis beyond the neonatal period is unnecessary.

Echocardiographic studies of the human fetus: prenatal diagnosis of congenital heart disease and cardiac dysrhythmias.

During obstetrical ultrasound examinations, 200 M-mode and 35 real-time two-dimensional echocardiographic studies were performed on 180 fetuses of high-risk pregnancies. Fetal gestational ages ranged from 18 to 41 weeks. M-mode "sweeps" demonstrating mitral- and septal-aortic fibrous continuity were obtained in 115 studies. Paradoxic septal motion in 50 fetuses suggested relarive right ventricular volume loading. Congenital cardiac malformations were accurately diagnosed in a 34-week fetus with pulmonary atresia and hypoplastic right ventricle and in a 28-week fetus with a univentricular heart. Congenital complete atrioventricular block was diagnosed in a 28-week fetus and atrial flutter with variable atrioventricular block was diagnosed in a 38-week fetus. The use of echocardiographic studies to evaluate cardiac structure and rhythm in utero assists in counseling prospective parents and in planning postnatal management for their offspring.

Outcome of prenatally detected cardiac malformations.

Reliable, prenatal detection of congenital heart disease has become possible over the past decade with the evolution of fetal echocardiography. We have documented the outcome of 170 cardiac defects diagnosed prenatally since 1984. Of 170 cases, 55 (32%) had major extracardiac malformations and 45 (28%) chromosomal abnormalities (16 had both). Elective termination was chosen in 77 (45%) pregnancies. Of 93 continuing pregnancies 15 were stillborn and 43 died postnatally (48% of these fetuses and infants had extracardiac or chromosomal anomalies, or both). Thirty-five patients survive at 1 to 80 months (mean 36). Aneuploidy or extracardiac defects are present in 20% of survivors. Nonimmune hydrops secondary to cardiac failure was present in 7 continuing pregnancies and none of these patients survived. The prognosis of prenatally diagnosed cardiac lesions is negatively influenced by the presence of cardiac failure, aneuploidy or extracardiac malformations, or a combination of these. Optimal counseling and management requires the identification of these conditions when present.

Transesophageal echocardiographic guidance of transcatheter closure of atrial septal defect.

Transcatheter closure of atrial septal defect (ASD) was accomplished in 10 of 11 patients aged 13 months to 46 years (weight range 11 to 77 kg). Transesophageal echocardiography (TEE) was used simultaneously with fluoroscopic imaging in 4 of these patients aged 4.5 to 46 years (weight range 19 to 77 kg). TEE was used to ascertain defect size, position and number of defects and to ascertain appropriate seating of the defect occluder within the atrial defect. In 2 patients TEE-assisted transcatheter ASD closure was accomplished after previous attempts at transcatheter ASD closure, unaided by TEE, had been unsuccessful. The only unsuccessful ASD closure procedure occurred in the smallest patient in the series (an 11-kg 13-month-old), a child who was too small to undergo TEE using our 11-mm diameter endoscopic probe. The concomitant use of TEE with fluoroscopic imaging provides information that is unique and complementary and may improve the efficacy and safety of the transcatheter technique for ASD closure. The recent availability of a 7-mm diameter TEE probe will extend the use of TEE into the infant age group and may decrease the discomfort and potential morbidity of TEE in older patients.

Predictors of rhythm disturbances and subsequent morbidity after the Fontan operation.

The electrocardiographic, hemodynamic and surgical data of 30 patients who underwent a Fontan operation between 1977 and 1986 were retrospectively reviewed to identify the incidence and predictors of immediate and late postoperative arrhythmias and associated morbidity in long-term survivors. Of 4 patients who died less than 1 year after operation (mortality 13%), 1 death was related to an arrhythmia. Three patients were not in sinus rhythm before operation and were excluded from the statistical analysis that examined predictors of arrhythmias. The remaining 23 long-term survivors have been followed 6.3 +/- 2.6 years (mean +/- standard deviation) since surgery and all remain in New York Heart Association functional class I or II. Ten patients (43%) developed immediate postoperative arrhythmias (less than or equal to 30 days) whereas 11 (48%) had late arrhythmias. With up to 10.7 years of follow-up, the proportion of patients free from late arrhythmias continues to decline. Arrhythmias included bradyarrhythmias, atrial tachyarrhythmias, the tachy-brady syndrome and supraventricular ectopic activity. Immediate postoperative arrhythmias predicted late arrhythmias (p = 0.022). The preoperative electrocardiogram was the only variable useful in predicting both immediate and late postoperative arrhythmias. A more negative P-wave deflection in lead V1 (-2.4 +/- 0.7 vs -1.4 +/- 1.2 mV, p = 0.02) predicted patients with immediate postoperative arrhythmias, whereas both greater P-wave duration and a more negative deflection in this lead predicted late arrhythmias (103 +/- 14 vs 83 +/- 20 ms, p = 0.01, and -2.5 +/- 0.8 vs -1.3 +/- 1.0 mV, p = 0.005, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Fetal echocardiography. A tool for evaluation of in utero cardiac arrhythmias and monitoring of in utero therapy: analysis of 71 patients.

Fetal echocardiographic studies were performed in 71 patients referred for evaluation of cardiac rhythm disturbances at 24 to 40 weeks' gestation. After 2-dimensional echocardiographic study of cardiac structure was performed, M-mode echocardiograms were analyzed for measurement of cardiac rate, atrioventricular contraction sequence, atrioventricular valve motion, and duration of postectopic pauses. Arrhythmias were diagnosed in 59 patients. In 34 patients with isolated ectopic beats, the arrhythmia resolved during later pregnancy in 26 or within the first 5 days of life in 8. Six patients had mild sinus bradycardia and 8 had frequent sinus pauses; all 14 had resolution of the arrhythmia during pregnancy. Sustained arrhythmias occurred in 11 patients. Deaths occurred when there was associated fetal congestive heart failure (hydrops fetalis), structural heart disease, or both. M-mode echocardiography diagnosed supraventricular tachycardia in 3 fetuses. The echocardiogram was used thereafter for monitoring transplacental digoxin therapy.

Fenestrated Fontan operation with delayed transcatheter closure of atrial septal defect. Improved results in high-risk patients.

Ten patients, each with two or more risk factors for morbidity and death, underwent a fenestrated Fontan procedure in which a 4 to 6 mm circular fenestration was left between the systemic and pulmonary venous chambers. None died; a similar group of high-risk patients without fenestration had a mortality rate of 2 of 8. Patients with fenestration had significantly less drainage from the chest tube, less need for inotropic support, and shorter intensive care and hospital stays than did patients without fenestration. Comparison with a group of low-risk patients undergoing the Fontan operation showed no statistical difference in these postoperative parameters. Fenestrations were closed in all 10 patients at from 9 days to 6 months after operation by means of the transcatheter clamshell occluder device. Two patients had left pulmonary artery balloon angioplasty and three patients had other atrial communications closed with additional clamshell devices. During short-term follow-up periods averaging 18 months, all patients were clinically well; however, one patient with mitral atresia required reoperation for obstruction between the left atrium and the tricuspid valve, not related to the clamshell device. These data indicate that fenestration may be one method of achieving lower morbidity and mortality rates among high-risk patients undergoing the Fontan procedure.

Thirty-year follow-up of superior vena cava-pulmonary artery (Glenn) shunts.

The first superior vena cava-pulmonary artery shunt (Glenn shunt) in our series was performed in February 1958. From then through September 1988, 91 patients have undergone this procedure for a wide variety of congenital defects. We here report follow-up data available on all patients. Ages ranged from 2 days to 46 years (mean 6.8). Diagnoses were as follows: tricuspid atresia, 27; single ventricle, 22; tetralogy of Fallot, 14; D-transposition of the great arteries, ventricular septal defect, and pulmonary stenosis, 9; D-transposition, 5; Ebstein's anomaly, 4; pulmonary atresia + intact septum, 4; and others, 6. The hospital mortality rate was 7.7% (one death in the last 53 patients, 1.9%). Five deaths occurred in patients less than 6 months old. There were 20 late deaths (22%) with actuarial survival rates of 84% and 66% at 10 and 20 years, respectively. Pulmonary arteriovenous fistula formation was seen in 18 patients (19.7%), six of whom have undergone therapeutic embolization with improvement in saturation. The prevalence of pulmonary arteriovenous fistula increases with time after shunt. No long-term shunt thrombosis or stricture formation was seen. Fifty percent of shunts were still functioning at 20 years. Palliation was limited because of decrease in blood flow to the contralateral pulmonary artery, collaterals between the inferior and superior venae cavae, and pulmonary arteriovenous fistula formation. Improvement in saturation was obtained in eight otherwise inoperable patients by creation of a right axillary arteriovenous fistula up to 19 years after the Glenn shunt. Three patients had conversion of a Blalock-Taussig shunt to a Glenn shunt with improvement in congestive heart failure. Twenty-six patients have undergone a Fontan procedure with two deaths. Compared with the group having a Fontan procedure without a prior Glenn operation, there was no difference in early or late mortality. Thirty years after a Glenn shunt, the first patient in this series is working full time after having undergone a modified Fontan procedure in 1981. We conclude that the Glenn connection, usually with supplemental procedures to enhance oxygenation, has provided excellent physiologic palliation with low mortality up to 30 years with no late thrombosis or stricture formation. The incidence of pulmonary arteriovenous fistula increases with time and can be effectively treated with embolization. Physiologic repair after the Glenn shunt carries a low mortality. Although currently used infrequently, superior vena cava-pulmonary artery shunting remains a useful method of palliation in selected patients.(ABSTRACT TRUNCATED AT 400 WORDS)

Prenatal diagnosis of congenital heart disease affects preoperative acidosis in the newborn patient.

OBJECTIVES: Congenital heart disease is the leading cause of death in the first year after birth. Prenatal diagnosis of the disease can optimize the preoperative condition of the patient and may help in the prevention of acidosis. In this retrospective study we compared the occurrence of metabolic acidosis in patients with and without prenatal diagnosis of a congenital heart disease. METHODS: Data of 408 patients who needed an operation for congenital heart disease within 31 days of life were analyzed retrospectively. Arterial blood gases at fixed time intervals and worst blood gas of 81 patients with and 327 patients without a prenatal diagnosis were compared, categorizing the patients on ductus dependency, anticipated univentricular or biventricular repair, and left-sided, right-sided, or no heart obstruction. RESULTS: In the overall group significant differences in lowest pH, lowest base excess, and highest lactate level were found, with metabolic acidosis more common among the patients with a postnatal diagnosis. In the group of patients with ductus-dependent congenital heart disease, the difference between patients receiving a prenatal and those receiving a postnatal diagnosis was more significant than in the group with non-ductus-dependent lesions. Analyzing patients with right-sided, left-sided, and no obstruction separately, significant differences were found in the group with left-sided heart obstruction for lowest pH and base excess and in the group with right-sided heart obstruction for lowest base excess. CONCLUSIONS: Prenatal diagnosis of congenital heart disease minimizes metabolic acidosis in patients with congenital heart disease and may be associated with improved long-term outcome and prevention of cerebral damage among this fragile group of patients, although no significant effect on direct surgical outcome was encountered.

The antenatal diagnosis of congenital heart disease using fetal echocardiography: is color flow mapping necessary?

Doppler color flow mapping is widely used in fetal echocardiography. We studied the impact of color flow mapping on fetal cardiac diagnosess. Between January 1, 1989 and June 30, 1990, we performed 854 fetal echocardiograms on 776 fetuses. Color flow mapping was used in 45 of 48 fetuses diagnosed as having cardiac abnormalities. Scans were reviewed to assess how color flow mapping influenced the ultimate diagnoses. Color flow mapping was essential to the correct anatomical diagnoses in 13 fetuses (29%), helpful but not essential in 21 (47%), and added little to two-dimensional examination alone in 11 (24%). It was essential in determining the course and flow direction in the great vessels when outflow obstruction was present or with transposition, and it was helpful but not essential in locating small jets of atrioventricular valve regurgitation. It was not helpful when the anatomical abnormalities were clearly identified from two-dimensional examination alone. We conclude that color flow mapping is helpful in the delineation of anatomical diagnoses in three-quarters of cases of fetal heart disease, particularly when the great vessels are abnormal. It may speed examinations by directing pulsed Doppler sampling. We did not find it essential to the proper recognition of anatomically abnormal hearts.

Ectopic atrial tachycardia in utero.

BACKGROUND: The antenatal diagnosis of fetal arrhythmias helps direct medical management, which may include intrauterine therapy. Ectopic atrial tachycardia is an unusual arrhythmia in children, and we know of no previous reports of antenatal diagnosis of this particular arrhythmia. CASE: The diagnosis of fetal ectopic atrial tachycardia was suggested by the monitor tracing during labor and was subsequently confirmed by the postpartum behavior of the arrhythmia and its electrocardiographic characteristics. CONCLUSION: Ectopic atrial tachycardia, although uncommon, should be considered in the differential diagnosis of fetal tachycardias. The fetal monitor tracing may be useful in making this diagnosis antenatally, which may help to direct management both before and after birth.

Prenatal diagnosis of a human pseudoacardiac anomaly.

A unique case is presented of dichorionic-diamnionic twins, one of which contained a primitive heart arrested at an early stage of development and which resembled in many other respects a classic case of acardia. Lack of vascular anastomoses, the dichorionic nature of the twins, and ultrasonic evidence of independent heart rates suggest that the primary pathogenesis in acardia may be cardiac dysmorphogenesis rather than reversal of vascular flow. Ultrasonography and fetal echocardiography proved useful in delineating many of the features of the amorphous twin before delivery.