Successful treatment of fetal congestive heart failure secondary to tachycardia

Diagnosis and management of fetal heart failure

Congestive fetal heart failure, defined as inability of the heart to deliver adequate blood flow to organs such as the brain, liver, and kidneys, is a common final outcome of many intrauterine disease states that may lead to fetal demise. Advances in fetal medicine during the past 3 decades now provide the diagnostic tools to detect and also treat conditions that may lead to fetal heart failure. Fetal echocardiographic findings depend on severity of diastolic and systolic dysfunction of both ventricles. At an advanced stage, findings include cardiomegaly; valvar regurgitation; venous congestion; fetal edema and effusions; oligohydramnios; and preferential shunting of blood flow to the brain, heart, and adrenals in the distressed fetus. A useful diagnostic tool to quantify severity of heart failure is the cardiovascular profile score, which is a composite score based on 5 different echocardiographic parameters. To predict outcomes, the score should be interpreted in the context of the underlying disease, as different causes of intrauterine heart failure may have highly variable outcomes. Low fetal cardiac output may result from a myocardial disease (cardiomyopathy, myocarditis, ischemia), abnormal loading conditions (arterial hypertension, obstructive structural heart disease, atrioventricular malformations, twin-to-twin transfusion), arrhythmia, or external cardiac compression (pleural and/or pericardial effusions, cardiac tumours). Treatment options are available for several of these conditions.

Reversal of cardiomyopathy in patients with congestive heart failure secondary to tachycardia

OBJECTIVES

Tachycardia-induced cardiomyopathy (TCM) is a reversible cause of heart failure. Little is known of the characteristics of tachycardia associated with the development of left ventricular (LV) dysfunction and the reversal of cardiomyopathy after cure of tachycardia. This study aimed to examine the reversal of cardiomyopathy in patients undergoing ablation with congestive heart failure secondary to tachycardia.

METHODS

A total of 625 patients underwent radiofrequency ablation for tachycardiarrhymias between January 2009 and July 2011. Echocardiography analysis was performed to identify patients with depressed LV function, defined as a left ventricular ejection fraction <50 %. Patients with preexisting structural heart disease (n = 10) were excluded. NT-pro-B-type natriuretic peptide (NT-proBNP) assessment was performed before ablation in patients considered to have TCM (n = 17). Repeated echocardiography study and NT-proBNP assessment were measured after a mean follow-up of 3 months. Levels of NT-proBNP before and after ablation were compared. Reversal of cardiomyopathy was also assessed.

RESULTS

The incidence of TCM was 2.7 % (12 males; age, 35.8 ± 17.1 years). Successful ablation was performed in 16 of 17 patients (94.1 %). There was a significant improvement in left ventricular ejection fraction (36.7 ± 7.5 vs. 59.4 ± 9.7 %; P < 0.001). The mean left ventricular end-diastolic diameter before treatment was 59.5 ± 8.3 mm (range, 43 to 70), compared with 51.9 ± 7.4 mm (range, 40 to 67) (P = 0.009) after 3 months follow-up. The levels of NT-proBNP decreased after ablation procedure, from 4,092.6 ± 3,916.6 to 478.9 ± 881.9 pg/ml (P < 0.001). After successful ablation, ventricular function normalized in 15 of 17 (88.2 %) patients at a mean of 3 months.

CONCLUSIONS

Restoration of LV function and reversal of LV remodeling can be achieved with successful elimination of tachycardia in the majority of patients. NT-proBNP level elevates in subjects with TCM and decreases sharply after ablation.

Supraventricular tachycardia causing heart failure

PURPOSE OF REVIEW

Supraventricular tachycardia (SVT) causing heart failure is an important cause of tachycardia-induced cardiomyopathy.

RECENT FINDINGS

Advances in anti-arrhythmic drugs to achieve either rate or rhythm control, curative ablative therapy directed at the underlying tachycardia mechanism to restore sinus rhythm, and atrioventricular junction ablation with permanent pacemaker placement for better rate control have improved the outcome of SVT management and subsequently improved the heart failure symptomatology and in some cases reversed remodeling of the cardiac dysfunction.

SUMMARY

The aim of this review is to provide the reader with clinical presentation as well as the common SVTs causing heart failure, pathophysiology of SVT causing heart failure, evaluation and management of SVT causing heart failure, and prognosis of SVT causing heart failure.

Prenatal management of urogenital disorders

Antenatal sonography has markedly increased the detection of urogenital anomalies, including those conditions that lead to significant morbidity and mortality. Prenatal intervention is feasible to arrest and sometimes reverse the sequelae of bladder outlet obstruction but not necessarily renal damage. Myelomeningoceles, the most severe form of spina bifida, can be corrected in utero, with improvements in hydrocephalus seen along with a decreased incidence of ventricular shunting postnatally. Medical therapy to prevent virilization associated with congenital adrenal hyperplasia has been successful, with improved ability to detect its presence prenatally now possible. As further techniques evolve to correct underlying disease processes, it becomes important to critically assess the therapies, particularly with long-term outcome data.

Changes in ventricular dimensions and function during recovery of atrial tachycardia-induced cardiomyopathy treated with catheter ablation

A 25-year-old male with an atrial tachycardia-induced cardiomyopathy (TIC) presented to our institution with clinical heart failure, an ejection fraction of 10%, and a severely dilated left ventricle. He underwent successful ablation and had no recurrence of this arrhythmia. In this report, we document the acute and long-term follow-up (out to 10 years) of a single patient with a TIC and present the changes in left ventricular (LV) function and dimensions that occurred. Despite the apparent success of ablative therapy, this case report highlights the importance of routine clinical and echocardiographic follow-up in patients with longstanding TIC.

Prenatal management of urogenital disorders

Antenatal sonography has increased the detection of urogenital anomalies markedly, including conditions that lead to significant morbidity and mortality. Prenatal intervention is feasible to arrest and sometimes reverse the sequelae of bladder-outlet obstruction, but not necessarily renal damage. Myelomeningoceles, the most severe form of spina bifida,can be corrected in utero, with improvements in hydrocephalus and a decreased incidence of ventricular shunting postnatally. Medical therapy to prevent virilization associated with congenital adrenal hyperplasia has been successful, with improved ability to detect its presence prenatally. As techniques evolve to correct underlying disease processes,it becomes important to assess the therapies critically, particularly with long-term outcome data.

Heart Failure and Sudden Death in Patients With Tachycardia-Induced Cardiomyopathy and Recurrent Tachycardia

BACKGROUND

Tachycardia-induced cardiomyopathy is a reversible cause of heart failure. We hypothesized that although left ventricular ejection fraction measurements normalize after heart rate or rhythm control in patients with tachycardia-induced cardiomyopathy, recurrent tachycardia may have abrupt and deleterious consequences.

METHODS AND RESULTS

Patients with tachycardia-induced cardiomyopathy that developed over years were evaluated and treated. Tachycardia episodes and outcomes were assessed. Twenty-four patients were identified. All had NYHA functional class III heart failure or greater on presentation. One third were heart transplant candidates. There were 17 men and 7 women with a mean age of 46+/-16 years and mean left ventricular ejection fraction of 0.26+/-0.09 at the index visit. The cause was atrial fibrillation (n=13), atrial flutter (n=4), atrial tachycardia (n=3), idiopathic ventricular tachycardia (n=1), permanent junctional reciprocating tachycardia (n=2), and bigeminal ventricular premature contractions (n=1). Within 6 months of rate control or correction of the rhythm, left ventricular ejection fraction improved or normalized and symptoms abated in all. Five patients had tachycardia recur. In these patients, left ventricular ejection fraction dropped precipitously and heart failure ensued within 6 months, even though the initial impairment took years. Rate control eliminated heart failure and improved or normalized ejection fraction in 6 months. Three of 24 patients died suddenly and unexpectedly.

CONCLUSIONS

Tachycardia-induced cardiomyopathy develops slowly and appears reversible by left ventricular ejection fraction improvement, but recurrent tachycardia causes rapid decline in left ventricular function and development of heart failure. Sudden death is possible.

Lack of interaction of digoxin and P-glycoprotein inhibitors, quinidine and verapamil in human placenta in vitro

OBJECTIVE

To determine the effect of quinidine and verapamil, known antiarrhythmic agents and P-glycoprotein (Pgp) inhibitors, on digoxin transport from the maternal to the fetal compartment in the isolated perfused human placenta.

STUDY DESIGN

Isolated placental cotyledons from normal human placentae (n=20) were dually perfused with M199 medium enriched with albumin (0.3%) and glucose (0.1%). The maternal and the fetal circulation flow rates were 12 and 6 ml/min, respectively. Closed circulations were used to evaluate steady state transplacental gradient formation. In six placentae quinindine was added to the maternal circuit; after 45 min of perfusion, digoxin was added to the maternal circulation. The effect of verapamil on digoxin transfer from the maternal to the fetal compartments was explored in five placentae. In six additional placentae the transfer of digoxin was studied in the absence of quinidine. Transplacental passage of digoxin was calculated from repeated fetal and maternal perfusate samples. Digoxin levels were determined in perfusate samples by fluorescence polarization immunoassay. Antipyrine was added to the maternal reservoir of all placentae as reference substance.

RESULTS

The transfer of digoxin (alone) and in the presence of quinidine or verapamil was 10.93+/-3.71, 9.00+/-5.2 and 12.94+/-4.86%, respectively. The levels of digoxin in the fetal compartment, 0.62+/-0.20, 0.48+/-0.29 and 0.60+/-0.26 ng/ml, respectively, were not significantly affected by quinidine and verapamil. These Pgp modulators, also did not influence significantly the steady state levels of digoxin in the maternal compartment.

CONCLUSION

Neither quinidine nor verapamil affected the transplacental transfer of digoxin in vitro in normal human placentae. In contrast to the other tissues, they do not inhibit Pgp activity in term human placentae.

Diffusion characteristics of placental preparations affect the digoxin passage across the isolated placental lobule

Our aim was to evaluate the isolated placental lobule to study maternofetal transplacental digoxin transfer and accumulation in placental tissue in vitro. Digoxin passage across the isolated lobule of 10 human placentas was calculated from repeated fetal and maternal perfusate samples, and placental tissue digoxin concentrations were measured at the end of the experiments. To determine the degree of overlap of the fetal and the maternal circulation, the antipyrine clearance was used. Digoxin disappearance from the maternal circuit was not significantly affected by the degree of overlap. In contrast, the increase of digoxin in the fetal compartment was significantly higher in "well-perfused" placentas (antipyrine clearance > 1.60 ml/min; n = 5) than in "malperfused" placentas (antipyrine clearance < 1.50 ml/min; n = 5) (end-feto to initial maternal digoxin ratio 0.44 +/- 0.08 vs. 0.30 +/- 0.08; p < 0.05), whilst the accumulation in placental tissue was higher in the latter group (0.45 +/- 0.07 vs. 0.62 +/- 0.10 ng/mg protein; p < 0.05). We conclude that the isolated placental lobule is suitable to quantify transplacental digoxin transfer in vitro, but the diffusion characteristics of each preparation have to be considered.

Parathyroid hormone levels in preterm and term labor

This prospective study was undertaken to test the hypothesis that parathyroid hormone (PTH) might be involved in preterm or term labor. Four groups of patients were formed, 15 patients in each group. The preterm labor group were patients who were admitted to our perinatal care unit with preterm labor and unruptured membranes (< 35 weeks' gestation). The preterm or term nonlabor control groups were patients matched for gestational age, maternal age, and parity, who were not in labor. The term labor group were patients matched for maternal age and parity who were in active labor. Mean (+/-SD) level of biologically intact PTH was 18.9 +/- 10.6 pgr/mL, 7.6 +/- 4.7 pgr/mL, 20.8 +/- 10.1 pgr/mL, 13.7 +/- 5.3 pgr/mL in preterm labor group, preterm nonlabor group, term labor group, and term nonlabor group, respectively (p < 0.05). No statistically significant differences were observed in the levels of calcium, phosphorus, magnesium, or albumin. We therefore suggest that PTH may have a role in preterm or term labor. The nature of its role should be investigated in further studies.

Atrial flutter in the human fetus: diagnosis, hemodynamic consequences, and therapy

In the context of a large program of prenatal echocardiographic detection of fetal heart disease, special attention was paid to the in utero detection and identification of fetal heart rate disorders. This article focuses on 18 cases of tachycardiac fetuses. It provides information on how to identify the nature of the detected tachycardia, the hemodynamic consequences of tachycardia, the particular characteristics of fetal atrial flutter, and the efficacy of the transmaternal treatment of fetal tachycardia. It also describes an original way to grade and score the degree of fetal heart failure that proved useful for the assessment and monitoring of in utero therapeutic procedures. The results presented stress the efficacy of digoxin for fetal atrial flutter as well as the usefulness of prenatal echocardiography in the assessment of anatomical, functional, and rhythmic conditions of the fetal heart.

Cardiac abnormalities associated with hydrops fetalis

Cardiovascular abnormalities are associated with hydrops fetalis in 26% of cases reported in the modern era. These include not only structural abnormalities, but also cardiac arrhythmias, failure, tumors, myopathy, infection, inflammation, infarction, and arterial calcification. Cardiac structural abnormalities may be causative or seen only in association with hydrops fetalis. Structural lesions that result in right atrial pressure or volume overload seem to be most commonly associated with hydrops fetalis. Fetal cardiac tumors, cardiomyopathy, myocarditis, myocardial infarction, and arterial calcification probably result in hydrops fetalis by a similar mechanism. Fetal tachyarrhythmia has been shown to result in elevation of atrial pressure and atrial natriuretic peptide. Fetal tachyarrhythmias are the most treatable of cardiac causes of hydrops fetalis. Fetal bradyarrhythmias are less easily treatable and less certainly a causative mechanism of hydrops fetalis.

Prune-belly syndrome in a female, complicated by intestinal malrotation after successful antenatal treatment of hydrops fetalis

The authors report a female case of prune-belly syndrome having an antenatal sonographic diagnosis of hydrops fetalis and treated prenatally with transplacental digitalis administration. The findings of this case suggest that the clinical entity includes various phenotypes or aberrants having different origins.

Fetal arrhythmias: intrauterine diagnosis, treatment and prognosis

Fetal echocardiography can provide useful information for the evaluation of fetal arrhythmias. Between 1980 and 1993, 44 fetuses with arrhythmias were diagnosed in utero at 12 and 40 weeks of gestation in Kurume University Hospital. Fetal bradycardia, tachycardia and ectopic beats were revealed in 17, seven and 20 fetuses, respectively, and their clinical features and prognosis were evaluated. In the 17 fetuses with bradycardia, eight were associated with congenital heart defect, and six of these developed to fetal hydrops. Of the 17 fetuses, four died in utero, one was terminated, and six died after birth. The other six cases survived. Three of these had a pacemaker implanted after birth. In the seven fetuses with tachycardia, transplacental anti-arrhythmic drugs were administered in five cases and conversion of the arrhythmia was achieved in four. None of the cases was associated with any congenital heart defect, and none died. Three infants had paroxysmal tachycardia postnatally. In the 20 fetuses with ectopic beats, arrhythmia was observed postnatally in 10, but all of these were resolved within 3 months after birth. Fetal bradycardias carried a poor prognosis in most cases and further studies are required to establish effective treatment. Some cases of fetal tachycardia developed recurrent tachycardia postnatally. Close follow-up of the newborn is therefore necessary.

Umbilical venous pressure in nonimmune hydrops fetalis: correlation with cardiac size

OBJECTIVES

Our objectives were to examine the relationship between umbilical venous pressure and cardiac size in nonimmune hydrops fetalis and to assess the role of cardiac failure in the pathogenesis of the disease.

STUDY DESIGN

Fourteen fetuses with nonimmune hydrops fetalis were investigated in a tertiary referral unit with high-resolution ultrasonography, echocardiography, and fetal blood sampling. Fetal heart size was assessed by measurement of the cardiothoracic ratio. Umbilical venous pressure was measured at the time of fetal blood sampling with a fluid-filled system.

RESULTS

The 10 fetuses with elevated umbilical venous pressures had significantly increased cardiothoracic ratios (p = 0.02). These fetuses also had ascites. Four other fetuses had normal-sized hearts, normal umbilical venous pressures, and no ascites. There was a linear relationship between cardiothoracic ratio and umbilical venous pressure (r = 0.75, p = 0.003).

CONCLUSION

Measurement of umbilical venous pressure validates cardiothoracic ratio as a noninvasive assessment of cardiac function in nonimmune hydrops.

Intrauterine treatment on non-immune hydrops fetalis

In 51 cases with non-immunologic hydrops fetalis (NIHF), perinatal management was performed based on our protocol. Twenty-two cases were treated by albumin and/or packed red cell (PRC) injection into the fetal abdominal cavity, and 9 cases by transplacental digitalization. Among the cases treated by albumin and/or PRC injection, 6 of 8 cases without pleural effusion recovered in utero, and all 6 cases are alive. However, of 14 cases with pleural effusion, none recovered in utero, and only one case is alive. Of 9 cases treated by transplacental digitalization, 2 cases recovered in utero, and only one case is alive. All fetuses with congenital heart anomaly died. This evidence indicates that albumin and/or PRC injection into the fetal abdominal cavity is an effective procedure for in utero treatment of NIHF without pleural effusion, but suggests that in NIHF resulting from either congenital heart anomaly and/or heart failure, the survival rate may not be increased by transplacental digitalization.

Successful ultrasound-guided intrauterine blood transfusion in severe non-immune hydrops fetalis

Non-immune hydrops fetalis has varied etiology, high mortality and few known successful treatment modalities. A rare case of non-immune fetal hydrops with severe anemia diagnosed prenatally and treated successfully by repeated ultrasound-guided intrauterine blood transfusions is presented.

Hydrops revisited: literature review of 1,414 cases published in the 1980s

This paper reviews 47 series of hydrops fetalis (804 cases) and 610 individual cases published since 1980. From this large number of cases, guidelines are derived for prenatal diagnosis and management.

Cardiac abnormalities and nonimmune hydrops fetalis: a coincidental, not causal, relationship

Few conditions associated with nonimmune hydrops fetalis have had a demonstrable causal relationship. Congenital heart disease is often said to be a cause of nonimmune hydrops fetalis and antenatal closure of the foramen ovale is the cardiac abnormality most frequently reported in association with hydrops. In order to examine the role of congenital heart disease in hydrops, and, in particular, that of antenatal closure of the foramen ovale, we reviewed all autopsy cases with hydrops fetalis over an 11 year period and compared cardiac anomalies with those of nonhydropic controls. The incidence of various congenital heart malformations was not significantly different among these groups, suggesting that factors in addition to cardiac anomalies must be considered in the pathogenesis of nonimmune hydrops fetalis.

Perinatal mortality at King Fahd Hospital of the University Al-Khobar, Saudi Arabia

The perinatal deaths of all singleton births that occurred at King Fahd Hospital of the University, Al-Khobar, Saudi Arabia during a 4-year period are analysed. The causes of death are classified into 12 groups using an extended modification of the Aberdeen classification. There were 165 perinatal deaths in 8057 singleton births, giving a perinatal mortality rate of 20.47 per 1000 total births. Fetal malformations occurred in 29 (17.57%) cases. Of the remaining 136 normal infants, 77 (56.6%) were stillbirths and 59 (43.4%) died within 1 week of delivery. Spontaneous premature labor was the commonest cause of death (23.52%) followed by birth trauma (11%) and maternal diseases (9.55%). The cause of death was not known in 22 (16.17%) cases. In conclusion, prevention of premature labor, better intrapartum fetal monitoring, early recognition of fetal distress and improvement of neonatal care should reduce the perinatal mortality rate.

Transplacental passage of digoxin in the case of nonimmune hydrops fetalis

Successful treatment of intrauterine fetal tachyarrhythmia was reported in several cases recently. It was also pointed out that placental transfer of digoxin is unsatisfactory under certain conditions. However, it has not been clearly shown in which cases fetal digoxin level does not reach the maternal level. We present a case of nonimmune hydrops fetalis due to congenital atrial flutter in which digoxin concentration in the sera of the mother and the neonate showed significant dissociation, and discuss perinatological matters about the digoxin treatment and the factor that obstructs the transplacental passage of digoxin. Conclusively, we recommend that maternal digoxin concentration should be raised to near toxic level if the resolution of fetal and placental hydrops is not attained in the initial digoxin loading.

Intrauterine supraventricular tachyarrhythmias and transplacental digitalisation

Six newborn infants with intrauterine supraventricular tachyarrhythmias (five cases of atrial flutter and one of supraventricular tachycardia) are described. Transplacental digitalisation was attempted in three cases. Supraventricular tachycardia associated with hydrops fetalis, detected in a fetus at a gestation of 31 weeks, was successfully converted to normal sinus rhythm eight days after the mother began treatment with digoxin. The serum concentration of digoxin in cord blood almost equalled the maternal concentration in three cases. In the remaining three cases treatment with digitalis was effective in converting tachyarrhythmias to sinus rhythm after delivery. With maintenance digoxin therapy, the prognosis of fetal tachyarrhythmias seems to be good, once conversion to sinus rhythm has been accomplished.

Present status of intrauterine treatment of hydrocephalus and its future

At a time when the intrauterine diagnosis of hydrocephalus is common and pioneering efforts of antenatal therapy are evolving, an assessment of intrauterine treatment of this disorder becomes pertinent. Consequently, the current status of the intrauterine treatment of fetal hydrocephalus is presented. The new data from the International Fetal Surgery Registry at the University of Manitoba in Winnipeg are discussed. The technical problems of antenatal shunting, the clinical trials, and experimental treatment are assessed. The prognostication and possible new approaches in intrauterine treatment of hydrocephalus are presented as well as the new diagnostic and surgical techniques. The outcome of the antenatal diagnosis and treatment of fetal hydrocephalus is evaluated.

Intrauterine treatment of fetal tachycardia

The presence of sustained tachycardia in a fetus can result in congestive heart failure, hydrops, and eventual fetal death. With the increased use of advanced technology in routine obstetric practice, fetal tachycardias are being diagnosed with greater frequency. Recently, administration of antiarrhythmic medications to the mother has been successful in slowing the fetal heart rate and preventing or reversing potentially lethal complications in the fetus. The medications that have been used to treat fetal tachycardia and their potential effects on the mother are discussed. A case study and nursing protocol are presented.

Intra-uterine tachycardia associated with multicystic encephalomalacia (MCE)

Multiple cystic brain lesions in neonates have been described as a result of a variety of causes. All events described thus far in association with multicystic encephalomalacia (MCE) seem to point to hypoxic-ischaemic injury as the common factor for this particular form of central nervous system damage. We describe a neonate in whom repeated, prolonged episodes of intrauterine tachycardia had been documented. Congestive heart failure and fetal hydrops were present at birth and MCE at the age of 13 wk. The obvious relationship between this child's intrauterine tachycardia and his MCE points to the fact that any fetus with prolonged tachycardia should be considered at risk of severe brain damage.

Twin transfusion syndrome: successful in utero treatment with digoxin

A pregnancy complicated by twin transfusion syndrome is presented. When signs of cardiac failure (edema, ascites and hydramnios) persisted in the recipient twin, maternal digoxin therapy was instituted at 27 weeks' gestation. The signs of failure resolved, and the twins were delivered electively by cesarean section at 34 weeks. At birth, the syndrome was confirmed by examination of the infants and placenta. Both infants survived. Digoxin therapy is recommended for fetal heart failure from circulatory overload in twin transfusion.

Nonimmune hydrops fetalis--a rational attitude of management

A rational attitude of management of the nonimmune hydrops fetalis (NIHF) is stressed in order to achieve an optimal outcome of both the mother and the newborn. Of the two cases reported, both had an underlying cardiac condition. The first was due to rapid supraventricular tachyarrhythmia and responded favorably to intrauterine medication with digoxin and the subsequent delivery of a well baby. In the second case, cesarean section was performed unnecessarily for a fetal indication, since the hydropic infant died soon after birth from a severe cardiac malformation which was not unequivocally diagnosed prior to birth.

New concepts and drugs in the treatment of congestive heart failure

This article seeks to make clear the basic differences in the treatment of heart failure between therapeutic maneuvers that are aimed at improving the mechanical loading conditions of the heart and those that are aimed at augmenting the fundamental contractile or inotropic state of the myocardium. Emphasis is placed on recognizing that treatment expectations must be viewed within an age- or maturity-dependent framework, since a diminished margin of cardiocirculatory reserve exists in the smallest and youngest patients that limits the extent of benefit that may be derived from diverse treatment approaches.

Fetal cardiac structure and function as studied by ultrasound

Present combined two-dimensional real-time and M-mode echocardiograph systems allow detailed analysis of fetal cardiac structure and function. Standard scanning planes for systematic investigation of various cardiac structures are described. There is a curvilinear increase in left ventricular volume (Qlv), stroke volume (Qlvs), and output Q'lv) during the last trimester of pregnancy with a mean Q'lv value at term of 126 +/- 11 ml/kg/min. Scanning for cardiac defects should preferably be done between 18 and 24 weeks of gestation. In a total of 444 patients referred to our ultrasound unit for ultrasonic analysis of fetal cardiac structure, a total of 13 cardiac defects were diagnosed. The incidence of structural cardiac defects present among those with fetal dysrhythmia was 15%.

Successful treatment of fetal supraventricular tachycardia with maternal digoxin therapy

In a fetus with supraventricular tachycardia (SVT) and cardiac failure, normal sinus rhythm (NSR) was restored with maternal digoxin therapy at 26 weeks' gestation. The diagnosis of cardiac failure was based on ultrasound evidence of ascites and scalp edema. Cardiac failure was attributed to the persistent SVT. The infant remained in NSR and was delivered at 36 weeks' gestation because of persistent ascites. Intracardiac anatomy was normal. This case confirms the usefulness of prenatal ultrasound examinations in the diagnosis of fetal SVT and cardiac failure and illustrates the effectiveness and safety of transplacental digoxin therapy in the management of fetal SVT.

Absence of the aortic valve: antenatal and postnatal two-dimensional and Doppler echocardiographic features

Antenatal and postnatal two-dimensional and gated pulsed Doppler echocardiography, beginning at 32 weeks' gestation, were used to evaluate the cardiovascular contribution to nonimmunologic hydrops in a gravida 1, para 0 nineteen year old woman. Antenatal two-dimensional imaging demonstrated a hypoplastic left heart variant of complete common atrioventricular (AV) canal. Antenatal gated pulsed Doppler examination of the fetal thoracoabdominal aorta revealed atypical pandiastolic retrograde flow. Postnatal noninvasive examination at 36 weeks' gestational age was unchanged from the prenatal study. Postmortem examination confirmed the noninvasive anatomic findings and revealed polysplenia. The mechanism of pandiastolic retrograde flow was attributable to "absence of the aortic valve," a previously unreported congenital cardiac anomaly, which resulted in severe antenatal and postnatal aortic regurgitation.

Nonimmune hydrops fetalis: antenatal diagnosis and management

An 8-year (1975-1982) study of 26 cases of nonimmune fetal hydrops revealed the main causes to be: anomalies (11/26), tachyarrhythmias (4/26), and twin-to-twin transfusion (4/26). The perinatal mortality was 19/26 (76%). Based on this series, and a review of the literature, a plan for the antenatal diagnosis and management of these cases is outlined.

Nonimmunologic hydrops fetalis

Twenty cases of nonimmunologic hydrops fetalis were reviewed. The incidence of nonimmunologic hydrops fetalis was 1/2,029 (20 cases in 40,588 deliveries). The diverse etiologies of nonimmunologic hydrops fetalis are demonstrated. The incidence of erythroblastosis fetalis caused by Rh isoimmunization declined markedly. The perinatal mortality rate was 14/18 or 78%. Prematurity, the presence of congenital anomalies, and the severity of hydrops fetalis contribute to this poor prognosis. However, a better understanding of the pathophysiology of hydrops fetalis, along with early detection by ultrasonography, preterm delivery with the liberal use of cesarean section, and availability of high-risk perinatal units, may enable us to improve the prognosis. A precise diagnosis should be attempted by careful antenatal and postnatal evaluation, so that accurate genetic counseling can be offered.

[Fetal heart. Present investigative means]

Non invasive exploration of the fetal heart has been greatly facilitated by utilisation of high resolution echography using pulsed Doppler combined with B-scan. Investigation of the fetal heart in human medicine opens three important fields of interest. Better knowledge of fetal hemodynamics. Measurement of fetal heart function. Recognition of congenital heart disease. Acquisition of some fundamental knowledge is required for an ultrasonic approach to fetal echocardiography. Embryogenetic data lead to an understanding of the periods of vulnerability for each cardiac segment, whereas an understanding of physiology of the fetal circulation helps to explain the consequences of fetal congenital heart diseases and the methods used to evaluate fetal cardiac function. One section is devoted to the etiology of congenital heart disease. The most important cardiopathies encountered in cases of chromosomal anomalies and genetic disease as well as those due to environmental causes are presented so that the echographist may relate the examination to the clinical picture. In most instances the diagnosis of congenital heart disease is made by routine morphologic scanning of the fetal heart. Indications are given for the best orientation of the scans. All echographists should have precise knowledge of the echographic semeiology of the normal heart. When a cardiopathy or an anomaly of cardiac rhythm are recognized or suspected, the examination should be repeated with help of a cardiopediatrician so as to make an exact diagnosis and take the right decision. Study of fetal heart function is the most recent field for progress and covers in addition to the evaluation of congenital heart disease the development of new parameters allowing recognition of fetal jeopardy. Pulsed Doppler has already allowed the acquisition of interesting facts and certainly is one of the most exciting new inroads for progress in the field of fetal cardiology.

Arrhythmia and structural abnormalities of the fetal heart

Thirty fetuses with cardiac arrhythmias were referred for ultrasonography. This included cross sectional and M mode echocardiography and pulsed Doppler analysis of the fetal heart. Three types of arrhythmias were observed: ectopic beats, tachyarrhythmias, and bradycardia. Ectopic beats were associated with cardiac structural abnormalities in two cases, resulting in fetal death in one. Tachycardia was not associated with structural defect, but death from cardiac failure occurred in one patient. Transplacental treatment for tachyarrhythmia was not successful in our experience. In the group with bradycardia four cases had congenital cardiac abnormalities and the mortality rate was 50%. When a fetal cardiac arrhythmia has been established careful structural and rhythm analysis is of vital importance in facilitating prognosis, planning of time and mode of delivery, and monitoring of transplacental treatment where indicated.

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.

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.

Intrauterine and postnatal atrial fibrillation in the Wolff-Parkinson-White syndrome

A fetal tachyarrhythmia was discovered at the thirty-second week of gestation of a 22-year old woman. Fetal echocardiography revealed atrial fibrillation with rapid ventricular rate, without any other demonstrable cardiac abnormality. In spite of therapeutic maternal blood levels of digoxin, the fetal ventricular rate and cardiac size increased, which prompted us to perform cesarean section at the thirty-fourth week of gestation. A baby with a Wolff-Parkinson-White syndrome but no other cardiac anomaly was delivered. Recurrent episodes of nonsustained atrial fibrillation with conduction over the accessory pathway occurred in the first hours of life. The Wolff-Parkinson-White pattern was not present on subsequent ECG recordings. The use of echocardiography in the diagnosis and management of this rare fetal tachyarrhythmia is emphasized.