Prenatal diagnosis and In Utero treatment of Torsades de Pointes associated with congenital long QT syndrome

Cuneo, Bettina F.; Ovadia, Marc; Strasburger, Janette F.; Zhao, Hui; Petropulos, Tom; Schneider, John C.; Wakai, Ronald T.

doi:10.1016/s0002-9149(03)00343-6

Cited by 90 publications

(71 citation statements)

References 14 publications

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“…Heart failure, bradycardia, cardiac hypertrophy, and tachyarrhythmias are frequent features of the antenatal presentation of LQTS. 15 This case provides evidence that late-term fetal loss, like SIDS, can stem from unsuspected LQTS. Fetal demise after the sixth month of gestation is rare, occurring in Ͻ4 per 1000 pregnancies (National Center for Health Statistics, http:// www.cdc.gov/nchs/about/major/fetaldth/abfetal.htm), and known causes (Rh incompatibility, maternal autoimmune disease, thrombophilia, infection with TORCH pathogens, major congenital malformations) were excluded in each of the 3 pregnancies reported here.…”

Section: Discussionmentioning

confidence: 72%

Recurrent Third-Trimester Fetal Loss and Maternal Mosaicism for Long-QT Syndrome

et al. 2004

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Background-The importance of germ-line mosaicism in genetic disease is probably underestimated, even though recent studies indicate that it may be involved in 10% to 20% of apparently de novo cases of several dominantly inherited genetic diseases. Methods and Results-We describe here a case of repeated germ-line transmission of a severe form of long-QT syndrome (LQTS) from an asymptomatic mother with mosaicism for a mutation in the cardiac sodium channel, SCN5A. A male infant was diagnosed with ventricular arrhythmias and cardiac decompensation in utero at 28 weeks and with LQTS after birth, ultimately requiring cardiac transplantation for control of ventricular tachycardia. The mother had no ECG abnormalities, but her only previous pregnancy had ended in stillbirth with evidence of cardiac decompensation at 7 months' gestation. A third pregnancy also ended in stillbirth at 7 months, again with nonimmune fetal hydrops. The surviving infant was found to have a heterozygous mutation in SCN5A (R1623Q), previously reported as a de novo mutation causing neonatal ventricular arrhythmia and LQTS. Initial studies of the mother detected no genetic abnormality, but a sensitive restriction enzyme-based assay identified a small (8% to 10%) percentage of cells harboring the mutation in her blood, skin, and buccal mucosa. Cord blood from the third fetus also harbored the mutant allele, suggesting that all 3 cases of late-term fetal distress resulted from germ-line transfer of the LQTS-associated mutation. Conclusions-Recurrent late-term fetal loss or sudden infant death can result from unsuspected parental mosaicism for LQTS-associated mutations, with important implications for genetic counseling.

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Section: Discussionmentioning

confidence: 72%

Recurrent Third-Trimester Fetal Loss and Maternal Mosaicism for Long-QT Syndrome

et al. 2004

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“…Several studies have already reported the usefulness of fMCG in the diagnosis and management of fetal arrhythmias (5,7). Since fMCG provides detailed diagnosis of fetal arrhythmias, it is feasible to administer antiarrhythmic agents transplacentally based on accurate fMCG-based diagnosis (5,7,8).One disadvantage of the fMCG waveforms is their tendency to be largely affected by fetal orientation and movement, making it difficult to compare the waveforms among fetuses in various presentations. fMCG waveforms even fluctuate during measurement in the same fetus.…”

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confidence: 99%

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Standardization of the PQRST Waveform and Analysis of Arrhythmias in the Fetus Using Vector Magnetocardiography

et al. 2006

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Fetal magnetocardiography (fMCG) is useful for analysis of fetal cardiac events. However, fetal presentation and movement affect the fMCG waveform, making it difficult to standardize the waveform. The aim of this study was to investigate whether the use of vector magnetometers can compensate for these limitations. We studied 59 fetuses (gestational age, 22-40 wk, median, 32), including 41 with uncomplicated pregnancies and 18 with fetal cardiac disease. fMCG was recorded twice in each case, and the two waveforms were compared with each other in uncomplicated subjects to investigate the effects of fetal presentation. The superconducting quantum interference device (SQUID) system used in this study was a 12-channel vector magnetometer, by which the three components of the magnetic field (Bx, By, Bz) could be detected simultaneously at four recording points. By constructing the three components, a composite waveform (Bxyz) was obtained. The configuration of the composite waveforms was similar among normal fetuses always with positive polarity, independent of fetal presentation and movement. The difference in the time intervals (PR, QRS, and ventricular activation time [VAT]) between the first and second measurements was minimal in the composite waveforms (Bxyz) compared with that in each channel (Bx, By, Bz). Even before signal averaging, waveforms with high time resolution were recorded in at least one of the three components, making it possible to analyze fetal arrhythmias precisely. Our results indicate that vector magnetocardiography is potentially useful for standardization of the fMCG waveforms and to provide a more complete and accurate analysis of fetal arrhythmias. fMCG has gathered increasing interest in recent years, particularly its potential clinical application (1-5). fMCG has an advantage over fetal electrocardiography recorded on the maternal abdomen in detecting fetal heart signals because magnetic fields are far less insulated by vernix caseosa and less interfered by maternal signals (6). fMCG may also be advantageous to fetal echocardiography for precise analysis of arrhythmias because it reflects the electric not mechanical properties of the heart (3), although the latter is a more prevalent and valuable method with relevant time resolution. Several studies have already reported the usefulness of fMCG in the diagnosis and management of fetal arrhythmias (5,7). Since fMCG provides detailed diagnosis of fetal arrhythmias, it is feasible to administer antiarrhythmic agents transplacentally based on accurate fMCG-based diagnosis (5,7,8).One disadvantage of the fMCG waveforms is their tendency to be largely affected by fetal orientation and movement, making it difficult to compare the waveforms among fetuses in various presentations. fMCG waveforms even fluctuate during measurement in the same fetus. Furthermore, fMCG data somewhat vary depending on the superconducting quantum interference device (SQUID) system used and the protocol of data acquisition (9). Nevertheless, the magnetic field ...

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“…A number of recent reports show fMCG to be a highly effective means of diagnosing fetal arrhythmia. [1][2][3][4] In cases of lifethreatening fetal arrhythmia, it can improve clinical management 4,5 and enhance transitional care to the newborn period.…”

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Giant Fetal Magnetocardiogram P Waves in Congenital Atrioventricular Block

Strasburger

Cuneo

et al. 2004

Circulation

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Background-Cardiogram signal amplitude is a key index of hypertrophy but has not been investigated extensively in utero. In this study, magnetocardiography was used to assess P and QRS amplitude in normal subjects and subjects with fetal arrhythmia. Methods and Results-The study cohort consisted of 68 normal fetuses and 25 with various arrhythmias: 9 reentrant supraventricular tachycardia (SVT), 2 ventricular tachycardia (VT), 2 sinus tachycardia, 2 blocked atrial bigeminy, 2 congenital second-degree atrioventricular (AV) block, and 8 congenital complete AV block. Subjects with congenital AV block, all presenting with bradycardia, showed large QRS amplitude, exceedingly large P-wave amplitude, and long P-wave duration. The 2 subjects with VT, both with poor ventricular function, also exhibited large P waves. SVT was associated with only moderate signal amplitude elevation. Conclusions-The data imply that AV block in utero is accompanied by hypertrophy, which is more pronounced for the atria than the ventricles. We hypothesize that the hypertrophy results from a compensatory response associated with regulation of cardiac output and is likely to be observable in other arrhythmias and disease states. Magnetocardiography may be more sensitive than fetal echocardiography for detection of atrial hypertrophy in utero. Key Words: arrhythmia Ⅲ heart block Ⅲ hypertrophy Ⅲ electrophysiology Ⅲ tachycardia T he fetal magnetocardiogram (fMCG) is the magnetic analog of the fetal ECG. Although it is similar to fetal ECG in many respects, fMCG provides better signal quality as the result of the favorable transmission properties of magnetic signals. A number of recent reports show fMCG to be a highly effective means of diagnosing fetal arrhythmia. [1][2][3][4] In cases of lifethreatening fetal arrhythmia, it can improve clinical management 4,5 and enhance transitional care to the newborn period.Assessment of signal amplitude is an important aspect of cardiogram interpretation, largely because elevated amplitude is a primary indicator of hypertrophy; however, fMCG signal amplitude has not been used extensively in rhythm evaluation for several reasons. First, signal amplitude has not been adequately characterized even in normal fetuses. Prior normative studies have focused mainly on measurement of cardiac waveform intervals and the success rate of QRS detection. 6 -8 Assessment of P-wave amplitude has not been reported. Second, interpretation of signal amplitude is likely to be difficult. Compared with postnatal cardiograms, the fMCG exhibits highly variable signal amplitude as the result of its strong dependence on such factors as gestational age, fetal position, and detection coil configuration. Despite this, Horigome et al 9 succeeded in showing that QRS amplitude is significantly increased in cardiomegaly. In addition, our group has demonstrated the utility of transient signal amplitude variations for assessing fetal breathing movements, 10 fetal truncal movements, 11 and the association of fetal truncal movement with onset and...

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Prenatal diagnosis and In Utero treatment of Torsades de Pointes associated with congenital long QT syndrome

Cited by 90 publications

References 14 publications

Recurrent Third-Trimester Fetal Loss and Maternal Mosaicism for Long-QT Syndrome

Recurrent Third-Trimester Fetal Loss and Maternal Mosaicism for Long-QT Syndrome

Standardization of the PQRST Waveform and Analysis of Arrhythmias in the Fetus Using Vector Magnetocardiography

Giant Fetal Magnetocardiogram P Waves in Congenital Atrioventricular Block

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