Color M-mode sonography for evaluation of fetal arrhythmias

Fetal Supraventricular Tachycardia: What the Adult Cardiologist Needs to Know

Fetal supraventricular tachycardia management is challenging, with consequences for both the fetus and the mother. If left untreated, fetal hydrops may ensue, at which point delivery and treatment of the arrhythmia is preferred. However, if the fetus is not at term nor near-term, significant doses of antiarrhythmics may be needed to achieve adequate transplacental bioavailability. Although digoxin has classically been the mainstay of treatment, the use of flecainide or sotalol as monotherapy or in combination with digoxin is being studied. Interdisciplinary team management and shared decision-making between the physician and patient are key to achieving successful outcomes. Adult cardiologists, particularly inpatient consultation services or through burgeoning cardio-obstetrics programs, may, in some practice settings, be asked to evaluate or comanage pregnant women with fetal arrhythmia.

Progression of left ventricular diastolic function in the neonate and early childhood from transmitral color M-mode filling analysis

BACKGROUND

We implemented sophisticated color M-mode analysis to assess age-dependent progression of left ventricular (LV) diastolic function.

METHODS

Normal infants were prospectively enrolled for serial echocardiograms at 1 week, 1 month, 6 months, 1 year, and 2 years. From color M-mode scans, propagation velocity (V_P), strength of filling (V_S), and intraventricular pressure difference (IVPD) in 3 segments along apex-to-mitral valve scan line were measured.

RESULTS

Age-wise comparisons of diastolic filling from 121 echocardiograms in 31 infants showed V_P (cm/s), V_S (cm²/s), and E-wave IVPD (mmHg) at 1 week to be 66.2 ± 11.9, 75.3 ± 19.9, and 1.5 ± 0.4, respectively, while V_P, V_S, and E-wave IVPD at 1 month were 80.3 ± 14.4, 101.2 ± 28.3, and 2.42 ± 1.1, respectively. There were significant differences in V_P and segmental IVPD between first week and first month (p < 0.005) and IVPD between the age groups (p < 0.001).

CONCLUSIONS

Comprehensive analysis of transmitral color M-mode data is feasible in infants, enabling calculation of pressure drop between the LV base and apex and strength of propagation from two distinct slopes. Profound changes very early followed by relatively constant filling mechanics in later infancy indicate significant LV maturation occurring during the first month of life.

IMPACT

We implemented sophisticated analytic methods for color M-mode echocardiography in infants to assess age- and dimension-dependent changes in left ventricular diastolic function. Comprehensive characterization of transmitral color M-mode flow was feasible, enabling calculation of pressure drop between left ventricular base and apex and strength of propagation. Left ventricular diastolic filling function has predictable maturational progression, with significant differences in the intraventricular pressure between infants from birth to 2 years. This study forms the basis for future studies to examine alteration of early diastolic filling in congenital heart disease.

Fetal arrhythmias: diagnosis and treatment

Fetal arrhythmias are common, and they may resolve spontaneously in majority of the cases. Sustained fetal arrhythmias associated with major structural heart disorders, hydrops fetalis, and fetal heart failure warrant intrauterine pharmaceutical conversion of heart rhythm or early pacemaker implant in order to avoid fetal demise. Fetal atrial flutter (AF) and supraventricular tachycardia (SVT) resemble in terms of the effects of intrauterine therapies. Digoxin is more suitable for rhythm conversion of fetal AF and SVT in fetuses free of hydrops fetalis, while sotalol shows better effects for those with hydrops fetalis. In fetal cases of atrioventricular blocks, an etiological treatment for the maternal antibody exposure by steroids could be an alternative remedy. In this article, the clinical diagnosis and treatment of fetal arrhythmias are presented, and advantages and disadvantages of antiarrhythmic agents for fetal arrhythmias are compared.

Fetal arrhythmias: Surveillance and management

Fetal arrhythmias warrant sophisticated surveillance and management, especially for the high-risk pregnancies. Clinically, fetal arrhythmias can be categorized into 3 types: premature contractions, tachyarrhythmias, and bradyarrhythmias. Fetal arrhythmias include electrocardiography, cardiotocography, echocardiography and magnetocardiography. Oxygen saturation monitoring can be an effective way of fetal surveillance for congenital complete AV block or SVT during labor. Genetic surveillance of fetal arrhythmias may facilitate the understanding of the mechanisms of the arrhythmias and provide theoretical basis for diagnosis and treatment. For fetal benign arrhythmias, usually no treatment but a close follow-up is need, while persistant fetal arrhythmias with congestive heart dysfunction or hydrops fetalis, intrauterine or postnatal treatments are required. The prognoses of fetal arrhythmias depend on the type and severity of fetal arrhythmias and the associated fetal conditions. Responses of fetal arrhythmias to individual treatments and clinical schemes are heterogeneous, and the prognoses are poor particularly under such circumstances.

Recommendations for Prenatal Echocardiography: A Report from International Prenatal Cardiology Collaboration Group

International Prenatal Cardiology Collaboration Group (IPCCG) links specialists from prenatal cardiology all over the world. In this recommendation we would like to focus on the fetal/prenatal echocardiography official report. So far many recommendations focused mainly on technical aspects of the fetal heart examination.