Fetal and Neonatal Magnetophysiology

Completed

Conditions: Long QT Syndrome
Fetal Arrhythmia
Abnormality in Fetal Heart Rate or Rhythm

Interventions: Device: magnetocardiography
Device: postnatal ECG
Device: fetal echocardiography

Registration Number: NCT01903564

Lead Sponsor: University of Wisconsin, Madison

Brief Summary: Fetal research and clinical practice has been hampered by a lack of suitable investigational techniques. Currently, ultrasound is the only widely used method of studying fetal anatomy and physiology, but it has significant limitations for assessment of cardiac rhythm. The proposed study will allow us to investigate fetal magnetocardiography (fMCG) as a new tool for the study of normal and abnormal fetal heart rate and rhythm, with a goal of demonstrating probable benefit from use of the device in patients with serious fetal arrhythmia. We propose a study that will last 1-2 years and will provide data to aid in assessing the safety and effectiveness of fMCG for diagnosis and management of patients with abnormal fetal heart rate and rhythm. We hope that the data from the study will support a Humanitarian Device Exemption (HDE) application for the subject device. The safety and efficacy study designs are described below. High-risk subjects will undergo echocardiography as part of their routine clinical management, and our results will be compared to the echocardiography results, as well as with postnatal ECG, when available. (Since many arrhythmias resolve prior to birth, either due to resolution of disease or due to treatment, only a limited number of diseases allow postnatal comparison). For rhythms that persist after birth, the diagnostic utility of fMCG and echocardiography will be assessed by computing the sensitivity (Sn) and specificity (Sp) relative to postnatal ECG for the following prenatal modalities: (i) the fMCG, (ii) the original (referral) echo, (iii) if available, the in-lab echocardiogram at the time of the fMCG study. Secondary endpoints will assess changes in diagnosis and in clinical management due to the additional information provided by fMCG, compared to the information provided by echocardiography alone.

Detailed Description: Not available

Recruitment & Eligibility

Status: COMPLETED

Sex: Female

Target Recruitment: 39

Inclusion Criteria

Normal subjects: normal, healthy adult women with uncomplicated pregnancies

High-risk cohort: The primary inclusion criterion is diagnosis of serious fetal arrhythmia, which is defined as sustained low or high heart rate. Low heart rate, or bradycardia, and high heart rate, or tachycardia, are based on normative values for gestation (usually below 110 -120 beats/min, or above 160-180 beats/min). Intermittent bradycardia and tachycardia are also important to detect because these arrhythmias may become incessant over the course of pregnancy and have implications for patient management. Abnormal repolarization, such as long QT syndrome (LQTS), is another important class of arrhythmia. Fetuses with a family history of LQTS or a suspicious rhythm (low heart rate, intermittent AV block, or ventricular tachycardia) will also be studied.

Exclusion Criteria

The pregnant women subjects must by aged 18 or older. High-risk subjects cannot participate if their physician in consultation with the lead physician of the study does not grant permission for them to participate in the study due to risk of travel or other reason.

Study & Design

Study Type: OBSERVATIONAL

Study Design: Not specified

Arm && Interventions

Group	Intervention	Description
high-risk	fetal echocardiography	pregnant women with pregnancies complicated by fetal arrhythmia or the risk of fetal arrhythmia
high-risk	magnetocardiography	pregnant women with pregnancies complicated by fetal arrhythmia or the risk of fetal arrhythmia
normal	fetal echocardiography	pregnant women with uncomplicated pregnancies
normal	magnetocardiography	pregnant women with uncomplicated pregnancies
high-risk	postnatal ECG	pregnant women with pregnancies complicated by fetal arrhythmia or the risk of fetal arrhythmia

Primary Outcome Measures

Name	Time	Method
Percentage of Subjects Experiencing Adverse Events Unrelated to Device	15 weeks' gestation till up to 1 month after birth	Percentage of subjects experiencing adverse events unrelated to device
Percentage of Subjects Experiencing Adverse Events Related to Device	15 weeks' gestation till up to 1 month after birth	Percentage of Subjects Experiencing Adverse Events Related to Device
Percentage of Subjects Experiencing Symptoms	15-40 weeks' gestation	Percentage of subjects experiencing symptoms
Number of Participants With Concordance of fMCG and Postnatal ECG for Diagnosis of Long QT Syndrome	Birth to age 1 week	Number of Participants with Concordance of fMCG and Postnatal ECG for Diagnosis of Long QT Syndrome based on measurement of rate-corrected QT interval (QTc)

Secondary Outcome Measures

Name	Time	Method
Percentage of Fetuses With a Family History of Long QT Syndrome Who a Change in Diagnosis Due to fMCG	15 weeks' gestation to birth	Percentage of fetuses with a family history of long QT syndrome who a change in diagnosis due to fMCG
Percentage of Fetuses With a Family History of Long QT Syndrome Who Had a Change in Management Due to fMCG	15 weeks' gestation to birth	Percentage of fetuses with a family history of long QT syndrome who had a change in management due to fMCG