Fetal Arrhythmia, Abnormality in Fetal Heart Rate or Rhythm, Long QT Syndrome
Conditions
Keywords
fetus, fetal arrhythmia, fetal heart rate, long QT syndrome
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.
Interventions
DEVICEmagnetocardiography
recording of magnetic heart activity
DEVICEpostnatal ECG
postnatal ECG
DEVICEfetal echocardiography
fetal echocardiography
Sponsors
Shared Medical Technology, Inc.
Medical College of Wisconsin
National Heart, Lung, and Blood Institute (NHLBI)
University of Wisconsin, Madison
Study design
Observational model
COHORT
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
FEMALE
Age
18 Years to 60 Years
Healthy volunteers
Yes
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.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Percentage of Subjects Experiencing Symptoms | 15-40 weeks' gestation | Percentage of subjects experiencing symptoms |
| 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 |
| 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) |
| 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 |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| 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 |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Normal pregnant women with uncomplicated pregnancies
magnetocardiography: recording of magnetic heart activity
fetal echocardiography: fetal echocardiography | 10 |
| High-risk pregnant women with pregnancies complicated by fetal arrhythmia or the risk of fetal arrhythmia
magnetocardiography: recording of magnetic heart activity
postnatal ECG: postnatal ECG
fetal echocardiography: fetal echocardiography | 29 |
| Total | 39 |
Baseline characteristics
| Characteristic | High-risk | Normal | Total |
|---|---|---|---|
| Age, Categorical <=18 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical >=65 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical Between 18 and 65 years | 29 Participants | 10 Participants | 39 Participants |
| Age, Continuous | 32.0 years | 31.8 years | 31.9 years |
| Region of Enrollment United States | 29 participants | 10 participants | 39 participants |
| Sex: Female, Male Female | 29 Participants | 10 Participants | 39 Participants |
| Sex: Female, Male Male | 0 Participants | 0 Participants | 0 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 0 / 10 | 0 / 29 |
| other Total, other adverse events | 0 / 10 | 0 / 29 |
| serious Total, serious adverse events | 0 / 10 | 2 / 29 |
Outcome results
Primary
Number of Participants With Concordance of fMCG and Postnatal ECG for Diagnosis of Long QT Syndrome
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)
Time frame: Birth to age 1 week
Population: Fetuses with a family history of long QT syndrome
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Normal | Number of Participants With Concordance of fMCG and Postnatal ECG for Diagnosis of Long QT Syndrome | 0 Participants |
| High-risk | Number of Participants With Concordance of fMCG and Postnatal ECG for Diagnosis of Long QT Syndrome | 6 Participants |
Primary
Percentage of Subjects Experiencing Adverse Events Related to Device
Percentage of Subjects Experiencing Adverse Events Related to Device
Time frame: 15 weeks' gestation till up to 1 month after birth
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Normal | Percentage of Subjects Experiencing Adverse Events Related to Device | 0 Participants |
| High-risk | Percentage of Subjects Experiencing Adverse Events Related to Device | 0 Participants |
Primary
Percentage of Subjects Experiencing Adverse Events Unrelated to Device
Percentage of subjects experiencing adverse events unrelated to device
Time frame: 15 weeks' gestation till up to 1 month after birth
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Normal | Percentage of Subjects Experiencing Adverse Events Unrelated to Device | 0 Participants |
| High-risk | Percentage of Subjects Experiencing Adverse Events Unrelated to Device | 10 Participants |
Primary
Percentage of Subjects Experiencing Symptoms
Percentage of subjects experiencing symptoms
Time frame: 15-40 weeks' gestation
Population: Symptoms include premature labor, vaginal bleeding, uterine cramping, nausea/vomiting, dizziness, dsypnea, syncope, palpitations, or fatigue during the study session.
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Normal | Percentage of Subjects Experiencing Symptoms | 0 Participants |
| High-risk | Percentage of Subjects Experiencing Symptoms | 0 Participants |
Secondary
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 a change in diagnosis due to fMCG
Time frame: 15 weeks' gestation to birth
Population: Fetuses with family history of LQTS
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Normal | Percentage of Fetuses With a Family History of Long QT Syndrome Who a Change in Diagnosis Due to fMCG | 0 Participants |
| High-risk | Percentage of Fetuses With a Family History of Long QT Syndrome Who a Change in Diagnosis Due to fMCG | 3 Participants |
Secondary
Percentage of Fetuses With a Family History of Long QT Syndrome Who Had a Change in Management Due to fMCG
Percentage of fetuses with a family history of long QT syndrome who had a change in management due to fMCG
Time frame: 15 weeks' gestation to birth
Population: Fetuses with a family history of fetal long QT syndrome
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Normal | Percentage of Fetuses With a Family History of Long QT Syndrome Who Had a Change in Management Due to fMCG | 0 Participants |
| High-risk | Percentage of Fetuses With a Family History of Long QT Syndrome Who Had a Change in Management Due to fMCG | 2 Participants |