Fetal atrial Flutter & Supraventricular Tachycardia (FAST) Therapy Trial

Recruitment & Eligibility

Status: Authorised-recruitment may be ongoing or finished

Sex: All

Target Recruitment: 600

Inclusion Criteria

1) Mother has provided written informed consent to participate in the RCT
2) One of the following conditions: Fetal AF without hydrops (RCT A) or SVT without hydrops (RCT B) or SVT with hydrops (RCT C)
3) Tachyarrhythmia that is significant enough to justify immediate transplacental pharmacological treatment:
a) Tachycardia = 170 bpm during 100% of observation time of at least 30 minutes and gestational age <30 weeks
b) Tachycardia = 180 bpm during at least 10% of observation time of 30 minutes or longer
c) Tachycardia = 280 bpm, irrespective of SVA duration
d) Tachycardia with fetal hydrops, irrespective of SVA duration
4) Gestational age <37 0/7 weeks at time of enrollment
5) Untreated at time of enrollment
6) Singleton Pregnancy
7) Healthy mother with ± normal baseline findings including:
a) ECG without significant abnormalities (sinus rhythm; QTc = 0.47; PR = 0.2 sec; QRS: = 0.12 sec; isolated PACs or PVCs or isolated complete right bundle branch block allowed)
b) Resting heart rate = 50 bpm
c) Systolic BP = 85 mmHg

Are the trial subjects under 18? yes
Number of subjects for this age range: 600
F.1.2 Adults (18-64 years) no
F.1.2.1 Number of subjects for this age range 0
F.1.3 Elderly (>=65 years) no
F.1.3.1 Number of subjects for this age range 0

Exclusion Criteria

1) Fetal AF with hydrops (condition is too infrequent to be studied in a separate RCT)
2) Any maternal-fetal conditions associated with high odds of premature delivery and/or death (e.g. severe IUGR; premature rupture of membrane; life-threatening maternal disease (incl. pre-eclampsia; HELLP syndrome); severe congenital fetal abnormalities (T 13 or 18; surgery or death expected < 1 month))
3) Any relevant preexisting maternal heart condition (open heart surgery; sick sinus syndrome; long QT, Brugada syndrome; ventricular tachycardia; WPW syndrome; high-degree heart block; cardiomyopathy)
4) Relevant preexisting maternal obstructive airway disease including asthma
5) Maternal history of chronic substance abuse
6) Maternal intake of QT-prolonging medication
7) Maternal serum potassium level <3.3 mEq/L (at start of treatment)
8) Maternal ionized serum calcium level of <1 mmol/l (at start of treatment)
9) Maternal serum creatinine level >1.1 mg/dl

Study & Design

Study Type: Interventional clinical trial of medicinal product

Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
Main Objective: To establish and clarify the best treatment for the specific fetal heart condition including studying the side effect profile. The outcome will be determined by proportion of term deliveries of live born children with a normal cardiac rhythm.;Secondary Objective: To establish which treatment is the most effective and safest in each fetal group. ;Primary end point(s): The proportion of a term delivery (defined as 40 ± 2 gestational weeks) of a live-born child with a normal cardiac rhythm.;Timepoint(s) of evaluation of this end point: 40 ± 2 gestational weeks ; 260-294 days

Secondary Outcome Measures

Name	Time	Method

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