FAST Trial Registry: Prospective Observational Cohort Study of Fetal Atrial Flutter & Supraventricular Tachycardia
The FAST Trial Registry is a prospective observational cohort study of fetuses with a new diagnosis of atrial flutter (AF) or supraventricular tachycardia (SVT) that is severe enough to consider prenatal treatment (see eligibility criteria below). Aims of the Registry include to establish a large clinical database to determine and compare the efficacy and safety of different prenatal treatment strategies including observation without immediate treatment, transplacental antiarrhythmic fetal treatment and direct fetal treatment from the time of tachycardia diagnosis to death, neonatal hospital discharge or to a maximum of 30 days after birth.
• Mother has provided written informed consent to participate
• Fetal AF or SVT with or without hydrops
• Tachyarrhythmia that is significant enough to justify immediate transplacental pharmacological treatment:
‣ Tachycardia ≥ 180 bpm during at least 10% of observation time of 30 minutes or longer
⁃ Tachycardia ≥ 170 bpm during +100% of time (≤ 30 0/7 weeks of gestation)
⁃ Tachycardia ≥ 280 bpm (irrespective of SVA duration)
⁃ SVT with fetal hydrops (irrespective of duration)
• Gestational age \<36 0/7 weeks at time of enrollment
• Singleton Pregnancy
• Healthy mother with ± normal pre-treatment cardiovascular findings:
‣ ECG within normal range (sinus rhythm; QTc ≤ 0.47; PR ≤ 0.2 sec; QRS: ≤ 0.12 sec; insignificant anomalies; isolated premature beats; isolated complete right bundle
⁃ Maternal resting heart rate ≥ 50 bpm
⁃ Maternal systolic BP ≥ 85 mmHg