TY  - CHAP
M1  - Book, Section
TI  - Tachyarrhythmias
A1  - Bianchi, Diana W.
A1  - Crombleholme, Timothy M.
A1  - D'Alton, Mary E.
A1  - Malone, Fergal D.
PY  - 2015
T2  - Fetology: Diagnosis and Management of the Fetal Patient, 2e
AB  - Key  PointsFetal  tachyarrhythmias  include  isolated  extrasystoles,  supraventricular  tachycardia,  and  atrial  flutter.Approximately  1%  of  fetuses  are  diagnosed  with  an  arrhythmia.Isolated  extrasystoles  are  the  most  common  tachyarrhythmias  and  are  for  the  most  part  benign.Supraventricular  tachycardia  is  the  most  common  serious  dysrhythmia  detected  prenatally.  The  majority  are  re-entrant  and  are  identified  by  a  fetal  heart  rate  of  greater  than  200  beats  per  minute  with  one-to-one  atrial-to-ventricular  activity.  Congenital  heart  disease  is  associated  with  this  arrhythmia  5%  to  10%  of  cases.The  rate  with  atrial  flutter  is  usually  between  300  and  500  beats  per  minute.  The  ventricular  response  depends  on  the  degree  of  atrioventricular  block.  This  dysrhythmia  has  a  poor  prognosis  due  to  the  fact  that  it  is  associated  with  hydrops  and  with  congenital  heart  defects.Fetal  dysrhythmias  have  the  potential  for  serious  sequelae  including  fetal  hydrops.Fetal  arrhythmias  are  diagnosed  by  fetal  echocardiography  that  includes  M-mode  assessment  and  Doppler  analysis.  A  full  anatomical  survey  including  a  detailed  survey  of  the  fetal  heart  should  also  be  performed.Although  premature  atrial  and  ventricular  contractions  are  considered  benign,  sustained  tachyarrhythmia  may  develop  in  up  to  1%  of  fetuses  diagnosed  with  this  condition.  Thus,  serial  fetal  heart  rate  auscultation  is  suggested.Spontaneous  resolution  of  supraventricular  tachycardia  has  been  reported.For  the  most  part,  fetal  supraventricular  tachycardia  associated  with  congenital  heart  defects  has  been  associated  with  a  poor  prognosis.Gestational  age  is  an  important  factor  when  determining  how  best  to  manage  a  fetal  dysrhythmia.Digoxin  is  the  first-line  therapy  for  isolated  fetal  tachyarrhythmia.  Procainamide,  flecainide,  and  sotolol  are  reserved  for  second-line  treatment.If  hydrops  is  concomittent,  the  tachyarrhythmia  may  take  longer  to  resolve.Intermittent  fetal  tachycardia  without  evidence  of  fetal  hemodynamic  compromise  can  be  observed  closely  instead  of  undergoing  medical  therapy.Refractory  cases  to  maternal  medical  management  have  been  treated  with  direct  fetal  therapy.The  newborn  should  be  evaluated  thoroughly  for  signs  of  cardiac  abnormalities.  Approximately  50%  of  infants  will  relapse  after  birth.  
SN  - 
PB  - McGraw-Hill Education
CY  - New York, NY
Y2  - 2024/04/19
UR  - obgyn.mhmedical.com/content.aspx?aid=1106397743
ER  -