title: Fetal cardiovascular hemodynamics in the presence of complete atrioventricular block.
abstract: OBJECTIVE
  Our purpose was to follow serially the hemodynamic adaptation to a congenital complete heart block in a human fetus.
  
  
  METHODS
  Longitudinal and serial M-mode and Doppler echocardiography over a 10-week span were performed on a fetus affected by complete heart block. Ventricular fractional shortening, size, and flow across the atrioventricualr valves and outflow tracts were determined starting at 20 weeks up to the time of delivery. Neonatal Doppler follow-up was performed at 2 days of life after implantation of a temporary pacemaker.
  
  
  RESULTS
  The right and left ventricles were able to adapt to sustained bradycardia by increasing their size. This ventricular dilatation was also associated with an increase in fractional shortening, which was associated with ventricualr free wall hypertrophy. When ventricualr heart rate decreased to 38 beats/min, fractional shortening decreased, this was associated with the rapid onset of ascites and pericardial effusion.
  
  
  CONCLUSIONS
  In the presence of sustained bradycardia ventricular output can increase, because this fetus was able to increase ventricular size and fractional shortening and wall thickness.
authors.affiliation: Department of Obstetrics and Gynecology, Bowman Gray School of Medicine of Wake Forest University, Winston-Salem, NC 27157.
authors.forename: J C
authors.initials: JC
authors.lastname: Veille
authors.forename: W
authors.initials: W
authors.lastname: Covitz
mesh_terms: D000328:Adult; D015150:Echocardiography, Doppler; D005260:Female; D005315:Fetal Diseases / Q000473:pathology / Q000503:physiopathology*; D005318:Fetal Heart / Q000000981:diagnostic imaging; D006327:Heart Block / Q000473:pathology / Q000503:physiopathology*; D006340:Heart Rate, Fetal; D006352:Heart Ventricles / Q000473:pathology; D006801:Humans; D011247:Pregnancy; D011248:Pregnancy Complications; D012859:Sjogren's Syndrome / Q000150:complications; D013967:Thyroiditis, Autoimmune / Q000150:complications; D016216:Ultrasonography, Prenatal; D016277:Ventricular Function, Left