Chapter 192 Fetal Heart Rate Testing: Tachycardia
INTRODUCTION
Description: Tachycardia is an increase in the baseline heart rate (generally above 160 beats per minute [bpm]). Mild tachycardia is generally defined as 161 to 180 bpm, and severe tachycardia as greater than 180 bpm, for more than 3 minutes.
ETIOLOGY AND PATHOGENESIS
Causes: Maternal fever (most common); intra-amniotic infection (fetal tachycardia may occur even before maternal fever is present); fetal congenital heart disease; depressed fetal oxygenation; fetal acidosis; fetal anemia or blood loss; medication effects (atropine, terbutaline); maternal hypotension.
