Heart rate is the number of cardiac cycles per minute and is a fundamental vital sign assessed during every echocardiographic and obstetric ultrasound examination. On echocardiography, heart rate affects many measurements and calculations, including cardiac output and diastolic filling parameters. In obstetric ultrasound, the fetal heart rate is documented at every examination, with the normal range between 110 and 160 beats per minute in the second and third trimesters. Abnormalities in heart rate, whether too fast (tachycardia) or too slow (bradycardia), can indicate various conditions requiring further evaluation and management.
Sonography Term