What are sinusoidal patterns?

SINUSOIDAL PATTERN

24 It is a regular, smooth, undulating form typical of a sine wave that occurs with a frequency of two to five cycles per minute and an amplitude range of five to 15 bpm. It is also characterized by a stable baseline heart rate of 120 to 160 bpm and absent beat-to-beat variability.

What causes a sinusoidal pattern?

FETAL CONDITIONS ASSOCIATED WITH SHR PATTERN: SHR pattern has been reported with the following fetal conditions: (1) severe fetal anemia of several etiologies; (2) effects of drugs, particularly narcotics; (3) fetal asphyxia/hypoxia; (4) fetal infection; (5) fetal cardiac anomalies; (6) fetal sleep cycles; and (7)

What is sinusoidal pattern FHR?

Sinusoidal fetal heart rate pattern (FHR) is regarded by most authors as signifying a compromised fetus. In most cases, this is secondary to fetal anemia of different causes, usually Rh isoimmunization, more rarely to fetomaternal transfusion, bleeding vasa previa, placental chorioangioma, or traumatic amniocentesis.

What category is a sinusoidal pattern?

Category III: Abnormal The new NICHD guidelines label four FHR patterns as abnormal. One of the abnormal patterns is a sinusoidal heart rate, defined as a pattern of regular variability resembling a sine wave, with fixed periodicity of 3–5 cycles/ min and amplitude of 5–40 bpm.

What is sinusoidal pattern on CTG?

A sinusoidal pattern is an oscillating pattern which is typically smooth and regular. It has a relatively fixed period of 2-5 cycles per minute and has an amplitude of between 5 and 15 bpm around the baseline rate. Baseline variability is absent and there are no accelerations.

How long does a sinusoidal pattern last?

These authors noted that SHR pattern appeared approximately 19 min following alphaprodine administration and persisted for approximately 60 min. All infants were delivered with normal 5-minute Apgar scores without any perinatal deaths. In 27 cases of sinusoidal FHR pattern during labor, Ayromlooi et al.

How do I read my FHR?

When you’re looking at the screen, the fetal heart rate is usually on the top and the contractions at the bottom. When the machine prints out graph paper, you’ll see the fetal heart rate to the left and the contractions to the right. Sometimes it’s easier to read printouts by looking at them sideways.

What causes high fetal heart rate?

The most common reasons for a fetal heart rate that is too fast, known as tachycardia, are supraventricular tachycardia and atrial flutter. “With fast rhythms, we can give medications to the mom, which get to the baby through the placenta and convert the fetal heart rate back to normal,” Dr. Michelfelder said.

Why are sinusoidal signals important?

One reason for the importance of sinusoids is that they are fundamental in physics. Many physical systems that resonate or oscillate produce quasi-sinusoidal motion. Another reason sinusoids are important is that they are eigenfunctions of linear systems (which we’ll say more about in §4.1. 4).

Can narcotics cause sinusoidal pattern?

Other narcotics, such as butorphanol and nalbuphine, cause a sinusoidal fetal heart rate pattern that can mimic signs of hypoxia, although these drugs do not cause hypoxic injury.

What is pseudo sinusoidal pattern?

Pseudo-sinusoidal FHR patterns include all patterns in which undulatory waveforms, or regular FHR baseline oscillations of constant amplitude, alternate with episodes of normal baseline variability or activity [13].

What is FHR in pregnancy scan?

Fetal heart rate monitoring measures the heart rate and rhythm of your baby (fetus). This lets your healthcare provider see how your baby is doing. Your healthcare provider may do fetal heart monitoring during late pregnancy and labor. The average fetal heart rate is between 110 and 160 beats per minute.

What is a Category 3 fetal heart rate?

Objective. NICHD Category III (CIII) fetal heart rate tracing (FHR) is defined as having either sinusoidal pattern or absent baseline variability plus recurrent late decelerations, recurrent variable decelerations, or bradycardia.

What is low fetal heart rate?

In general, a low fetal heart rate is considered to be fewer than 100-120 beats per minute. This condition is also known as fetal bradycardia. A low fetal heart rate can be an early marker of potential miscarriage.

What causes low baseline fetal heart rate?

The most common causes of intrapartum bradycardia include poor uterine perfusion, maternal hypotension (e.g. after epidural placement), umbilical cord prolapse or occlusion, rapid fetal descent, tachysystole, placental abruption, or uterine rupture.

What causes sinusoidal CTG?

The pathophysiological basis of the sinusoidal pattern is incompletely understood, but it occurs in association with severe fetal anemia, as is found in anti-D allo-immunisation, fetal-maternal hemorrhage, twin-to-twin transfusion syndrome and ruptured vasa praevia.

What are baroreceptor decelerations?

Baroreceptor Decelerations – occur secondary to an. increase in fetal systemic blood pressure (occlusion of. umbilical arteries during compression of the cord) ⇒ Rapid fall then rapid recovery to baseline.

What is shouldering on CTG?

deceleration called “shouldering” – denotes healthy fetus. — progression to: tachycardia, ↓ variability, loss or exaggerated “shouldering”, late recovery, biphasic deceleration –