Sinusoidal Heart Rate Pattern Research Articles

Remifentanil attenuates cardiac dysfunction, lipid peroxidation and immune disorder in rats with isoproterenol-induced myocardial injury via JNK/NF-KB p65 inhibition.

BackgroundMyocardial injury caused by myocardial ischemia (MI) is still a severe condition that can result in apoptosis, oxidative stress, and inflammation. Remifentanil is a selective, ultra-short-acting, µ-opioid receptor agonist opioid. It can improve sinusoidal heart rate patterns in the fetus, for bupivacaine-induced cardiotoxicity, and with lipopolysaccharide (LPS)-induced cardiomyocytes injuries. This study aimed to explore the cardioprotective effects of remifentanil in MI model rats.MethodsSprague Dawley (SD) rats were split into five groups at random, including a control group, Isop group, low-dose remifentanil treatment group (10 µg/kg), medium-dose remifentanil treatment group (20 µg/kg), and a high-dose remifentanil treatment group (40 µg/kg). The MI model was achieved by subcutaneously injecting rats with isoproterenol (85 mg/kg) for two consecutive days. With the expression of apoptotic molecules, myocardial systolic function index, inflammation, antioxidant enzymes, and the myocardial enzyme taken into account, the data was analyzed.ResultsAfter treatment with remifentanil, the left ventricular wall thickness (LVWT), left ventricular end-systolic volume (LVESV), left ventricular ejection fraction (LVEF), fraction shortening (FS), and heart rate (HR) were significantly increased in comparison with the Isop group. Creatine kinase-MB (CK-MB), Mb, and cTnl expressions were decreased. Meanwhile, the levels of cleaved caspase-3 and caspase-9 were decreased. Remarkably, the levels of reactive oxidative species (ROS), malondialdehyde (MDA), and lactate dehydrogenase (LDH) were observed to be repressed, while the levels of superoxide dismutase (SOD) was significantly increased. More importantly, the levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-6, and interferon (IFN)-γ were decreased.ConclusionsRemifentanil has significant potential as a therapeutic intervention strategy for ameliorating myocardial injury after MI and these findings provide the rationale for further clinical studies.

Trust the heart to save the brain: changes in heart rate patterns have the potential to be a biomarker for hypoxic ischaemic brain injury.

Trust the heart to save the brain: changes in heart rate patterns have the potential to be a biomarker for hypoxic ischaemic brain injury.

Early sinusoidal heart rate patterns and heart rate variability to assess hypoxia-ischaemia in near-term fetal sheep.

•Therapeutic hypothermia needs to be started as early as possible in the first 6h after acute injury caused by hypoxia-ischaemia (HI), but the severity and timing of HI are often unclear. In this study we evaluated whether measures of heart rate variability (HRV) might provide early biomarkers of HI. •The duration but not magnitude of suppression of HRV power and conversely increased sample entropy of the heart rate were associated with severity of HI, such that changes in the first 3h did not discriminate between groups. •Relative changes in HRV power bands showed different patterns between groups and therefore may have the potential to evaluate the severity of HI. •Aberrant fetal heart rate patterns and increased arginine vasopressin levels in the first hour after moderate and severe HI were correlated with loss of EEG power after 3days' recovery, suggesting potential utility as early biomarkers of outcome. Therapeutic hypothermia is partially neuroprotective after acute injury caused by hypoxia-ischaemia (HI), likely because the timing and severity of HI are often unclear, making timely recruitment for treatment challenging. We evaluated the utility of changes in heart rate variability (HRV) after HI as biomarkers of the timing and severity of acute HI. Chronically instrumented fetal sheep at 0.85 gestational age were exposed to different durations of umbilical cord occlusion to produce mild (n=6), moderate (n=8) or severe HI (n=8) or to sham occlusion (n=5). Heart rate (HR) and HRV indices were assessed until 72h after HI. All HI groups showed suppressed very low frequency HRV power and elevated sample entropy for the first 3h; more prolonged changes were associated with greater severity of HI. Analysis of relative changes in spectral power showed that the moderate and severe groups showed a shift towards higher HRV frequencies, which was most marked after severe HI. This shift was associated with abnormal rhythmic HR patterns including sinusoidal patterns in the first hour after HI, and with elevated plasma levels of arginine vasopressin, which were correlated with subsequent loss of EEG power by day3. In conclusion, absolute changes in HRV power in the first 3h after acute HI were not significantly related to the severity of HI. The intriguing relative shift in spectral power towards higher frequencies likely reflects greater autonomic dysfunction after severe HI. However, sinusoidal HR patterns and elevated vasopressin levels may have utility as biomarkers of severe HI.

Sinusoidal heart rate pattern: Reappraisal of its definition and clinical significance.

To address the clinical significance of sinusoidal heart rate (SHR) pattern and review its occurrence, define its characteristics, and explain its physiopathology. In 1972, Manseau et al. and Kubli et al. described an undulating wave form alternating with a flat or smooth baseline fetal heart rate (FHR) in severely affected, Rh-sensitized and dying fetuses. This FHR pattern was called 'sinusoidal' because of its sine waveform. Subsequently, Modanlou et al. described SHR pattern associated with fetal to maternal hemorrhage causing severe fetal anemia and hydrops fetalis. Both Manseau et al. and Kubli et al. stated that this particular FHR pattern, whatever its pathogenesis, was an extremely significant finding that implied severe fetal jeopardy and impending fetal death. UNDULATING FHR PATTERN: Undulating FHR pattern may be due to the following: (1) true SHR pattern; (2) drugs; (3) pre-mortem FHR pattern; (4) pseudo-SHR pattern; and (5) equivocal FHR patterns. 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) sucking and rhythmic movements of fetal mouth. DEFINITION OF TRUE SHR PATTERN: Modanlou and Freeman proposed the following definition for the interpretation of true SHR pattern: (a) stable baseline FHR of 120-160 bpm; (b) amplitude of 5-15 bpm, rarely greater; (c) frequency of 2-5 cycles per minute; (d) fixed or flat short-term variability; (e) oscillation of the sinusoidal wave from above and below a baseline; and (f) no areas of normal FHR variability or reactivity. Since its early recognition, the physiopathology of SHR became a matter of debate. Murata et al. noted a rise of arginine vasopressin levels in the blood of posthemorrhagic/anemic fetal lamb. Further works by the same authors revealed that with chemical or surgical vagotomy, arginine vasopressin infusion produced SHR pattern, thus providing the role of autonomic nervous system dysfunction combined with the increase in arginine vasopressin as the etiology. SHR is a rare occurrence. A true SHR is an ominous sign of fetal jeopardy needing immediate intervention. The correct diagnosis of true SHR pattern should also include fetal biophysical profile and the absence of drugs such as narcotics.

Intrapartum fetal heart rate tracings: accuracy of interpretation is unaffected by level of providers’ training

Objective: The ACOG Technical Bulletin of July 1995 suggests that intrapartum fetal heart rate patterns should be interpreted as reassuring or nonreassuring. The bulletin describes a nonreassuring fetal heart tracing (FHT) as having one or more of the following components: abnormal baseline (ie, tachycardia, decreased variability); the presence of variable decelerations that are persistent, progressively deeper and longer lasting; late decelerations that are persistent; prolonged deceleration greater than 60 seconds; and a sinusoidal heart rate pattern. A reassuring FHT implies the absence of these patterns. We sought to investigate the accuracy of interobserver interpretation of FHT in labor. Method: Three hundred sixty intrapartum FHTs were evaluated by obstetric residents, attendings, nurses, and maternal–fetal medicine specialists (MFMs). Tracings were accompanied by a questionnaire addressing classification of FHT, a proposed approach, and anticipated fetal outcome. Participants were blinded to actual outcomes. Results: 1) Of reassuring FHTs, 96% were identified with no significant difference in rate of identification in each provider group; 2) 80% of nonreassuring patterns were identified with similar rates of identification within each provider group; and 3) there was no significant interobserver difference in the correct interpretation of tracings between residents (75.5%), attendings (81.9%), MFMs (77.4%), and nurses (85%). Conclusion: Our data suggest that theTechnical Bulletin’s recommended classification of intrapartum FHT tracings as reassuring versus nonreassuring is successful in providing a simple, accurate method of recognition regardless of the providers’ level of obstetric training.

Power spectral analysis of R-R interval variability before and during the sinusoidal heart rate pattern in fetal lambs

Objective: The appearance of the sinusoidal heart rate pattern found on fetal cardiotocograms has not been fully explained, either physiologically or clinically. In this study we performed power spectral analysis on the sinusoidal heart rate pattern obtained by administration of arginine vasopressin and atropine sulfate to investigate its frequency components in fetal lambs with long-term instrument implantation. Study Design: Eleven tests were performed in 4 fetal lambs at 120 to 130 days’ gestation. An artificial sinusoidal heart rate pattern was obtained by administration of atropine sulfate and arginine vasopressin in 9 tests. An autoregression model was used to compare the spectral patterns before and during the sinusoidal heart rate pattern. Results: Marked decreases in low-frequency (0.025-0.125 cycles/beat) and high-frequency (0.2-0.5 cycles/beat) areas were observed in the presence of the sinusoidal heart rate pattern. However, there were no significant changes in the very-low-frequency area (0.01-0.025 cycles/beat), which corresponds to the frequency of the sinusoidal heart rate pattern. Conclusion: The sinusoidal heart rate pattern may represent a very low-frequency component inherent in fetal heart rate variability that appears when low- and high-frequency components are reduced as a result of strongly suppressed autonomic nervous activity. (Am J Obstet Gynecol 2000;182:1227-32.)

Two sinusoidal heart rate patterns in fetal lambs undergoing extracorporeal membrane oxygenation

Objectives: The study analyzed the phase relationship between fetal heart rate and arterial blood pressure fluctuation during sinusoidal heart rate patterns in fetal lambs. Study Design: Thirty-two fetal lambs were placed on extracorporeal membrane oxygenation after cesarean delivery at ages ranging between 113 and 133 days’ gestation. Sinusoidal heart rate patterns persisting for >10 minutes were analyzed. The relationships between the sinusoidal heart rate cycles and the arterial blood pressure cycles were quantitatively expressed in degrees by timing the zenith and the nadir of each and assigning a phase-angle index (with 0 [360] and 180 degrees being synchronized and reciprocal, respectively). Simultaneous blood samples were taken from the 4 different sites of the fetal circulation for blood gas and acid-base analysis when the sinusoidal heart rate pattern appeared. Regional cerebral blood flow was determined by means of the colored microsphere technique in 8 fetuses with sinusoidal patterns and 7 control fetuses. Results: Sinusoidal heart rate patterns were observed in 13 (40.6%) of the 32 fetal lambs. Two types of fetal heart rate and arterial blood pressure relationship could be recognized during sinusoidal pattern, the reciprocal type (n = 7) and the synchronized type (n = 9). A reciprocal type of sinusoidal pattern preceded a synchronized type pattern in 3 lambs that showed sinusoidal patterns at different stages of the experiment. The reciprocal type was associated with a higher baseline heart rate and amplitude of the sinusoidal heart rate pattern than was the synchronized type. The synchronized type was associated with a lower pH and base excess than was the reciprocal type. The cerebral blood flow in the medulla oblongata was significantly lower during the synchronized type pattern than during the reciprocal type pattern. Conclusion: There are 2 types of sinusoidal heart rate pattern. A synchronized type sinusoidal heart rate pattern may indicate more advanced fetal compromise than is associated with a reciprocal type pattern. (Am J Obstet Gynecol 1999;180:462-8.)

Severe fetomaternal hemorrhage: a review.

The etiology, clinical presentation, obstetrical antecedents, and outcome of pregnancies complicated by large fetomaternal hemorrhage (FMH) were reviewed by doing a MEDLINE search from 1966 to the present and manual search before 1966. One hundred thirty-four infants with FMH > 50 dl were reported in the literature. The primary variables: birth weight, gestational age, presence of sinusoidal fetal heart rate pattern, decrease or absent fetal body movements (FBM) estimated the amount of fetomaternal bleeding and the pretransfusion hemoglobin. Other variables included the condition of the infants at birth, erythroblasts, and reticulocyte blood counts at birth, as well as the year of publication. Thirty-five of the 134 cases were preterm. Twenty infants born to mothers reporting decreased or absent FBM survived. FBM was absent in 17 cases for a period ranging between 24 hours and 7 days. In this group, six infants survived, five were stillborn, and five died in the neonatal period. A sinusoidal heart rate (SHR) pattern was reported in 21 cases. A SHR pattern was associated with decreased FBM in 13 cases (39.3 percent). Fifteen cases with sinusoidal fetal heart rate pattern survived (71.4 percent). Both decreased or absent FBM and SHR patterns were reported more often in 1990 or later than before 1990 (P < .0017 and P < .008, respectively). The cause of FMH was not known in 82 percent of the cases. The most common presenting symptoms of FMH were anemia at birth (35.2 percent), decreased or absent FBM (26.8 percent), and unexpected stillbirths (12.5 percent). Seventeen intrauterine transfusions were performed in nine cases (eight survived). A negative correlation was found between pretransfusion hemoglobin and FMH (r = -0.35; P = .0019). No significant difference was found between the cases with FMH of > 200 ml or < 200 ml. Thus, decreased or absent FBM, SHR pattern, or hydrops fetalis are late signs of FMH. Other means of early detection are needed. The role of intrauterine transfusion (IUT) needs to be better defined. The inadequate outcome data indicate the need to follow infants born with large FMH into childhood to document the effect on the central nervous system.

Massive fetomaternal hemorrhage

We evaluated the potential prognostic factors for fetomaternal hemorrhage (FMH). Sinusoidal heart rate pattern and decrease in fetal movement are considered important signs of FMH. However these findings were detected in only two of six cases of FMH and were thought to be late signs of FMH. Fetal hemoglobin levels in the maternal circulation for infants born alive following FMH were less than 5%. Our findings suggest that this amount of blood loss could cause fetal death.

Experimentally induced intermittent sinusoidal heart rate pattern and sleep cycle in fetal lambs

OBJECTIVE: Intermittent sinusoidal heart rate pattern, an early indicator of fetal anemia, has been speculated to have a positive correlation with fetal sleep cycles. To test this hypothesis, intermittent sinusoidal heart rate patterns were produced experimentally with arginine vasopressin in six methylatropinized fetal lambs that were demonstrating clear rapid-eye-movement and non-rapid-eye-movement sleep cycling. STUDY DESIGN: Eleven trials of arginine vasopressin infusion (40 to 160 mIU per body per minute) were performed on each of six chronically instrumented fetal lambs subsequent to parasympathetic blocking doses of methylatropine (300 to 400 μg). An intermittent sinusoidal heart rate pattern was observed in relation to fetal sleep cycles. RESULTS: Alteration between rapid-eye-movement and non-rapid-eye-movement sleep was observed in methylatropinized fetuses. In the six fetuses that showed intermittent sinusoidal heart rate patterns subsequent to arginine vasopressin infusion, the fetal heart rate tracing and fetal electrocorticogram demonstrated alternate sinusoidal pattern and reactive heart rate patterns during high- and low-voltage electrocorticogram activity, respectively. CONCLUSION: These findings support the hypothesis that fetal sleep cycling has a positive correlation with the periodic appearance of intermittent sinusoidal heart rate patterns. (AM J OBSTET GYNECOL 1994;170:1421-4.)

Experimentally induced intermittent sinusoidal heart rate pattern and sleep cycle in fetal lambs

<b>OBJECTIVE:</b> Intermittent sinusoidal heart rate pattern, an early indicator of fetal anemia, has been speculated to have a positive correlation with fetal sleep cycles. To test this hypothesis, intermittent sinusoidal heart rate patterns were produced experimentally with arginine vasopressin in six methylatropinized fetal lambs that were demonstrating clear rapid-eye-movement and non-rapid-eye-movement sleep cycling. <b>STUDY DESIGN:</b> Eleven trials of arginine vasopressin infusion (40 to 160 mlU per body per minute) were performed on each of six chronically instrumented fetal lambs subsequent to parasympathetic blocking doses of methylatropine (300 to 400 μg). An intermittent sinusoidal heart rate pattern was observed in relation to fetal sleep cycles. <b>RESULTS:</b> Alteration between rapid-eye-movement and non-rapid-eye-movement sleep was observed in methylatropinized fetuses. In the six fetuses that showed intermittent sinusoidal heart rate patterns subsequent to arginine vasopressin infusion, the fetal heart rate tracing and fetal electrocorticogram demonstrated alternate sinusoidal pattern and reactive heart rate patterns during high- and low-voltage electrocorticogram activity, respectively. <b>CONCLUSION:</b> These findings support the hypothesis that fetal sleep cycling has a positive correlation with the periodic appearance of intermittent sinusoidal heart rate patterns.

Sinusoidal heart rate pattern in a second twin caused by massive feto-maternal haemorrhage

Sinusoidal heart rate pattern in a second twin caused by massive feto-maternal haemorrhage

Identification of Acute Transplacental Hemorrhage in a Low-Risk Patient as a Result of Daily Counting of Fetal Movements

In this report, we describe a case of acute, massive fetomaternal hemorrhage that was detected during the 32nd week of pregnancy by maternal perception of decreased fetal movement and suggestion of a sinusoidal heart rate pattern. Additional evaluation revealed an abnormal biophysical profile (2 of 10) and intermittent late decelerations. Because of the substantially decreased fetal reserve, cesarean section was emergently performed. A 1,880-g female infant was delivered. She had an initial hemoglobin concentration of 1.9 g/dl and a hematocrit of 5.7% but did well after appropriate transfusion therapy. This case confirms the importance of daily counting of fetal movements in low-risk patients. In addition, it emphasizes that early diagnosis and treatment of massive fetomaternal hemorrhage can improve infant survival.

Intermittent sinusoidal heart rate pattern in vagotomized fetal lambs

Our aims were to investigate the relationship between the dose of arginine vasopressin and the pattern and duration of arginine vasopressin-induced sinusoidal fetal heart rate and to elucidate the correlation between intermittent sinusoidal heart rate and fetal sleep cycle. Sinusoidal heart rate pattern was induced by intravenous arginine vasopressin infusion at doses from 2 to 78 mlU/min into 11 chronically instrumented fetal lambs with bilateral cervical vagotomy. Appearance and frequency of sinusoidal heart rate, intermittent sinusoidal heart rate, and persistent sinusoidal heart rate were observed along with fetal tracheal pressure and electrooculogram. Intermittent sinusoidal heart rate response to low, medium, and high doses of arginine vasopressin appeared in 73.3%, 50.0%, and 33.3% of experiments, respectively. Intermittent sinusoidal heart rate appeared more frequently than persistent sinusoidal heart rate with lower doses (p < 0.02). When intermittent sinusoidal heart rate was induced, the incidence of sinusoidal patterns significantly increased during non-rapid-eye-movement sleep in comparison with rapid-eye-movement sleep (p < 0.01). Appearance of sinusoidal heart rate seems to be related to the dose of arginine vasopressin infused. Appearance of sinusoidal heart rate is also influenced by fetal sleep cycle; sinusoidal heart rate is more likely to appear during non-rapid-eye-movement sleep than during rapid-eye-movement sleep. These results support the hypothesis that persistent sinusoidal heart rate correlates with severity of stress.

Sinusoidal Fetal Heart Rate Pattern During Labor

Of 1280 consecutive fetuses monitored internally with a scalp electrode for at least 10 minutes during labor, 54 (4.2%) demonstrated the sinusoidal heart rate (SHR) pattern. Seven of these demonstrated the SHR pattern for more than 90 minutes. In six of these seven cases, the SHR pattern occurred during oxytocin administration. The SHR group did not differ from the 1226 fetuses not demonstrating the SHR pattern (NSHR group) in Apgar scores, incidence of other fetal heart rate abnormalities, or passage of meconium. The scalp pH was obtained from three fetuses in the SHR group and was above 7.30 in each. Alphaprodine administration during labor was associated with development of the SHR pattern, whereas other narcotic administration was not. The significance of "atypical" SHR pattern with increased amplitude is discussed, along with the need to adhere to strict definition of the SHR pattern.

Ruptured vasa praevia indicated by a sinusoidal fetal heart rate pattern: a case report

A sinusoidal heart rate pattern is usually considered to signify fetal distress. A case is reported in which the diagnosis vasa praevia was considered 20 h after a short period of vaginal bleeding, after the occurrence of a sinusoidal heart-rate pattern.

Sinusoidal fetal heart rate pattern due to massive feto-maternal transfusion

A 30-year-old woman presented with mild adbominal discomfort and decreased fetal movements in the 34th week of her third pregnancy. Fetal monitoring revealed a sinusoidal heart rate pattern, and abdominal delivery was promptly performed, with the newborn having a hematocrit of 7% due to massive feto-maternal transfusion. Fetal resuscitation was followed by a favorable outcome. The sinusoidal heart rate is discussed, with emphasis on the need for proper and prompt recognition of its significance.

Chronic, massive fetomaternal hemorrhage treated with repeated fetal intravascular transfusions

We report the first known case of chronic, massive fetomaternal hemorrhage managed by serial fetal intravascular transfusions. Timing of transfusions was guided by fetal heart rate patterns and fetal movement evaluation. Despite severe anemia and a sinusoidal heart rate pattern, the fetus demonstrated normal blood gases and no sign of hydrops.

Sinusoidal Heart Rate Pattern and an Normal Biophysical Profile in a Severely Compromised Fetus

Sinusoidal Heart Rate Pattern and an Normal Biophysical Profile in a Severely Compromised Fetus

Sinusoidal Heart Rate Pattern And An Normal Biophysical Profile In A Severely Compromised Fetus

A case is described in which a woman complained of weakened fetal movements, and a persistent sinusoidal heart rate pattern was demonstrated in the presence of normal fetal breathing movements, normal fetal tone, and normal amount of amniotic fluid. In view of the subjective complaints and disregarding the normal biophysical profile, termination of pregnancy was performed. A compromised, severely anemic fetus was delivered by cesarean section. The role of sinusoidal heart rate pattern and the limitations of biophysical scores as a single determinant of fetal well being are discussed.