Browsing by Subject "RATE-VARIABILITY"

Sort by: Order: Results:

Now showing items 1-5 of 5
  • Virtanen, Juhani; Somppi, Sanni; Tornqvist, Heini; Jeyhani, Vala; Fiedler, Patrique; Gizatdinova, Yulia; Majaranta, Päivi; Väätäjä, Heli; Cardo, Anna Valldeoriola; Lekkala, Jukka; Tuukkanen, Sampo; Surakka, Veikko; Vainio, Outi; Vehkaoja, Antti (2018)
    The functionality of three dry electrocardiogram electrode constructions was evaluated by measuring canine heart rate during four different behaviors: Standing, sitting, lying and walking. The testing was repeated (n = 9) in each of the 36 scenarios with three dogs. Two of the electrodes were constructed with spring-loaded test pins while the third electrode was a molded polymer electrode with Ag/AgCl coating. During the measurement, a specifically designed harness was used to attach the electrodes to the dogs. The performance of the electrodes was evaluated and compared in terms of heartbeat detection coverage. The effect on the respective heart rate coverage was studied by computing the heart rate coverage from the measured electrocardiogram signal using a pattern-matching algorithm to extract the R-peaks and further the beat-to-beat heart rate. The results show that the overall coverage ratios regarding the electrodes varied between 45-95% in four different activity modes. The lowest coverage was for lying and walking and the highest was for standing and sitting.
  • Hablitz, Lauren M.; Vinitsky, Hanna S.; Sun, Qian; Staeger, Frederik Filip; Sigurdsson, Björn; Mortensen, Kristian N.; Lilius, Tuomas O.; Nedergaard, Maiken (2019)
    The glymphatic system is responsible for brain-wide delivery of nutrients and clearance of waste via influx of cerebrospinal fluid (CSF) alongside perivascular spaces and through the brain. Glymphatic system activity increases during sleep or ketamine/xylazine (K/X) anesthesia, yet the mechanism(s) facilitating CSF influx are poorly understood. Here, we correlated influx of a CSF tracer into the brain with electroencephalogram (EEG) power, heart rate, blood pressure, and respiratory rate in wild-type mice under six different anesthesia regimens. We found that glymphatic CSF tracer influx was highest under K/X followed by isoflurane (ISO) supplemented with dexmedetomidine and pentobarbital. Mice anesthetized with a-chloralose, Avertin, or ISO exhibited low CSF tracer influx. This is the first study to show that glymphatic influx correlates positively with cortical delta power in EEG recordings and negatively with beta power and heart rate.
  • Tarvonen, Mikko; Hovi, Petteri; Sainio, Susanna; Vuorela, Piia; Andersson, Sture; Teramo, Kari (2021)
    Introduction The aim of the present study was to identify possible associations of fetal heart rate (FHR) patterns during the last 2 hours of labor with fetal asphyxia expressed by umbilical artery acidemia at birth and with neonatal complications in a large obstetric cohort. Material and methods Cardiotocographic recordings from 4988 singleton term childbirths over 1 year were evaluated retrospectively and blinded to the pregnancy and neonatal outcomes in a university teaching hospital in Helsinki, Finland. Umbilical artery pH, base excess and pO(2), low Apgar scores at 5 minutes, need for intubation and resuscitation, early neonatal hypoglycemia, and neonatal encephalopathy were used as outcome variables. According to the severity of the neonatal complications at birth, the cohort was divided into three groups: no complications (Group 1), moderate complications (Group 2) and severe complications (Group 3). Results Of the 4988 deliveries, the ZigZag pattern (FHR baseline amplitude changes of >25 bpm with a duration of 2-30 minutes) occurred in 11.7%, late decelerations in 41.0%, bradycardia episodes in 52.9%, reduced variability in 36.7%, tachycardia episodes in 13.9% and uterine tachysystole in 4.6%. No case of saltatory pattern (baseline amplitude changes of >25 bpm with a duration of >30 minutes) was observed. The presence of the ZigZag pattern or late decelerations, or both, was associated with cord blood acidemia (odds ratio [OR] 3.3, 95% confidence interval [CI] 2.3-4.7) and severe neonatal complications (Group 3) (OR 3.3, 95% CI 2.4-4.9). In contrast, no significant associations existed between the other FHR patterns and severe neonatal complications. ZigZag pattern preceded late decelerations in 88.7% of the cases. A normal FHR preceded the ZigZag pattern in 90.4% of the cases, whereas after ZigZag episodes, a normal FHR pattern was observed in only 0.9%. Conclusions ZigZag pattern and late decelerations during the last 2 hours of labor are significantly associated with cord blood acidemia at birth and neonatal complications. The ZigZag pattern precedes late decelerations, and the fact that normal FHR pattern precedes the ZigZag pattern in the majority of the cases suggests that the ZigZag pattern is an early sign of fetal hypoxia, which emphasizes its clinical importance.
  • FINNRESUSCI Study Grp; Oksanen, Tuomas; Tiainen, Marjaana; Vaahersalo, Jukka; Bendel, Stepani; Varpula, Tero; Skrifvars, Markus; Pettilä, Ville; Wilkman, Erika (2018)
    Background: Optimal hemodynamic goals in post-resuscitation patients are not clear. Previous studies have reported an association between lower heart rate and good outcome in patients receiving targeted temperature management (TTM) after out-of-hospital cardiac arrest. Methods: We analyzed heart rate (HR) and outcome data of 504 post-resuscitation patients from the prospectively collected database of the FINNRESUSCI study. One-year neurologic outcome was dichotomized by the Cerebral Performance Category (CPC) to good (1-2) or poor (3-5). Results: Of 504 patients, 40.1% (202/504) had good and 59.9% (302/504) had poor one-year neurologic outcome. Patients with good outcome had lower time-weighted mean HR during the first 48 h in the ICU (69.2 bpm [59.2-75.1] vs. 76.6 bpm [65.72-89.6], p <0.001) and the first 72 h in the ICU (71.2 bpm [65.0-79.0] vs. 77.1 bpm [69.1-90.1, p <0.001]). The percentage of HR registrations below HR threshold values (60, 80 and 100 bpm) were higher for patients with good neurologic outcome, p <0.001 for all. Lower time-weighted HR for 0-48 h and 0-72 h, and a higher percentage of HR recordings below threshold values were independently associated with good neurological one-year outcome (p <0.05 for all). When TTM and non-TTM patients were analyzed separately, HR parameters were independently associated with one-year neurologic outcome only in non-TTM patients. Conclusion: Lower heart rate was independently associated with good neurologic outcome. Whether HR in post-resuscitation patients is a prognostic indicator or an important variable to be targeted by treatment, needs to be assessed in future prospective controlled clinical trials.
  • Karvonen, Risto; Sipola, Marika; Kiviniemi, Antti M.; Tikanmäki, Marjaana; Järvelin, Marjo-Riitta; Eriksson, Johan G.; Tulppo, Mikko P.; Vaarasmäki, Marja; Kajantie, Eero (2019)
    Objective To evaluate postexercise heart rate recovery (HRR) in adults born preterm. Study design We studied the association between preterm birth and postexercise HRR in 545 adults (267 women) at 23.3 years of age (range 19.9-26.3 years). One hundred three participants were born early preterm ( Results Mean peak HR was 159.5 bpm in the early preterm (P = .16 with controls), 157.8 bpm in the late preterm (P = .56), and 157.0 bpm in the control group. Mean HRR 30 seconds after exercise was 3.2 bpm (95% CI 1.1-5.2) lower in the early preterm group and 2.1 bpm (0.3-3.8) lower in the late preterm group than the full term controls. Mean 60s HRR was 2.5 (-0.1 to 5.1) lower in the early preterm group and 2.8 bpm (0.6-4.9) lower in the late preterm group. Mean maximum slope after exercise was 0.10 beats/s (0.02-0.17) lower in the early preterm group and 0.06 beats/s (0.00-0.12) lower in the late preterm group. Conclusions Our results suggest reduced HRR after exercise in adults born preterm, including those born late preterm. This suggests altered reactivation of the parasympathetic nervous system, which may contribute to cardiovascular risk among adults born preterm.