TY - JOUR
T1 - Power spectral analysis of R-R interval variability before and during the sinusoidal heart rate pattern in fetal lambs
AU - Suzuki, Taku
AU - Okamura, Kunihiro
AU - Kimura, Yoshitaka
AU - Watanabe, Takanori
AU - Yaegashi, Nobuo
AU - Murotsuki, Jun
AU - Uehara, Shigeki
AU - Yajima, Akira
PY - 2000/1/1
Y1 - 2000/1/1
N2 - 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.
AB - 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.
KW - Fetal lamb
KW - Power spectral analysis
KW - Sinusoidal heart rate pattern
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U2 - 10.1067/mob.2000.104221
DO - 10.1067/mob.2000.104221
M3 - Article
C2 - 10819863
AN - SCOPUS:0034041116
VL - 182
SP - 1227
EP - 1232
JO - American Journal of Obstetrics and Gynecology
JF - American Journal of Obstetrics and Gynecology
SN - 0002-9378
IS - 5
ER -