Table 3.
Heart rate variability (HRV) and other complications such as pulmonary disease or seizures (n=376).
| Author, year, country | Case | Control | Study design | Measures | Findings | |||||||
| Pulmonary system (n=375) | ||||||||||||
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|
Amador-Licona et al [31], 2009, Mexico | 178 pregnant women (88 obese, BMI>27 kg/m2); age: 28.2 years; exclusion criteria: no chronic diseases (eg, hypertension, diabetes) | 90 nonobese (BMI >18.5 kg/m2 and <24.9 kg/m2); age: 26.6 years; exclusion criteria: no chronic diseases (eg, hypertension, diabetes) | Longitudinal: exposures of spirometry, 10-min oximetry; outcome of HRV by 60-minute electrocardiograph monitoring; both exposure and outcome were assessed twice between 8 AM and 10 AM during pregnancy, at GAa of 24-28 weeks and 36-37 weeks | Spirometry (using EasyOne 2001-2 spirometer, NDD) and oximetry (using the Onix 2001 oximeter; HRV using a 3-channel Holter recorder (model GBI-3S, Galix Biomedical Instrumentation Inc) | Change in FEV1/FVC during pregnancy was linked to the LFc/HFd metric in the third trimester after adjusting for confounding factors such as insulin, weight gain, and blood pressure (β=−0.42; P<.001). | ||||||
|
|
Liao and Jaw [32], 2011, Taiwan | n=2; case 1 (sudden acute dyspnea with cyanosis): 36-year-old primigravid woman was admitted in active labor with no history of epilepsy, cardiopulmonary, or renal disease; caes 2 (acute dyspnea with cyanosis): 35-year-old, gravid 2, para 1 woman was admitted at 37 weeks of gestation due to labor pain and ruptured membranes. | 105 healthy pregnant women with no complication during labor | Longitudinal: exposures of amniotic fluid embolism and disseminated intravascular coagulopathy; outcome of HRV (entropy) was assessed continuously after admission to labor until recovery form the complication. | Amniotic fluid embolism and disseminated intravascular coagulopathy: specialist’s diagnosis; HRV: ECGe | HRV significantly decreased in amniotic fluid embolism and disseminated intravascular coagulopathy and increased in ICUf during recovery from these complications. | ||||||
| Central nervous system (n=1) | ||||||||||||
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|
Faber et al [33], 2004, Netherland | n=1; 21-year-old gravid 1, para 0 woman had epilepsy due to a frontotemporal arteriovenous malformation in the 24th week of gestation | N/Ag | Longitudinal: exposure of HRV (frequency domain: VLFh, LF, HF, LF/HF) was assessed starting from 20 weeks of GA through 24 weeks of GA for 30 minutes every 4 weeks and for 12 minutes until the onset of seizure; outcome of grand mal seizure | HRV: N/A; grand mal seizure: tonic-clonic convulsions diagnosed by a specialist | HRV showed significant alterations at 12 minutes prior to the seizure: VLF increased; LF was delayed, and HF remained unchanged. HF, however, started to increase afterward. | ||||||
aGA: gestational age.
bFEV1/FVC: forced expiratory volume at 1 second to forced vital capacity.
cLF: low frequency.
dHF: high frequency.
eECG: electrocardiogram.
fICU: intensive care unit.
gN/A: not applicable.
hVLF: very low frequency.