Noninvasive cardiac monitoring in pregnancy: impedance cardiography versus echocardiography.

OBJECTIVE: The objective of this study was to report thoracic impedance cardiography (ICG) measurements and compare them with echocardiography (echo) measurements throughout pregnancy and in varied maternal positions. METHOD: A prospective cohort study involving 28 healthy parturients was performed using ICG and echo at three time points and in two maternal positions. Pearson's correlations, Bland-Altman plots and paired t-tests were used for statistical analysis. RESULT: Significant agreements between many but not all ICG and echo contractility, flow and resistance measurements were demonstrated. Differences in stroke volume (SV) due to maternal position were also detected by ICG in the antepartum (AP) period. Significant trends were observed by ICG for cardiac output and thoracic fluid content (TFC; P<0.025) with advancing pregnancy stages. CONCLUSION: ICG and echo demonstrate significant correlations in some but not all measurements of cardiac function. ICG has the ability to detect small changes in SV associated with maternal position change. ICG measurements reflected maximal cardiac contractility in the a AP period yet reflected a decrease in contractility and an increase in TFC in the postpartum period.

The contribution of heart disease to pregnancy-related mortality according to the pregnancy mortality surveillance system.

OBJECTIVE: The objective of this study was to demonstrate the increasing importance of heart disease as a cause of pregnancy-related mortality in Hawaii and the rest of the United States. STUDY DESIGN: Hawaii's Department of Public Health identified all pregnancy-associated death certificates from 1991 to 2007. Hospital records and autopsy reports were reviewed to determine whether deaths were pregnancy-related. RESULT: From 1991 to 2007, Hawaii registered 156 deaths occurring within 1 year of pregnancy, which represented 4.2% of the total number of women who died in the same 17 to 46 years age group and 9.0% of the total number of women who died in the same 17 to 34 years age group. The pregnancy-related mortality ratio was 22.4 and the pregnancy-associated mortality ratio was 50. The leading cause of pregnancy-associated mortality was heart disease (20.5%) followed by cancer (18.6%) and suicide/homicide (12.2%). Pregnancy-related deaths (n=70) were attributed to heart disease (45.7%) followed by sepsis (14.2%) and hemorrhage (12.9%). The new Hawaii death certificate beginning in 2006 increased the detection of both pregnancy-related and -associated deaths. CONCLUSION: Heart disease is the most common cause of pregnancy-related mortality in Hawaii, and with improved ascertainment, may be determined to be the most common cause of pregnancy-related mortality in the rest of the United States.

Maternal and fetal outcomes in pregnancies affected by von Willebrand disease type 2.

We report a case series that lends support for both the maternal and neonatal safety of vaginal delivery in pregnancies complicated by heritable von Willebrand disease types 2A and 2B. With proper hematologic support, a cesarean delivery may be indicated only for obstetric reasons.

The effects of attenuation of frequency segments on binaural localization of sound.

Perceived location of tonal stimuli d and narrow noise bands presented in two-dimensional space varies in an orderly manner with changes in stimulus frequency. Hence, frequency has a referent in space that is most apparent during monaural listening. The assumption underlying the present study is that maximum sound pressure level measured at the ear canal entrance for the various frequencies serves as a prominent spectral cue for their spatial referents. Even in binaural localization, location judgments in the vertical plane are strongly influenced by spatial referents. We measured sound pressure levels at the left ear canal entrance for 1.0-kHz-wide noise bands, centered from 4.0 kHz through 10.0 kHz, presented at locations from 60 degrees through -45 degrees in the vertical plane; the horizontal plane coordinate was fixed at -90 degrees. On the basis of these measurements, we fabricated three different bandstop stimuli in which differently centered 2.0-kHz-wide frequency segments were filtered from a broadband noise. Unfiltered broadband noise served as the remaining stimulus. Localization accuracy differed significantly among stimulus conditions (p < .01). Where in the vertical plane most errors were made depended on which frequency segment was filtered from the broadband noise.

Pulmonary edema in obstetric patients is rapidly resolved except in the presence of infection or of nitroglycerin tocolysis after open fetal surgery.

OBJECTIVES: This study was designed to determine the etiology, course, and severity of pulmonary edema in obstetric patients in a tertiary care center. STUDY DESIGN: A retrospective study was carried out on 16,810 deliveries from University of California, San Francisco, 1985-1995. Diagnosis and severity of lung injury were defined by a 4-point system that was based on the chest radiograph, oxygenation, positive end-expiratory pressure, and lung compliance. Resolution of pulmonary edema was defined by improvement in the chest radiograph and hypoxemia (ratio of arterial oxygen tension to inspired oxygen concentration) scores or by extubation. RESULTS: Pulmonary edema developed in 86 patients, or 0.5% of all obstetric cases. It usually showed extensive air space consolidation on the chest radiograph and arterial hypoxemia. Although 43% of the patients had severe pulmonary dysfunction, the average time to resolution of pulmonary edema was 2.4 days. Only 45% of patients required admission to the intensive care unit and only 15% required intubation and positive-pressure ventilation. Patients with infection (mean of 7.2 days) or fetal surgery (mean of 3.8 days) had the most severe, protracted course. CONCLUSION: Although obstetric pulmonary edema is associated with extensive radiographic infiltrates and severe hypoxemia, resolution occurs rapidly in most patients, limiting the need for intensive care support.

Differential expression of G1 cyclins during human placentogenesis.

Cyclins are proteins that support the progression of cell-cycle stages in proliferating cells. The purpose of this study was to determine which of the cyclin genes is involved in the regulation of normal human trophoblast proliferation. The presence and cellular localization of four G1 cyclins D1, D2, D3 and E, were determined by immunohistochemistry. This analysis indicated that cyclins E and D3 are the predominant cyclins in villous trophoblast. D2 was present only within the villous core, in fetal macrophages. Positive immunoreactivity for cyclin D1 was strongest in second and third trimester placentae, in the cells lining the intravillous vessels with additional reactivity in extravillous cytotrophoblasts. Because cyclin E protein was present in a greater percentage of cells than those that are dividing, Western blot analysis was performed to validate the fidelity of the immunohistochemistry data. The results of the Western analysis revealed that two forms of cyclin E protein of the appropriate size were present. Data collected from this study suggest that within the trophoblast lineage, cyclins D3 and E are important cell cycle regulatory proteins, and further, that cyclin E may function in trophoblast terminal differentiation as well.