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Dependency of magnetocardiographically determined fetal cardiac time intervals on gestational age, gender and postnatal biometrics in healthy pregnancies.

Van Leeuwen P, Lange S, Klein A, Geue D, Grönemeyer DH - BMC Pregnancy Childbirth (2004)

Bottom Line: Gender differences were found only for the QRS complex from the 31st week onward (p < 0.05).The influence on the P wave or QRS complex of biometric data, collected in a subgroup in whom recordings were available within 1 week of birth, did not display statistical significance.Fetal development is thus in part reflected in the CTI and may be useful in the identification of intrauterine growth retardation.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Biomagnetism, Research and Development Center for Microtherapy (EFMT), Universitätsstr, 142, 44799 Bochum, Germany. petervl@microtherapy.de

ABSTRACT
BACKGROUND: Magnetocardiography enables the precise determination of fetal cardiac time intervals (CTI) as early as the second trimester of pregnancy. It has been shown that fetal CTI change in course of gestation. The aim of this work was to investigate the dependency of fetal CTI on gestational age, gender and postnatal biometric data in a substantial sample of subjects during normal pregnancy. METHODS: A total of 230 fetal magnetocardiograms were obtained in 47 healthy fetuses between the 15th and 42nd week of gestation. In each recording, after subtraction of the maternal cardiac artifact and the identification of fetal beats, fetal PQRST courses were signal averaged. On the basis of therein detected wave onsets and ends, the following CTI were determined: P wave, PR interval, PQ interval, QRS complex, ST segment, T wave, QT and QTc interval. Using regression analysis, the dependency of the CTI were examined with respect to gestational age, gender and postnatal biometric data. RESULTS: Atrioventricular conduction and ventricular depolarization times could be determined dependably whereas the T wave was often difficult to detect. Linear and nonlinear regression analysis established strong dependency on age for the P wave and QRS complex (r2 = 0.67, p < 0.001 and r2 = 0.66, p < 0.001) as well as an identifiable trend for the PR and PQ intervals (r2 = 0.21, p < 0.001 and r2 = 0.13, p < 0.001). Gender differences were found only for the QRS complex from the 31st week onward (p < 0.05). The influence on the P wave or QRS complex of biometric data, collected in a subgroup in whom recordings were available within 1 week of birth, did not display statistical significance. CONCLUSION: We conclude that 1) from approximately the 18th week to term, fetal CTI which quantify depolarization times can be reliably determined using magnetocardiography, 2) the P wave and QRS complex duration show a high dependency on age which to a large part reflects fetal growth and 3) fetal gender plays a role in QRS complex duration in the third trimester. Fetal development is thus in part reflected in the CTI and may be useful in the identification of intrauterine growth retardation.

No MeSH data available.


Related in: MedlinePlus

Scatter plots of fetal CTI vs. gestational age Duration of CTI with respect to gestational age: disjunct intervals (P wave, PQ interval, QRS complex, ST segment, T wave) in the top two rows, composite intervals (PR, QT and QTc interval) in the bottom row (males ◊, females +).
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Figure 3: Scatter plots of fetal CTI vs. gestational age Duration of CTI with respect to gestational age: disjunct intervals (P wave, PQ interval, QRS complex, ST segment, T wave) in the top two rows, composite intervals (PR, QT and QTc interval) in the bottom row (males ◊, females +).

Mentions: The CTI showed varying dependency on gestational age: Figure 3 shows that, of the contiguous, disjunct intervals, in particular the duration of the P wave and QRS complex increased clearly over time whereas the PQ interval showed a slight tendency to decrease with age. The ST segment and T wave duration demonstrated a wide spread without a clear trend. The composite intervals were characterized by a modest positive relationship to week of gestation, primarily reflecting the influence of the depolarization times. Regression analysis confirmed the visual impression (Table 1) with statistically significant slopes for all intervals except the ST segment and the T wave. The model fits were especially good for the P wave and the QRS complex. Implementing non-linear models improved the fit for the PQ and PR interval as well as the QRS complex.


Dependency of magnetocardiographically determined fetal cardiac time intervals on gestational age, gender and postnatal biometrics in healthy pregnancies.

Van Leeuwen P, Lange S, Klein A, Geue D, Grönemeyer DH - BMC Pregnancy Childbirth (2004)

Scatter plots of fetal CTI vs. gestational age Duration of CTI with respect to gestational age: disjunct intervals (P wave, PQ interval, QRS complex, ST segment, T wave) in the top two rows, composite intervals (PR, QT and QTc interval) in the bottom row (males ◊, females +).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC411040&req=5

Figure 3: Scatter plots of fetal CTI vs. gestational age Duration of CTI with respect to gestational age: disjunct intervals (P wave, PQ interval, QRS complex, ST segment, T wave) in the top two rows, composite intervals (PR, QT and QTc interval) in the bottom row (males ◊, females +).
Mentions: The CTI showed varying dependency on gestational age: Figure 3 shows that, of the contiguous, disjunct intervals, in particular the duration of the P wave and QRS complex increased clearly over time whereas the PQ interval showed a slight tendency to decrease with age. The ST segment and T wave duration demonstrated a wide spread without a clear trend. The composite intervals were characterized by a modest positive relationship to week of gestation, primarily reflecting the influence of the depolarization times. Regression analysis confirmed the visual impression (Table 1) with statistically significant slopes for all intervals except the ST segment and the T wave. The model fits were especially good for the P wave and the QRS complex. Implementing non-linear models improved the fit for the PQ and PR interval as well as the QRS complex.

Bottom Line: Gender differences were found only for the QRS complex from the 31st week onward (p < 0.05).The influence on the P wave or QRS complex of biometric data, collected in a subgroup in whom recordings were available within 1 week of birth, did not display statistical significance.Fetal development is thus in part reflected in the CTI and may be useful in the identification of intrauterine growth retardation.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Biomagnetism, Research and Development Center for Microtherapy (EFMT), Universitätsstr, 142, 44799 Bochum, Germany. petervl@microtherapy.de

ABSTRACT
BACKGROUND: Magnetocardiography enables the precise determination of fetal cardiac time intervals (CTI) as early as the second trimester of pregnancy. It has been shown that fetal CTI change in course of gestation. The aim of this work was to investigate the dependency of fetal CTI on gestational age, gender and postnatal biometric data in a substantial sample of subjects during normal pregnancy. METHODS: A total of 230 fetal magnetocardiograms were obtained in 47 healthy fetuses between the 15th and 42nd week of gestation. In each recording, after subtraction of the maternal cardiac artifact and the identification of fetal beats, fetal PQRST courses were signal averaged. On the basis of therein detected wave onsets and ends, the following CTI were determined: P wave, PR interval, PQ interval, QRS complex, ST segment, T wave, QT and QTc interval. Using regression analysis, the dependency of the CTI were examined with respect to gestational age, gender and postnatal biometric data. RESULTS: Atrioventricular conduction and ventricular depolarization times could be determined dependably whereas the T wave was often difficult to detect. Linear and nonlinear regression analysis established strong dependency on age for the P wave and QRS complex (r2 = 0.67, p < 0.001 and r2 = 0.66, p < 0.001) as well as an identifiable trend for the PR and PQ intervals (r2 = 0.21, p < 0.001 and r2 = 0.13, p < 0.001). Gender differences were found only for the QRS complex from the 31st week onward (p < 0.05). The influence on the P wave or QRS complex of biometric data, collected in a subgroup in whom recordings were available within 1 week of birth, did not display statistical significance. CONCLUSION: We conclude that 1) from approximately the 18th week to term, fetal CTI which quantify depolarization times can be reliably determined using magnetocardiography, 2) the P wave and QRS complex duration show a high dependency on age which to a large part reflects fetal growth and 3) fetal gender plays a role in QRS complex duration in the third trimester. Fetal development is thus in part reflected in the CTI and may be useful in the identification of intrauterine growth retardation.

No MeSH data available.


Related in: MedlinePlus