Estimation of the electrical axis of the fetal heart

Larks, Saul D.

doi:10.1016/0002-9378(65)90585-5

Cited by 25 publications

(14 citation statements)

References 4 publications

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“…The mean values for the fetal cardiac axis of +144.5" and f143.3" showed the expected predominance of right axis shift. The values are some 10" greater than those described by Larks (1965) but are well within the expected range. The mean value for the neonatal cardiac axis was f134" and was similar to values previously described.…”

Section: Fetal and Neonatal Cardiac Axes And Apgar Scoressupporting

confidence: 65%

“…The only significant correlation between the QRS configuration of the second sample of the fetal ECG and the neonatal leads was demon- strated with Lead I1 (r = +0.26<p 0.01) and on this basis it was decided to apply the methods used by Larks (1965) to determine fetal cardiac axis. As this method was dependent on expressing the algebraic sum of the positive and negative deflections after correction to a value of 10, it was necessary to convert the R/S ratios to equivalent values.…”

Section: Fetal and Neonatal Cardiac Axesmentioning

confidence: 99%

“…These values were then used to estimate cardiac axis from the nomogram described by Larks (1965). The mean values for the theoretical fetal cardiac axis early and late in labour, and the neonatal cardiac axis are shown in Table IT.…”

Section: Fetal and Neonatal Cardiac Axesmentioning

confidence: 99%

“…An analysis was made of clinical condition at birth in relation to changes in cardiac axis during Larks (1965) and Larks and Larks (1965) has shown that fetal complexes recorded from maternal abdominal leads resemble Lead I1 of the neonatal ECG, and therefore the theoretical projection of the fetal ECG on the appropriate side of the Einthoven triangle can be used to estimate the fetal cardiac axis. Larks pointed out that, as the sine function is a double-valued function, it is not possible to specify completely the quadrant in which the angle falls.…”

Section: Fetal and Neonatal Cardiac Axes And Apgar Scoresmentioning

confidence: 99%

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Vectorcardiography and Acid‐base Balance in the Human Fetus

Symonds

1972

BJOG

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Summary An analysis of the configuration of the fetal electrocardiogram assessed by recording the ratio of the positive and negative deflections of the QRS complex has been performed in relation to the QRS complex of the neonatal electrocardiogram. Changes in R/S ratios in the fetal electrocardiogram late in labour were significantly related to changes in Lead II of the neonatal electrocardiogram. On the basis of the method described by Larks (1965) the mean cardiac axis of the fetus early in labour was +144.5° and late in labour +143.2°. The mean neonatal cardiac axis recorded within five hours after delivery was +134°. The fetal cardiac axis showed a significant shift to the left in relation to fetal acidosis and hyperkalaemia. Similar changes were seen in the neonatal electrocardiogram in relation to biochemical changes.

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Section: Fetal and Neonatal Cardiac Axes And Apgar Scoressupporting

confidence: 65%

Section: Fetal and Neonatal Cardiac Axesmentioning

confidence: 99%

Section: Fetal and Neonatal Cardiac Axesmentioning

confidence: 99%

Section: Fetal and Neonatal Cardiac Axes And Apgar Scoresmentioning

confidence: 99%

See 2 more Smart Citations

Vectorcardiography and Acid‐base Balance in the Human Fetus

Symonds

1972

BJOG

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“…It is known that the orientation of the fetal electrical heart axis can vary between +100 and +160 degrees in mid-term fetuses [22] and between +90 and +180 degrees in term fetuses during labour [23]. Similar inter-person variation in the orientation of the electrical heart axis is present in neonates and adults [24–27].…”

Section: Introductionmentioning

confidence: 99%

The electrical heart axis and ST events in fetal monitoring: A post-hoc analysis following a multicentre randomised controlled trial

et al. 2017

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ObjectiveReducing perinatal morbidity and mortality is one of the major challenges in modern health care. Analysing the ST segment of the fetal electrocardiogram was thought to be the breakthrough in fetal monitoring during labour. However, its implementation in clinical practice yields many false alarms and ST monitoring is highly dependent on cardiotocogram assessment, limiting its value for the prediction of fetal distress during labour. This study aims to evaluate the relation between physiological variations in the orientation of the fetal electrical heart axis and the occurrence of ST events.MethodsA post-hoc analysis was performed following a multicentre randomised controlled trial, including 1097 patients from two participating centres. All women were monitored with ST analysis during labour. Cases of fetal metabolic acidosis, poor signal quality, missing blood gas analysis, and congenital heart disease were excluded. The orientation of the fetal electrical heart axis affects the height of the initial T/QRS baseline, and therefore the incidence of ST events. We grouped tracings with the same initial baseline T/QRS value. We depicted the number of ST events as a function of the initial baseline T/QRS value with a linear regression model.ResultsA significant increment of ST events was observed with increasing height of the initial T/QRS baseline, irrespective of the fetal condition; correlation coefficient 0.63, p<0.001. The most frequent T/QRS baseline is 0.12.ConclusionThe orientation of the fetal electrical heart axis and accordingly the height of the initial T/QRS baseline should be taken into account in fetal monitoring with ST analysis.

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The electrical axis of the fetal heart: A new criterion for fetal well-being or distress

Larks

1965

American Journal of Obstetrics and Gynecology

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Estimation of the electrical axis of the fetal heart

Cited by 25 publications

References 4 publications

Vectorcardiography and Acid‐base Balance in the Human Fetus

Vectorcardiography and Acid‐base Balance in the Human Fetus

The electrical heart axis and ST events in fetal monitoring: A post-hoc analysis following a multicentre randomised controlled trial

The electrical axis of the fetal heart: A new criterion for fetal well-being or distress

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