Publications by authors named "Owen I Miller"

15 Publications

  • Page 1 of 1

Fetal Speckle-Tracking: Impact of Angle of Insonation and Frame Rate on Global Longitudinal Strain.

J Am Soc Echocardiogr 2020 Sep 15;33(9):1141-1146.e2. Epub 2020 May 15.

Fetal Cardiology Unit, Department of Congenital Heart Disease, Evelina London Children's Hospital, Guy's & St. Thomas' NHS Trust, London, United Kingdom; Harris Birthright Centre for Fetal Medicine, Fetal Medicine Research Institute, King's College Hospital, London, United Kingdom; School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom. Electronic address:

Background: There is a growing body of research on fetal speckle-tracking echocardiography because it is considered to be an angle-independent modality. The primary aim of this study was to investigate whether angle of insonation and acquisition frame rate (FR) influence left ventricular endocardial global longitudinal peak strain (GLS) in the fetus.

Methods: Four-chamber views of 122 healthy fetuses were studied at three different angles of insonation (apex up/down, apex oblique, and apex perpendicular) at high and low acoustic FRs. GLS was calculated, and a linear mixed-model analysis was used for analysis. Six hundred fifty-six fetal echocardiographic clips were analyzed (288 in the second trimester, at a median gestation of 21 weeks [interquartile range (IQR), 1 week], and 368 in the third trimester, at a median gestation of 36 weeks [IQR, 2 weeks]).

Results: Angle of insonation and FRs were significant determinants of GLS. Ventricular septum perpendicular to the ultrasound beam was associated with higher (more negative) GLS compared with apex up/down (at high FR: -21.8% vs -19.7%, P < .001; at low FR: -24.1% vs -21.4%, P < .001). Higher frames per second (FPS; median 149 FPS [IQR, 33 FPS] = 61 frames per cycle [FPC] [IQR, 17 FPC]) compared with lower FPS (median 51 FPS [IQR, 15 FPS] = 22 FPC [IQR, 7 FPC]) at the same insonation angle resulted in lower GLS (apex up/down: -19.7% vs -21.4%, P < .001; apex oblique: -21.2% vs -22.7%, P < .001; apex perpendicular: -21.8% vs -24.1%, P < .001).

Conclusions: The present findings show that insonation angle and FR influence GLS significantly. These factors need to be considered when comparing studies with different acquisition protocols, when establishing normative values, and when interpreting pathology. Speckle-tracking echocardiography cannot be considered an angle-independent modality during fetal life.
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http://dx.doi.org/10.1016/j.echo.2020.03.013DOI Listing
September 2020

Application of the Boston Technical Performance Score to intraoperative echocardiography.

Echo Res Pract 2019 Sep 9;6(3):63-70. Epub 2019 Jul 9.

Department of Congenital Heart Disease, Evelina London Children's Hospital, London, UK.

Background: The Technical Performance Score (TPS) developed by Boston Children's Hospital showed surgical outcomes correlate with adequacy of technical repair when implemented on pre-discharge echocardiograms. We applied this scoring system to intraoperative imaging in a tertiary UK congenital heart surgical centre.

Methods: After a period of training, intraoperative TPS (epicardial and/or transesophageal echocardiography) was instituted. TPS was used to inform intraoperative discussions and recorded on a custom-made database using the previously published scoring system. After a year, we reviewed the feasibility, results and relationship between the TPS and mortality, extubation time and length of stay.

Results: From 01 September 2015 to 04 July 2016, there were 272 TPS procedures in 251 operations with 208 TPS recorded. Seven patients had surgery with no documented TPS, three had operations with no current TPS score template available. Patients left the operating theatre with TPS optimal in 156 (75%), adequate 34 (16%) and inadequate 18 (9%). Of those with an optimal score on leaving theatre, ten had more than one period of cardiopulmonary bypass. All four deaths <30 days after surgery (1.9%) had optimal TPS. There was a statistically significant difference in extubation times in the RACHS category 4 patients (3 days vs 5 days,  < 0.05) and in PICU and total length of stay in the RACHS category three patients (2 and 8 days vs 12.5 and 21.5 days respectively) if leaving theatre with an inadequate result.

Conclusions: Application of intraoperative TPS is feasible and provides a way of objectively recording intraoperative imaging assessment of surgery. An 'inadequate' TPS did not predict mortality but correlated with a longer ventilation time and longer length of stay compared to those with optimal or adequate scores.
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http://dx.doi.org/10.1530/ERP-19-0032DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6689121PMC
September 2019

Effect of Prenatal Laterality Disturbance and Its Accompanying Anomalies on Survival.

Am J Cardiol 2018 08 20;122(4):663-671. Epub 2018 Jun 20.

Department of Congenital Heart Disease, Evelina London Children's Hospital, Guy's & St Thomas' Hospitals, London SE1 7EH, United Kingdom.

In this retrospective, observational study of fetuses diagnosed with a laterality disturbance we describe the findings and outcome of fetuses diagnosed between 1980 and 2017 at a tertiary fetal-pediatric cardiology unit. In addition we sought to identify features which impact on outcome. Left atrial isomerism (LAI) was diagnosed in 177 babies and right atrial isomerism (RAI) in 100. Major structural heart disease was present in all cases of RAI and 91% with LAI. Complete heart block (CHB) was present in 40% of LAI. For surviving live-born infants a biventricular circulation was feasible in 3% with RAI and 43% with LAI. The median survival for live-borns with LAI was 13 months (range 0 to 272 months) and for RAI 19 months (range 0.3 to 292 months). The median postnatal survival with CHB was 0.2 months (range 0 to 228 months) compared to 44 months with sinus rhythm (interquartile range 0 to 272 months; p <0.0001). The 5-year survival was 1980 to 1989, RAI 0%, LAI 0%; 1990 to 1999, RAI 62%, LAI 54%; 2000 to 2009, RAI 59%, LAI 53%; 2010 to 2017, RAI 67%, LAI 75% by era. The rate of intrauterine death remained. Risk factors for death/transplantation for RAI were total anomalous pulmonary venous drainage, left heart obstruction (hazard ratios 2.7, p = 0.048; 5.8, p = 0.03) and for LAI: CHB, anomalous pulmonary venous drainage and right heart obstruction (hazard ratios 11.5, 6.2, 3.8, respectively (p = 0.008, p = 0.003, p <0.001)). In conclusion, laterality disturbances represent a complex form of congenital heart disease and although survival is improved, it remains poor especially in the presence of anomalous pulmonary venous drainage, stenotic and/or atretic valves, and CHB.
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http://dx.doi.org/10.1016/j.amjcard.2018.04.040DOI Listing
August 2018

Partial anomalous left pulmonary artery.

Eur Heart J Cardiovasc Imaging 2018 02;19(2):237

Evelina London Children's Hospital, Westminster Bridge Road, London SE1?7EH, UK.

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http://dx.doi.org/10.1093/ehjci/jex242DOI Listing
February 2018

Usefulness of the Prenatal Echocardiogram in Fetuses With Isolated Transposition of the Great Arteries to Predict the Need for Balloon Atrial Septostomy.

Am J Cardiol 2017 05 9;119(9):1463-1467. Epub 2017 Feb 9.

Department of Congenital Heart Disease, Evelina London Children's Hospital, Guy's & St Thomas' NHS Foundation Trust, London, United Kingdom.

The outcome of the arterial switch operation for transposition of the great arteries (TGA) is excellent, but there is still associated preoperative mortality. Hypoxemia due to inadequate mixing of the pulmonary and systemic circulations may be implicated. Prediction of early hypoxemia by prenatal echocardiographic criteria has proved difficult. We aimed to identify prenatal echocardiographic features that may predict the need for emergency balloon atrial septostomy (BAS) in isolated TGA. Third trimester fetal echocardiograms of the last 40 cases of isolated TGA were reviewed without knowledge of the postnatal outcome. Measurements of the arterial valves, arterial duct, total septal length (TSL), and foramen ovale (FO) length were made, in addition to a subjective assessment of the atrial septum. The first postnatal echocardiogram and charts were reviewed. Comparison with 40 gestation-matched control fetuses was performed. The FO length in normal fetuses was not significantly different from those with TGA who did not require an emergency BAS but was significantly smaller in fetuses with TGA who required an emergency BAS (p = 0.01). An emergency BAS was required in 12 of 40 cases. All 3 cases with limited movement of the atrial septum required emergency BAS. A hypermobile atrial septum was observed in 10 cases and was not associated with emergency BAS (p = 0.8). The FO:TSL was significantly smaller in those who required an emergency BAS with good predictive value (area under the receiver operating characteristics curve: 0.80). The sensitivity for FO:TSL <0.5 was 99%. There was no significant difference in arterial duct, pulmonary valve, or branch pulmonary artery diameters between those cases requiring emergency BAS and those who did not. In conclusion, the likelihood of an emergency BAS is increased by FO:TSL <0.5 and a fixed appearance of the flap valve. Hypermobile and/or aneurysmal atrial septum did not indicate inadequate postnatal mixing in our group.
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http://dx.doi.org/10.1016/j.amjcard.2017.01.017DOI Listing
May 2017

A systematic three-dimensional echocardiographic approach to assist surgical planning in double outlet right ventricle.

Echocardiography 2013 Feb 21;30(2):234-8. Epub 2012 Nov 21.

Department of Congenital Heart Disease, Evelina Children's Hospital, London, UK.

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http://dx.doi.org/10.1111/echo.12037DOI Listing
February 2013

Subjective evaluation of right ventricular systolic function in hypoplastic left heart syndrome: how accurate is it?

J Am Soc Echocardiogr 2013 Jan 23;26(1):52-6. Epub 2012 Oct 23.

Department of Paediatric Cardiology, Level 6 Evelina Children's Hospital, London, United Kingdom.

Background: The geometry and heterogeneity of the right ventricle in hypoplastic left heart syndrome makes objective echocardiographic assessment of systolic function challenging. Consequently, subjective echocardiographic assessment of right ventricular (RV) function is still routinely undertaken. The aims of this study were to compare this with magnetic resonance imaging (MRI), investigate the impact of experience and training on the accuracy of subjective assessment, and critically analyze the role of echocardiography to detect impaired systolic function.

Methods: A retrospective analysis of prospectively acquired data was performed. Children with hypoplastic left heart syndrome underwent routine preoperative cardiac MRI and echocardiography under the same general anesthetic. Echocardiograms were reviewed, and members of the congenital heart disease team with differing echocardiography experience subjectively graded RV systolic function (good, moderate, or poor). This was compared with MRI-derived ejection fraction.

Results: Twenty-eight patients at different palliative stages were included. Twenty-eight observers were divided into five experience categories (congenital heart disease junior trainees to attending cardiologists). Median agreement was 47.6% (range, 31.4%-58.2%), with the lowest agreement among junior trainees and the highest among attending cardiologists. When used as a screening test for poor RV systolic function, the median sensitivity of echocardiography was 0.89 (range, 0.86-0.96), and median specificity was 0.45 (range, 0.26-0.55). The highest sensitivity was observed among junior trainees but with the lowest specificity. The highest specificity was observed among attending cardiologists (0.55).

Conclusions: Agreement between echocardiographic and MRI RV ejection fraction improves with experience but remains suboptimal. When used as a screening test for poor RV function, echocardiography is sensitive, but specificity is heavily influenced by operator experience.
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http://dx.doi.org/10.1016/j.echo.2012.09.020DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3548410PMC
January 2013

Tissue Doppler time intervals and derived indices in hypoplastic left heart syndrome.

Eur Heart J Cardiovasc Imaging 2012 May 8;13(5):400-7. Epub 2011 Dec 8.

Division of Imaging Sciences and Biomedical Engineering, Rayne Institute, Lambeth Wing, St Thomas' Hospital, Westminster Bridge Road, London SE1 7EH, UK.

Aims: To describe tissue Doppler time intervals and derived indices in hypoplastic left heart syndrome (HLHS) across surgical stages, taking account of age-related changes in the heart rate. Correlation of the myocardial performance index (MPI) and the systolic to diastolic (S:D) time ratio with other echocardiographic and magnetic resonance imaging (MRI) measures of cardiac performance.

Methods And Results: Fifty-seven patients at different stages of HLHS palliation were studied prospectively using tissue Doppler imaging of the right ventricular free wall, with simultaneous cardiac MRI in the majority. Both isovolumic contraction time and isovolumic relaxation time were prolonged compared with the normal left and right ventricle: median (range) z-scores for the tricuspid annulus 1.9 (-1.2 to 9.3) and 1.3 (-2.0 to 5.5), respectively. When adjusted for heart rate, the ejection, systolic, and diastolic times in HLHS were not significantly different from published normal data. The MPI was increased at all surgical stages in HLHS. Neither MPI nor heart rate-specific S:D time ratio z-score correlated with MRI ejection fraction or indexed cardiac output when the confounding effect of significant tricuspid regurgitation was taken into consideration.

Conclusion: The prolongation in isovolumic relaxation and contraction times may be due to adaptation or reduced myocardial performance. Differences in the S:D time ratio between surgical stages can be accounted for by the heart rate alone. Neither MPI z-score nor S:D z-score correlated with MRI or other echocardiographic indices of systolic or diastolic function with the exception of a negative correlation between central venous pressure and S:D ratio z-score.
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http://dx.doi.org/10.1093/ejechocard/jer271DOI Listing
May 2012

Clinical application of a micro multiplane transoesophageal probe in congenital cardiac disease.

Cardiol Young 2012 Apr 19;22(2):170-7. Epub 2011 Aug 19.

Department of Congenital Heart Disease, Evelina Children's Hospital, Guy's & St Thomas' NHS Foundation Trust, London, United Kingdom.

Aim: To assess the quality of imaging modalities of a new micro multiplane transoesophageal echocardiogram probe.

Method: This is a prospective study of micro transoesophageal echocardiogram S8-3t probe used at a single institution between 15 December, 2009 and 15 March, 2010. The images were compared with standard paediatric or adult probes where possible. Assessors prospectively rated imaging quality - two dimensional, colour flow imaging, pulse wave, and continuous wave Doppler - with a subjective 4-point scale (1 = poor to 4 = excellent).

Results: A total of 24 studies were performed on 23 patients, with a median weight = 11.7 kilograms (2.6-72 kilograms) and a median age of 3 years (0.16-60 years). Of the 23 patients, one neonate (2.8 kilograms) had transient bradycardia on probe insertion. Imaging in patients less than 10 kilograms was of full diagnostic value and new information was obtained in eight out of ten patients. Pulse wave and continuous wave Doppler was consistently good across all weight groups. There were high frame rates and good imaging quality to a depth of 4-6 centimetres in all studies. A comparison with a larger alternative probe was available for 12 studies (weight 11.9-72 kilograms). The median micro transoesophageal two-dimensional image quality score was 3 (2-4) and 4 (3-4) with the comparative probe. For the 10- to 30-kilogram group, image quality with the micro transoesophageal echocardiogram probe was judged as inferior to larger standard probes. Adult sized patients had good imaging of near the field, allowing guidance for percutaneous device closure of the atrial septum.

Conclusion: The micro multiplane transoesophageal echocardiogram probe provides imaging of diagnostic quality in neonates. In larger patients, it offers good imaging of near field structures. In the intermediate-sized child (10-30 kilograms), standard paediatric probes provide better imaging.
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http://dx.doi.org/10.1017/S1047951111000977DOI Listing
April 2012

Toward defining pulmonary sequestration in infancy using two-dimensional echocardiography and novel high temporal resolution "keyhole" three-dimensional magnetic resonance angiography.

Congenit Heart Dis 2011 Sep-Oct;6(5):488-91. Epub 2011 Jul 31.

Department of Paediatric Cardiology, Evelina Children's Hospital, London, UK.

This article describes a rare case of pulmonary sequestration presenting in infancy with mixed systemic and pulmonary venous drainage. This case illustrates the clinical application of the high temporal resolution three-dimensional "keyhole" magnetic resonance angiography technique in the neonatal age group to achieve a diagnosis noninvasively. Further insight into the classification of pulmonary sequestration is also given.
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http://dx.doi.org/10.1111/j.1747-0803.2011.00551.xDOI Listing
January 2012

3D echocardiography of the atrial septum: anatomical features and landmarks for the echocardiographer.

JACC Cardiovasc Imaging 2010 Sep;3(9):981-4

Department of Congenital Cardiology, Evelina Children’s Hospital, London, UK.

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http://dx.doi.org/10.1016/j.jcmg.2010.03.015DOI Listing
September 2010

Prevalence of increased nuchal translucency in fetuses with congenital cardiac disease and a normal karyotype.

Cardiol Young 2009 Sep 29;19(5):441-5. Epub 2009 Jul 29.

Department of Fetal and Paediatric Cardiology, Evelina Children's Hospital, London, UK.

Objectives: Our aims were to estimate the prevalence of increased nuchal translucency in fetuses with a normal karyotype that were subsequently diagnosed with congenital cardiac disease on fetal echocardiography, and to assess whether there is a link between increased nuchal translucency and specific congenital cardiac malformations.

Methods: We reviewed all patients referred to King's College Hospital and the Evelina Children's Hospital in London for fetal echocardiography between January 1998 and December 2007. We investigated the proportion of chromosomally normal fetuses with congenitally malformed hearts in which nuchal thickness was increased, both overall and with specific defects.

Results: We identified 2133 fetuses with congenital cardiac disease by prenatal echocardiography. Of those, 707 were excluded due to abnormal karyotype, and 690 were excluded due to unknown karyotype. The remaining 736 were eligible for inclusion. Among 481 fetuses with documented congenital cardiac disease and normal chromosomes, making up 23% of the overall cohort, 224 had increased nuchal thickness defined as equal or greater than 2.5 millimetres, this being 0.47 of the inclusive cohort, with 95% confidence intervals from 0.42 to 0.51. These proportions were significantly higher than the expected proportion of the normal population, which was 0.05 (p < 0.001). The only diagnosis for which the proportion of fetuses with nuchal translucency measurement equal or greater than 2.5 millimetres was higher than the others was atrioventricular septal defect, with 0.62 of this cohort having abnormal values, with 95% confidence intervals from 0.47 to 0.77 (p = 0.038).

Conclusion: We found that nearly half of prenatally diagnosed fetuses with congenitally malformed hearts, when examined ultrasonically in the first or early-second trimester, had increased nuchal thickness. We recommend, therefore, referral of all fetuses with increased nuchal translucency for fetal echocardiography.
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http://dx.doi.org/10.1017/S1047951109990655DOI Listing
September 2009

Idiopathic pulmonary trunk aneurysm causing airway obstruction in an infant.

Heart Lung Circ 2007 Dec 12;16(6):454-6. Epub 2007 Mar 12.

Sydney Children's Hospital, High Street, Randwick, NSW 2031, Australia.

We report a case of idiopathic pulmonary trunk aneurysm in an infant, in which the main clinical picture was airway obstruction. Aneurysmorraphy was the chosen surgical approach and showed to be successful on 13 months follow-up.
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http://dx.doi.org/10.1016/j.hlc.2006.10.024DOI Listing
December 2007

Surgical substrates of postoperative junctional ectopic tachycardia in congenital heart defects.

J Thorac Cardiovasc Surg 2002 Apr;123(4):624-30

Cardiothoracic Unit, Great Ormond Street Hospital for Children National Health Service Trust, and the Institute of Child Health, London, United Kingdom.

Background: Junctional ectopic tachycardia is a major cause of postoperative morbidity after surgery for congenital cardiac disease. To elucidate the mechanism of junctional ectopic tachycardia, surgical correlations were studied in four types of congenital heart defects involving closure of a ventricular septal defect, relief of right ventricular outflow tract obstruction, or both.

Methods: Between 1997 and 1999, a total of 343 consecutive patients underwent repair of tetralogy of Fallot (n = 114), common truncus arteriosus (n = 10), ventricular septal defect (n = 161), and atrioventricular septal defect (n = 58). Variables studied included demographic and bypass data, surgical approaches toward ventricular septal defect closure and relief of right ventricular outflow tract obstruction, and resection as opposed to division of muscle bundles.

Results: Junctional ectopic tachycardia occurred most frequently after repair of tetralogy of Fallot (n = 25; 21.9%), with no cases occurring after repair of common trunk, 6 occurring after repair of ventricular septal defect (3.7%), and 6 occurring after repair of atrioventricular septal defect (10.3%). Stepwise logistic regression revealed that resection of muscle bundles (P <.0001), higher bypass temperatures (P <.03), and relief of right ventricular outflow tract obstruction through the right atrium (P <.05) significantly and independently predicted postoperative junctional ectopic tachycardia.

Conclusions: Relief of right ventricular outflow tract obstruction appears to be more important in the causation of junctional ectopic tachycardia than does ventricular septal defect closure, which may explain the higher incidence of this complication after tetralogy of Fallot repair. Muscular resection seems to be more arrhythmogenic than is simple division. Increased traction through the right atrium for relief of right ventricular outflow tract obstruction would fit the hypothesis that enhanced automaticity of the His bundle, the morphologic substrate for junctional ectopic tachycardia, may result from direct trauma or infiltrative hemorrhage of the conduction system. When feasible, techniques avoiding both extensive muscle resection and excessive traction should be applied during resection of right ventricular outflow tract obstruction.
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http://dx.doi.org/10.1067/mtc.2002.121046DOI Listing
April 2002