Bio

Clinical Focus


  • Pediatric Cardiology
  • Pediatric Cardiac Critical Care

Academic Appointments


Professional Education


  • Fellowship: Boston Children's Hospital Dept of Critical Care (2020) MA
  • Board Certification: American Board of Pediatrics, Pediatric Cardiology (2018)
  • Fellowship: Baylor College Pediatric Cardiology Residency at Texas Childrens Hospital (2018) TX
  • Board Certification: American Board of Pediatrics, Pediatrics (2015)
  • Residency: Baylor College of Medicine Pediatric Residency (2015) TX
  • Medical Education: Texas A and M University Office of the Registrar (2012) TX

Publications

All Publications


  • An Analysis of Hospital Mortality After Cardiac Operations in Children With Down Syndrome. Seminars in thoracic and cardiovascular surgery Dhillon, G. S., Ghanayem, N. S., Broda, C. R., Lalani, S. R., Mery, C. M., Shekerdemian, L. S., Staffa, S. J., Morris, S. A. 2020

    Abstract

    Children with Down syndrome (DS) have lower mortality compared to nonsyndromic (NS) children after atrioventricular septal defect (AVSD) repair. Limited data exist regarding hospital mortality and utilization after other congenital heart disease (CHD) operations in DS. We compared hospital mortality and utilization after CHD operations in both populations and hypothesized that the survival benefit in children with DS is not consistent across CHD lesions. The Texas Inpatient Public Use Datafile was queried for all patients <18 years old undergoing operations for CHD between 1999 and 2016. Hospital mortality, length-of-stay and charges were compared between DS and NS groups, stratified by CHD operation using mixed-effects multivariable analyses and propensity score matching analyses adjusting for prematurity, low birth weight, age, and sex. Over the 18-year period, 2841 cases with DS underwent CHD operations compared to 25,063 NS cases. The most common types of interventions performed in DS were AVSD repair, isolated ventricular septal defect (VSD) repair and tetralogy of Fallot (TOF) repair. By multivariable analyses, DS was associated with lower mortality after isolated AVSD repair (RR 0.40 [IQR 0.20-0.79]), and higher hospital mortality after bidirectional Glenn anastomosis (BDG) (RR 5.17 [IQR 2.10-12.77]) and TOF/pulmonary atresia repair (RR 9.71 [IQR 2.16-43.68]) compared to NS children. Similar results were noted using propensity score matching. Children with DS had lower mortality after AVSD repair than NS children, but higher mortality after operations for BDG and TOF/pulmonary atresia. Further study is needed to determine if the presence of pulmonary hypertension in DS modifies the association between DS and mortality depending on cardiac lesion.

    View details for DOI 10.1053/j.semtcvs.2020.06.037

    View details for PubMedID 32621963

  • Drug-Eluting Stents Compared With Bare Metal Stents for Stenting the Ductus Arteriosus in Infants With Ductal-Dependent Pulmonary Blood Flow. The American journal of cardiology Aggarwal, V., Dhillon, G. S., Penny, D. J., Gowda, S. T., Qureshi, A. M. 2019; 124 (6): 952?59

    Abstract

    There have been no clinical studies evaluating the use of drug-eluting stents (DES) versus bare metal stents (BMS) for infants who underwent ductus arteriosus (DA) stent placement for ductal-dependent pulmonary blood flow (PBF). We aimed to compare the use of second-generation (fluoropolymer-coated everolimus) DES to BMS in infants who underwent DA stenting for ductal-dependent PBF. A retrospective study of infants who underwent DA stenting for ductal-dependent PBF from January 2004 to March 2018 at a single tertiary care pediatric hospital was performed. Of 94 infants identified, 71 (46 BMS and 25 DES) met inclusion criteria. Baseline characteristics of the DES and BMS cohorts were comparable. The patent lumen to stent diameter on subsequent angiographic evaluation was 81% in DES as compared with 50% in BMS group; p?=?0.01. There were 2 deaths early in our experience, both in the BMS group. Unplanned reinterventions were less in the DES group (3, 12% patients) compared with the BMS group (13, 28%), p?=?0.03. Pulmonary artery size as assessed using Nakata and pulmonary artery symmetry index was comparable in both the groups. There was no difference in infection rates between the groups. On multivariate analysis, prematurity, BMS, and lower oxygen saturations at discharge were associated with subsequent unplanned reintervention (p?=?0.01, 0.03 and 0.03, respectively). In conclusion, our clinical experience suggests that in infants who underwent DA stenting for ductal-dependent PBF, (fluoropolymer-coated everolimus eluting) DES results in less luminal loss and lower unplanned reintervention for cyanosis as compared with BMS implantation.

    View details for DOI 10.1016/j.amjcard.2019.06.014

    View details for PubMedID 31350000

  • Cardiac Arrest in the Pediatric Cardiac ICU: Is Medical Congenital Heart Disease a Predictor of Survival? Pediatric critical care medicine : a journal of the Society of Critical Care Medicine and the World Federation of Pediatric Intensive and Critical Care Societies Dhillon, G. S., Lasa, J. J., Aggarwal, V., Checchia, P. A., Bavare, A. C. 2019; 20 (3): 233?42

    Abstract

    Children with medical cardiac disease experience poorer survival to hospital discharge after cardiopulmonary arrest compared with children with surgical cardiac disease. Limited literature exists describing epidemiology and factors associated with mortality in this heterogeneous population. We aim to evaluate the clinical characteristics and outcomes after cardiopulmonary arrest in medical cardiac patients.We performed a retrospective review of pediatric cardiac patients who underwent cardiopulmonary resuscitation in a tertiary care cardiac ICU. Surgical cardiac patients underwent cardiac surgery immediately prior to ICU admission. Nonsurgical cardiac patients were divided into two groups based on the presence of congenital heart disease: congenital heart disease medical or noncongenital heart disease medical. Clinical and outcome variables were collected. Primary outcome was survival to hospital discharge.Texas Children's Hospital cardiac ICU.Patients admitted to Texas Children's Hospital cardiac ICU between January 2011 and December 2016.None.Of 150 cardiopulmonary arrest events reviewed, 90 index events were included (46 surgical, 26 congenital heart disease medical, and 18 noncongenital heart disease medical). There was no difference in primary outcome among the three groups. The absence of an epinephrine infusion precardiopulmonary arrest was associated with increased odds of survival in the congenital heart disease medical group (p = 0.03). Noncongenital heart disease medical patients experienced pulseless ventricular tachycardia/ventricular fibrillation more frequently than congenital heart disease medical patients (p = 0.02). Congenital heart disease medical patients had trends toward longer cardiac arrest durations, higher prevalence of neurologic sequelae postcardiopulmonary arrest, and higher mortality when extracorporeal support at cardiopulmonary resuscitation was employed.Although trends in first documented rhythm, neurologic sequelae, and inotropic support prior to cardiopulmonary arrest were noted between groups, no significant differences in survival after cardiac arrest were seen. Larger scale studies are needed to better describe factors associated with cardiopulmonary arrest as well as survival in heterogeneous medical cardiac populations.

    View details for DOI 10.1097/PCC.0000000000001810

    View details for PubMedID 30785870

  • The impact of fetal endoscopic tracheal occlusion in isolated left-sided congenital diaphragmatic hernia on left-sided cardiac dimensions PRENATAL DIAGNOSIS Dhillon, G. S., Maskatia, S. A., Loar, R. W., Colquitt, J. L., Mehollin-Ray, A. R., Ruano, R., Belfort, M. A., Olutoye, O. O., Kailin, J. A. 2018; 38 (11): 812?20

    Abstract

    Fetal endoscopic tracheal occlusion (FETO) is offered to fetuses with congenital diaphragmatic hernia (CDH) and severe lung hypoplasia to promote lung growth and may secondarily affect left heart growth. The effects of FETO on left heart hypoplasia (LHH) are not described post-CDH repair.A retrospective analysis was performed for fetuses with left-sided CDH who underwent FETO and severity-matched controls from 2007 to 2016 at our institution. Echocardiographic, ultrasound, and MRI data were reviewed. Left heart dimensions were assessed prenatally and postnatally. Primary clinical outcome evaluated was death.Twelve FETO patients and 18 controls were identified. Fetal LHH was noted in both groups and worsened after FETO. Postnatal mitral valve dimensions were larger in the FETO group pre-CDH repair (P=.03). Post-CDH repair, mitral valve and left ventricular dimensions were not significantly different between groups (P=.79 and P=.63 respectively) while FETO aortic valve dimensions were smaller (P=.04). Extracorporeal membrane oxygenation use was lower in the FETO group. No associations were found between left heart dimensions and outcomes.Although increased lung growth was seen after FETO, fetal LHH persisted with relative normalization seen post-repair. Persistent LHH post-FETO could be secondary to a small contribution of pulmonary venous return to the fetal left heart and increased intrathoracic pressures post-FETO.

    View details for PubMedID 30047996

  • Predictive value of oxygenation index for outcomes in left-sided congenital diaphragmatic hernia. Journal of pediatric surgery Bruns, A. S., Lau, P. E., Dhillon, G. S., Hagan, J., Kailin, J. A., Mallory, G. B., Lohmann, P., Olutoye, O. O., Ruano, R., Fernandes, C. J. 2018; 53 (9): 1675?80

    Abstract

    Congenital Diaphragmatic Hernia (CDH) is associated with significant morbidity and mortality. This study compares the efficacy of the highest oxygenation index in the first 48 h (HiOI) versus current prenatal indices to predict survival and morbidity.Medical records of 50 prenatally diagnosed, isolated, left-sided CDH patients treated from January 2011 to April 2016 were reviewed. Data abstracted included HiOI, lung to head ratio (LHR), observed to expected total fetal lung volume (O/E TFLV), percent liver herniation (%LH), 6 month survival, respiratory support at discharge, ventilator days and length of stay. Data were analyzed using parametric and nonparametric tests and regression analyses as appropriate.HiOI was associated with significantly increased LOS (p<0.001), respiratory support at discharge (p<0.001), greater ventilator days (p=0.001) and higher odds of death (p=0.004) with risk of death increasing by 5% for every one-unit increase in OI. HiOI was statistically a better predictor of LOS than O/E TFLV (p=0.007) and %LH (p=0.02).In isolated, left-sided CDH patients, HiOI is associated with higher mortality, greater length of stay, more ventilator days and increased respiratory support at discharge. HiOI is a better predictor of length of stay than O/E TFLV and %LH.Retrospective Study LEVEL OF EVIDENCE: II.

    View details for DOI 10.1016/j.jpedsurg.2017.12.023

    View details for PubMedID 29428594

  • Transposition of the great arteries: When echocardiography does not match the clinical picture. Journal of clinical ultrasound : JCU Dhillon, G. S., Fernandes, C. J., Khan, A., Heinle, J. S., Lopez, K. N. 2018; 46 (9): 617?22

    Abstract

    Aortopulmonary window (APW) is a rare form of congenital heart disease seen in isolation or with complex cardiac lesions. APW has been associated with other cardiac defects such as interrupted aortic arch and Tetralogy of Fallot, but few cases have been reported of APW associated with transposition of the great arteries (TGA). In a newborn with TGA and intact ventricular septum, diagnosis of APW requires a high index of suspicion. This article reviews the literature on TGA with APW and illustrates the importance of additional evaluation in neonates with TGA when oxygen saturation and PaO2 do not match predicted clinical values.

    View details for DOI 10.1002/jcu.22615

    View details for PubMedID 30160304

  • Fetal left-sided cardiac structural dimensions in left-sided congenital diaphragmatic hernia - association with severity and impact on postnatal outcomes PRENATAL DIAGNOSIS Kailin, J. A., Dhillon, G. S., Maskatia, S. A., Cass, D. L., Shamshirsaz, A. A., Mehollin-Ray, A. R., Cassady, C. I., Ayres, N. A., Wang, Y., Belfort, M. A., Olutoye, O. O., Ruano, R. 2017; 37 (5): 502-509

    Abstract

    Fetuses with congenital diaphragmatic hernia (CDH) demonstrate varying degrees of left heart hypoplasia. Our study assesses the relationship between fetal left-sided cardiac structural dimensions, lung size, percentage liver herniation, lung-to-head ratio, postnatal left-sided cardiac structural dimensions, and postnatal outcomes.We performed a retrospective cohort study of fetuses with left-sided CDH who had prenatal echocardiographic, ultrasound, and magnetic resonance imaging examinations at our institution between January 2007 and March 2015. Postnatal outcomes assessed include use of inhaled nitric oxide (iNO), use of extracorporeal membrane oxygenation, and death.Fifty-two fetuses with isolated left-sided CDH were included. Multivariate logistic regression models indicated that smaller fetal aortic valve z-score was associated with postnatal use of iNO (p=0.03). Fetal mitral valve z-score correlated with lung-to-head ratio (p=0.04), postnatal mitral valve z-score correlated with percent liver herniation (p=0.03), and postnatal left ventricular end-diastolic dimension z-score correlated with liver herniation <20% (p=0.04).We identified associations between smaller fetal left-sided cardiac structural dimensions and classic CDH indices. Smaller aortic valve z-score was associated with iNO use; however, left heart dimensions showed no association with extracorporeal membrane oxygenation or mortality. Further study into the impact of left-sided hypoplasia on outcomes in CDH is worthy of evaluation in a larger, prospective study. 2017 John Wiley & Sons, Ltd.

    View details for DOI 10.1002/pd.5045

    View details for Web of Science ID 000401561200012

    View details for PubMedID 28370263

  • Heart in a Heart. JACC. Cardiovascular interventions Dhillon, G. S., Qureshi, A. M. 2017; 10 (13): 1372?73

    View details for DOI 10.1016/j.jcin.2017.04.029

    View details for PubMedID 28624379

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