NeoCardioLab Research Day

Recordings of the NeoCardioLab research half-day (October 30, 2025)

Guest Speakers - Conférenciers Invités

Dr. Tiscar Cavallé-Garrido is significantly involved in the Department of Pediatrics at the Montreal Children’s Hospital, acting as the Director of both the Pediatric Cardiology Training Program and the Pediatric Advanced Imaging Fellowship. She completed her university and medical degrees at the University of Valencia in Spain and completed her residency in General Pediatrics and Pediatric Cardiology in Valencia and at the Hospital for Sick Children, in Toronto, where she also completed her fellowship in Pediatric and Fetal Echocardiography and Cardiovascular Research. 

Dr. Frederic Dallaire us from the Universite de Sherbrooke, where he acts as the Director of mother-child research at the Centre de Recherche du CHUS. He earned his undergraduate degree at Universite Laval before pursuing his PhD in epidemiology and his MD at Laval as well. His current research involves identifying risk factors for Tetralogy of Fallot as well as assessing current diagnostics for other congenital heart defects. Dr. Dallaire has also founded the Canadian Congenital & Pediatric Cardiology Research Network, which supports Canadian cardiology investigators across the country. 

Dr. Nagib Dahdah is a pediatric cardiologist and researcher at CHU Sainte-Justine who focuses on studying Kawasaki disease and the axis between metabolic and cardiovascular health. He completed his medical studies at Saint-Joseph University in Beirut, Lebanon. His training in pediatrics and pediatric cardiology spans several countries, including Lebanon, France, the United States, and eventually Canada. Dr. Dahdah founded the Kawasaki Arab Initiative, a non-profit organization which focuses on improving the health of Kawasaki patients in the Arab world.

Program

12:00 – 12:15 – Arrival of participants

12:15 – 12:30 – Welcome remarks while participants enjoy lunch

Guest lectures (40 min and 10 min questions)

12:30 – 1:15 – Guest Lecture – Dr. Tiscar Cavalle-Garrido

1:15 – 2:00 – Guest Lecture – Dr. Frédéric Dallaire

2:00 – 2:45 – Guest Lecture – Dr. Nagib Dahdah

2:45 – 3:00 – Break

Student Segment:

3:00 – 4:15 – 5 Student Presentations

4:15 – 4:30 (end) – Closing Remarks

Thank You / Remerciements

Student Abstracts

Oral Presentation by Daniel Moses 3:00 pm 

Neonatal outcomes related to the early discovery of impaired cardiac function NORDIC-PREM: The 7-10 days 4D-left-ventricle sub-analysis. 

Co-authors: Pasinee Kanaprach MD, Carolina Michel Macias, MD.. Daniela Villegas M, MSc, Jessica Simoneau, DIT, Catherine Daignault, RN, Tiscar Cavalle-Garrido, MD, Adrian Dancea, MD, Guilherme Sant’Anna, MD, Gabriel Altit, MD 

Background: Extremely preterm infants (<29 weeks’ gestation) undergo profound cardiovascular adaptation during the early postnatal period. Developmental immaturity may impair myocardial remodeling and function. As part of the prospective NORDIC-PREM cohort, this study aimed to characterize left ventricular (LV) structure and function at 7–10 days of life using advanced four-dimensional (4D) echocardiography, exploring associations between early perinatal factors and LV mechanics in the first week of life. 

Methods: This prospective single-center cohort included 138 extremely preterm infants admitted to the Montreal Children’s Hospital NICU. 4D echocardiograms obtained between days 7–10 were analyzed by a blinded expert using TOMTEC to quantify LV volumes, mass, deformation (strain), and torsion. In this preliminary analysis of the first 40 infants, participants were stratified by the median cohort birthweight (932 g). 

Results: Infants with lower birthweight (<932 g, n=20) were more frequently intubated within 30 minutes of life (30% vs 5%, P=0.04). Compared with higher-birthweight peers, they exhibited smaller LV end-diastolic volumes (1.47 vs 1.83 mL, P=0.04), reduced stroke volume (0.89 vs 1.13 mL, P=0.02), lower LV mass (P=0.04), shorter LV length (19.3 vs 21.2 mm, P=0.01), and more negative global longitudinal strain (–27.9% vs –24.5%, P=0.048). Notably, LV torsion was higher in the low-birthweight group (6.85 vs 4.40 degrees/cm, P=0.02), indicating different ventricular mechanics despite preserved ejection fraction. 

Conclusion: Among extremely preterm neonates, low birthweight is strongly associated with smaller LV size, higher torsion, and greater myocardial deformation within the first 10 days of life—features reflecting adaptive but potentially maladaptive remodeling. These structural and functional signatures parallel a more complex respiratory course and prolonged hospitalization. Ongoing analysis of the full 138-infant cohort will determine whether these early LV metrics predict later complications such as BPD, PH, or mortality, supporting targeted surveillance and individualized cardiovascular care for this vulnerable population.

Oral Presentation by Zoey Nicely 3:10 pm 

Prospective 4D Echocardiographic Characterization of Left Ventricular Function in CDH. 

Co-authors: Alexie Fonta Holder, Tamires De Mello Guimarães, Carolina Michel Macias, Shiran Moore, Punnanee Wutthigate, Madison Meehan, Anie Lapointe, Audrey Hébert, Daniela Villegas Martinez, Jessica Simoneau, Tiscar Cavallé-Garrido, Guilherme Sant’Anna, Pramod Puligandla, Gabriel Altit.

Background: In congenital diaphragmatic hernia (CDH), left ventricular (LV) underdevelopment may result from abnormal fetal streaming, cardiac compression, ventricular interactions, or underfilling from the pulmonary venous return. Postnatally, smaller LV size/function have been linked to worse outcomes. Prospective longitudinal data are scarce. We aimed to describe LV parameters using 4D echocardiography and compare infants with vs. without intrathoracic liver herniation, a marker of severity. We hypothesized that those with liver-up would show persistently abnormal LV metrics in their first 2 weeks of life at 3 timepoints. 

Methods: Prospective single-center cohort (Nov 2019–Oct 2024) including prenatally or postnatally diagnosed CDH ≥34 weeks, free of major malformations/genetic syndromes. Informed consent was obtained. 4D echocardiograms were acquired at <24 h, day 3–5, and 2 weeks or discharge (whichever arrived first). LV parameters were reconstructed using TomTec by a blinded extractor. Patients were stratified by liver position (up vs. down) since 20% were post-natal diagnosis. Primary objective: evaluate effect of severity and time on LV parameters across the 3 timepoints using mixed effect models adjusted for birthweight. 

Results: Of 22 approached infants, 14 were included (8 with, 6 without intrathoracic liver herniation) – Figure 1. None required ECMO or died. Baseline demographics were similar except there is a higher proportion of type C/D CDH (75% vs 0%, p=0.03), longer hospitalization (median 70 vs 11 days, p=0.02), and longer intubation (17 vs 5 days, p=0.03) in liver-up patients – Table 1. Mixed-effects modeling (Table 2) showed that, in all infants, time was significantly associated with increases in stroke volume, EF, LV mass, twist, and torsion, suggesting progressive LV adaptation. However, the interaction for liver-up status and time was associated with smaller LV end-systolic volume (β=0.33, p=0.0497), lower ejection fraction (EF) (β=−5.97, p=0.03), lower systolic twist (β=−8.08, p=0.01) and torsion (β=−2.75, p=0.02), indicating persistent impairment in LV performance in liver-up group across time. 

Conclusion: Liver-up CDH babies show persistently abnormal LV performance despite time-related adaptation. 4D-LV metrics may help flag the sickest infants, guide timing of interventions, and target those needing closer surveillance in future prospective studies.

Oral Presentation by Dr. Shahad Daali 3:20 pm 

Right ventricular function and dimensions by 4D-Echocardiography in extreme premature infants at 36 weeks – A Prospective Study. 

Co-authors: Silvia Nogara, MD, Carolina Michel Macias, MD, Shiran S Moore, MD, Audrey Hebert, MD, Nina Nouraeyan, MD, Christine Drolet, MD, Anie Lapointe, MD, Andreanne Villeneuve, MD, Brahim Bensouda, MD, Daniela Villegas Martinez, MSc, Jessica Simoneau, DIT, Tiscar Cavalle-Garrido, MD, Adrian Dancea, MD, Guilherme Sant’Anna, MD, Gabriel Altit, MD.

Introduction: The right ventricle (RV) is particularly vulnerable in extreme prematurity, where adverse cardio-respiratory interactions may impair its growth and function. Its complex geometry can now be assessed using 4D Speckle-Tracking Echocardiography (STE). We evaluated RV size and function at 36 weeks postmenstrual age (PMA) and examined whether infants with adverse pulmonary phenotypes displayed distinct RV remodeling patterns. 

Methods: We conducted a single-center, prospective observational study of infants born <29 weeks’ gestation (2019–2023). 4D RV echocardiography was performed at 36 weeks PMA. Infants with major malformations or genetic syndromes were excluded. Images were analyzed offline with TomTec Arena by a blinded reviewer. Data were stratified by respiratory support at time of imaging (36 weeks), and multivariable regression models were adjusted for weight at imaging and postnatal steroid exposure. 

Results: A total of 147 infants were included (Figure 1), with a mean GA of 26.3 weeks, birth weight 880 grams, and 48% male (Table 1). Infants requiring respiratory support or oxygen at echocardiography had lower GA, birth weight, and imaging weight, with higher steroid exposure (73% vs 28%, p<.001). These infants had smaller RV end-diastolic (3.65 vs 4.60 mL, p=.0007) and systolic volumes (1.5 vs 1.9 mL, p=.002) and lower stroke volume (2.25 vs 2.6 mL, p=.001). RV dimensions were reduced, including base diameter (11.3 vs 12.3 mm, p=.003) and mid-cavity diameter (12.1 vs 12.8 mm, p=.03). Functional indices were lower, with reduced TAPSE (8.3 vs 9.2 mm, p=.02) and less negative septal longitudinal strain (−18.5% vs −21.3%, p=.02). After adjustment, base diameter (β −0.74, p=.03), fractional area change (β −3.06, p=.03), and TAPSE (β −0.79, p=.02) remained independently associated with respiratory support. Less negative septal (β 3.31, p=.02) and free-wall strain (β 2.65, p=.04) were also independently associated with oxygen need. 

Conclusion: Preterm infants requiring respiratory support at 36 weeks PMA show smaller RV volumes, reduced systolic indices, and abnormal deformation patterns, suggesting impaired RV growth and performance. These findings underscore the importance of RV-focused monitoring and early identification of infants at risk for adverse cardiopulmonary outcomes.

Oral Presentation by Lina Ikhlef 3:30 pm 

Patterns of Cardiorespiratory Events in the Immediate Post-Extubation Period in Extremely Preterm Infants 

Co-authors: Ana Saavedra Ruiz, Robert E. Kearney, Guilherme Sant'anna, Wissam Shalish.

Background: Respiratory pauses, desaturations and bradycardias frequently occur in extremely preterm infants post-extubation, often leading to clinical instability and reintubation. Objective: (1) To describe the interrelationships of respiratory pauses, bradycardias, and desaturations in extremely preterm infants during the immediate post-extubation period; (2) To assess for differences in event patterns between infants with successful vs failed extubation. 

Methods: Secondary, retrospective analysis of a crossover trial at the Montreal Children's Hospital NICU (2016-2018) including infants ≤1250g. Measures included breathing patterns from respiratory inductive plethysmography, heart rate (HR) from electrocardiography, and oxygen saturation (SpO2) from pulse oximetry for 2h immediately post-extubation. Desaturations were defined as SpO2 <90% for >2s and bradycardias as HR <100 bpm for >5s. Respiratory pause analysis was conducted using an Automated Unsupervised Respiratory Event Analysis algorithm to identify respiratory pauses >3s. Event frequencies, durations, transition probabilities and temporal relationships were described using summary statistics and compared between infants with successful and failed extubation using nonparametric statistical tests. 

Results: Across 56.7h of monitoring (mean 2.1h/infant) in 27 infants (GA 26 [25.4, 26.4] wks; birth weight 770g [610, 915]), 1,174 pauses, 834 desaturations, and 54 bradycardias were recorded (Fig 1). Median (IQR) durations were 4.9s (3.7, 8.2) for pauses, 59.7s (31.5, 94.5) for desaturations, and 6.6s (5.8, 9.9) for bradycardias. Most events occurred in isolation (pauses 96%, desaturations 82%, bradycardias 89%). More complex event sequences included pauses transitioning into desaturations (3.4%), desaturations transitioning into pauses (16.8%), and bradycardias transitioning into pauses (7.4%) (Table 1). The likelihood of a desaturation or bradycardia following a pause increased with longer pauses (Fig 2). Compared to successfully extubated infants, reintubated infants had a greater number of pauses >10s (p=0.01) and pause durations (6.0s [5.1–7.1] vs 7.3s [6.0–9.4]; p=0.048). Other event frequencies, transition probabilities, and timing relationships did not differ significantly between groups (Table 1). 

Conclusion: Brief respiratory pauses, bradycardias, and desaturations are common but mostly isolated immediately post-extubation in extremely preterm infants. Reintubated infants exhibited longer and more frequent pauses, suggesting pause dynamics may offer insights into an infant’s risk of reintubation.

Oral Presentation by Phoenix Plessas-Azurduy 3:50 pm 

Dexamethasone is associated with Ductal Closure in Extremely Preterm Infants with Evolving Lung Disease.

Co-authors: Joshua Hazan Mea, Thomas Sonea, Pasinee Kanaprach, Sariya Sahussarungsi, Carolina Michel Macias, Shiran Sara Moore, Punnanee Wutthigate, Jessica Simoneau, Daniela Villegas Martinez, Andréanne Villeneuve, Anie Lapointe, Guilherme Sant’Anna, Gabriel Altit.

BACKGROUND: Dexamethasone (DEXA) is commonly administered to premature neonates with evolving lung disease, particularly those requiring mechanical ventilation. Among this population, extremely premature infants frequently present with a patent ductus arteriosus (PDA), a condition strongly associated with the development of bronchopulmonary dysplasia (BPD). Although DEXA is widely used to prevent and manage BPD, its influence on PDA closure remains poorly understood, especially in settings where conservative PDA management is practiced. 

OBJECTIVE: This study aimed to evaluate the trajectory of PDA size and closure rates following DEXA administration in preterm neonates. We hypothesized that DEXA treatment would be associated with a reduction in PDA diameter and an increased likelihood of closure. 

METHODS: A prospective observational cohort study was conducted involving preterm neonates born at <29 weeks gestational age (GA) who received DEXA for evolving BPD. Serial echocardiographic assessments were performed at seven predefined timepoints: baseline (prior to DEXA initiation), days 3, 7, and 14 of treatment, 1- and 2-weeks post-treatment, and at 36 weeks corrected GA. PDA size and profile was measured by a blinded evaluator using standardized protocols. Due to repeated measurements, data was analyzed using a generalized estimating equations (GEE) model or a random mixed effects model. 

RESULTS: Between 2021 and 2024, 57 neonates were enrolled of which 53 had a PDA at baseline (59% male, 79% inborn). The mean birth GA was 24.3 weeks (SD: 5.3), and the mean birthweight was 759 g (SD: 192 g). On day 7 of DEXA, (62%) were confirmed to be closed or restrictive by echocardiography and on day 7 post-DEXA N=28/37 (76%) were closed or restrictive. With each timepoint, there was an increase in the likelihood of PDA closure (: 0.35, p <0.001). By 36 weeks corrected GA, 95% of infants demonstrated either complete closure or a restrictive PDA. Of the 53 enrolled, 5 infants were exposed to pharmacological treatment for PDA closure. 

CONCLUSION: DEXA administration was associated with a consistent temporal reduction in PDA size and patency. These findings suggest that, beyond its established pulmonary benefits, DEXA may contribute t