Progression of an Artificial Intelligence Chatbot (ChatGPT) for Pediatric Cardiology Educational Knowledge Assessment

Artificial intelligence chatbots, like ChatGPT, have become powerful tools that are disrupting how humans interact with technology. The potential uses within medicine are vast. In medical education, these chatbots have shown improvements, in a short time span, in generalized medical examinations. We evaluated the overall performance and improvement between ChatGPT 3.5 and 4.0 in a test of pediatric cardiology knowledge. ChatGPT 3.5 and ChatGPT 4.0 were used to answer text-based multiple-choice questions derived from a Pediatric Cardiology Board Review textbook. Each chatbot was given an 88 question test, subcategorized into 11 topics. We excluded questions with modalities other than text (sound clips or images). Statistical analysis was done using an unpaired two-tailed t-test. Of the same 88 questions, ChatGPT 4.0 answered 66% of the questions correctly (n = 58/88) which was significantly greater (p < 0.0001) than ChatGPT 3.5, which only answered 38% (33/88). The ChatGPT 4.0 version also did better on each subspeciality topic as compared to ChatGPT 3.5. While acknowledging that ChatGPT does not yet offer subspecialty level knowledge in pediatric cardiology, the performance in pediatric cardiology educational assessments showed a considerable improvement in a short period of time between ChatGPT 3.5 and 4.0.

Mechanical atrioventricular valve replacement in patients with single ventricle palliation

OBJECTIVES

Atrioventricular valve (AVV) replacements in patients with single-ventricle circulations pose significant surgical risks and are associated with high morbidity and mortality.

METHODS

From 1997 to 2021, 16 consecutive patients with functionally single-ventricle physiology underwent mechanical AVV replacement. Primary outcome was transplant-free survival. Secondary outcomes included major postoperative morbidity.

RESULTS

The median age of AVV replacement was 2 years old (interquartile range 0.6-3.8 years). All AVV replacements were performed with a St. Jude Medical mechanical valve, median 24 mm (range, 19-31mm). Extracorporeal membrane oxygenation (ECMO) was required in 4 patients. Operative mortality was 38% (6/16). There were 2 late deaths and 3 transplants. Transplant-free survival was 50% at 1 year, 37.5% at 5 years, and 22% at 10 years. Transplant-free survival was higher for patients with preserved ventricular function (P = 0.01). Difference in transplant-free survival at 1 year was 75% vs 25%, at 5 years was 62.5% vs 12.5% and at 10 years was 57% vs 0%. Three (19%) patients had complete heart block requiring permanent pacemaker insertion. 6 of 13 patients (46%) patients reached Fontan completion (3 patients operated at/after Fontan). Significant bleeding events occurred in 8 patients (50%) with 3 patients suffering major cerebrovascular accidents. There were 6 events of valve thrombosis in 5 patients, resulting in 2 deaths and 2 heart transplants.

CONCLUSIONS

Mechanical valve replacement carries significant morbidity and mortality risk. While it successfully salvages about half of patients with preserved ventricular function, careful consideration of alternative options should be made before embarking upon mechanical valve replacement.

Melody Mitral Valve Is a Promising Alternative to Mechanical Valve Replacement for Young Children

PURPOSE

The purpose of this study was to compare outcomes of Melody mitral valve to mechanical mitral valve replacement (MVR) for young children.

DESCRIPTION

Children who underwent Melody MVR from 2014 to 2020 were case-matched to mechanical MVR patients. Transplant-free survival and cumulative incidence of reintervention were compared. A subanalysis was performed for infants aged < 1 year (9 Melody MVRs and their matches).

EVALUATION

Twelve children underwent Melody MVR. Two children (17%) salvaged from mechanical support died. Five of 10 survivors (50%) had subsequent MVR. At 1 and 3 years, transplant-free survival (Melody: 83%, 83%; mechanical: 83%, 67%; P = .180) and reintervention (Melody: 9%, 39%; mechanical: 0%, 18%; P = .18) were equivalent between groups. For children < 1 year of age, Melody MVR had a modest survival benefit (Melody: 89%, 89%; mechanical: 80%, 60%; P = .046), while rate of reintervention remained equivalent (Melody: 13%, 32%; mechanical: 0%, 22%; P = .32).

CONCLUSIONS

For patients < 1 year old, Melody MVR offers a promising alternative and is a reasonable bridge to mechanical MVR, which can be performed safely at an older age. Further studies are necessary to corroborate these findings.

Prospective Assessment of Coronary Artery Flows Before and After Cardiopulmonary Bypass in Children With a Spectrum of Congenital Heart Disease

Background

Normative data for the effect of cardiopulmonary bypass (CPB) on coronary artery Doppler velocities by transesophageal echocardiography in paediatric patients with congenital heart disease (CHD) are lacking. The objective of the study was to prospectively examine the effects of CPB on coronary artery flow patterns by transesophageal echocardiography before and after CPB in children with CHD.

Methods

All cases undergoing CHD surgery at the Hospital for Sick Children, Toronto, were eligible. The excluded cases included Norwood operation, heart transplantation, or weight <2.5 kg. Coronary Dopplers and coronary flow reserve (CFR) for the right coronary artery (RCA) and left anterior descending (LAD) were obtained. Multivariable analyses using linear regression models were performed, adjusted for age and cross-clamp time.

Results

From May 2017 to June 2018, 69 children (median age at surgery: 0.7 years, interquartile range [IQR]: 0.4-3.7 years; median weight: 7.4 kg, IQR: 5.8-13.3 kg) were included. They were grouped into shunt lesions (N = 26), obstructive lesions (N = 26), transposition of the great arteries (N = 5), and single ventricle (N = 12). N = 39 (57%) were primary repairs, and 56 (81%) had 1 CPB run. For RCA and LAD peak velocities, there was an increase from pre- to post-CPB in RCA peak 39 cm/s (IQR: 30-54 cm/s) to 65 cm/s (IQR: 47-81 cm/s), P < 0.001, mean CFR 1.52 (IQR: 1.25-1.81), and LAD peak 49 cm/s (IQR: 39-60 cm/s) to 70 cm/s (IQR: 52-90 cm/s), P < 0.001, mean CFR 1.48 (IQR: 1.14-1.77).

Conclusions

Coronary flow velocities increase from pre- to post-CPB in congenital heart lesions. CFR is consistent across all lesions but is relatively low compared with the adult population.

Pre-intervention morphologic and functional echocardiographic characteristics of neonates with critical left heart obstruction: a Congenital Heart Surgeons Society (CHSS) inception cohort study

AIMS

The aims of this study were to provide a detailed descriptive analysis of pre-intervention morphologic and functional echocardiographic parameters in a large, unselected, multicentre cohort of neonates diagnosed with critical left heart obstruction and to compare echocardiographic features between the different subtypes of left-sided lesions.

METHODS AND RESULTS

Pre-intervention echocardiograms for 651 patients from 19 Congenital Heart Surgeons' Society (CHSS) institutions were reviewed in a core lab according to a standardized protocol including >150 morphologic and functional variables. The four most common subtypes of lesions were: aortic atresia (AA)/mitral atresia (MA) (29% of patients), AA/mitral stenosis (MS) (20%), aortic stenosis (AS)/MS (26%), and isolated AS (iAS) (18%). Only 17% of patients with AS/MS had an apex-forming left ventricle, compared with 0% of those with AA/MA and AA/MS (P < 0.0001). Aortic arch hypoplasia and coarctation were common across all four groups, while those with AA/MA and AA/MS had the smallest ascending aorta diameters. Flow in the ascending aorta was retrograde in 43% and 10% of the patients with AS/MS and iAS, respectively. The right ventricle was apex forming in 100% of patients with AA/MA and AA/MS, 96% with AS/MS and 70% with iAS (P < 0.0001). Moderate to severe tricuspid regurgitation was present in 13% of all patients.

CONCLUSION

This large multi-institutional study generates insight into the distribution of the functional and morphologic spectrum in patients with critical left-sided heart disease and identifies differences in these functional and morphologic characteristics between the main anatomic subtypes of critical left heart obstruction.

Right ventricular function during exercise in children after heart transplantation

Aims

Right ventricular (RV) dysfunction is a common problem after heart transplant (HTx). In this study, we used semi-supine bicycle ergometry (SSBE) stress echocardiography to evaluate RV systolic and diastolic reserve in paediatric HTx recipients.

Methods and results

Thirty-nine pediatric HTx recipients and 23 controls underwent stepwise SSBE stress echocardiography. Colour tissue doppler imaging (TDI) peak systolic (s') and peak diastolic (e') velocities, myocardial acceleration during isovolumic contraction (IVA), and RV free wall longitudinal strain were measured at incremental heart rates (HR). The relationship with increasing HR was evaluated for each parameter by plotting values at each stage of exercise versus HR using linear and non-linear regression models. At rest, HTx recipients had higher HR with lower TDI velocities (s': 5.4 ± 1.7 vs. 10.4 ± 1.8 cm/s, P < 0.001; e': 6.4 ± 2.2 vs.12 ± 2.4 cm/s, P < 0.001) and RV IVA values (IVA: 1.2 ± 0.4 vs. 1.6 ± 0.8 m/s2, P = 0.04), while RV free wall longitudinal strain was similar between groups. At peak exercise, HR was higher in controls and all measurements of RV function were significantly lower in HTx recipients, except for RV free wall longitudinal strain. When assessing the increase in each parameter vs. HR, the slopes were not significantly different between patients and controls except for IVA, which was lower in HTx recipients.

Conclusion

In pediatric HTx recipients RV systolic and diastolic functional response to exercise is preserved with a normal increase in TDI velocities and strain values with increasing HR. The blunted IVA response possibly indicates a mildly decreased RV contractile response but it requires further investigation.

Improving Prenatal Diagnosis of Coarctation of the Aorta

BACKGROUND

The purpose of the study was to evaluate the association between fetal echocardiographic measurements and the need for intervention (primary coarctation repair, staged coarctation repair, or catheter intervention) in prenatally diagnosed coarctation of the aorta.

METHODS

A single-centre retrospective cohort study (2005-2015) of 107 fetuses diagnosed with suspected coarctation of the aorta in the setting of an apex-forming left ventricle and antegrade flow across the mitral and aortic valves.

RESULTS

Median gestational age at diagnosis was 32 weeks (interquartile range, 23-35 weeks). Fifty-six (52%) did not require any neonatal intervention, 51 patients (48%) underwent a biventricular repair. In univariable analysis, an increase in ascending aorta (AAo) peak Doppler flow velocity (odds ratio [OR], 1.40 [95% confidence interval [CI], 1.05-1.91] per 20 cm/s; P = 0.03) was associated with intervention. No intervention was associated with larger isthmus size (OR, 0.23; P < 0.001), transverse arch diameter (OR, 0.23; P < 0.001), and aortic (OR, 0.72; P = 0.02), mitral (OR, 0.58; P = 0.001), and AAo (OR, 0.53; P < 0.001) z-scores. In multivariable analysis, higher peak AAo Doppler (OR, 2.51 [95% CI, 1.54-4.58] per 20 cm/s; P = 0.001) and younger gestational age at diagnosis (OR, 0.81 [95% CI, 0.70-0.93] per week; P = 0.005) were associated with intervention, whereas a higher AAo z-score (OR, 0.65 [95% CI, 0.43-0.94] per z; P = 0.029) and transverse arch dimension (OR, 0.44 [95% CI, 0.18-0.97]; P = 0.05) decreased the risk of intervention.

CONCLUSIONS

In prenatally suspected coarctation, the variables associated with intervention comprised smaller AAo and transverse arch size, earlier gestational age at diagnosis, and the additional finding of a higher peak AAo Doppler.

Contemporary Outcomes and Factors Associated With Mortality After a Fetal or Postnatal Diagnosis of Common Arterial Trunk

BACKGROUND

Common arterial trunk (CAT) is a rare anomaly with a spectrum of pathology. We sought to identify current trends and factors associated with postnatal outcomes.

METHODS

This was a single-centre review including 153 live births with planned surgery. Patients were analyzed as 2 cohorts based on era of CAT diagnosis (1990 to 1999 vs 2000 to 2014) and complexity of disease (simple vs complex). "Complex" required the association with significant aortic arch obstruction, truncal valve (TV) stenosis/regurgitation, and/or branch pulmonary artery (PA) hypoplasia, respectively.

RESULTS

Sixteen (10%) died preoperatively, and this outcome was associated with significant TV stenosis (odds ratio [OR] 4.55; P = 0.01) and regurgitation (OR 3.17; P = 0.04); 130 (95%) of 137 operated infants underwent primary complete repair. Their survival rates to 1 year improved from 54% to 85% after 2000, although this outcome remained substantially lower for cases with a complex vs simple CAT repair (76% vs 95%; OR 6.46; P = 0.006). Other risk factors associated with decreased 1-year survival included diagnosis before 2000 (OR 4.48; P = 0.038) and a lower birth weight (OR 8.0 per kg weight; P = 0.001). Finally, of 93 survivors beyond year 1 of life, 76 (82%) had undergone a total of 224 reinterventions. Only 15 (16%) were alive without any surgical or catheter-based reintervention at study end.

CONCLUSIONS

Despite recent surgical improvements, postnatal mortality continues to be substantial if CAT is complicated by significant pathology of the TV, aortic arch, or branch PAs. Reoperations and catheter interventions are eventualities for most patients during childhood.

Transcatheter left ventricular outflow tract stent placement in a low birth weight child with hypoplastic left ventricle, mitral atresia, transposition of the great arteries, ventricular septal defect and severe pulmonary stenosis

A baby boy, the first of triplets born at 33 weeks gestation weighing 1.88 kg, presented with neonatal cyanosis and was diagnosed with mitral atresia, hypoplastic left ventricle, ventricular septal defect, d-transposition of the great arteries, severe pulmonary stenosis, and hypoplastic branch pulmonary arteries. He was treated with prostaglandin until seven weeks of age. The patent ductus arteriosus was curly Q and not suitable for stent placement. Cardiac catheterization was undertaken and using an antegrade approach, a Multi-Link Ultra stent was implanted across the left ventricular outflow tract (LVOT) and inflated to 5 mm to improve antegrade pulmonary blood flow. This allowed reasonable pulmonary arterial growth to allow the patient undergo bidirectional Glenn shunt at five months of age. This first report of LVOT stenting in this setting may provide an alternative to placement of a systemic to pulmonary arterial shunt when ductal stenting is not possible.

Using mathematical modelling to inform on the ability of stormwater ponds to improve the water quality of urban runoff

This paper concerns the mathematical modelling of flow and solute transport through stormwater ponds. The model is based on appropriate lumped system conservation equations that are solved using standard numerical techniques. The model was used to route a first flush pollution scenario through a cylindrical pond for 16 combinations of elevation and diameter of a submerged pipe outlet, in conjunction with a high level weir. Higher pipe elevations and smaller pipe diameters created larger pond volumes and hence led to greater dilution of the pollutant. In contrast, lower pipe elevations created larger storage volumes, leading to better flow attenuation. Interestingly, larger pipe diameters improved peak flow attenuation, even though the storage used decreased.

Characterization of a Vascular Wilt of Erythroxylum coca Caused by Fusarium oxysporum f. sp. erythroxyli Forma Specialis Nova

A new forma specialis of Fusarium oxysporum (F. oxysporum f. sp. erythroxyli) pathogenic to Erythroxylum coca and E. novogranatense is described. The pathogen was isolated from the vascular tissue of diseased plants from an Erythroxylum plantation in Hawaii. This pathogen causes vascular wilt symptoms and death in both E. coca and E. novogranatense plants as soon as 7 weeks after soil infestation. The pathogenicity of seven isolates from the affected field was determined in field and growth-chamber studies. Genetic variation was not detected among the seven Hawaiian isolates, using arbitrarily primed polymerase chain reaction. The seven isolates could be differentiated from a strain isolated from a diseased E. coca plant from South America. All Hawaiian isolates and the South American isolate belonged to a single vegetative compatibility group.