Application of Cardiovascular Computed Tomography to the Assessment of Patients With Hypertrophic Cardiomyopathy.

Hypertrophic cardiomyopathy is a common inherited cardiac condition in which regional myocardial thickening and scarring can lead to a range of symptoms including breathlessness, dizziness, chest pain, and collapse with loss of consciousness. It is vital to be able to understand the mechanisms behind these epiphenomena and to be able to distinguish, for example, between syncope because of arrhythmia versus syncope because of mechanical outflow tract obstruction. Therefore, we require a technique that can characterize anatomy, physiology, and myocardial substrate. Traditionally, this role has been the preserve of cardiac magnetic resonance (CMR) imaging. This review makes the case for cardiac computed tomography (CT) as an alternative imaging method. We review the use of functional CT to identify the components of outflow tract obstruction (and obstruction at other levels, which may be simultaneous), and as an aid to interventional and surgical planning. We demonstrate the added value of multiplanar isotropic reformats in this condition, particularly in cases where the diagnosis may be more challenging or where complications (such as early apical aneurysm) may be difficult to recognize with 2-dimensional techniques. In conclusion, our aim is to convince readers that cardiac CT is a highly valuable and versatile tool, which deserves wider usage and greater recognition in those caring for patients with hypertrophic cardiomyopathy.

Preventing sedentary lifestyles among young children born with congenital heart defects: A feasibility study of physical activity rehabilitation after surgical or catheterization intervention.

BACKGROUND: Children with congenital heart disease (CHD) often have inactive lifestyles and motor skill deficits beginning in infancy. The least active infants continue to be the least active children at school age. Enhancing physical activity and motor development in infancy, at the time of CHD treatment, may prevent inactive lifestyle habits. METHODS: All children being treated, through surgery or catheterization, for congenital heart disease are eligible if they are 3 to 72 months of age at enrollment. The Peabody Motor Development Scales (Version 2) and 7-day accelerometry (Actigraph GT9X Link) assess motor skills and physical activity prior to treatment and 7 weeks, 6 months and 12 months post-treatment. Participants are randomized 3:1 to intervention:control. Until 7 weeks post-treatment, intervention activities focus on regaining pre-treatment mobility and midline crossing. From 7 weeks to 6 months post-treatment, the intervention is individualized to each child's assessment results and is parent-led, delivered at home and play-based. CONCLUSION: This feasibility study will provide essential data for a randomized controlled trial to evaluate play-based, parent-delivered interventions optimized to support age-appropriate physical activity and motor skills among young children with CHD. Preliminary intervention efficacy data will inform an evidence-based sample size calculation, optimize intervention timing, and identify hypotheses on the motor skill-physical activity connection and the impact of play-based, parent-led interventions during recovery from CHD treatment. Long-term, the goal is to optimize motor skill and active lifestyles among young children with CHD, enabling their healthy growth and development and enhancing childhood quality of life. TRIAL REGISTRATION: Clinical trials registration: NCT04619745.

Pulmonary Autograft Coronary-Cameral Fistula Leading to LVOT Pseudoaneurysm Post Ross Procedure.

We report the case of a presumed coronary-cameral fistula arising directly below the commissures of the noncoronary cusp (NCC) and left coronary cusp (LCC) of the pulmonary autograft, leading to left ventricular outflow tract pseudoaneurysm and late tamponade post Ross procedure.

Prevention of post-cardiac surgery vitamin D deficiency in children with congenital heart disease: a pilot feasibility dose evaluation randomized controlled trial.

BACKGROUND: The vast majority of children undergoing cardiac surgery have low vitamin D levels post-operative, which may contribute to greater illness severity and worse clinical outcomes. Prior to the initiation of a large phase III clinical trial focused on clinical outcomes, studies are required to evaluate the feasibility of the study protocol, including whether the proposed dosing regimen can safely prevent post-operative vitamin D deficiency in this high-risk population. METHODS: We conducted a two-arm, double-blind dose evaluation randomized controlled trial in children requiring cardiopulmonary bypass for congenital heart disease. Pre-operatively, participants were randomized to receive cholecalciferol representing usual care (< 1 year = 400 IU/day, > 1 year = 600 IU/day) or a higher dose approximating the Institute of Medicine tolerable upper intake level (< 1 year = 1600 IU/day, > 1 year = 2400 IU/day). The feasibility outcomes were post-operative vitamin D status (primary), vitamin D-related adverse events, accrual rate, study withdrawal rate, blinding, and protocol non-adherence. RESULTS: Forty-six children were randomized, and five withdrew prior to surgery, leaving 41 children (21 high dose, 20 usual care) in the final analysis. The high dose group had higher 25-hydroxyvitamin D concentrations both intraoperatively (mean difference + 25.9 nmol/L; 95% CI 8.3-43.5) and post-operatively (mean difference + 17.2 nmol/L; 95% CI 5.5-29.0). Fewer participants receiving high-dose supplementation had post-operative serum 25-hydroxyvitamin D concentrations under 50 nmol/L, compared with usual care (RR 0.31, 95% CI 0.11-0.87). Post-operative vitamin D status was associated with the treatment arm and the number of doses received. There were no cases of hypercalcemia, and no significant adverse events related to vitamin D. While only 75% of the target sample size was recruited (limited funding), the consent rate (83%), accrual rate (1.5 per site month), number of withdrawals (11%), and ability to maintain blinding support feasibility of a larger trial. CONCLUSIONS: Pre-operative daily high-dose supplementation improved vitamin D status pre-operatively and at time of pediatric ICU admission. The protocol for a more definitive trial should limit enrollment of children with at least 30 days between randomization and surgery to allow adequate duration of supplementation or consider a loading dose. TRIAL REGISTRATION: ClinicalTrials.gov, NCT01838447. Registered on April 24, 2013.

Retroesophageal Infracardiac Total Anomalous Pulmonary Venous Drainage.

This case report describes the management of a term baby, born cyanotic, who was preoperatively diagnosed to have an obstructed total anomalous pulmonary venous drainage (TAPVD) in association with a functionally univentricular heart. An urgent repair of the anomalous pulmonary venous drainage was done, and a modified Blalock-Taussig shunt was constructed. Intraoperative difficulties were encountered when the pulmonary venous confluence was not seen in the usual location in the posterior mediastinal space, anterior to the esophagus. This report describes the rare finding of infracardiac TAPVD that is located in the retroesophageal space.

Infected Rastelli Conduit in an Immunocompromised Patient That Was Not Visible on Transthoracic Echocardiogram.

An 18-year-old man with a history of right ventricle to pulmonary artery conduit implantation for repair of congenital heart disease and vasculitis requiring chronic immunosuppression with azathioprine presented to the University of Ottawa with bacteremia. A transthoracic echocardiogram revealed no abnormalities at the site of the conduit. A fludeoxyglucose positron emission tomography scan was subsequently obtained that demonstrated an infected right ventricle to pulmonary artery conduit. It is important to remember that, as is true for classic valve endocarditis, an unremarkable transthoracic echocardiogram does not rule out an infected conduit in this population, and nuclear imaging may have important diagnostic utility.

Un homme de 18 ans, chez qui on avait implanté un conduit ventricule droit-artère pulmonaire (VD-AP) pour réparer une cardiopathie congénitale et qui avait des antécédents de vascularite nécessitant une immunosuppression continue par l'azathioprine, s'est présenté à l'hôpital affilié à l'Université d'Ottawa pour une bactériémie. Une échocardiographie transthoracique n'a révélé aucune anomalie au site du conduit. Elle a été suivie d'un examen de tomographie par émission de positrons (TEP) au fludésoxyglucose, qui a mis en évidence une infection du conduit VD-AP. Il est important de retenir que, comme dans le cas d'une endocardite valvulaire classique, un échocardiogramme transthoracique sans particularité ne permet pas d'exclure une infection de conduit dans cette population, et que l'imagerie nucléaire peut être d'une grande utilité diagnostique.

Calcitriol trend following pediatric cardiac surgery and association with clinical outcome.

BACKGROUND: Consistent with accepted practice in stable ambulatory populations, the majority of ICU research has evaluated vitamin D status using a single blood 25-hydroxyvitamin D (25(OH)D) level. Only a limited number of ICU studies have measured the active hormone, 1,25-dihydroxyvitamin D (calcitriol) and none have used change in calcitriol levels to evaluate axis functioning. The objective of this study was to describe the impact of Congenital Heart Disease (CHD) surgery on calcitriol levels and evaluate the relationship between change in postoperative levels and clinical course. METHODS: Secondary analysis of a prospective cohort study of 56 children undergoing surgery for CHD. RESULTS: Mean calcitriol levels dropped from 122.3 ± 69.1 pmol/L preoperatively to 65.3 ± 36.5 pmol/L (p < 0.0001) at PICU admission. The majority (61%, n = 34) were unable to increase calcitriol levels in the 48 h immediately following surgery. Post operative trend in calcitriol was inversely related to cardiovascular dysfunction, fluid requirements, ventilatory support and PICU length of stay (p < 0.01). CONCLUSION: CHD patients had significant dysfunction of the vitamin D axis immediately postoperatively, demonstrated by both a significant intraoperative decline in calcitriol and inability to increase levels. Interventional research will be required to determine whether the use of calcitriol, in addition to cholecalciferol, reduces postoperative illness severity.

Long venous cannula on the arterial position for VA-ECMO.

Differential hypoxia and the arterial mixing zone are two important factors in managing peripheral veno-arterial extracorporeal membrane oxygenation (VA-ECMO). With the aim of improving perfusion to the aortic arch branches and coronaries, we describe our approach for VA-ECMO cannulation: bicaval drainage through the femoral vein and proximal retrograde ECMO flow using a multi-stage venous cannula inserted in the femoral artery and the tip placed at the proximal descending thoracic aorta. We report the use of this VA-ECMO approach on a 15-year-old female with combined cardiorespiratory failure and on a 12-year-old male with acute cardiac failure.

Prevention of vitamin D deficiency in children following cardiac surgery: study protocol for a randomized controlled trial.

BACKGROUND: Vitamin D is a pleiotropic hormone important for the recovery of organ systems after critical illness. Recent observational studies have suggested that three out of every four children are vitamin D deficient following cardiac surgery, with inadequate preoperative intake and surgical losses playing important contributory roles. Observed associations between postoperative levels, cardiovascular dysfunction and clinical course suggest that perioperative optimization of vitamin D status could improve outcome. With this two-arm, parallel, double blind, randomized controlled trial (RCT), we aim to compare immediate postoperative vitamin D status in children requiring cardiopulmonary bypass for congenital heart disease who receive preoperative daily high dose vitamin D supplementation (high-dose arm) with those who receive usual intake (low-dose arm). METHODS/DESIGN: Eligibility requirements include age (>36 weeks, <18 years) and a congenital heart defect requiring cardiopulmonary bypass surgical correction. Enrollment of 62 participants will take place at a single Canadian tertiary care center over a period of 2 years. Children randomized to the high-dose group will receive age-based dosing that was informed by the Institute of Medicine (IOM) daily tolerable upper intake level (<1 year old = 1,600 IU/day, >1 year old = 2,400 IU/day). Children in the low-dose arm will receive usual care based on IOM recommendations (<1 year old = 400 IU, >1 year old = 600 IU). The primary outcome measure is immediate postoperative vitamin D status, using blood 25(OH)D. DISCUSSION: Maintaining adequate postoperative vitamin D levels following surgery could represent an effective therapy to speed recovery following CHD surgery. The proposed research project will determine whether preoperative supplementation with a dosing regimen based on the IOM recommended daily upper tolerable intake will prevent postoperative vitamin-D deficiency in the majority of children. The results will then be used to inform the design of a large international RCT exploring whether preoperative optimization of vitamin D status might improve short and long-term outcomes in this vulnerable population. TRIAL REGISTRATION: Clinicaltrials.gov Identifier--NCT01838447 Date of registration: 11 April 2013.

Impact of anesthesia and surgery for congenital heart disease on the vitamin d status of infants and children: a prospective longitudinal study.

BACKGROUND: Vitamin D is recognized as a pleiotropic hormone important for the functioning of organ systems, including those central to critical illness pathophysiology. Recent studies have reported associations between vitamin D status and outcome among critically ill adults and children. Preoperative vitamin D status, impact of operative techniques, and relationship between immediate postoperative vitamin D levels and clinical course have not been described in the pediatric congenital heart disease (CHD) population. The objective of this study was to describe the impact of CHD surgery on vitamin D status and relationship between postoperative levels and clinical course. METHODS: A prospective cohort study was conducted from 2009 to 2011 at a single tertiary care pediatric hospital. A total of 58 children with CHD were enrolled and blood collected preoperatively, intraoperatively, and postoperatively. Serum 25-hydroxyvitamin D (25OHD) was measured using liquid chromatography-mass spectrometry. RESULTS: The mean preoperative 25OHD was 58.0 nM (SD, 22.4), with 42% being deficient (<50 nM). Postoperatively, we identified a 40% decline in 25OHD to 34.2 nM (SD, 14.5) with 86% being deficient. Intraoperative measurements determined that initiation of cardiopulmonary bypass coincided with abrupt decline. CHD patients requiring catecholamines had lower postoperative 25OHD (38.2 vs. 26.5 nM, P=0.007), findings confirmed through multivariate logistic regression. Lower postoperative 25OHD was associated with increased fluid requirements and intubation duration. CONCLUSIONS: Most CHD patients are vitamin-D deficient postoperatively due to low preoperative levels and a significant intraoperative decline. Interventional studies will be required to determine whether prevention of postoperative vitamin D deficiency improves outcome.

Brachial artery occlusion in a young adult with an ACTA2 thoracic aortic aneurysm.

Mutations of the ACTA2 gene, which encodes the smooth muscle cell-specific isoform of α-actin protein, have recently been found to be among the most common genetic abnormalities observed in patients with familial thoracic aortic aneurysms/dissection (TAAD). Other reported vascular manifestations caused by these mutations include premature coronary artery disease and stroke. We report a young adult who presented with an acute brachial artery occlusion and was subsequently found to have aortopathy and an ACTA2 mutation. This expands the spectrum of vascular disease associated with ACTA2 mutation to include acute limb ischemia.

Therapeutic strategies, including a high surgical ligation rate, for patent ductus arteriosus closure in extremely premature infants in a North American centre.

OBJECTIVE: To document the rate of surgical ligation of a patent ductus arteriosus (PDA) in extremely premature infants who had received more than one course of indomethacin. Outcomes were compared among three subgroups (ligation, further indomethacin and no further treatment) of infants who received at least one course of indomethacin, and between two subgroups (one course of indomethacin and more than one course) among infants who underwent ligation. STUDY DESIGN: A retrospective chart review of all 23 weeks+0 days to 26 weeks+6 days' gestational age infants with a PDA born between 1994 and 2005 was performed. Secondary outcomes were compared among the subgroups. RESULTS: The final study population consisted of 196 extremely premature infants with a PDA. The rate of surgical ligation in the 88 infants who received more than one course of indomethacin was 64%. The ligation subgroup, in comparison with the no further treatment subgroup, spent a greater median time on mechanical ventilation (39 versus 29 days, P<0.001) and in hospital (115 versus 92 days P=0.002), while trending toward lower mortality (18% versus 40%, P=0.07). The PDA closed following the first course of indomethacin in only 20% of infants. CONCLUSIONS: A majority of extremely premature infants receiving more than one course of indomethacin underwent surgical ligation. Repeated indomethacin courses were generally well tolerated, but were mostly unsuccessful. Ligation appears to have potential risks and benefits. A randomized trial should be performed after studies define a hemodynamically significant PDA that will result in morbidity and/or mortality unless treated.

OBJECTIF: Étayer le taux de ligatures chirurgicales de persistances du canal artériel (PCA) chez des grands prématurés qui avaient reçu plus d'une série de traitement à l'indométhacine. Les chercheurs ont comparé les issues entre les trois sous-groupes (ligature, nouvelle série de traitement à l'indométhacine et aucun traitement supplémentaire) et les nourrissons qui avaient reçu au moins une série de traitement à l'indométhacine, ainsi qu'entre deux sous-groupes (une série de traitement à l'indométhacine et plus d'une dose) et les nourrissons qui avaient eu une ligature. MÉTHODOLOGIE: Les chercheurs ont procédé à l'analyse rétrospective des dossiers de tous les nourrissons de 23+0 à 26+6 semaines d'âge gestationnel ayant une PCA, qui étaient nés entre 1994 et 2005. Ils ont comparé les issues secondaires entre les sous-groupes. RÉSULTATS: La population finale à l'étude se composait de 196grands prématurés ayant une PCA. Le taux de ligatures chirurgicales chez les 88 nourrissons qui avaient reçu plus d'une série de traitement à l'indométhacine s'élevait à 64 %. Le sous-groupe ligaturé, par rapport au sous-groupe n'ayant pas reçu de traitement supplémentaire, présentait une durée médiane plus élevée sous ventilation mécanique (39 jours par rapport à 29, P<0,001) et d'hospitalisation (115 jours par rapport à 92, P=0,002), tout en manifestant une tendance vers une mortalité moins élevée (18 % par rapport à 40 %, P=0,07). La PCA s'est fermée après la première dose d'indométhacine chez seulement 20% des nourrissons. CONCLUSIONS: La majorité des grands prématurés qui avaient reçu plus d'une série de traitement à l'indométhacine ont subi une ligature chirurgicale. Les nouvelles séries de traitement à l'indométhacine étaient généralement bien tolérées, mais la plupart étaient sans effet sur la PCA. La ligature semble s'associer à des risques et bienfaits potentiels. Il faudrait procéder à un essai aléatoire après que des études auront défini une PCA significative sur le plan hémodynamique qui s'associe à une morbidité ou une mortalité à moins d'être traitée.