Congenital Cardiac Anesthesia Society
A Section of the the Society for Pediatric Anesthesia

{“questions”:{“9i62x”:{“id”:”9i62x”,”mediaType”:”image”,”answerType”:”text”,”imageCredit”:””,”image”:”https:\/\/ccasociety.org\/wp-content\/uploads\/2023\/08\/Picture1-CCAS-832023.png”,”imageId”:”6703″,”video”:””,”imagePlaceholder”:””,”imagePlaceholderId”:””,”title”:”Author: Nicholas Houska, DO and Dustin Nash, MD – University of Colorado, Children\u2019s Hospital Colorado \r\n\r\nA 4-month-old infant has just undergone repair of Tetralogy of Fallot with a transannular patch, removal of right ventricular muscle bundles and ventricular septal defect (VSD) closure. Six hours postoperatively, the patient\u2019s heart rate gradually increases to 230 beats per minute with concurrent hypotension. The electrocardiogram (ECG) demonstrates a narrow complex tachycardia. An atrial electrogram is performed and illustrated below (From author\u2019s library). What is the MOST likely diagnosis?\r\n\r\n\r\n”,”desc”:”EXPLANATION \r\nJunctional ectopic tachycardia (JET) is an arrythmia most frequently seen in infants and children. It may be congenital in nature, but more commonly occurs postoperatively after cardiac surgery. JET originates from the area near the atrioventricular (AV) node and Bundle of His. It is most frequently associated with VSD closure, repair of Tetralogy of Fallot, and atrioventricular septal defect repair. Other risk factors for the development of JET include age less than 6 months, prolonged surgical time, prolonged cross clamp time, and the use of inotropes. The pathophysiology of postoperative JET is incompletely understood but is thought to be associated with trauma, stretch, and ischemia of the conduction system leading to the loss of cell membrane integrity. The etiology is likely multi-factorial but is ultimately related to increased sympathetic tone and automaticity. JET can be associated with significant morbidity and mortality. Additionally, it may be difficult to diagnose and treat. JET occurs with a frequency of 5-10% after congenital cardiac surgery. For these reasons, it is important for clinicians to have a high index of suspicion for JET and provide prompt diagnosis and treatment. \r\n\r\nJunctional ectopic tachycardia is typically a narrow complex tachycardia with ventriculo-atrial (VA) dissociation. The ventricular rate is typically irregular and higher than the atrial rate except in the less common instance of one to one (1:1) VA conduction. Onset is gradual with no initiating ectopic beat. Patients with JET have a heart rate greater than the 95th percentile for age, otherwise it is termed accelerated junctional rhythm. Diagnosis can be difficult on a standard surface ECG due to the difficulty in identifying atrial depolarization (P wave). In patients with atrial pacing leads, an atrial electrogram can be performed by connecting the atrial lead directly to one of the leads on a standard ECG. This allows identification of atrial depolarization in side by side comparison with ventricular depolarization in the other leads. The ECG below shows dissociation of ventricular depolarization (V) at a rate of 195 beats per minute (bpm) from atrial depolarization (A) at a rate of 170 bpm, which confirms the diagnosis of JET. Red squares are highlighting the association of QRS complexes on the standard ECG with the signals on the atrial electrogram. \r\n\r\nPostoperative JET is typically self-limited, but treatment may be indicated for hemodynamic instability. Treatment includes attenuating sympathetic stimulation by reducing inotrope dose, optimizing analgesia and sedation, and administration of dexmedetomidine. Correction of electrolytes and induction of mild hypothermia are also mainstays of treatment. Adenosine will not terminate JET but will cause AV dissociation when JET is difficult to identify. Amiodarone is the drug of choice for treatment. In refractory cases with hemodynamic instability, extracorporeal membrane oxygenation and\/or catheter ablation may be indicated. \r\n\t\r\n(Source: author\u2019s library)\r\n \r\nREFERENCES \r\nAlasti M, Mirzaee S, Machado C, et al. Junctional ectopic tachycardia (Jet). J Arrhythmia <\/em>.2020;36(5):837-844.\r\n\r\nKaltman JR, Madan N, Vetter VL, Rhodes LA. Arrhythmias and sudden cardiac death. In: Pediatric Cardiology<\/em>. Elsevier; 2006:171-194.\r\n\r\nSasikumar N, Kumar R, Balaji S. Diagnosis and management of junctional ectopic tachycardia in children. Ann Pediatr Card<\/em>. 2021;14(3):372.\r\n\r\nAshraf M, Goyal A. Junctional ectopic tachycardia. In: StatPearls<\/em>. StatPearls Publishing; 2023. Accessed July 21, 2023. https:\/\/www.ncbi.nlm.nih.gov\/books\/NBK560851\/\r\n”,”hint”:””,”answers”:{“wud5a”:{“id”:”wud5a”,”image”:””,”imageId”:””,”title”:”A. Atrioventricular nodal reentrant tachycardia (AVNRT)”},”kh7ns”:{“id”:”kh7ns”,”image”:””,”imageId”:””,”title”:”B. Ventricular Tachycardia”},”ptlqh”:{“id”:”ptlqh”,”image”:””,”imageId”:””,”title”:”C. Junctional Ectopic Tachycardia”,”isCorrect”:”1″}}}}}

{“questions”:{“115eb”:{“id”:”115eb”,”mediaType”:”image”,”answerType”:”text”,”imageCredit”:””,”image”:””,”imageId”:””,”video”:””,”imagePlaceholder”:””,”imagePlaceholderId”:””,”title”:”Author: Nicholas Houska, DO and Raveendra Morchi, MD – University of Colorado, Children’s Hospital Colorado \r\n\r\nA 4-month-old male presents for surgical closure of a large ventricular septal defect (VSD) due to failure to thrive and feeding intolerance. Which of the following types of VSD is associated with the HIGHEST risk of injury to the conduction system and subsequent heart block during surgical closure?”,”desc”:”EXPLANATION \r\nSeptation of the ventricles occurs in the first trimester and is intimately related to development of the atrioventricular canals and the outflow tracts. The muscular septum forms from an infolding of ventricular muscle which develops to align with the conal septum of the ventricular outflow tracts. The final area of septation is the membranous septum which develops from the endocardial cushions. The development of the of the atrioventricular node, His-Purkinje system, and bundle branches anatomically coincide with the development of the ventricular septum. \r\n\r\nThere are multiple systems of nomenclature in common usage to describe and classify VSDs, which has led to significant confusion in the literature and clinical practice. To provide uniformity of language and improve communication, the International Society for Nomenclature of Pediatric and Congenital Heart Disease has proposed a classification system which has been accepted by the World Health Organization into the 11th iteration of the international classification of diseases. Under this classification, VSDs are divided into four major groups with descriptors added for the various subtypes within each group. The four groups are: perimembranous central, inlet, trabecular muscular, and outlet. Of these, the perimembranous central type is the most common, comprising greater than 80% of clinically significant VSDs. \r\n\r\nOne of the most serious complications after surgical closure of a ventricular septal defect (VSD) is complete heart block, having a significant impact on long term morbidity. Perimembranous VSDs are intimately associated with the conduction system at the inferoposterior margin, namely the AV node, Bundle of His, and right bundle branch, and are at the highest risk of surgically-induced heart block (see the image below \u2013 by R. Morchi, MD, used by permission). Careful surgical technique and suture placement in this area is essential to prevent damage to the conduction system and subsequent heart block. There is also risk of perioperative heart block after closure of an inlet VSD due to close proximity to the conduction system. Trabecular muscular and outlet VSDs are located in a more remote location from the major components of the conduction system and are much less likely to result in surgical heart block after surgical closure. With improvement in surgical techniques over the years, the current incidence of complete heart block after VSD closure is less than one percent.\r\n\r\n\t\r\n\r\n\r\n \r\n\r\n \r\nREFERENCES \r\nLopez L, Houyel L, Colan SD, et al. Classification of ventricular septal defects for the eleventh iteration of the international classification of diseases\u2014striving for consensus: a report from the international society for nomenclature of paediatric and congenital heart disease. The Annals of Thoracic Surgery <\/em>. 2018;106(5):1578-1589.\r\n\r\nGholampour-Dehaki M, Zareh A, Babaki S, Javadikasgari H. Conduction disorders in continuous versus interrupted suturing technique in ventricular septal defect surgical repair. Res Cardiovasc Med <\/em>. 2016;5(1).\r\n\r\nJonas RA. Vnetricular Septal Defect. In: Comprehensive Surgical Management of Congenital Heart Disease <\/em>.2nd ed. CRC Press; 2014. 331-346.\r\n\r\nAndersen H\u00d8, de Leval MR, Tsang VT, Elliott MJ, Anderson RH, Cook AC. Is complete heart block after surgical closure of ventricular septum defects still an issue? The Annals of Thoracic Surgery <\/em>. 2006;82(3):948-956.\r\n\r\nLamers WH, Moorman AFM. Cardiac septation: a late contribution of the embryonic primary myocardium to heart morphogenesis. Circulation Research <\/em>. 2002;91(2):93-103.\r\n”,”hint”:””,”answers”:{“21lqw”:{“id”:”21lqw”,”image”:””,”imageId”:””,”title”:”A. Perimembranous Central”,”isCorrect”:”1″},”6djzy”:{“id”:”6djzy”,”image”:””,”imageId”:””,”title”:”B. Trabecular Muscular”},”7yr2w”:{“id”:”7yr2w”,”image”:””,”imageId”:””,”title”:”C. Outlet”}}}}}

{“questions”:{“97cp5”:{“id”:”97cp5″,”mediaType”:”image”,”answerType”:”text”,”imageCredit”:””,”image”:””,”imageId”:””,”video”:””,”imagePlaceholder”:””,”imagePlaceholderId”:””,”title”:”Authors: Jeffrey C. Waldman MD, and Nicholas M. Houska, DO – Children\u2019s Hospital Colorado, University of Colorado School of Medicine, Aurora, CO \r\n\r\nThe duration of cardiopulmonary resuscitation (CPR) in a heart transplant donor is a known risk factor for decreased post-transplant survival. What DURATION of CPR performed on a heart transplant donor is associated with decreased post-transplant survival? “,”desc”:”EXPLANATION \r\nThe mortality of children awaiting heart transplantation is higher than any other solid organ transplant. Infants have the highest rate of waitlist mortality (25-30%), and children demonstrate a significantly higher risk of death compared to adults. This is related to the limited availability of donor organs and recipient factors such as age, weight, diagnosis, clinical status, and limited options for mechanical circulatory support. \r\n\r\nDonor characteristics that are associated with refusal for organ donation include gender, blood-type, Centers for Disease Control (CDC) \u201chigh risk\u201d criteria, reduced left ventricular ejection fraction (LVEF), and inotrope usage. Historically, there has been a decrease in the number of organs accepted for transplantation when a donor undergoes CPR. Among pediatric cardiac transplant physicians\/providers, there is also considerable variability in the evaluation of transplant donors, with no standardization of criteria for donor candidacy. \r\n\r\nA retrospective study by Kulshrestha et al from 2001 to 2021 using the United Network for Organ Sharing (UNOS) database compared the acceptance rate of donor hearts according to 1) whether the donor received CPR and 2) the duration of CPR. More than five thousand heart transplant recipients under the age of 18 years old were identified and survival analysis was performed to identify the duration of CPR which resulted in decreased post-transplant survival. A duration of CPR greater than 55 minutes in the donor resulted in a statistically significant decrease in post-transplant survival versus duration of CPR less than 55 minutes (mean survival 11.3 vs 10.2 years, p=0.03). During the study period, 51% of donors received CPR before organ procurement. Acceptance rate of the heart was lower when the donor received CPR as compared to no CPR (54 vs 66%, p less than 0.001) and decreased as the duration of CPR increased. Among the recipient cohort, 52% received a heart from a donor requiring CPR. With an inflection point in survival identified, the recipient cohort was divided into three groups: no donor CPR, CPR \u2264 55 minutes, and CPR greater than 55 minutes. Differences between the groups were identified and further analysis was performed to control for confounding variables. There was no difference in graft failure in recipients who received a heart transplant from a donor NOT requiring CPR as compared to recipients with a donor that had CPR \u2264 55 minutes. CPR duration greater than 55 minutes predicted worse post-transplant survival (HR 1.4 [1.03-1.90]) relative to no CPR, but CPR duration less than or equal to 55 minutes did not predict worsened survival (HR 1.02 [0.90-1.17]) relative to no CPR. Other significant variables affecting post-transplant survival include donor age, race of the recipient, renal dysfunction and dialysis in the recipient, extracorporeal membrane oxygenation in the recipient, and congenital heart disease in the recipient. \r\n\r\n \r\nREFERENCES \r\nAlmond CS, Thiagarajan RR, Piercey GE, et al. Waiting list mortality among children listed for heart transplantation in the United States. Circulation <\/em>. 2009;119:717-27.\r\n\r\n\r\nDipchand AI. Current state of pediatric cardi ac transplantation. Ann Cardiothorac Surg <\/em>. 2018;7:31-55.\r\n\r\nGodown J, Kirk R, Joong A, et al. Variability in donor selection among pediatric heart transplant providers: Results from an international survey. Pediatr Transplant <\/em>. 2019;23:e13417.\r\n\r\nKulshrestha K, Greenberg JW, Guzman-Gomez AM, et al. Up to an hour of donor resuscitation does not affect pediatric heart transplantation survival. Ann Thorac Surg <\/em>. Published online June 2023:S0003497523005696.\r\n”,”hint”:””,”answers”:{“mqpbo”:{“id”:”mqpbo”,”image”:””,”imageId”:””,”title”:”A.\t> 15 minutes”},”avdqu”:{“id”:”avdqu”,”image”:””,”imageId”:””,”title”:”B.\t> 35minutes”},”57ae6″:{“id”:”57ae6″,”image”:””,”imageId”:””,”title”:”C.\t> 55 minutes”,”isCorrect”:”1″}}}}}

{“questions”:{“unq3h”:{“id”:”unq3h”,”mediaType”:”image”,”answerType”:”text”,”imageCredit”:””,”image”:””,”imageId”:””,”video”:””,”imagePlaceholder”:””,”imagePlaceholderId”:””,”title”:”Author: Nicholas Houska, DO – University of Colorado, Children\u2019s Hospital Colorado \r\n\r\nA 1-week-old, 3.6 kg neonate is admitted to the cardiac intensive care unit with decreased responsiveness, poor urine output and diminished femoral pulses. A transthoracic echocardiogram reveals coarctation of the aorta.\r\n \r\nWhat is the MOST likely coexisting congenital heart defect in this patient?”,”desc”:”EXPLANATION \r\nBicuspid aortic valve (BAV) is the most common congenital heart defect with a prevalence of 1-2%. Coarctation of the aorta (CoA) occurs in three out of every 10,000 live births but is more common when occurring in conjunction with other congenital heart defects. BAV and CoA have a male to female predominance of 2:1to 4:1. In addition, both are associated with Turner syndrome. While approximately 7% of patients with a BAV will also have a coarctation of the aorta, upwards of 85 % of patients with CoA will have concurrent bicuspid aortic valve. The frequent association of CoA and BAV together suggest an underlying generalized arteriopathy. This may place patients at risk for future complications and the need for further catheter and surgical based interventions. Bicuspid aortic valve is the most common cause of aortic valve stenosis and aortic valve replacement in patients under 60 years of age. \r\n\r\nCoarctation of the aorta can lead to hypertension, which often persists even after complete repair. Approximately 10% of patients with aortic coarctation also have intracranial aneurysms, increasing the risk of cerebrovascular accidents. Other complications include congestive heart failure, endocarditis, and aortic dissection and rupture secondary to dilatation of the aorta. The rate of recurrence of aortic coarctation requiring reintervention after surgical repair is reported to be 5-15%. Due to the long-term complications of BAV and CoA, regular follow-up with a cardiologist is recommended. \r\n\r\n\r\n\r\n \r\nREFERENCES \r\nSinning C, Zengin E, Kozlik-Feldmann R, et al. Bicuspid aortic valve and aortic coarctation in congenital heart disease-important aspects for treatment with focus on aortic vasculopathy. Cardiovasc Diagn Ther<\/em>. 2018;8(6):780-788. \r\n\r\nWarnes CA. Bicuspid aortic valve and coarctation: two villains part of a diffuse problem. Heart <\/em>.2003;89(9):965-966. \r\n\r\nTorok RD, Campbell MJ, Fleming GA, Hill KD. Coarctation of the aorta: Management from infancy to adulthood. World J Cardiol<\/em>. 2015;7(11):765-775. \r\n\r\nBacha E, Hijazi ZM. (2023) Management of coarctation of the aorta. UpToDate<\/em>. Retrieved July 4, 2023, from: https:\/\/www.uptodate.com\/contents\/management-of-coarctation-of-the-aorta\r\n”,”hint”:””,”answers”:{“w39rf”:{“id”:”w39rf”,”image”:””,”imageId”:””,”title”:”A.\tAtrial Septal Defect”},”wnj42″:{“id”:”wnj42″,”image”:””,”imageId”:””,”title”:”B.\tBicuspid Aortic Valve”,”isCorrect”:”1″},”q1x1x”:{“id”:”q1x1x”,”image”:””,”imageId”:””,”title”:”C.\tVentricular Septal Defect”}}}}}

{“questions”:{“y4n0w”:{“id”:”y4n0w”,”mediaType”:”image”,”answerType”:”text”,”imageCredit”:””,”image”:””,”imageId”:””,”video”:””,”imagePlaceholder”:””,”imagePlaceholderId”:””,”title”:”Author: Nicholas Houska, DO – University of Colorado. Children\u2019s Hospital Colorado \r\n\r\nA 12-year-old female with a history of repaired Tetralogy of Fallot during infancy presents for surgical pulmonary valve replacement. Due to coronary anatomy, transcatheter pulmonary valve implantation is not an option. Which type of surgical pulmonary valve replacement is associated with the HIGHEST incidence of infective endocarditis?”,”desc”:”EXPLANATION \r\n\r\nReconstruction of the right ventricular outflow tract with implantation of an extracardiac pulmonary-valved conduit may be necessary in patients with both acquired and congenital heart disease. Alternatively, the pulmonary valve may be replaced with a bioprosthetic or mechanical valve. Conduits used for this purpose include cryopreserved pulmonic or aortic homografts, Contegra conduits, and transcatheter pulmonary valves (Melody and Edwards SAPIEN). Homograft conduits have been used for the last 50-60 years, while Contegra conduit use began in the last 20-25 years. Contegra conduits are made of bovine jugular vein with a trileaflet venous valve. The Melody and Edwards SAPIEN valves are two types of percutaneously implanted pulmonary valves. The Melody valve is composed of bovine jugular vein with a trileaflet venous valve sutured into an expandable platinum stent. The Edwards SAPIEN valve is comprised of bovine pericardium that is shaped into a trileaflet valve and mounted onto an expandable cobalt-chromium frame. One large nationwide registry-based study that included all patients with at least one pulmonary valve replacement prior to 2018 by Stammnitz et al demonstrated that pulmonary valve replacement (PVR) with a bovine jugular vein valve (Contegra conduit or Melody valve) has the highest risk of infective endocarditis (IE) irrespective of mode of deployment, either surgical or percutaneous. In this study, the overall incidence of IE was 4.8% after a median follow up of 10 years per patient. Patients with a Contegra conduit had an incidence of IE of 5.4% while those with a homograft had an incidence of 1.3%. There was a 0% incidence of IE in patients with a mechanical valve or Edwards SAPIEN valve. The risk for IE was higher for surgically implanted Contegra grafts (HR, 5.62; 95% CI, 2.42\u201313.07; P<0.001) and transcatheter Melody Valves (HR, 7.81; 95% CI, 3.20\u201319.05; P<0.001) compared to homografts. The median time interval from PVR to infective endocarditis was 3 and 5 years for Contegra conduit and Melody valves respectively. The increased risk of IE with Contegra conduits and transcatheter Melody valves as compared to homograft conduits has been demonstrated in smaller studies as well. \r\n\r\n \r\nREFERENCES \r\nStammnitz C, Huscher D, Bauer UMM, et al. Nationwide registry\u2010based analysis of infective endocarditis risk after pulmonary valve replacement. JAHA<\/em>. 2022;11(5): e022231. \r\n\r\nHaas NA, Bach S, Vcasna R, et al. The risk of bacterial endocarditis after percutaneous and surgical biological pulmonary valve implantation. Int J cardiol<\/em>. 2018; 268:55-60. \r\n\r\nGr\u00f6ning M, Tahri NB, S\u00f8ndergaard L, Helvind M, Ersb\u00f8ll MK, Andersen H\u00d8. Infective endocarditis in right ventricular outflow tract conduits: a register-based comparison of homografts, Contegra grafts and Melody transcatheter valves. Eur J Cardiothorac Surg <\/em>.2019; 56(1):87-93.\r\n”,”hint”:””,”answers”:{“ppo92”:{“id”:”ppo92″,”image”:””,”imageId”:””,”title”:”A.\tHomograft conduit”},”x61h5″:{“id”:”x61h5″,”image”:””,”imageId”:””,”title”:”B.\tMechanical valve”},”6b9lm”:{“id”:”6b9lm”,”image”:””,”imageId”:””,”title”:”C.\tValved bovine jugular vein conduit (Contegra)”,”isCorrect”:”1″}}}}}