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

{“questions”:{“0856e”:{“id”:”0856e”,”mediaType”:”image”,”answerType”:”text”,”imageCredit”:””,”image”:””,”imageId”:””,”video”:””,”imagePlaceholder”:””,”imagePlaceholderId”:””,”title”:”Authors: Destiny F. Chau MD, Arkansas Children\u2019s Hospital \/University of Arkansas for Medical Sciences, Little Rock, AR and Meera Gangadharan MD, Childrens Memorial Hermann Hospital\/McGovern Medical School, Houston, TX \r\n\r\nA 7-day-old, 3.5 kg male infant with a history of Transposition of the Great Arteries (TGA) is scheduled for the arterial switch operation. A transthoracic echocardiogram reports situs solitus, levocardia, and {S,D,D} segmental anatomy. Which of the following MOST accurately describes the segmental anatomy {S,D,D}? “,”desc”:”EXPLANATION \r\nThe growth in knowledge surrounding the embryologic basis of cardiac development necessitates a consistent classification system to accurately describe and classify the many variations in cardiovascular defects. Standardization of the cardiac nomenclature and a universally accepted classification system is critical for appropriately diagnosing and disseminating accurate information across professional specialties caring for congenital heart disease (CHD) patients. Unfortunately, at present time, there is not one universally accepted classification system. \r\n\r\nThe sequential segmental approach is a widely accepted diagnostic evaluation of CHD. There are many publications describing this approach to the evaluation and diagnosis of CHD and the steps involved in a structural assessment. The segmental approach was initially described by Van Praagh and colleagues and rests upon an examination of cardiac anatomy in segments. The anatomy of each segment and the relationship of each segment to the others represents the underpinning of segmental analysis. A second system described by Robert Anderson and colleagues added to this concept but minimized the focus on the relationships between segments by using a model based on blood flow through the heart, which focused on characterizing the connections between the segments, termed a sequential segmental approach. In each segment, right and left-sided structures are evaluated based on the morphology, relative orientations, proximal and distal connections, and presence of abnormalities such as shunts and stenosis. Generally, clinicians have been segregated into followers of the Van Praagh or Anderson approach though many medical professionals have opted for a position in the middle. The chosen classification system for use at a particular institution is often based on preference. \r\n\r\n\r\nDefining the thoraco-abdominal organ position and cardiac position\/apex orientation are important components of the cardiac evaluation and should precede the sequential segmental analysis. Embryologically, all major organ systems are initially positioned in the midline and have mirror image symmetry. During normal development, the cardiovascular, respiratory and gastrointestinal systems become asymmetric, referred to as visceral situs solitus.<\/em> Abnormal situs development can result in mirror-image visceral situs (visceral situs inversus)<\/em> or an ambiguous visceral situs (visceral situs ambiguous).<\/em> Mirror image arrangement describes reversed left-right position and orientation of the organs. Situs ambiguous refers to elements of situs solitus and situs inversus in the same patient. \r\n\r\n\r\nCardiac position is often described as the thoracic position where the majority of the cardiac mass is located: levocardia (left-hemithorax), dextrocardia (right-hemithorax) and mesocardia (mid-thorax). Although these prior terms have also been used to describe the base-to-apex orientation, the apex orientation is often, although not always, in agreement to the cardiac position within the chest. Dextrocardia describes the cardiac apex pointing towards the right side of the chest, mesocardia indicates apex pointing inferiorly, and levocardia pointing to the left side of the chest. Displacement of the heart into the right or left thorax should be indicated by the terms dextropositioning or levopositioning, respectively. \r\n\r\n\r\nThe Van Praagh style uses a unique three-letter notation, or code, inside curly brackets such as {X,X,X}. The letters are abbreviations that represent the sidedness or anatomic arrangement (situs) of the three main cardiac segments of the heart in venoarterial sequence (atria, ventricles, and great arteries). A normal heart is coded {S,D,S}. Atrial situs describes the arrangement of the atria as ascertained by the position of the morphologic right and left atria. When the atria are identified, their situs can then be defined. Similarly the same approach is followed for the ventricles. In the Van Praagh shorthand notation, the types of atrial situs are \”S\” for situs solitus <\/em>(normal arrangement), \”I\” for situs inversus <\/em>and \”A\” for situs ambiguous <\/em>(indeterminate arrangement). \r\n\r\n\r\nThe ventricular segment is described by the type of ventricular loop (handedness of the ventricular mass) and the relationship between the atria and ventricles in three-dimensional space. In the normal D-loop (\u201cD\u201d) heart, the ventricles are normally related and the morphologic right ventricle is right-handed relative to morphologic left ventricle which is left-handed. L-looping of the ventricles is also known as inverted ventricles (morphologic right ventricle is left-handed and morphologic left ventricle is right-handed). The types of ventricular situs (loop or topology) per the Van Praagh system include: solitus <\/em>or D-loop ventricles (D), inverted <\/em>or L-loop ventricles (L); and ambiguous or X-loop ventricles (X). \r\n\r\n\r\nThe great arterial situs is described by the spatial relations between great arteries and the semilunar valves (anterior-posterior and right-left position). In patients with normally related great arteries, the main pulmonary artery is anterior to the aorta and then courses leftward. The aorta is posterior to the main pulmonary artery and courses to the right. The pulmonary valve is anterior to and to the left of the aortic valve. The Van Praagh system describes the types of great arterial situs as follows: 1) solitus <\/em>(aortic valve posterior and to the right of the pulmonary valve)- normally related great arteries (S) or D-transposition (aorta is anterior and to the right of the pulmonary trunk); 2) inversus <\/em>(aortic valve to left of the pulmonary valve)- inverted, normally related great arteries (I), or L-transposition\/malposition (L); 3) ambiguous (right-left location of the aortic valve directly anterior to pulmonary valve is neither a right nor left location- A-transposition\/malposition (A). \r\n\r\n\r\nIn this case scenario, this patient is reported to have situs solitus, levocardia, and {S,D,D} segmental anatomy. The Van Praagh segmental system denotes {S,D,D} as \”S\” for situs solitus or normal atrial arrangement, \”D\” for D-looped or normally related ventricles (morphologic right ventricle is right-handed and the morphologic left ventricle is left-handed), and \”D\” for D-malposed or transposed great arteries, with the aorta to the right of the pulmonary trunk rather than posterior to the main pulmonary artery. \r\n\r\nREFERENCES \r\n \r\n\r\nVan Praagh R. Terminology of congenital heart disease. Glossary and commentary. Circulation.<\/em> 1977;56(2):139-143. \r\n\r\n\r\nAnderson RH, Shirali G. Sequential segmental analysis. Ann Pediatr Cardiol. <\/em>2009; 2: 24-35. \r\n\r\n\r\nJacobs JP, Anderson RH, Weinberg PM, et al. The nomenclature, definition and classification of cardiac structures in the setting of heterotaxy. Cardiol Young.<\/em> 2007;17 Suppl 2:1-28. 07001138\r\n\r\n\r\nKussman BD, Miller-Hance WC. Development of the cardiovascular system and nomenclature for congenital heart disease. In: Andropoulos DB, ed. Anesthesia for Congenital Heart Disease. 3rd ed. Hoboken, NJ; Wiley-Blackwell. 2015: 42-82. \r\n\r\n\r\nEdwards WD, Maleszewski JJ. Classification and terminology of cardiovascular anomalies. In: Allen HD, Driscoll DJ, Shaddy RE and Feltes, TF, eds. Moss and Adams’ heart disease in infants, children and adolescents, including the fetus and young adult. 8th ed. Philadelphia, PA; Lippincott Williams & Wilkins. 2013: 32-51.\r\n\r\n”,”hint”:””,”answers”:{“sy3cc”:{“id”:”sy3cc”,”image”:””,”imageId”:””,”title”:”A.\tInverted atria, normally related ventricles, aorta to the right of the pulmonary trunk”},”3vv34″:{“id”:”3vv34″,”image”:””,”imageId”:””,”title”:”B.\tNormal atria, inverted ventricles, aorta to the left of the pulmonary trunk”},”8dxzi”:{“id”:”8dxzi”,”image”:””,”imageId”:””,”title”:”C.\tNormal atria, normally related ventricles, aorta to the right of the pulmonary trunk”,”isCorrect”:”1″},”d2fxj”:{“id”:”d2fxj”,”image”:””,”imageId”:””,”title”:”D.\tInverted atria, indeterminate ventricles, aorta anterior to the pulmonary trunk”}}}}}

{“questions”:{“un5e3”:{“id”:”un5e3″,”mediaType”:”image”,”answerType”:”text”,”imageCredit”:””,”image”:””,”imageId”:””,”video”:””,”imagePlaceholder”:””,”imagePlaceholderId”:””,”title”:”Authors: Destiny F. Chau, MD – Arkansas Children\u2019s Hospital\/University of Arkansas for Medical Sciences, Little Rock, AR and Lawrence Greiten, MD \u2013 Pediatric Cardiothoracic Surgery, Arkansas Children\u2019s Hospital\/University of Arkansas for Medical Sciences, Little Rock, AR \r\n\r\nA 14-month-old, 10 kg male toddler with complex multilevel left ventricular outflow tract obstruction and aortic insufficiency is status post the Ross-Konno procedure during which the perfusionist uses del Nido cardioplegia. Which of the following additives is unique to del Nido cardioplegia?”,”desc”:”EXPLANATION \r\nAdequate myocardial protection during periods of cardiac arrest and myocardial ischemia while on cardiopulmonary bypass (CPB) is of paramount importance for good outcomes after cardiac surgery. Poor myocardial protection can lead to irreversible myocardial damage from ischemia and has been is associated with increased postoperative morbidity and mortality. \r\n\r\nThe principles of myocardial protection center on maximally reducing metabolic rate, supporting aerobic and anaerobic metabolism, preserving intracellular pH, and minimizing intracellular metabolic injury due to sodium, calcium, and oxygen free-radical accumulation. Visible end-points of myocardial protection are mechanical cardiac arrest, lack of electrical activity on the ECG and hypothermic core body temperature. Cardioplegia solutions for myocardial protection have been researched for over 40 years. Currently, there are a number of cardioplegia solutions with variable compositions, ranging from commercial to customized institutional solutions. They can be broadly classified as crystalloid cardioplegia or blood- cardioplegia depending upon the addition of blood to the cardioplegia solution. Additionally, techniques and protocols for the administration of cardioplegia vary widely depending on the patient population, surgical procedure, surgeon preference and institutional factors. Cardioplegia dose is dependent upon the particular cardioplegia formulation and the expected time of myocardial arrest. Limiting the total number and frequency of repeated cardioplegia doses is desired to reduce overall manipulation of the heart, reduce the aortic cross-clamp time and prevent myocardial edema. \r\n\r\n\r\nA common characteristic of cardioplegia solutions is high potassium concentration in order to induce contractile arrest through membrane hyperpolarization. Components such as magnesium, mannitol, sodium bicarbonate, and lidocaine are present in cardioplegia for a number of reasons. Lidocaine is a sodium channel blocker and antiarrhythmic. Sodium channel blockage increases myocyte refractory time. Additionally, sodium channel blockage helps to counteract the negative impact of hyperkalemic arrest by polarizing the cell membrane and preventing intracellular sodium and calcium accumulation. Magnesium is a natural calcium channel blocker and reduces the accumulation of intracellular calcium. Low intracellular calcium concentrations have been associated with reduced myocardial injury. Sodium bicarbonate is a buffer which scavenges excess hydrogen ions and assists with maintaining intracellular pH. Hyperosmotic mannitol scavenges free radicals and reduces myocardial swelling. The addition of red blood cells to cardioplegia has been shown to preserve myocardial metabolism and function, resulting in less metabolic ischemic stress and reperfusion injury when compared to crystalloid-cardioplegia. In addition, red blood cells contain carbonic anhydrase, an enzyme that facilitates the scavenging of hydrogen ions to generate carbon dioxide and water. \r\n\r\n\r\nA survey of the utilization of cardioplegia solutions by congenital cardiac surgical programs in North America found that blood-based cardioplegia formulations are predominantly used by 86% of respondents. Use of the del Nido solution was reported most commonly in 38% of respondents, followed by customized solutions in 32%. \r\n\r\n\r\nOriginally, the same cardioplegia formulations used in adults were also used in pediatric patients. However, in the 1990\u2019s, the del Nido cardioplegia solution was created for myocardial protection of the immature myocardium of neonates and pediatric patients. At the present time, it is increasingly being utilized for myocardial preservation during adult cardiac surgery. \r\n\r\n\r\nAlthough the current del Nido cardioplegia solution has evolved from the original cardioplegia formulations, it is unique in that it contains lidocaine. It contains a base solution of Plasma-Lyte A, with an electrolyte composition resembling extracellular fluid. A one-liter formulation of del Nido cardioplegia includes the following: Plasmalyte-A (1L), magnesium (2 g, 4 mL), potassium chloride (26 mEq, 13 mL), mannitol (3.26 g, 16 mL), sodium bicarbonate (13 mEq, 13 mL) and lidocaine (130 mg, 13 mL). Calcium is not added, although a small amount of calcium is derived from the addition of whole blood. This formulation is deemed to arrest the heart in diastole. The del Nido solution is generally used as a single-dose of 20 mL\/kg. Larger doses may be needed for patients with a thickened myocardium, aortic insufficiency or other conditions where myocardial protection is more challenging. Compared to other formulations, del Nido cardioplegia has been reported to provide comparable myocardial protection, longer cardiac arrest time from a single dose, and lower total volumes of cardioplegia solution with less hemodilution. \r\n\r\n\r\nIt is important for cardiac anesthesiologist to be familiar with cardioplegia solution types used during cardiac surgeries. Multiple dosing with high total volume for complex surgeries leads to hemodilution. Although the accumulation of cardioplegia components such as potassium and lidocaine are usually not clinically significant, awareness and perspective on this information is relevant. \r\nREFERENCES \r\nSinha P. Myocardial Protection. In: Jonas RA, ed. Comprehensive Surgical Management of Congenital Heart Disease.<\/em> 2nd Edition. Boca Raton, Florida: CRC Press, Taylor and Francis Group, LLC; 2014: 214-216. \r\n\r\n\r\nWaterford SD, Ad N. Del Nido cardioplegia: Questions and (some) answers. J Thorac Cardiovasc Surg.<\/em> 2021;S0022-5223(21)01676-7. \r\n\r\n\r\nMatte GS, del Nido PJ. History and use of del Nido cardioplegia solution at Boston Children’s Hospital [published correction appears in J Extra Corpor Technol. 2013 Dec;45(4):262]. J Extra Corpor Technol.<\/em> 2012;44(3):98-103. \r\n\r\n\r\nGinther RM Jr, Gorney R, Forbess JM. Use of del Nido cardioplegia solution and a low-prime recirculating cardioplegia circuit in pediatrics. J Extra Corpor Technol.<\/em> 2013;45(1):46-50. \r\n\r\n\r\nKotani Y, Tweddell J, Gruber P, et al. Current cardioplegia practice in pediatric cardiac surgery: a North American multi-institutional survey. Ann Thorac Surg.<\/em> 2013;96(3):923-929. \r\n\r\n\r\nHaranal M, Chin HC, Sivalingam S, et al. Safety and Effectiveness of Del Nido Cardioplegia in Comparison to Blood-Based St. Thomas Cardioplegia in Congenital Heart Surgeries: A Prospective Randomized Controlled Study. World J Pediatr Congenit Heart Surg.<\/em> 2020;11(6):720-726. \r\n\r\n”,”hint”:””,”answers”:{“9ilh7”:{“id”:”9ilh7″,”image”:””,”imageId”:””,”title”:”A.\tPotassium “},”rliok”:{“id”:”rliok”,”image”:””,”imageId”:””,”title”:”B.\tMagnesium”},”fc7ht”:{“id”:”fc7ht”,”image”:””,”imageId”:””,”title”:”C.\tMannitol”},”pxye6″:{“id”:”pxye6″,”image”:””,”imageId”:””,”title”:”D.\tLidocaine”,”isCorrect”:”1″}}}}}

{“questions”:{“p4uw2”:{“id”:”p4uw2″,”mediaType”:”image”,”answerType”:”text”,”imageCredit”:””,”image”:””,”imageId”:””,”video”:””,”imagePlaceholder”:””,”imagePlaceholderId”:””,”title”:”Authors: Ahmed Zaghw, MB.BCH – University of California, Davis, CA and Destiny Chau, MD – Arkansas Children\u2019s Hospital \/University of Arkansas for Medical Sciences, Little Rock, AR \r\n\r\nA 4-month-old male infant undergoes full repair for Tetralogy of Fallot. During the first 24 hours postoperatively, the patient develops a hemodynamically significant arrhythmia requiring aggressive medical intervention. What is the MOST COMMON type of arrhythmia occurring after pediatric cardiac surgery?\r\n”,”desc”:””,”hint”:””,”answers”:{“d6xty”:{“id”:”d6xty”,”image”:””,”imageId”:””,”title”:”A.\tComplete heart block”},”y5ah9″:{“id”:”y5ah9″,”image”:””,”imageId”:””,”title”:”B.\tJunctional ectopic tachycardia “,”isCorrect”:”1″},”7zeg0″:{“id”:”7zeg0″,”image”:””,”imageId”:””,”title”:”C.\tAtrial ectopic tachycardia”},”ehc31″:{“id”:”ehc31″,”image”:””,”imageId”:””,”title”:”D.\tSecond degree atrioventricular heart block”}}}},”results”:{“3z56y”:{“id”:”3z56y”,”title”:””,”image”:””,”imageId”:””,”min”:”0″,”max”:”1″,”desc”:”EXPLANATION \r\nEarly postoperative arrhythmias after congenital cardiac surgery occurs with a reported incidence of 7.5% to 48%. Commonly encountered rhythm derangements include junctional ectopic tachycardia (JET), complete heart block, and supraventricular tachycardia. In the postoperative period, arrhythmias are poorly tolerated and may lead to life-threatening hemodynamic instability due to diminished cardiac output. Arrhythmias are commonly associated with surgery in proximity to the sinus node or the AV node. They may also be related to an atriotomy or a ventriculotomy incision. Additional risk factors for early postoperative arrhythmias include electrolyte abnormalities, myocardial ischemia, myocardial inflammation, increased sympathetic tone, prolonged cardiopulmonary bypass and aortic cross-clamp duration, and the use of arrhythmogenic vasoactive medications. \r\n\r\nBradyarrhythmias diminish cardiac output due to a decrease in heart rate. Furthermore, bradyarrhythmia in combination with non-sinus rhythm may impair cardiac filling and decrease resultant stroke volume due to a disruption in atrioventricular (AV) synchrony. Tachyarrhythmias reduce cardiac output by decreasing stroke volume due to a shorter diastolic filling time, and while occurring simultaneously with non-sinus rhythm may similarly compromise cardiac output due to a loss of AV synchrony. When causing a decrease in cardiac output, both bradyarrhythmias and tachyarrhythmias result in decreased myocardial oxygen supply, thus creating an imbalance in myocardial oxygen supply and demand. Tachyarrhythmias may cause additional disparity in myocardial oxygen supply and demand because of increased myocardial oxygen demand secondary to an elevated heart rate. \r\n\r\nOverall, JET is the most commonly reported rhythm disturbance after pediatric congenital cardiac surgery. It occurs most frequently after repair of Tetralogy of Fallot, ventricular septal defects, atrioventricular septal defects, Transposition of the Great Arteries, and total anomalous pulmonary venous return. The incidence of JET after Tetralogy of Fallot repair is reported to occur in up to 20% of patients. \r\nManagement of JET includes reducing core temperature, atrial pacing, and anti-arrhythmic drugs such as amiodarone. For medically refractory cases, support with extracorporeal membrane oxygenation may be indicated. Cardioversion is generally deemed ineffective for terminating JET. \r\nSusceptibility to a particular rhythm disturbance differs by cardiac lesion and type of cardiac surgery. After orthotopic heart transplantation, atrial fibrillation is the most common arrhythmia in the early postoperative period, occurring in up to 24% of patients. Some reports suggest that the biatrial surgical method is associated with a greater risk of atrial tachyarrhythmias as compared to the bicaval technique. Of note, early cardiac graft rejection may present clinically with atrial tachyarrhythmias. \r\n \r\nComplete heart block is the most common postoperative bradyarrhythmia, with a reported incidence of 1.5% to 17.8%. Temporary pacing is an important treatment modality for the postoperative management of bradyarrhythmia with most cases recovering within 1- 2 weeks after surgery. \r\nIn conclusion, in the early postoperative period after congenital cardiac surgery, JET is the most common arrhythmia overall. Complete heart block is the most common bradyarrhythmia. The majority of arrhythmias are transient and self-limiting with adequate medical management. \r\n\r\nREFERENCES \r\nDelaney JW, Moltedo JM, Dziura JD, et al. Early postoperative arrhythmias after pediatric cardiac surgery. J Thorac Cardiovasc Surg.<\/em> 2006;131(6):1296-1300. \r\n\r\nTalwar S, Patel K, Juneja R, et al. Early postoperative arrhythmias after pediatric cardiac surgery. Asian Cardiovasc Thorac Ann.<\/em> 2015;23(7):795-801. \r\n\r\nNelson JS, Vanja S, Maul TM, et al. Early arrhythmia burden in pediatric cardiac surgery fast-track candidates: Analysis of incidence and risk factors. Progress in Pediatric Cardiology.<\/em> 2019;(52): 8-12.\r\n\r\nSahu MK, Das A, Siddharth B, et al. Arrhythmias in children in early postoperative period after cardiac surgery. World J Pediatr Congenit Heart Surg.<\/em> 2018;9(1):38-46. \r\n\r\nJoglar JA, Wan EY, Chung MK, et al. Management of arrhythmias after heart transplant: current state and considerations for future research. Circ Arrhythm Electrophysiol. <\/em> 2021;14(3):e007954. \r\n\r\nIshaque S, Akhtar S, Ladak AA, et al. Early postoperative arrhythmias after pediatric congenital heart disease surgery: a 5-year audit from a lower- to middle-income country. Acute Crit Care.<\/em> 2022;37(2):217-223. \r\n\r\nValdes SO, Kim JJ, Miller-Hance WC. Arrhythmias: diagnosis and management. In: Andropoulos DB, ed. Anesthesia for Congenital Heart Disease. 3rd ed. Hoboken, NJ; Wiley-Blackwell. 2015: 404-436.\r\n\r\n\r\n\r\n”,”redirect_url”:””}}}

{“questions”:{“u2t8o”:{“id”:”u2t8o”,”mediaType”:”image”,”answerType”:”text”,”imageCredit”:””,”image”:””,”imageId”:””,”video”:””,”imagePlaceholder”:””,”imagePlaceholderId”:””,”title”:”Authors: Bryce Ferry, DO and Destiny F. Chau, MD – Arkansas Children\u2019s Hospital\/University of Arkansas for Medical Sciences, Little Rock, AR \r\n\r\nA 7-year-old male child presents to the emergency room with a history of syncope while playing soccer. He also has a family history of sudden death at a young age. Workup demonstrates a normal electrocardiogram at rest, a structurally normal heart on transthoracic echocardiogram, and a right heart biopsy demonstrating normal myocardium. Genetic testing reveals a mutation in the RYR2 gene. Which of the following conditions is MOST LIKELY in this patient?”,”desc”:””,”hint”:””,”answers”:{“6av5d”:{“id”:”6av5d”,”image”:””,”imageId”:””,”title”:”A. Arrhythmogenic right ventricular cardiomyopathy “},”3gk8b”:{“id”:”3gk8b”,”image”:””,”imageId”:””,”title”:”B. Long QT syndrome”},”bn5hw”:{“id”:”bn5hw”,”image”:””,”imageId”:””,”title”:”C. Catecholaminergic polymorphic ventricular tachycardia “,”isCorrect”:”1″},”8nebs”:{“id”:”8nebs”,”image”:””,”imageId”:””,”title”:”D. Brugada syndrome”}}}},”results”:{“r279t”:{“id”:”r279t”,”title”:””,”image”:””,”imageId”:””,”min”:”0″,”max”:”1″,”desc”:”EXPLANATION \r\nSyncope due to cardiac disease can be life-threatening. Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a rare arrhythmogenic disorder characterized by bidirectional or polymorphic ventricular tachycardia (VT) that is triggered by an adrenergic surge secondary to exercise or emotional stress. CPVT may result from mutations in the cardiac ryanodine receptor gene (RYR2), which is inherited in an autosomal dominant pattern or the calsequestrin gene CASQ2, inherited in an autosomal recessive pattern. These genes are likely involved in calcium release from the sarcoplasmic reticulum. To date, other genes have also been implicated in CPVT. \r\nThe mean age of symptom presentation is between 7 and 12 years old with syncope being a common presenting sign. Diagnostic workup often reveals a normal resting baseline electrocardiogram (ECG) and a structurally normal heart on echocardiography. However, an exercise or pharmacologic stress test typically reveals bidirectional or polymorphic VT. In children who cannot perform a stress test, a Holter monitor or an event recorder can aid in detecting an abnormal ECG during periods of adrenergic stress. Typically, when the heart rate goes above a threshold of 100-120 beats per minute (BPM), the ECG will demonstrate premature ventricular complexes (PVCs) followed by short runs of non-sustained VT. With continued stress, the VT can degenerate into ventricular fibrillation (VF). Self-resolution of the arrhythmia can occur when the stress occurs over a short time period. \r\nThe first line treatment of CPVT is nonselective beta blockers, such as nadolol, often at high doses to achieve clinical effectiveness. It may also be clinically indicated to add flecainide or a calcium-channel blocker to beta blocker therapy. With persistent syncope or progression to cardiac arrest, the recommendation is an implantable cardioverter defibrillator. When left untreated, CPVT will result in cardiac arrest in up to 30% and recurrent syncope in up to 80% of affected patients. \r\nAnesthetic management for patients with CPVT centers on preventing periods of adrenergic stress and catecholamine surges. To this point, a patient’s emotional distress and pain should be anticipated and prevented. It is imperative that beta blockers are continued during the perioperative period. Adrenergic drugs are to be avoided and tachycardia should be promptly treated. Prevention of postoperative nausea and vomiting and adequate pain control is important. Patients with the cardiac ryanodine gene (RYR2) do not seem susceptible to malignant hyperthermia, which is linked to the RYR1 receptor. \r\nArrhythmogenic cardiomyopathy, also known as arrhythmogenic right ventricular dysplasia\/cardiomyopathy, is a rare non-ischemic cardiomyopathy in which the right ventricular myocardium is replaced by fibrofatty tissue that may lead to arrythmias, dyspnea, and possible syncopal episodes. Arrhythmogenic cardiomyopathy can develop during childhood, but most cases arise during the third to fourth decade of life. Long QT syndrome can present similarly to CPVT with regards to emotional or physical stress but instead displays prolongation of the QT interval on the resting ECG. Brugada syndrome may also present with syncope, but often has characteristic ECG findings of variable ST segment abnormalities. This patient’s presentation, diagnostic findings, and genetic results are most consistent with catecholaminergic polymorphic ventricular tachycardia. \r\n\r\nREFERENCES \r\nPflaumer A, Davis AM. Guidelines for the diagnosis and management of catecholaminergic polymorphic ventricular tachycardia. Heart Lung Circ.<\/em> 2012;21(2):96-100. \r\n\r\nOmiya K, Mitsui K, Matsukawa T. Anesthetic management of a child with catecholaminergic polymorphic ventricular tachycardia undergoing insertion of implantable cardioverter defibrillator : a case report.JA Clin Rep.<\/em> 2020;6(1):16. \r\n\r\nStaikou C, Chondrogiannis K, Mani A. Perioperative management of hereditary arrhythmogenic syndromes. Br J Anaesth.<\/em> 2012;108(5):730-744. \r\n\r\nBrugada J, Campuzano O, Arbelo E, Sarquella-Brugada G, Brugada R. Present status of Brugada syndrome: JACC State-of-the-Art Review. J Am Coll Cardiol.<\/em> 2018;72(9):1046-1059. \r\n\r\nShah SR, Park K, Alweis R. Long QT Syndrome: A comprehensive review of the literature and current evidence. Curr Probl Cardiol.<\/em> 2019;44(3):92-106. \r\n\r\nGandjbakhch E, Redheuil A, Pousset F, Charron P, Frank R. Clinical diagnosis, imaging, and genetics of arrhythmogenic right ventricular cardiomyopathy\/dysplasia: JACC State-of-the-Art Review. J Am Coll Cardiol.<\/em> 2018;72(7):784-804. \r\n\r\n”,”redirect_url”:””}}}

{“questions”:{“joghu”:{“id”:”joghu”,”mediaType”:”image”,”answerType”:”text”,”imageCredit”:””,”image”:””,”imageId”:””,”video”:””,”imagePlaceholder”:””,”imagePlaceholderId”:””,”title”:”Authors: Christopher Busack MD, Chinwe Unegbu MD, and Daniela Perez-Velasco DO \u2013 Children\u2019s National Hospital \r\n\r\nAn 11-year-old adolescent male with a history of recurrent syncope after intense emotional distress and a structurally normal heart presents for a cardioneuroablation procedure. Which of the following arrhythmias represents the STRONGEST indication for the cardioneuroablation procedure targeting epicardial parasympathetic ganglionic plexuses? “,”desc”:”EXPLANATION \r\nNeurally mediated syncope (NMS) or Neurally Mediated Reflex Syncope (NMRS) traditionally refers to syncope owing to an imbalance of sympathetic and parasympathetic tone. Enhanced parasympathetic tone due to vagal nerve stimulation can lead to dramatic slowing of the sinus node or atrioventricular nodes resulting in prolonged sinus bradycardia, junctional rhythm, pauses, sinus arrest, asystole or second or third-degree atrioventricular block. Triggering factors for NMS vary widely and include orthostatic stress, emotional stress, urination, coughing, swallowing, physical exercise, and stimulation of the carotid sinus in susceptible patients.\r\nTypically, a patient with NMS will feel warmth, nausea, and lightheadedness and may appear pale before abruptly losing consciousness. Occasionally, patients do not experience any symptoms prior to syncope. Prior to a diagnosis of NMS, other causes of syncope must be ruled out by means of history, physical examination and appropriate tests. Frequently, the cause of syncope is identified during initial clinical evaluation and no further testing is needed. When the cause of syncope is not clear, a stepwise approach is required for diagnosis. The differential diagnosis for syncope is broad and includes structural heart disease, neurologic disease, cardiac disease, and arrhythmias such as life-threatening ventricular tachycardia, rapid supraventricular tachycardia and prolonged asystole. Prolonged asystole is the most common arrythmia (> 50%) leading to syncope in patients without significant structural heart disease and a normal ECG. If an arrhythmia is suspected, a 24-hour Holter or long-term event monitor can be used to establish the diagnosis. Invasive electrophysiology studies can be performed to distinguish whether syncope is caused by an arrhythmia such as ventricular tachycardia, sinus node dysfunction or intracardiac conduction delay. Often, syncope is due to a mixed pathology. \r\nIn the absence of structural heart disease and with a suspicion of NMS, a head-up-tilt-table (HUTT) test is performed to confirm the diagnosis. This is a provocative test with an orthostatic challenge to determine a patient\u2019s susceptibility to syncope. The test is considered positive if symptoms are reproduced along with objective evidence of a sudden decrease in blood pressure or decrease in heart rate. \r\n\r\nMedical therapy for NMS consists of beta blockers, alpha agonists, selective serotonin reuptake inhibitors, fludrocortisone, and anticholinergics. Pacemaker therapy can be helpful for patients refractory to medical therapy. According to the American College of Cardiology\/American Heart Association, minimal carotid sinus pressure that induces asystole greater than three seconds in the absence of medications that depress sinoatrial or atrioventricular (AV) node conduction is considered a class I indication for pacemaker placement when the result is recurrent syncope. NMS with severe bradycardia reproduced during HUT testing is a class IIb indication for pacemaker insertion. The North American Vasovagal Pacemaker study published in 1993, which involved 54 patients with frequent syncopal spells and positive HUT tests, demonstrated that recurrence of syncope was significantly reduced in patients with pacemakers (22%) versus those without pacemakers (70%). Though pacemaker therapy is used in the treatment of NMS, the decision to implant a pacemaker is difficult and challenging in young patients with structurally normal hearts. \r\n\r\nA novel therapy for NMS is cardioneuroablation (CNA) and was first described by Pachon in 2005 in 21 patients with a mean age of 48 years and diagnoses varying from NMS, functional high grade atrioventricular block and sinus node dysfunction. The CNA procedure is performed percutaneously and is based on radiofrequency ablation. The therapy targets vagal efferent postganglionic neurons innervating the sinoatrial (SA) or atrioventricular (AV) node. The postganglionic neurons are primarily located in discrete epicardial structures known as fat pads. Long-term vagal denervation of the atria, SA and AV nodes can be achieved by radiofrequency catheter ablation of these fat pads. \r\n\r\nIn 2017, Aksu and colleagues conducted a literature review to assess efficacy of CNA for treatment of NMS, which included five observational studies and five case reports. The review demonstrated reduced vagal tone lasting for at least 12 months after the procedure with improved tolerance of repeated head-up tilt testing. An additional study by Pachon et al published in 2011 demonstrated a significant decrease in atropine test positivity following CNA. However, in long-term follow up, patients demonstrated increased atropine test positivity suggesting either partial reinnervation and\/or partial ablation. \r\n\r\nAlthough initial reports of CNA have been positive, no formal guidelines exist regarding specific indications or contraindications for the procedure. The 2018 European Society of Cardiology guidelines do acknowledge the novel procedure as a possible treatment modality for NMS, but state that current evidence is insufficient to confirm the efficacy of vagal ganglia ablation. A 2022 prospective, randomized control trial by Piotrowski and colleagues included patients with documented symptomatic cardioinhibitory or mixed vasovagal syncope and positive atropine test. Patients who underwent CNA had less frequent syncope and better quality of life at 24-month follow-up. \r\n\r\nReports of complications from CNA have been sparse. A case report by Kumthekar et al published in 2020 describes a pediatric patient that developed paroxysmal atrial fibrillation after CNA. The arrhythmia was well controlled with medical therapy, and subsequently resolved. A study of long-term outcomes after CNA, published by Sun et al in 2016, noted one patient with inappropriate but transient sinus tachycardia. \r\n\r\nChoice A is the correct answer as high-grade third-degree AV block in a structurally normal heart is more likely to be related to NMS and would be a strong indication for CNA. Choices B and C are not typical arrhythmias related to NMS but rather cardiac disease. Choice D, sinus arrhythmia, is not correct as it is a commonly encountered variation of normal sinus rhythm. \r\n\r\n\r\nREFERENCES \r\n1.\tPachon JC, Pachon EI, Pachon JC, et al. \”Cardioneuroablation\”–new treatment for neurocardiogenic syncope, functional AV block and sinus dysfunction using catheter RF-ablation. Europace.<\/em> 2005;7(1):1-13. doi: 10.1016\/j.eupc.2004.10.003 \r\n\r\n2.\tPachon JC, Pachon EI, Cunha Pachon MZ, et. al. Catheter ablation of severe neurally meditated reflex (neurocardiogenic or vasovagal) syncope: cardioneuroablation long-term results. Europace.<\/em> 2011;13:1231\u20131242. doi:10.1093\/europace\/eur163\r\n\r\n3.\tZaqqa M, Massumi A. Neurally mediated syncope. Tex Heart Inst J.<\/em> 2000;27(3):268-272. \r\n\r\n4.\tKumthekar RN, Sumihara K, Moak JP. Pediatric radiofrequency ablation of cardiac parasympathetic ganglia to achieve vagal denervation. HeartRhythm Case Rep.<\/em> 2020;6(11):879-883. doi: 10.1016\/j.hrcr.2020.09.004 \r\n\r\n5.\tAksu T, G\u00fcler TE, Bozyel S, et. al. Cardioneuroablation in the treatment of neurally mediated reflex syncope: a review of the current literature. Turk Kardiyol Dern Ars.<\/em> 2017;45(1):33-41. doi: 10.5543\/tkda.2016.55250. \r\n\r\n6.\tHussain S, Raza Z, Kumar TVV, et al. Diagnosing Neurally Mediated Syncope Using Classification Techniques. J Clin Med.<\/em> 2021;10(21):5016. doi: 10.3390\/jcm10215016 \r\n\r\n7.\tTask Force for the Diagnosis and Management of Syncope; European Society of Cardiology (ESC); European Heart Rhythm Association (EHRA); Heart Failure Association (HFA); Heart Rhythm Society (HRS), Moya A, Sutton R, Ammirati F, et. al. Guidelines for the diagnosis and management of syncope (version 2009). Eur Heart J.<\/em> 2009;30(21):2631-2671. doi: 10.1093\/eurheartj\/ehp298 \r\n\r\n8.\tMoya A, Brignole M, Menozzi C, et al; International Study on Syncope of Uncertain Etiology (ISSUE) Investigators. Mechanism of syncope in patients with isolated syncope and in patients with tilt-positive syncope. Circulation.<\/em> 2001;104(11):1261-1267. doi: 10.1161\/hc3601.095708 \r\n\r\n9.\tGregoratos G, Cheitlin M, Conill A, et al. ACC\/AHA Guidelines for Implantation of Cardiac Pacemakers and Antiarrhythmia Devices: Executive Summary\u2014a report of the American College of Cardiology\/American Heart Association Task Force on Practice Guidelines (Committee on Pacemaker Implantation). Circulation.<\/em>1998;97:1325-1335. doi:10.1161\/01.cir.97.13.1325 \r\n\r\n10.\tConnolly SJ, Sheldon R, Roberts RS, et al. The North American Vasovagal Pacemaker Study (VPS). A randomized trial of permanent cardiac pacing for the prevention of vasovagal syncope. J Am Coll Cardiol. <\/em>1999;33:16-20. doi:10.1016\/s0735-1097(98)00549-x \r\n\r\n11.\tSun W, Zheng L, Qiao Y, et al. Catheter Ablation as a Treatment for Vasovagal Syncope: Long-Term Outcome of Endocardial Autonomic Modification of the Left Atrium. J Am Heart Assoc. <\/em> 2016;5(7):e003471.doi:10.1161\/JAHA.116.003471 \r\n\r\n12.\tBrignole M, Moya A, de Lange FJ, et al; ESC Scientific Document Group. 2018 ESC Guidelines for the diagnosis and management of syncope. Eur Heart J. 2018 Jun 1;39(21):1883-1948. doi: 10.1093\/eurheartj\/ehy037. \r\n\r\n13.\tPiotrowski R, Baran J, Sikorska A, Krynski T, Kulakowski P. Cardioneuroablation for Reflex Syncope: Efficacy and Effects on Autonomic Cardiac Regulation-A Prospective Randomized Trial. JACC Clin Electrophysiol. 2022 Aug 28:S2405-500X(22)00680-6. doi: 10.1016\/j.jacep.2022.08.011.\r\n”,”hint”:””,”answers”:{“lpdtd”:{“id”:”lpdtd”,”image”:””,”imageId”:””,”title”:”A. Third degree atrioventricular block “,”isCorrect”:”1″},”9gaf7″:{“id”:”9gaf7″,”image”:””,”imageId”:””,”title”:”B. Non-sustained ventricular tachycardia”},”melsv”:{“id”:”melsv”,”image”:””,”imageId”:””,”title”:”C. Paroxysmal supraventricular tachycardia”},”uxqjt”:{“id”:”uxqjt”,”image”:””,”imageId”:””,”title”:”D. Sinus arrhythmia”}}}}}