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

{“questions”:{“8uhfq”:{“id”:”8uhfq”,”mediaType”:”image”,”answerType”:”text”,”imageCredit”:””,”image”:””,”imageId”:””,”video”:””,”imagePlaceholder”:””,”imagePlaceholderId”:””,”title”:”Author: Sana Ullah, MB ChB, FRCA – Children\u2019s Medical Center, Dallas \r\n\r\nWhat is the MOST COMMON syndrome associated with pulmonary arteriovenous malformations?”,”desc”:”EXPLANATION \r\nPulmonary arteriovenous malformations (AVMs) are structurally abnormal blood vessels which form direct communications between the pulmonary arterial and pulmonary venous circulations, producing a right-to-left shunt bypassing the alveolar gas exchange regions and the normal filtering functions of the lungs. The most common cause of pulmonary AVMs is Osler-Weber-Rendu syndrome, which is also known as Hereditary Hemorrhagic Telangiectasia (HHT). Osler-Weber-Rendu is inherited in an autosomal dominant manner and affects approximately 1 in 5,000 to 8,000 people. In addition to AVMs, smaller telangiectatic vessels that are prone to bleeding are frequently found in nasal, mucocutaneous, hepatic, gastrointestinal and cerebral vascular beds. \r\nPulmonary AVMs can also develop after surgical palliation with the bidirectional cavopulmonary shunt and produce significant systemic desaturation. The purported mechanism is due to the lack of a \u201chepatic factor\u201d that bypasses the pulmonary circulation after the bidirectional cavopulmonary shunt. Once the hepatic venous return is redirected back into the pulmonary circulation after Fontan completion, the pulmonary AVMs generally regress over a period of weeks to months. \r\nThe major clinical manifestations of pulmonary AVMs are recurrent bleeding manifesting as hemoptysis or hemothorax, systemic desaturation due to right-to-left shunting, ischemic strokes due to paradoxical thromboembolism, and cerebral abscesses resulting from bacteria in the blood that bypasses the filtering mechanism of the lungs. There is also an increased risk of pregnancy-related deaths in pregnant women with pulmonary AVMs. As a result of pulmonary AVMs, a rare but interesting phenomenon, is platypnea-orthodeoxia, which is best described as systemic desaturation and increased shortness of breath on standing up but improvement on lying flat. This is because most pulmonary AVMs are in the basal regions of the lungs thereby increasing the right-to-left shunt due to increased blood flow on assuming the upright posture. \r\nComputed tomography of the chest is the gold-standard for diagnosis of pulmonary AVMs and offers better resolution than MRI. Contrast echocardiography using agitated saline injected into an arm vein and imaging the left side of the heart can also be used, but it lacks specificity even though it is highly sensitive. Transcatheter embolization is recommended for treatment of all pulmonary AVMs that are amenable to vessel access. \r\nScimitar syndrome is a rare variant of partial anomalous pulmonary venous return of a portion or the entirety of the right lung to the inferior vena cava. The abnormal venous channel forms a characteristic curved shadow on chest x-ray along the right heart border which resembles a sword known as a scimitar. Associated abnormalities include hypoplasia of the right lung, secondary dextroposition of the heart, and pulmonary sequestration of portions of the right. The sequestered lung does not take part in gas exchange and is prone to recurrent bleeding and infection. Management of Scimitar Syndrome is largely determined by the degree of volume overload to the heart and associated cardiac anomalies. Lung segments affected by sequestration may need to be resected. Kartagener\u2019s syndrome is an autosomal recessive disorder characterized by primary ciliary dyskinesis resulting in a triad of situs inversus totalis, chronic sinusitis, and bronchiectasis. Alagille syndrome is an autosomal dominant disorder consisting of bile duct paucity and cholestasis, characteristic triangular facies, widespread vascular anomalies, and congenital heart disease. The congenital heart disease often manifests as peripheral pulmonary arterial stenosis or hypoplasia, pulmonary valve stenosis, and\/or Tetralogy of Fallot. Treatment of pulmonary arterial stenosis often requires a combination of surgical and transcatheter based techniques. Approximately 15% of patients eventually develop liver failure requiring transplantation. Many of these patients harbor a mutation in the JAG1 gene. \r\n\r\n \r\nREFERENCES \r\nShovlin CL. Pulmonary Arteriovenous Malformations. Am J Respir Crit Care Med <\/em> . 2014; 190(11): 1217-1228. \r\nVida VL, Guariento A. A sword threatening the heart: The scimitar syndrome. JCTVS Techniques <\/em>.2020; 1: 75-80.\r\nTretter JT, McElhinney DB. Cardiac, Aortic, and Pulmonary Vascular Involvement in Alagille Syndrome. 2018. In: Kamath B., Loomes K. (eds) Alagille Syndrome. Springer, Cham. https:\/\/doi.org\/10.1007\/978-3-319-94571-2_6\r\n\r\nKamath BM, Spinner NB, Emerick KM, et al. Vascular anomalies in Alagille syndrome: A significant cause of morbidity and mortality. Circulation. <\/em>2004; 109:1354-1358.\r\n\r\n\r\n”,”hint”:””,”answers”:{“e3zth”:{“id”:”e3zth”,”image”:””,”imageId”:””,”title”:”A.\tScimitar syndrome”},”omyi8″:{“id”:”omyi8″,”image”:””,”imageId”:””,”title”:”B.\tOsler-Weber-Rendu syndrome”,”isCorrect”:”1″},”3x7h8″:{“id”:”3x7h8″,”image”:””,”imageId”:””,”title”:”C.\tKartagener\u2019s syndrome”},”48z12″:{“id”:”48z12″,”image”:””,”imageId”:””,”title”:”D.\tAlagille syndrome”}}}}}

{“questions”:{“9erfa”:{“id”:”9erfa”,”mediaType”:”image”,”answerType”:”text”,”imageCredit”:””,”image”:””,”imageId”:””,”video”:””,”imagePlaceholder”:””,”imagePlaceholderId”:””,”title”:”Author: Melissa Colizza, MD – CHU Sainte-Justine Montreal, Quebec \r\n\r\nA 7-year-old girl with suprasystemic idiopathic pulmonary hypertension is undergoing cardiac catheterization. During the procedure, the blood pressure decreases to 65\/35. Which of the following medications is MOST appropriate to treat the systemic hypotension? “,”desc”:”EXPLANATION \r\nPulmonary hypertension (PH) is one of the most important causes of perioperative mortality and morbidity in the pediatric population. The three most common causes of pulmonary hypertension in the pediatric population are bronchopulmonary dysplasia, congenital heart disease or left-sided heart disease, and idiopathic PH. Patients with PH often come to the cardiac catheterization lab for diagnostic or therapeutic procedures. The risk of significant cardiovascular events in patients with PH is related to the severity of the PH. Patients with suprasystemic pulmonary arterial pressure (PAP) are at high risk for morbidity and mortality. While it is important to maintain hemodynamics as close to baseline as possible for diagnostic procedures, vasopressors or inotropic agents are sometimes required to preserve appropriate coronary perfusion and myocardial function. \r\n\r\nPhenylephrine has a long history of successful use by anesthesiologists. Its main advantage is it increases the systemic vascular resistance (SVR) more than it does pulmonary vascular resistance (PVR), and thus helps minimize leftward shift of the ventricular septum, improving coronary perfusion and ventricular performance overall. Siehr et al. published a pilot study in 15 pediatric patients with severe pulmonary hypertension undergoing cardiac catheterization, comparing phenylephrine, epinephrine, and vasopressin. Phenylephrine did decrease the PVR:SVR ratio to slightly below 1.0 in some patients but had a more variable effect on PVR than norepinephrine or vasopressin, especially in patients with suprasystemic PH.\r\n\r\nNorepinephrine has been a first-line agent in both pediatric and adult PH. It is a powerful systemic vasoconstrictor, a mild inotrope and overall improves right ventricle to pulmonary artery coupling as well as coronary perfusion pressure. Studies in the early 2000\u2019s involving neonatal lambs with high-dose norepinephrine (0.5 mcg\/kg\/min) demonstrated both increased PAP and pulmonary blood flow, which supports the hypothesis of a pulmonary vasodilatory effects. Similar studies in human neonates have also suggested norepinephrine might decrease PVR because of a finding of improved oxygenation. However, these studies may have been confounded by the presence of a left-to-right shunt. Moreover, norepinephrine has been shown to increase PVR at high doses in both in vitro and in vivo studies. While it improves the PVR:SVR ratio, this may well be the result of increased SVR and cardiac output. \r\n\r\nArginine vasopressin has become increasingly popular over the last ten years for the treatment of systemic hypotension in the context of elevated PVR. As a non-catecholamine agent, it is effective in acidotic patients such as those in profound shock. While earlier human studies reported conflicting results on the effect of vasopressin on the pulmonary vasculature, more recent publications describe its successful use in PH patients. The aforementioned study by Siehr showed a consistent decrease in the PVR:SVR ratio as well as pulmonary arterial pressure to systemic arterial pressure (PAP:SAP) ratio with the use of vasopressin in the cardiac catheterization lab. An in-vitro study using human radial and pulmonary arteries compared the vasoconstrictor response of phenylephrine, norepinephrine, vasopressin and metaraminol and demonstrated that vasopressin had the weakest pulmonary vasoconstrictive response of these agents. Some animal and human studies have also hypothesized that vasopressin could induce pulmonary vasodilation via stimulation of the V1 receptor induced release of endothelial-derived nitric oxide but this finding remains inconsistent to date.\r\n\r\nThe evaluation and management of PH in the setting of noncardiac surgery has been comprehensively reviewed in a recent scientific statement from the American Heart Association (Rajagopal et al). Vasopressin is the preferred vasoconstrictor for low systemic blood pressure due to its minimal effects on PVR. However, high doses (0.08-0.1 U\/min) should be avoided due to the possibility of coronary vasoconstriction and right ventricular ischemia. Norepinephrine is a suitable alternative to vasopressin. Phenylephrine should be avoided due to its effect on increasing PVR, SVR and causing reflex bradycardia. Although epinephrine may also be considered, it can produce undesirable tachycardia, induce arrhythmias and increased myocardial oxygen consumption. \r\n\r\n\r\n \r\nREFERENCES \r\nSiehr SL, Feinstein JA, Yang W, Peng LF, Ogawa MT, Ramamoorthy C. Hemodynamic Effects of Phenylephrine, Vasopressin, and Epinephrine in Children With Pulmonary Hypertension: A Pilot Study. Pediatr Crit Care Med <\/em>. 2016;17(5):428-437. doi: 10.1097\/PCC.0000000000000716 \r\n\r\nCurrigan DA, Hughes RJ, Wright CE, Angus JA, Soeding PF. Vasoconstrictor responses to vasopressor agents in human pulmonary and radial arteries: an in vitro study. Anesthesiology<\/em>. 2014;121(5):930-936. doi: 10.1097\/ALN.0000000000000430\r\n\r\nTourneux P, Rakza T, Bouissou A, Krim G, Storme L. Pulmonary circulatory effects of norepinephrine in newborn infants with persistent pulmonary hypertension. J Pediatr<\/em>. 2008;153(3):345-349. doi: 10.1016\/j.jpeds.2008.03.007 \r\n\r\nColeman RD, Chartan CA, Mourani PM. Intensive care management of right ventricular failure and pulmonary hypertension crises. Pediatr Pulmonol<\/em>. 2021;56(3):636-648. doi: 10.1002\/ppul.24776\r\n\r\nRajagopal S, Ruetzler K, Ghadimi K et al. Evaluation and management of pulmonary hypertensionin noncardiac surgery: A scientific statement from the American Heart Association. Circulation. 2023; 147:1317-1343. https:\/\/doi.org\/10.1161\/CIR.0000000000001136\r\n\r\n\r\n”,”hint”:””,”answers”:{“22j2j”:{“id”:”22j2j”,”image”:””,”imageId”:””,”title”:”A.\tPhenylephrine”},”85oaz”:{“id”:”85oaz”,”image”:””,”imageId”:””,”title”:”B.\tNorepinephrine”},”4m8ay”:{“id”:”4m8ay”,”image”:””,”imageId”:””,”title”:”C.\tVasopressin”,”isCorrect”:”1″}}}}}

{“questions”:{“9fe0e”:{“id”:”9fe0e”,”mediaType”:”image”,”answerType”:”text”,”imageCredit”:””,”image”:””,”imageId”:””,”video”:””,”imagePlaceholder”:””,”imagePlaceholderId”:””,”title”:”Author: Melissa Colizza MD – CHU Saint-Justine, Montreal, Quebec \r\n\r\nA 2-year-old boy with Shone\u2019s complex, mild hypoplasia of the left ventricle, moderate mitral stenosis and moderate aortic regurgitation status-post balloon valvuloplasty of severe aortic valve stenosis is undergoing an elective Ross-Konno procedure and mitral valve repair. Which of the following factors is MOST likely associated with increased morbidity and mortality after biventricular repair of a borderline left heart disease?”,”desc”:”EXPLANATION \r\nBorderline left heart disease falls along the spectrum of hypoplastic left heart syndrome. It is characterized by the size of left-sided heart structures (aortic valve, mitral valve, LV end-diastolic volume) with z-scores of -2 to -5, as well as the presence of endocardial fibroelastosis (EFE).\r\nThe single ventricle pathway continues to have substantial mortality and morbidity including Fontan circulation failure with cyanosis and\/or ventricular dysfunction as well as end-organ dysfunction, such as Fontan-associated liver disease, protein-losing enteropathy, plastic bronchitis and lymphatic dysfunction. In the past two decades, there has been increasing interest and development of surgical techniques to establish a two-ventricle circulation in patients who traditionally would have been palliated via the single-ventricle pathway. Currently, there is no consensus whether a \u201cbad two-ventricle\u201d repair is better than a \u201cgood single-ventricle\u201d circulation, as long-term comparison data is unavailable. \r\nIn recent years, there have been increasing efforts to establish objective anatomic, physiologic, and hemodynamic criteria that could predict which patients with borderline left heart disease would be amenable to recruitment procedures to increase blood flow to the ventricle in order to stimulate growth and then allow for biventricular repair. Strategies to increase blood flow to the left ventricle include creating a fenestrated atrial septal defect, adding an additional source of pulmonary blood flow via a shunt, and resection of EFE tissue. Subsequent surgical decision making on whether to attempt biventricular repair depends on a comprehensive assessment based on multiple characteristics of the left heart structures and function including the following: 1) the size and structure of the mitral valve and its apparatus, 2) the size and function of the aortic valve, 3) the end-diastolic volume and pressure of the LV, 4) the apex-forming status of the LV, 5) the presence of EFE, and 6) the underlying anatomy of the congenital heart defect. \r\nAlthough no single factor has been shown to predict the success or failure of biventricular conversion, there are some data that can inform the decision making process. A retrospective single-institution study assessing outcomes of 51 patients undergoing biventricular repair over a period of thirteen years from 2003-2015 by Herrin et al concluded that a pre-operative left ventricular end-diastolic pressure (LVEDP) \u2265 13mmHg and post-operative right ventricular systolic pressure (RVSP) \u2265 three-quarters of the systemic systolic pressure, as well as the presence of \u2265 moderate EFE, were associated with an increased likelihood of death, transplant or conversion to single ventricle physiology. Data from cardiac magneting resonance (CMR) imaging studies can also be of prognostic value. A CMR study of 32 patients with single ventricles undergoing biventricular repair concluded that a left ventricular end diastolic volume \u2265 45ml\/m^{2 <\/sup>in hypoplastic left heart variants or \u226530ml\/m2 <\/sup> in patients with double outlet right ventricle or atrioventricular canal defect were associated with a greater likelihood of success (Banka et al). These elements illustrate that, while size matters, it is the overall capacity of the left-sided circulation to accommodate a full cardiac output at low filling pressures that allows for a successful biventricular repair. In the event of a failed repair that results in diastolic dysfunction, left atrial hypertension and subsequent pulmonary hypertension, patients could become ineligible for conversion to single-ventricle physiology or for heart transplantation. \r\n\r\n \r\nREFERENCES \r\nDavies SJ, DiNardo JA, Emani SM, Brown ML. A Review of Biventricular Repair for the Congenital Cardiac Anesthesiologist. Semin Cardiothorac Vasc Anesth<\/em>. 2023;27(1):51-63. doi: 10.1177\/10892532221143880\r\n\r\nHerrin MA, Zurakowski D, Baird CW, et al. Hemodynamic parameters predict adverse outcomes following biventricular conversion with single-ventricle palliation takedown. J Thorac Cardiovasc Surg<\/em>. 2017;154(2):572-582. 10.1016\/j.jtcvs.2017.02.070 \r\n \r\nAndersen ND, Scherba JC, Turek JW. Biventricular Conversion in the Borderline Hypoplastic Heart. Curr Cardiol Rep<\/em>. 2020;22(10):115. doi: 10.1007\/s11886-020-01363-5\r\n\r\nChiu P, Emani S. Left Ventricular Recruitment in Patients With Hypoplastic Left Heart Syndrome. Semin Thorac Cardiovasc Surg Pediatr Card Surg Annu<\/em>. 2021;24:30-36. doi: 10.1053\/j.pcsu.2021.03.001\r\n\r\nBanka P, Schaetzle B, Komarlu R, Emani S, Geva T, Powell AJ. Cardiovascular magnetic imaging parameters associated with early transplant-free survival in children with small left hearts following conversion from a univentricular to biventricular circulation. J Cardiovasc Magn Reson <\/em>.2014; 16:73. doi: 10.1186\/s12968-014-0073-1\r\n\r\n”,”hint”:””,”answers”:{“nneh6”:{“id”:”nneh6″,”image”:””,”imageId”:””,”title”:”A.\tPre-operative left ventricular end-diastolic pressure > 13mmHg”,”isCorrect”:”1″},”xtnke”:{“id”:”xtnke”,”image”:””,”imageId”:””,”title”:”B.\tLeft ventricular end -diastolic volume z-score of -2 to -5″},”7ot74″:{“id”:”7ot74″,”image”:””,”imageId”:””,”title”:”C.\tParachute mitral valve”}}}}}}

{“questions”:{“lz52i”:{“id”:”lz52i”,”mediaType”:”image”,”answerType”:”text”,”imageCredit”:””,”image”:””,”imageId”:””,”video”:””,”imagePlaceholder”:””,”imagePlaceholderId”:””,”title”:”Author: Destiny F. Chau, MD – Arkansas Children\u2019s Hospital \/University of Arkansas for Medical Sciences, Little Rock, AR \r\n\r\nA 19-year-old female with a history of Turner Syndrome, chronic hypertension and aortic coarctation repair in infancy presents for a surveillance cardiac MRI. She is recovering from a viral upper respiratory tract illness four weeks prior. On preoperative evaluation, she complains of new onset headache and sharp chest pain radiating to her upper back and stomach that started an hour ago, which is unchanged by position or deep breathing. Current vital signs are: HR 94, 179\/79, SpO2 97%, RR 22, Temp 36.8^{o<\/sup>C. Cardiac imaging six months prior demonstrated a bicuspic aortic valve with minimal gradient across the valve, repaired aortic coarctation, and an indexed aortic size of 2.5 cm\/m2<\/sup>. Physical exam reveals a webbed neck, mild micrognathia and Mallampati Class II airway. Which of the following is MOST likely etiology of chest pain? \r\n”,”desc”:”EXPLANATION \r\nTurner syndrome is a chromosomal abnormality associated with the haploinsufficiency of the X chromosome, whereby one copy is absent or deficient, and the remaining X chromosome is not adequate to produce the needed genetic product to preserve normal function. The diagnosis of Turner syndrome requires the individual to be phenotypically female, and it occurs with a frequency of 1:2,500 live female births. Clinical manifestations of this syndrome include cardiac and renal abnormalities, webbed neck, lymphedema, short stature, premature ovarian failure and abnormalities in other organ systems. The majority of patients with Turner syndrome have normal intelligence, although they may have associated learning disabilities. \r\n\r\nPatients with Turner syndrome have an increased risk of aortopathy and other congenital cardiovascular abnormalities, which are found in up to 50% of live born girls. Bicuspid aortic valve (~30%) and coarctation of the aorta (~18%) are the most common cardiac abnormalities that are observed in Turner syndrome patients. Other less frequent cardiac lesions include partial anomalous pulmonary venous return, ventricular septal defect, mitral valve anomalies and hypoplastic left heart syndrome. Patients with Turner syndrome are prone to the early development of systemic hypertension and aortic dilatation. Additionally, these patients are also pre-disposed to coronary artery disease, dyslipidemia, obesity, diabetes mellitus and stroke. Congenital and acquired cardiovascular disease is the major cause of death. Aortic dissection in Turner syndrome occurs earlier, at smaller aortic dilatation dimensions, and at approximately seven times the frequency of the general population. A recent scientific statement by the American Heart Association (Silberbach et al) states that Turner syndrome patients who are older than 15 years with bicuspid aortic valve, aortic coartation and\/or hypertension, and an indexed aortic size greater than 2.3 cm\/m2<\/sup> are considered to be at high cardiovascular risk and should undergo cardiac evaluation every 6 -12 months. The statement also highlights the importance of prompt recognition of the presenting signs and symptoms of aortic dissection, an often-fatal complication. \r\n\r\nPerioperative considerations for patients with Turner syndrome include a potential difficult airway due to the presence of short neck and micrognathia and other comordities involving the cardiovascular, renal and endocrine systems. As Turner syndrome patients advance in age, there is an increase in cardiovascular risk, portending to greater perioperative morbidity and mortality. The patient in the stem is at high cardiovascular risk and presents with the signs and symptoms of an aortic dissection. Though the patient is at risk for pericarditis given a recent viral upper respiratory tract infection, chest pain related to pericarditis is typically worsened by recumbent position or deep breathing. Chest pain may also be indicative of myocardial infarction, however the location and quality of chest pain described in the stem is more concerning for aortic dissection and rupture. The patient\u2019s blood pressure is elevated on presentation and should prompt timely blood pressure control but pales in comparison to potential aortic dissection. Effective communication with the cardiac and surgical teams for further evaluation and medical management of the blood pressure is imperative to minimize morbidity and mortality. \r\n\r\n\r\n \r\n\r\nREFERENCES \r\nSilberbach M, Roos-Hesselink JW, Andersen NH, et al. Cardiovascular health in Turner syndrome: A scientific statement from the American Heart Association. Circ Genom Precis Med <\/em>.2018;11(10):e000048. doi:10.1161\/HCG.0000000000000048\r\n\r\n\r\nMashour GA, Sunder N, Acquadro MA. Anesthetic management of Turner syndrome: a systematic approach. J Clin Anesth<\/em>. 2005;17(2):128-130. doi:10.1016\/j.jclinane.2004.06.010\r\n\r\n\r\nHuang AC, Olson SB, Maslen CL. A review of recent developments in Turner syndrome research. J Cardiovasc Dev Dis<\/em>. 2021;8(11):138. doi:10.3390\/jcdd8110138\r\n\r\n\r\nBondy CA; Turner Syndrome Study Group. Care of girls and women with Turner syndrome: a guideline of the Turner Syndrome Study Group. J Clin Endocrinol Metab<\/em>. 2007;92(1):10-25. doi:10.1210\/jc.2006-1374\r\n\r\n”,”hint”:””,”answers”:{“psh4k”:{“id”:”psh4k”,”image”:””,”imageId”:””,”title”:”A.\tMyocardial infarction “},”g4r9f”:{“id”:”g4r9f”,”image”:””,”imageId”:””,”title”:”B.\tAortic dissection “,”isCorrect”:”1″},”uw37a”:{“id”:”uw37a”,”image”:””,”imageId”:””,”title”:”C.\tPericarditis”}}}}}}

{“questions”:{“uwca7”:{“id”:”uwca7″,”mediaType”:”image”,”answerType”:”text”,”imageCredit”:””,”image”:””,”imageId”:””,”video”:””,”imagePlaceholder”:””,”imagePlaceholderId”:””,”title”:”Author: Destiny F. Chau MD – Arkansas Children\u2019s Hospital \/University of Arkansas for Medical Sciences, Little Rock, AR.\r\n\r\nA 6-month-old infant is undergoing a full repair for Tetralogy of Fallot. The patient separates from cardiopulmonary bypass (CPB) on milrinone 0.05 mcg\/kg\/min, dexmedetomidine 0.5 mcg\/kg\/h and morphine 0.025 mg\/kg\/h. The surgeon measures a right ventricular (RV)-to-aortic pressure ratio of 0.5, and right ventricular outflow tract (RVOT) gradient of 30 mmHg. Ten minutes later the vital signs are: BP 50\/38, HR 167 bpm in sinus rhythm, SpO2 100%, with adequate anesthetic depth. The transesophageal echocardiogram (TEE) is now showing hyperdynamic right ventricular systolic function with subvalvar obstruction. In addition to volume administration, what is the recommended next step in management? \r\n”,”desc”:”EXPLANATION \r\n\r\nTetralogy of Fallot is the most common type of cyanotic congenital heart disease, representing approximately 10% of all congenital heart defects with an estimated incidence of 1 in 2,500\u2013 3,000 live births. It was first comprehensively described by Etienne Fallot in 1888 as a group of four characteristic features: ventricular septal defect (VSD), overriding aorta, right ventricular outflow tract obstruction (RVOTO) and right ventricular hypertrophy. In 1924, Maude Abbott coined this cardiac abnormality as \u201ctetralogy of Fallot\u201d. \r\n\r\nTetralogy of Fallot was the cardiac anomaly for which the first Blalock-Taussig-Thomas shunt (BTTs) was performed to augment pulmonary blood flow in 1945. This successful operation launched the modern era of congenital cardiac repair. Although the timing, techniques and approaches of surgical repair, and overall medical management of TOF have evolved in the decades since the BTTs, the surgical goals remain the same: closure of the VSD and establishment of pulmonary blood flow. \r\n\r\n\r\nA 2022 expert consensus from the American Association for Thoracic Surgery by Miller et al published recommendations for the management of pediatric patients with tetralogy of Fallot. For assessing adequacy of surgical repair, the panel recommends direct pressure measurements to objectively evaluate for residual obstruction and guide any need for reintervention, and recommends to aim for RV-to-aortic pressure ratio of 0.5 or less with an RVOT gradient less than 30 to 40 mm Hg. These parameters must be considered in the context of the patient\u2019s condition and specific anatomic limitations to surgical resection. After relief of RVOTO , dynamic outflow obstruction associated with a hypertrophied RV is not uncommon, especially in the setting of relative hypovolemia and a hypercontractile right ventricle. Anticipatory management for set hemodynamic goals is indicated, which includes optimization of RV preload with adequate volume administration, minimization of hypercontractility, and maintaining adequate diastolic filling time via heart rate control. Hyperdynamic obstruction improves over time as the hypertrophied RV remodels once the primary obstruction has been reduced. \r\n\r\n\r\nIn the setting of adequate surgical results which in this case is supported by the initial RVOT gradient and RV-to-aorta pressure ratio, the hemodynamic decline in this patient is most likely due to hyperdynamic obstruction from the pre-existing hypertrophied RV. Management for this condition would be to maintain filling pressures with volume administration, minimization of inotropic agents such as calcium and epinephrine, and slowing of the heart rate to allow for increased diastolic filling time. An esmolol drip is helpful for controlling the tachycardia. If these medical interventions fail to restore hemodynamic stability, other etiologies should be sought. The surgeon should be notified and the cardiac status reevaluated via TEE and repeat pressure measurements as necessary. A return to CPB may be needed if evidence suggests that surgical reintervention is necessary. \r\n\r\n\r\n\r\n \r\n\r\nREFERECES \r\nSchmitz ML, Chau DF, Das RR, Thompson LL, Ullah S. Anesthesia for right-sided obstructive lesions. In: Andropoulos DB, Mossad EB, Gottlieb EA, eds. Anesthesia for Congenital Heart Disease <\/em>.4th ed. Hoboken, NJ; Wiley-Blackwell. 2023: 674-710. \r\n\r\n\r\nExpert Consensus Panel:, Miller JR, Stephens EH, et al. The American Association for Thoracic Surgery (AATS) 2022 Expert Consensus Document: Management of infants and neonates with tetralogy of Fallot. J Thorac Cardiovasc Surg<\/em>. 2023;165(1):221-250. doi:10.1016\/j.jtcvs.2022.07.025 \r\n\r\n\r\nWise-Faberowski L, Asija R, McElhinney DB. Tetralogy of Fallot: Everything you wanted to know but were afraid to ask. Paediatr Anaesth <\/em>.2019;29(5):475-482. doi:10.1111\/pan.13569 \r\n\r\n\r\nJonas A. Tetralogy of Fallot with pulmonary stenosis. In: Jonas A, ed. Comprehensive Surgical Management of Congenital Heart Disease<\/em>. 2nd Edition. Boca Raton, Florida: Taylor & Francis Group, LLC; 2014: 351-361.\r\n\r\n\r\n”,”hint”:””,”answers”:{“iiogb”:{“id”:”iiogb”,”image”:””,”imageId”:””,”title”:”A.\tReturn to CPB for reintervention”},”zej6b”:{“id”:”zej6b”,”image”:””,”imageId”:””,”title”:”B.\tAdminister calcium”},”q32hb”:{“id”:”q32hb”,”image”:””,”imageId”:””,”title”:”C.\tBolus esmolol and begin an infusion\r\n\r\n”,”isCorrect”:”1″}}}}}