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

{“questions”:{“ld468”:{“id”:”ld468″,”mediaType”:”image”,”answerType”:”text”,”imageCredit”:””,”image”:””,”imageId”:””,”video”:””,”imagePlaceholder”:””,”imagePlaceholderId”:””,”title”:”Author: Anna Hartzog MD\u2013 Children\u2019s National Hospital, Chinwe Unegbu MD \u2013 Children\u2019s National Hospital \r\n\r\nA 3-month-old male with Tetralogy of Fallot (TOF) with worsening cyanosis presents for surgical repair with infundibular muscle bundle resection and a transannular patch. Preoperatively, the patient has been on propranolol and his baseline heart rate is 120. Prior to separation from bypass, dopamine is started at 10 mcg\/kg\/min, the rectal temperature is 35.5 degrees Celsius, and the magnesium level is 2.1 mg\/dL. Upon separation from cardiopulmonary bypass (CPB), junctional ectopic tachycardia (JET) is noted with hemodynamic instability. What is the MOST LIKELY contributing factor to JET in this patient?\r\n”,”desc”:””,”hint”:””,”answers”:{“y7z7y”:{“id”:”y7z7y”,”image”:””,”imageId”:””,”title”:”A. Preoperative heart rate “},”64v8r”:{“id”:”64v8r”,”image”:””,”imageId”:””,”title”:”B. Intraoperative magnesium level”},”fab9v”:{“id”:”fab9v”,”image”:””,”imageId”:””,”title”:”C. Intraoperative inotropic requirement”,”isCorrect”:”1″},”70f49″:{“id”:”70f49″,”image”:””,”imageId”:””,”title”:”D. Rewarming target temperature”}}}},”results”:{“3cpjt”:{“id”:”3cpjt”,”title”:””,”image”:””,”imageId”:””,”min”:”0″,”max”:”1″,”desc”:”Junctional ectopic tachycardia (JET) is the most common tachyarrhythmia in the postoperative period in children undergoing congenital heart surgery. The reported incidence following pediatric cardiac surgery ranges widely from 2-22%, which is due to differences in study design and the diversity of cardiac lesions represented in those studies. \r\n\r\nCongenital heart defects that are known to be major contributors to postoperative JET include ventricular septal defect (VSD), Tetralogy of Fallot (TOF), and complete atrioventricular canal (CAVC). The incidence of JET is greater when the surgical intervention is in close proximity to the atrioventricular (AV) node and bundle of His, as is the case with TOF and CAVC repair. TOF repair is widely recognized as the surgical procedure most likely to be associated with the development of postoperative JET. The reported incidence of JET following TOF repair varies from 4 to 37% in the literature. A 2018 study by Paluszek et al. reported the incidence of JET in pediatric patients following TOF repair to be 13.3%. \r\n\r\n\r\nEarly postoperative JET typically occurs within the first forty-eight hours after pediatric cardiac surgery and is defined as a narrow complex tachycardia with a rate of \u2265 170 bpm. JET originates from the atrioventricular (AV) node or AV junction, which includes the bundle of His. There is often AV dissociation resulting in the ventricular rate exceeding the atrial rate but sometimes there is 1:1 retrograde ventriculoatrial conduction. JET typically manifests with a narrow QRS complex; however, if a bundle branch block is present, then the QRS complex may be wide. The exact etiology of JET is unknown; however, many hypothesize that JET may be the result of direct mechanical trauma (ie surgical sutures) or indirect stretch injury with or without edema to the conduction system which then precipitates automaticity of the AV node\/bundle of His. \r\n\r\n\r\nDespite generally being a self-limiting condition, JET can be associated with postoperative hemodynamic instability and morbidity due to hemodynamic deterioration secondary to extreme tachycardia, loss of AV synchrony, and compromised ventricular filling. In particular, the combination of JET and depressed myocardial function may result in a low cardiac output state and cardiogenic shock. \r\n\r\n\r\nRisk factors for postoperative JET include an increased baseline preoperative heart rate, cyanotic spells, non-use of beta-blockers in the preoperative period, low intraoperative magnesium and calcium levels, prolonged cardiopulmonary bypass (CPB) and\/or aortic cross clamp times, hypothermic circulatory arrest, increased complexity of the surgical procedure, and use of high dose inotropes. Postoperative JET is also associated with a younger age at the time of operation and lower body weight. Younger patients presenting for surgical repair have smaller hearts that are more prone to mechanical or stretch related injury of the conduction system. Both postoperative inotropic score and dopamine use have been independently associated with the occurrence of postoperative JET. This suggests that JET may be triggered by the arrhythmogenic properties of dopamine. \r\n\r\n\r\nInterventions known to reduce the occurrence of JET after pediatric cardiac surgery include minimization of CPB and aortic cross clamp time, correction of electrolyte imbalances especially magnesium and calcium, use of magnesium sulfate on CPB, optimization\/titration of inotropic support with the goal of minimizing exogenous catecholamines, correction of intravascular volume, avoidance of hyperthermia, and adequate use of sedatives and analgesics. Some patients with JET require external pacing to restore AV synchrony. Many antiarrhythmics have been used in the management of JET, including but not limited to digoxin, sotalol, procainamide, and amiodarone. No single antiarrhythmic has been found to be superior. Typically, the antiarrhythmic initiated is simply a matter of institutional preference. \r\n\r\n\r\nIn this question stem, the most likely contributing factor to JET is the use of dopamine. The use of propranolol preoperatively suggests heart rate control and should be preventative against JET. Likewise, the magnesium level prior to separation from CPB was within normal limits and would be preventative as well. The rewarming target temperature of 35.5 is appropriately low and preventative to hyperthermia induced JET. \r\n\r\n\r\nReferences \r\n\r\n1.\tAl-Sofyani KA, Jamalaldeen RI, Abusaif SM, Elassal AA, Al-Radi OO. The prevalence and outcome of junctional ectopic tachycardia in pediatric cardiac surgery: Journal of the Egyptian Society of Cardio-Thoracic Surgery<\/em>. 2017; 25(2): 128-132. \r\n\r\n2.\tPaluszek C, Brenner P, Pichlmaier M, et al. Risk Factors and Outcome of Post Fallot Repair Junctional Ectopic Tachycardia (JET): World J Pediatr Congenit Heart Surg<\/em>. 2019; 10(1): 50-57. doi: 10.1177\/2150135118813124. PMID: 30799715. \r\n\r\n\r\n3.\tDodge-Khatami A, Miller OI, Anderson RH, et al. Surgical substrates of postoperative junctional ectopic tachycardia in congenital heart defects. J Thorac Cardiovasc Surg<\/em>. 2002; 123(4): 624-630. \r\n\r\n4.\tIsmail MF, Arafat AA, Hamouda TE, et al. Junctional ectopic tachycardia following tetralogy of fallot repair in children under 2 years. J Cardiothorac Surg<\/em>. 2018; 13(1): 60. doi:10.1186\/s13019-018-0749-y \r\n\r\n5.\tManrique AM, Arroyo M, Lin Y, et al. Magnesium supplementation during cardiopulmonary bypass to prevent junctional ectopic tachycardia after pediatric cardiac surgery: a randomized controlled study. J Thorac Cardiovasc Surg<\/em>. 2010; 139: 162-169. \r\n\r\n6.\tEl Amrousy D, Elshehaby W, Elfeky W, Elshmaa N. Safety and efficacy of prophylactic amiodarone in preventing early junctional ectopic tachycardia (JET) in children after cardiac surgery and determination of its risk factor. Pediatr Cardiol<\/em>. 2016; 37: 734\u2013739.\r\n\r\n\r\n\r\n\r\n\r\n”,”redirect_url”:””}}}

{“questions”:{“3ictj”:{“id”:”3ictj”,”mediaType”:”image”,”answerType”:”text”,”imageCredit”:””,”image”:””,”imageId”:””,”video”:””,”imagePlaceholder”:””,”imagePlaceholderId”:””,”title”:”Author: Sana Ullah, MB ChB, FRCA \u2013 Children\u2019s Medical Center, Dallas\r\n\r\nA 6-year-old male child with a history of Kawasaki disease is undergoing pharmacological stress cardiac magnetic resonance imaging (MRI) with adenosine. Which of the following adenosine receptors is MOST LIKELY<\/em> associated with coronary vasodilation?\r\n”,”desc”:””,”hint”:””,”answers”:{“81vr6”:{“id”:”81vr6″,”image”:””,”imageId”:””,”title”:”A.\tA1″},”fv5xu”:{“id”:”fv5xu”,”image”:””,”imageId”:””,”title”:”B.\tA2A”,”isCorrect”:”1″},”ptx0g”:{“id”:”ptx0g”,”image”:””,”imageId”:””,”title”:”C.\tA2B”},”mcrw6″:{“id”:”mcrw6″,”image”:””,”imageId”:””,”title”:”D.\tA3″}}}},”results”:{“5colx”:{“id”:”5colx”,”title”:””,”image”:””,”imageId”:””,”min”:”0″,”max”:”1″,”desc”:”Adenosine is a naturally occurring purine nucleoside base that exerts varying effects via four different purinergic adenosine receptors. These various effects include the following: \r\n–A1 receptor activation in the atrioventricular node decreases conduction and produces a slowing of the heart rate. This effect is utilized in the diagnosis and treatment of certain supraventricular tachycardias particularly during electrophysiology (EP) studies.\r\n–A2A receptor activation in vascular smooth muscle, including the coronary arteries, produces vasodilation and decreases systemic blood pressure. \r\n–A2B and A3 receptor activation in bronchial smooth muscles causes bronchoconstriction. \r\n\r\n\r\nPharmacologic stress cardiac magnetic resonance imaging (MRI) is used for the initial evaluation and subsequent follow-up of pediatric patients with coronary abnormalities. Coronary abnormalities may occur in patients with a history of Kawasaki disease or perhaps in patients who have had surgical reimplantation of the coronary arteries, which may occur during the arterial switch operation or in patients with anomalous origins of coronary arteries. The principle behind pharmacological stress cardiac MRI is to produce maximal coronary vasodilation in \u201cnormal\u201d vessels, thereby producing a \u201csteal\u201d phenomenon in areas of myocardium supplied by the diseased vessels. These potentially ischemic regions can then be visualized by the administration of gadolinium contrast. \r\n\r\n\r\nAlthough protocols may vary slightly, a typical adenosine stress MRI involves the administration of adenosine as an infusion at 140 micrograms per kilogram per minute (mcg\/kg\/min) for a total of six minutes. At the three-minute time point, gadolinium contrast is given via a separate intravenous line. There is usually a modest increase in heart rate and a slight decrease in blood pressure. Non-sedated patients may experience nausea, flushing or chest pain. Due to a short half-life of less than 10 seconds, the effects of adenosine dissipate very quickly after discontinuing the infusion. \r\n\r\n\r\nAdenosine is contraindicated or extreme caution is warranted in certain patient groups including those with severe asthma or reactive airway disease, second or third degree heart block or sinus node dysfunction in the absence of a pacemaker, or in patients with unstable angina or acute coronary syndrome. \r\n\r\n\r\nMethylxanthine medications such as aminophylline, theophylline and caffeine antagonize adenosine binding at the A2A receptor and can reduce the coronary vasodilatory effects. In the case of serious adverse side effects, intravenous aminophylline can be administered as an antidote. Patients are typically advised to avoid caffeine-containing foods and beverages for at least 12 or preferably 24 hours before the test. \r\n\r\nRegadenoson is an alternative adenosine receptor agonist with more selectivity at the A2A receptor. Due to its selective nature, regadenoson is a more potent coronary vasodilator with a more prolonged duration of action. It is administered as an intravenous bolus and, therefore, there is no need for an additional intravenous line to administer gadolinium contrast. The peak coronary vasodilatory effect occurs after approximately two minutes, but the effect may last beyond thirty minutes due to its tri-phasic elimination kinetics. This may be disadvantageous in the case of serious side effects. Side effects may be uncommon due to receptor selectivity but similar in characteristic to those of adenosine. The cost of regadenoson is much higher than adenosine. \r\n\r\n\r\nReferences\r\n\r\n\r\n1)\tLayland J, Carrick D, Lee M, Oldroyd K, Berry C. Adenosine: Physiology, pharmacology, and clinical applications. J Am Coll Cardiol Intv<\/em>. 2014; 7: 581-591. \r\n\r\n2)\tFares M, Critser PJ, Arruda MJ, et al. Pharmacologic stress cardiovascular magnetic resonance in the pediatric population: A review of the literature, proposed protocol, and two examples in patients with Kawasaki disease. Congenit Heart Dis<\/em>. 2019; 14: 1166-1175.\r\n\r\n3)\tDoan TT, Wilkinson JC, Loar RW, Pednekar AS, Masand PM, Noel C. Regadenoson stress perfusion cardiac magnetic resonance imaging in children with Kawasaki disease and coronary artery disease. Am J Cardiol<\/em> 2019; 124: 1125-1132.”,”redirect_url”:””}}}

{“questions”:{“z49yi”:{“id”:”z49yi”,”mediaType”:”image”,”answerType”:”text”,”imageCredit”:””,”image”:””,”imageId”:””,”video”:””,”imagePlaceholder”:””,”imagePlaceholderId”:””,”title”:”Author: Sana Ullah, MB ChB, FRCA \u2013 Children\u2019s Medical Center, Dallas TX\r\n\r\nWhat is the MOST COMMON syndrome associated with pulmonary arteriovenous malformations ?\r\n\r\n”,”desc”:””,”hint”:””,”answers”:{“cye57”:{“id”:”cye57″,”image”:””,”imageId”:””,”title”:”A.\tScimitar syndrome”},”imdso”:{“id”:”imdso”,”image”:””,”imageId”:””,”title”:”B.\tOsler-Weber-Rendu syndrome”,”isCorrect”:”1″},”vlz1s”:{“id”:”vlz1s”,”image”:””,”imageId”:””,”title”:”C.\tKartagener\u2019s syndrome”},”vd63t”:{“id”:”vd63t”,”image”:””,”imageId”:””,”title”:”D.\tAlagille syndrome”}}}},”results”:{“9wcta”:{“id”:”9wcta”,”title”:””,”image”:””,”imageId”:””,”min”:”0″,”max”:”1″,”desc”:”Pulmonary 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\n\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\n\r\n\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. A rare but interesting phenomenon as a result of pulmonary AVMs 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\n\r\n\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\n\r\n\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. \r\n\r\n\r\nKartagener\u2019s syndrome is an autosomal recessive disorder characterized by primary ciliary dyskinesis resulting in a triad of situs inversus totalis, chronic sinusitis, and bronchiectasis. \r\n\r\n\r\nAlagille 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\n\r\nReferences\r\n\r\n\r\n1.\t Shovlin CL. Pulmonary Arteriovenous Malformations. Am J Respir Crit Care Med<\/em>. 2014; 190(11): 1217-1228. \r\n\r\n2.\t Vida VL, Guariento A. A sword threatening the heart: The scimitar syndrome. JCTVS Techniques<\/em>. 2020; 1: 75-80. \r\n\r\n3.\t Tretter 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\n4.\t Kamath 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”,”redirect_url”:””}}}

{“questions”:{“lcw7k”:{“id”:”lcw7k”,”mediaType”:”image”,”answerType”:”text”,”imageCredit”:””,”image”:””,”imageId”:””,”video”:””,”imagePlaceholder”:””,”imagePlaceholderId”:””,”title”:”Author: Sana Ullah, MB ChB, FRCA \u2013 Children\u2019s Medical Center, Dallas\r\n\r\nA 30-year-old patient with a history of extracardiac Fontan palliation has been diagnosed with hepatocellular carcinoma. Which of the following is the MOST<\/em> likely 1-year survival rate for Fontan patients diagnosed with hepatocellular carcinoma?\r\n”,”desc”:””,”hint”:””,”answers”:{“38e0f”:{“id”:”38e0f”,”image”:””,”imageId”:””,”title”:”A.\t20%”},”pyaoq”:{“id”:”pyaoq”,”image”:””,”imageId”:””,”title”:”B.\t50%”,”isCorrect”:”1″},”i8jc0″:{“id”:”i8jc0″,”image”:””,”imageId”:””,”title”:”C.\t70%”},”6i25b”:{“id”:”6i25b”,”image”:””,”imageId”:””,”title”:”D.\t90%”}}}},”results”:{“ytbdd”:{“id”:”ytbdd”,”title”:””,”image”:””,”imageId”:””,”min”:”0″,”max”:”1″,”desc”:”Fontan-associated liver disease (FALD) is a well-recognized complication of single ventricle palliation with the Fontan operation. The exact etiology is unclear but is related to chronically elevated central venous pressures and low cardiac output resulting in liver fibrosis and subsequent cirrhosis. Hepatocellular carcinoma (HCC) is a rare but serious complication of FALD. The reported prevalence of HCC after a Fontan operation is between 1-3% in different series of published studies. In a recent multicenter case series of 54 patients with a Fontan circulation and diagnosed with HCC, the mean age at diagnosis was 30+\/- 9.4 years with the youngest patient being 12 years of age. Additionally, the mean duration from Fontan surgery to HCC diagnosis was 21.6 +\/- 7.4 years and the 1-year survival was 50%. Survival was further decreased if the tumor was symptomatic, more than 4 cm in size, or had metastasized. \r\n\r\nDue to the numerous complications associated with the Fontan circulation, these patients require life-long follow up and regular screening for FALD. Recommendations for surveillance have recently been published which include a clinical assessment, liver function tests, serum biomarkers such as FibroSure and alpha-fetoprotein, imaging with an abdominal ultrasound, abdominal computed tomography scan or abdominal magnetic resonance imaging, and a liver biopsy. The surveillance interval should shorten with longer time elapsed from the Fontan completion. \r\n\r\n\r\nReferences\r\n\r\n\r\n1)\t Possner M, Gordon-Walker T, Egbe AC, et al. Hepatocellular carcinoma and the Fontan circulation: Clinical presentation and outcomes. Int J Cardiol<\/em>. 2021; 322: 142-148. \r\n2)\t Rychik J, Atz AM, Celermajer DS, et al. Evaluation and management of the child and adult with a Fontan circulation: A scientific statement from the American Heart Association. Circulation<\/em>. 2019; 140(6): 234-284. \r\n3)\tGorden-Walker TT, Bove K, Veldtman G. Fontan-associated liver disease: A review. J Cardiol<\/em>. 2019; 74: 223-232.\r\n\r\n\r\n\r\n”,”redirect_url”:””}}}

{“questions”:{“7155j”:{“id”:”7155j”,”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\nAn 11-month-old male infant with severe pulmonary valve stenosis and estimated peak systolic gradient of 110 mmHg presents for balloon pulmonary valvuloplasty. Immediately following balloon valvuloplasty, the vital signs are as follows: heart rate 165 beats per minute, blood pressure 53\/21, and oxygen saturation 60%. Which of the following measures is the MOST APPROPRIATE<\/em> next step in his management?\r\n”,”desc”:””,”hint”:””,”answers”:{“8203s”:{“id”:”8203s”,”image”:””,”imageId”:””,”title”:”A.\tEpinephrine bolus”},”e6blr”:{“id”:”e6blr”,”image”:””,”imageId”:””,”title”:”B.\tMilrinone bolus”},”aehh0″:{“id”:”aehh0″,”image”:””,”imageId”:””,”title”:”C.\tEsmolol bolus”,”isCorrect”:”1″},”iwrm6″:{“id”:”iwrm6″,”image”:””,”imageId”:””,”title”:”D.\tInhaled nitric oxide”}}}},”results”:{“7ck9i”:{“id”:”7ck9i”,”title”:””,”image”:””,”imageId”:””,”min”:”0″,”max”:”1″,”desc”:”This patient has developed a rare but serious complication colloquially known as a \u201csuicide right ventricle\u201d or dynamic right ventricular infundibular obstruction following balloon pulmonary valvuloplasty. Severe pulmonary valve stenosis can result in significant right ventricular hypertrophy and in particular right infundibular hypertrophy. An acute relief of the valvar gradient can suddenly unmask a previously unknown infundibular gradient leading to dynamic right ventricular outflow tract obstruction. The pathophysiology is similar to left ventricular outflow tract obstruction in the setting of hypertrophic cardiomyopathy. The mainstay of treatment is to reduce the heart rate and contractility with a beta blocker such as esmolol, labetalol, or propranolol. The decrease in contractility allows for improved ventricular filling during diastole. Beta blockade with oral propranolol may be necessary for a period of time after balloon valvuloplasty to allow for ventricular remodeling. In this case, esmolol is the appropriate treatment due to the fast onset of action given severe oxygen desaturation and hypotension. \r\n\r\nIn this case, an epinephrine bolus would not be helpful because the oxygen desaturation and hypotension are due to right ventricular infundibular obstruction rather than ventricular dysfunction. An epinephrine bolus would increase contractility and likely worsen the signs of infundibular obstruction. \r\n\r\nAlthough this patient likely has right ventricular diastolic dysfunction, a milrinone bolus would acutely produce systemic vasodilation and thereby worsen hypotension. \r\n\r\nInhaled nitric oxide would not be indicated in the treatment of right ventricular infundibular obstruction as it would reduce pulmonary arterial pressure rather than relieve infundibular obstruction. \r\n\r\nReferences: \r\n1)\tKhambatta H, Velado M, Gaffney J, Schechter W, Casta A. Management of right ventricular tract reactivity following pulmonary valve dilation after general anesthesia: experience of a medical mission. Pediatric Anesthesia. <\/em>2006; 16(10): 1087-1089. \r\n\r\n2)\tBen-Shachar G, Cohen M, Sivakoff M, Portman M, Riemenschneider T, Van Heeckeren D. Development of infundibular obstruction after percutaneous pulmonary balloon valvuloplasty. J Am Coll Cardiol. <\/em>1985; 5(3): 754-756. \r\n\r\n3)\tTharpar MK, Rao PS. Significance of infundibular obstruction following balloon valvuloplasty for valvar pulmonic stenosis. Am Heart J. <\/em>1989; 118: 99-103. \r\n\r\n”,”redirect_url”:””}}}