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

{“questions”:{“pk7hz”:{“id”:”pk7hz”,”mediaType”:”image”,”answerType”:”text”,”imageCredit”:””,”image”:””,”imageId”:””,”video”:””,”imagePlaceholder”:””,”imagePlaceholderId”:””,”title”:”Author: Melissa Colizza – CHU Sainte-Justine – Montreal, Quebec \r\n\r\nWhich of the following types of circulatory support requires the LOWEST level of systemic anticoagulation during combined heart-liver transplantation?\r\n”,”desc”:”EXPLANATION \r\nCombined heart-liver transplantation (CHLT) was first performed in 1984 and has become more frequent in the last decade. Indications have evolved to include metabolic diseases resulting in cardiomyopathy and end-stage liver disease leading to secondary heart failure. The most common indication for CHLT in the last decade was congenital heart disease with secondary liver disease. This was largely due to the growing number of patients palliated with a Fontan surviving to adulthood with concomitant Fontan-associated liver disease (FALD).\r\n\r\nCHLT is most commonly performed in sequential manner with cardiac transplantation on CPB first, followed by weaning from bypass and subsequent liver transplantation. Heparin may or may not be fully reversed prior to liver transplantation. Sequential cardiac then liver transplantation leads to hemodynamic derangements and additional stress on the cardiac allograft, particularly during inferior vena cava clamping and hepatic reperfusion. Several circulatory support strategies have been utilized to minimize central venous hypertension and optimize systemic cardiac output, including venovenous bypass and venoarterial extracorporeal membrane oxygenation (ECMO). \r\n\r\nVenovenous bypass (VVB) is the process during which blood is diverted from the infrahepatic IVC and portal vein and returned to the right heart via the axillary, subclavian, or internal jugular veins. The VVB circuit consists of heparin-bonded access catheters, a nonheparinized circuit, a centrifugal pump, and a blood warmer. There are options for an oxygenator and renal support. Anticoagulation management varies greatly across centers; VVB without anticoagulation has been described in the 1980s in circuits without an oxygenator, although more recent reports describe ACT targets like those used in VA ECMO. VA ECMO offers the benefits of full circulatory support of the heart and lungs, at the cost of greater levels of anticoagulation. The exact strategy for CHLT will depend on patient anatomy, cardiac allograft function, hemodynamic response to IVC test clamping and institutional preference.\r\n\r\nThere are case reports of simultaneous cardiac and liver transplantation while on full cardiopulmonary bypass (CPB). The benefits of performing both on CPB include the following, 1) a single period of reperfusion, 2) greater level of hemodynamic stability, particularly during liver reperfusion, 3) shorter cold ischemic time for the liver allograft, and 4) hemodynamic support of the newly transplanted heart with decreased venous congestion of the liver. However, en bloc liver and heart transplantation exposes patients to longer CPB duration and higher heparin doses.\r\n\r\nAnesthetic management of CHLT is challenging and has been comprehensively reviewed by Smeltz and colleagues. Patient preparation should include large bore venous access for fluid administration and blood product transfusion, arterial line placement in location(s) with consideration of the bypass cannulation plan, and central venous access above the IVC clamping site. If VVB is planned, central venous access should include the femoral vein in addition to a return cannula to the superior vena cava. Patients undergoing CHLT often have elevated pulmonary vascular resistance (PVR) secondary to cardiac disease or portopulmonary hypertension, which is a risk factor for right ventricular dysfunction. Thus, vasoactive agents with minimal effects on pulmonary vascular resistance, such as vasopressin and norepinephrine, and pulmonary vasodilators are advantageous. Significant vasoplegia and bleeding are expected along with administration of large quantities of blood products. Frequent laboratory assessment of hemostasis with point of care testing is necessary, especially in patients palliated with a Fontan and heavy collateral burden. Ideally, there must be a balance between adequate tissue perfusion and avoidance of volume overload, pulmonary edema, and right ventricular dysfunction. Thus, there should be major consideration of factor concentrate use to manage coagulopathy. \r\n\r\nVenovenous bypass requires the least amount of anticoagulation, especially with heparin-bonded circuits. VA ECMO generally requires higher levels of anticoagulation, but not as high as the anticoagulation required for full CPB.\r\n\r\n\r\n \r\nREFERENCES \r\nReardon LC, Lin JP, VanArsdell GS, et al. Orthotopic Heart and Combined Heart Liver Transplantation: the Ultimate Treatment Option for Failing Fontan Physiology. Curr Transplant Rep<\/em>. 2021;8(1):9-20. doi: 10.1007\/s40472-021-00315-4 \r\nTracy KM, Matsuoka LK, Alexopoulos SP. Update on combined heart and liver transplantation: evolving patient selection, improving outcomes, and outstanding questions. Curr Opin Organ Transplant<\/em>. 2023;28(2):104-109. doi: 10.1097\/MOT.0000000000001041 \r\nHofer RE, Christensen JM, Findlay JY. Anesthetic considerations for combined heart–liver transplantation in patients with Fontan-associated liver disease. Curr Opin Organ Transplant<\/em>. 2020;25(5):501-505. doi: 10.1097\/MOT.0000000000000800 \r\nGriffith BP, Shaw BW Jr, Hardesty RL, Iwatsuki S, Bahnson HT, Starzl TE. Veno-venous bypass without systemic anticoagulation for transplantation of the human liver. Surg Gynecol Obstet<\/em>. 1985;160(3):270-272. \r\nBarbara DW, Rehfeldt KH, Heimbach JK, Rosen CB, Daly RC, Findlay JY. The perioperative management of patients undergoing combined heart-liver transplantation. Transplantation<\/em>. 2015;99(1):139-144. doi: 10.1097\/TP.0000000000000231 \r\nSmeltz AM, Kumar PA, Arora H. Anesthesia for combined heart and liver transplantation. J Cardiothorac Vasc Anesth<\/em>. 2021; 35:3350-3361. doi.org\/10.1053\/j.jvca.2020.12.005\r\n”,”hint”:””,”answers”:{“3rcjj”:{“id”:”3rcjj”,”image”:””,”imageId”:””,”title”:”A.\tVenovenous bypass “,”isCorrect”:”1″},”3b6ps”:{“id”:”3b6ps”,”image”:””,”imageId”:””,”title”:”B.\tVenoarterial extracorporeal membrane oxygenation”},”papds”:{“id”:”papds”,”image”:””,”imageId”:””,”title”:”C.\tCardiopulmonary bypass”}}}}}

{“questions”:{“4zthb”:{“id”:”4zthb”,”mediaType”:”image”,”answerType”:”text”,”imageCredit”:””,”image”:””,”imageId”:””,”video”:””,”imagePlaceholder”:””,”imagePlaceholderId”:””,”title”:”Author: Melissa Colizza – CHU Sainte-Justine – Montreal, Quebec \r\n\r\nA one-year-old male has a cardiac arrest secondary to near drowning in a bathtub. After resuscitation and return of spontaneous circulation at the scene, the patient is intubated several hours after arrival to the intensive care unit due to rapidly evolving pulmonary edema and acute respiratory distress syndrome. Despite maximal mechanical ventilatory support, the patient is placed on veno-arterial extracorporeal membrane oxygenation (VA ECMO) via the right neck due to worsening arterial blood gases and hemodynamics. Twenty-four hours after VA ECMO initiation, the systemic oxygen saturation has decreased to 88% from 95% in all four limbs over several hours. Which of the following clinical factors is the MOST likely explanation for the decrease in systemic oxygen saturation?”,”desc”:”EXPLANATION \r\nExtra-corporal membrane oxygenation (ECMO) has been used since the 1970s for children with cardiopulmonary failure, in particular, post cardiotomy cardiac failure and respiratory failure due to congenital diaphragmatic hernia. Over the years, perfusion techniques and anticoagulation strategies have improved, which has led to an increased number of indications for ECMO and a recommendation for earlier ECMO initiation. Veno-arterial ECMO (VA-ECMO) is typically used for acute cardiac failure with or without respiratory failure, whereas veno-venous ECMO (VV-ECMO) is used for hypoxic or hypercarbic respiratory failure with preserved cardiac function despite maximal mechanical ventilatory support.\r\n\r\nThere are several VA ECMO cannulation strategies in use. In adults, adolescents, and larger children, femoral artery and femoral vein cannulation is most often used in the non-surgical setting due to the ease of vessel accessibility. In children less than 30 to 40 kilograms, neck cannulation via the internal jugular vein and the carotid artery is generally preferred, as the femoral vessels are smaller and do not accommodate cannulas large enough to generate adequate flows to provide full circulatory support. \r\n\r\nDuring VA-ECMO support, the patient\u2019s cardiopulmonary and systemic circulation are in a parallel configuration with the ECMO circuit. The blood supplied to the patient from the ECMO circuit via the arterial cannula originates from the oxygenator and is full saturated with oxygen unless set otherwise. Depending on the proportion of total systemic venous return draining to the ECMO venous reservoir, the remaining venous blood will pass through the lungs, return to the left atrium and then be ejected from the left ventricle into the aorta to mix with blood flow from the ECMO arterial cannula. In the presence of significant pulmonary pathology, there is likely significant pulmonary venous desaturation resulting in a systemic oxygen saturation (SpO2) less than 100%. With VA ECMO via carotid arterial cannulation, such as the one described in the stem, mixing occurs at the level of the carotid artery and ascending aorta. Therefore, the SpO2 will be lower than 100% in all four limbs. Management of this problem includes the following: (1) adjusting the mechanical ventilator settings to improve pulmonary gas exchange if possible; (2) increasing the ECMO flow rate such that a greater percentage of the total blood volume passes through the oxygenator and, (3) increasing the inspired concentration of oxygen in the ECMO sweep gas. \r\n\r\nNorth-South syndrome, or Harlequin phenomenon, is a condition in which the lower body systemic saturation is higher than the upper body. This differential hypoxemia occurs specifically in patients on VA ECMO with femoral cannulation and is caused by mixing of 100% oxygenated and relatively deoxygenated blood in the aorta. With femoral cannulation, 100% oxygenated blood from the femoral arterial cannula flows to the upper body via the thoracic aorta, aortic arch and ascending aorta in a retrograde fashion and mixes with the blood ejected from the left ventricle. In the setting of poor left ventricular (LV) function and low cardiac output, there is negligible mixing of retrograde blood from arterial cannula with antegrade blood via native cardiac output. However, in the setting of improving myocardial function\/cardiac output and poor pulmonary function, an increasing amount of blood is ejected from the left ventricle, which is relatively desaturated in comparison to blood from the femoral arterial cannula. Thus, 100% oxygenated blood from the ECMO arterial cannula will combine with blood ejected from the LV at a mixing zone in the aorta, called \u201cNorth-South\u201d line. Blood from \u201cSouth\u201d region will have a higher oxygen saturation than blood from the \u201cNorth\u201d region. The anatomic location of the North-South line will depend on ECMO flow rate, native ventricular function\/cardiac output, and systemic vascular resistance. Management of North-South syndrome usually involves adding an additional cannula to the ECMO circuit that delivers blood with 100% oxygen saturation to the superior vena cava\/right atrium. North-South syndrome is unlikely in the patient described in stem because there are carotid arterial and jugular venous cannulas present rather than femoral arterial and femoral venous cannulas. \r\n\r\nRecirculation is a clinical scenario that occurs during VV ECMO when a large proportion of the oxygenated blood from the outflow cannula is recycled through the inflow cannula and returns to the ECMO circuit without circulating through the patient. Most of the blood passing through the lungs and left ventricle will not have passed through the oxygenator and will be desaturated. However, the pre- and post-oxygenator blood will be bright red with a high oxygen saturation. The degree of recirculation depends on cannula type and position, ECMO pump flow, and cardiac output. Dual-lumen cannulas or long cannulas lying near each other increase the risk of recirculation. Right ventricular dysfunction\/low cardiac output also puts the patient at risk, as there is less forward blood flow. Additionally high pump flows may cause the inflow cannula to draw blood in from the outflow cannula and lead to recirculation. This is not possible in the patient described in the stem as the patient is on VA ECMO. \r\n\r\n\r\n\r\n\r\n \r\nREFERENCES \r\nGajkowski EF, Herrera G, Hatton L, Velia Antonini M, Vercaemst L, Cooley E. ELSO Guidelines for Adult and Pediatric Extracorporeal Membrane Oxygenation Circuits. ASAIO J<\/em>. 2022;68(2):133-152. doi:10.1097\/MAT.0000000000001630\r\n\r\nFalk L, Sallisalmi M, Lindholm JA, et al. Differential hypoxemia during venoarterial extracorporeal membrane oxygenation. Perfusion<\/em>. 2019;34(1_suppl):22-29. doi:10.1177\/0267659119830513\r\n\r\nXie A, Yan TD, Forrest P. Recirculation in venovenous extracorporeal membrane oxygenation. J Crit Care<\/em>. 2016; 36:107-110. \r\n\r\nMeyer RJ, Theodorou AA, Berg, RA. Childhood drowning. Pediatr Rev<\/em>. 2006; 27(5): 163-168. \r\n\r\nKim K II, Lee WY, Kim HS, Jeong JH, Ko HH. Extracorporeal membrane oxygenation in near-drowning patients with cardiac or pulmonary failure. Scan J Trauma Resusc Emerg Med<\/em>. 2014; 12: 77. \r\n\r\n”,”hint”:””,”answers”:{“tqatx”:{“id”:”tqatx”,”image”:””,”imageId”:””,”title”:”A)\tNorth-South Syndrome”},”rx1pe”:{“id”:”rx1pe”,”image”:””,”imageId”:””,”title”:”B)\tRecirculation”},”ylf0a”:{“id”:”ylf0a”,”image”:””,”imageId”:””,”title”:”C)\tImproved myocardial function”,”isCorrect”:”1″}}}}}

{“questions”:{“zman7”:{“id”:”zman7″,”mediaType”:”image”,”answerType”:”text”,”imageCredit”:””,”image”:””,”imageId”:””,”video”:””,”imagePlaceholder”:””,”imagePlaceholderId”:””,”title”:”Author: Melissa Colizza – CHU Sainte-Justine – Montreal, Quebec \r\n\r\nIn current era, what is the MOST common cardiac diagnosis in combined heart-liver transplant recipients? “,”desc”:”EXPLANATION \r\nThe first combined heart-liver transplantation (CHLT) was performed in 1984 and is now becoming an increasingly common procedure. The indications and outcomes of 369 CHLT recipients (from 1989 to 2020) listed in the United Network for Organ Sharing (UNOS) registry were recently reviewed by Alexopoulos and colleagues. In the era from 1989 to 2010, the most common cardiac indication\/diagnosis was restrictive\/infiltrative cardiomyopathy secondary to diseases such as amyloidosis or hemochromatosis. In the era from 2011 to 2020, congenital heart disease was the most common cardiac diagnosis, accounting for 30.9% of CHLT recipients followed by restrictive\/infiltrative cardiomyopathy in 26.8% and dilated cardiomyopathy in 21.1%. The most common liver diagnosis in current era of CHLT recipients was cardiac cirrhosis (40.4%). \r\nAs the population of patients with congenital heart disease surviving into adulthood has grown, there has been a corresponding rise in the prevalence of liver disease among children with single-ventricle physiology palliated with the Fontan. Liver dysfunction in Fontan patients is believed to be caused by the following two mechanisms: 1) Central hepatic vein and sinusoid dilation due to elevated central venous pressure and, 2) reduced hepatic perfusion secondary to low cardiac output. This results in a redistribution of oxygenated blood to periportal hepatocytes with subsequent atrophy, necrosis, and fibrosis of centrilobular hepatocytes, leading to cirrhosis and regenerative nodules. This heterogenous pattern is present in Fontan patients, particularly ten years post-Fontan-completion. Interestingly, neither invasive hemodynamic measurements nor laboratory abnormalities seem to directly correlate with the severity of fibrosis. Moreover, though portal hypertension develops over time, varices are less prevalent as there is already significant systemic venous hypertension. There is no clear consensus regarding criteria and timing for liver transplant evaluation in Fontan patients, nor which patients would benefit from CHLT. However, a recent scientific statement by the American Heart Association has proposed an algorithm for evaluation of liver disease in potential heart transplant candidates. \r\n\r\nWhile still uncommon overall, the number of CHLTs performed in North America has increased significantly in the last decade. Survival outcomes of CHLT for the overall cohort of 369 patients in the most recent analysis by Alexopoulos were 86.8%, 80.1%, and 77.9% at one, three, and five years respectively. In a multivariable regression analysis, recipient diabetes at listing, CHLT between 1989-2000 compared with 2011-2020, a transplant sequence of heart-after-liver versus liver-after-heart, and lower donor left ventricular ejection fraction were associated with increased mortality after CHLT. Concurrent heart and liver transplant also appears to be associated with improved outcomes, which is thought to be related to the ability of the liver to clear donor-specific HLA class I antibodies. \r\n\r\n\r\n \r\nREFERENCES \r\nAlexopoulos SP, Wu WK, Ziogas IA, et al. Adult Combined Heart-Liver Transplantation: The United States Experience. Transpl Int <\/em>.2022;35:10036. doi: 10.3389\/ti.2021.10036\r\n\r\n\r\nTracy KM, Matsuoka LK, Alexopoulos SP. Update on combined heart and liver transplantation: evolving patient selection, improving outcomes, and outstanding questions. Curr Opin Organ Transplant <\/em>.2023;28(2):104-109. doi: 10.1097\/MOT.0000000000001041\r\n\r\n\r\nKittleson MM, Sharma K, Brennan DC et al. Dual-Organ Transplantation: Indications, Evaluation, and Outcomes for Heart-Kidney and Heart-Liver Transplantation: A Scientific Statement From the American Heart Association. Circulation <\/em>.2023;148:622\u2013636. doi:10.1161\/CIR.0000000000001155 \r\n\r\n\r\nOrtega-Legaspi JM, Hoteit M, Wald J. Immune benefit of combined heart and liver transplantation. Curr Opin Organ Transplant<\/em>. 2020;25(5):513-518. doi:10.1097\/MOT.0000000000000801\r\n\r\n\r\nEmamaullee J, Zaidi AN, Schiano T, et al. Fontan-Associated Liver Disease: Screening, Management, and Transplant Considerations. Circulation<\/em>. 2020;142(6):591-604. doi: 10.1161\/CIRCULATIONAHA.120.045597\r\n”,”hint”:””,”answers”:{“yddgv”:{“id”:”yddgv”,”image”:””,”imageId”:””,”title”:”A.\tCongenital heart disease “,”isCorrect”:”1″},”kj3kk”:{“id”:”kj3kk”,”image”:””,”imageId”:””,”title”:”B.\tRestrictive\/Infiltrative cardiomyopathy “},”9lkir”:{“id”:”9lkir”,”image”:””,”imageId”:””,”title”:”C.\tDilated cardiomyopathy “}}}}}

{“questions”:{“jpsgq”:{“id”:”jpsgq”,”mediaType”:”image”,”answerType”:”text”,”imageCredit”:””,”image”:””,”imageId”:””,”video”:””,”imagePlaceholder”:””,”imagePlaceholderId”:””,”title”:”Author: Meera Gangadharan, MD, FASA, FAAP – University of Texas at Houston, McGovern Medical School, Children\u2019s Memorial Hermann Hospital \r\n\r\nA 2.5-year-old male with history of hypoplastic left heart syndrome palliated with a bidirectional Glenn is undergoing a pre-Fontan cardiac catheterization. Pertinent catheterization findings include a systemic arterial saturation (S_{a<\/sub>O2<\/sub>) of 73%, Qp<\/sub>:Qs<\/sub> of 0.8, and pulmonary vascular resistance (PVR) of 2.6 international woods units (iWU). Which of these hemodynamic variables is associated with the HIGHEST periprocedural risk of adverse event(s)?\r\n”,”desc”:”EXPLANATION \r\nRisk-stratification has become an important component of perioperative planning.. Procedural risk is the sum of the risk of the procedure and the risk imposed by the physiologic condition of the patient. Cardiac catheterization in patients with congenital heart disease is an evolving field with new procedures and technologies being developed and utilized in clinical practice. \r\n\r\nThe 2022 Procedural Risk in Congenital Cardiac Catheterization (PREDIC^{3<\/sup>T) study by Quinn and colleagues was used to create a risk assessment tool for pediatric cardiac catheterization procedures. In this study, data from 23,119 pediatric and adult congenital cardiac catheterization cases between January 2014 and January 2018 were analyzed from 13 centers in the United States. Electrophysiological studies were excluded. The primary outcome was the occurrence of a clinically significant adverse event or a high severity adverse event (HSAE). Levels of adverse event severity were graded from zero to five, based on previously established definitions. Levels one and two were none\/minor. Level three was a moderate severity event that resulted in a transient change in the patient\u2019s condition that may have been life-threatening if not treated, required additional medications or transfer to an ICU. Examples include unstable arrythmias with stable blood pressure but requiring intervention, or vascular damage that was not life threatening but required intervention. Level four was a major event that was life-threatening or required cardiopulmonary resuscitation or emergent surgical intervention. Level five was a catastrophic event needing heart-lung support with failure to wean from such support and resulting in death. For this study, levels three through five were considered HSAEs. The study demonstrated that an adverse event occurred in 10.9% of cases and a high severity adverse event (HSAE) occurred in 5.2% of cases. Patient factors that were associated with high-severity adverse events (HSAEs) listed in table 1. \r\n\r\n\r\n\r\n\r\n\r\nCases or procedures were also divided into six risk categories from zero to five (see Table 2). The risk category was an independent predictor of increased risk of HSAEs, with odds-ratios ranging from zero for risk category zero, to 5.25 for risk category five (p \u2264 0.005).\r\n\r\n\r\nTable 2: PREDIC3 <\/sup>T Case-Type Risk Categories \r\n\r\n \r\nTable from: Quinn BP, Yeh M, Gauvreau K, et al. Procedural Risk in Congenital Cardiac Catheterization (PREDIC3<\/sup>T). J Am Heart Assoc<\/em>. 2022;11(1):e022832. Used under Creative Commons License. \r\n\r\nAdditional scoring systems have been developed to quantify risk in cardiac catheterization procedures. In a 2016 study by Nykanen and colleagues, the Congenital Cardiac Interventional Study Consortium developed the Catheterization Risk Score for Pediatrics (CRISP) to predict the likelihood of serious adverse events occurring during cardiac catheterization. The factors included age, weight, inotropic support, organ failure, physiologic category, diagnosis, procedure category and procedure type (diagnostic, interventional or hybrid). The physiologic category was based on systemic saturation, indexed pulmonary vascular resistance, right ventricular systolic pressure \/systemic pressure ratio, anemia, right ventricular outflow obstruction and systemic atrio-ventricular valve regurgitation. Five risk scores were defined: with a CRISP score of five being the highest risk and CRISP score of one being the lowest risk for serious adverse events.\r\n\r\n\r\nThese various risk-assessment tools can also be useful for resource allocation during perioperative planning. A multispecialty society expert consensus statement published in 2016 by Odegard and colleagues offers guidance for pediatric cardiac catheterization procedures. The authors state that a pediatric cardiac anesthesiologist should provide care for patients presenting with a CRISP score equal to or greater than five. Anesthesiologists with a \u201cspecial expertise\u201d in congenital heart disease should provide care for patients with a CRISP score between two and four, and the sedation team can provide care for patients with a CRISP score of zero to one.\r\n\r\n\r\nBased on the PREDIC3<\/sup>T project, for single ventricle patients, a systemic arterial oxygen saturation below 78% increases the risk of experiencing a HSAE. A Qp<\/sub>:Qs<\/sub> of less than 1.5 and a PVR < 3iWU does not increase the risk of a HSAEs. \r\n\r\n\r\n\r\n \r\n\r\nREFERENCES \r\n\r\nNykanen DG, Forbes TJ, Du W, et al. CRISP: Catheterization RISk score for Pediatrics: A Report from the Congenital Cardiac Interventional Study Consortium (CCISC). Catheter Cardiovasc Interv<\/em>. 2016;87(2):302-309. doi:10.1002\/ccd.26300\r\n\r\n\r\nQuinn BP, Yeh M, Gauvreau K, et al. Procedural Risk in Congenital Cardiac Catheterization (PREDIC3<\/sup>T). J Am Heart Assoc<\/em>. 2022;11(1):e022832. doi:10.1161\/JAHA.121.022832\r\n\r\n\r\nOdegard KC, Vincent R, Baijal RG, et al. SCAI\/CCAS\/SPA Expert Consensus Statement for Anesthesia and Sedation Practice: Recommendations for Patients Undergoing Diagnostic and Therapeutic Procedures in the Pediatric and Congenital Cardiac Catheterization Laboratory. Anesth Analg. <\/em>.2016;123(5):1201-1209. doi:10.1213\/ANE.0000000000001608\r\n”,”hint”:””,”answers”:{“b0pzp”:{“id”:”b0pzp”,”image”:””,”imageId”:””,”title”:”(A)\tSa<\/sub>O2<\/sub> of 73%”,”isCorrect”:”1″},”ofrl1″:{“id”:”ofrl1″,”image”:””,”imageId”:””,”title”:”(B)\tQp<\/sub>:Qs<\/sub> of 0.8″},”90c7e”:{“id”:”90c7e”,”image”:””,”imageId”:””,”title”:”(C)\tPVR of 2.6 iWU”}}}}}}}

{“questions”:{“47rhv”:{“id”:”47rhv”,”mediaType”:”image”,”answerType”:”text”,”imageCredit”:””,”image”:””,”imageId”:””,”video”:””,”imagePlaceholder”:””,”imagePlaceholderId”:””,”title”:”Author: Sana Ullah, MB ChB, FRCA – Children\u2019s Health, Dallas \r\n\r\nA 36-year-old male who recently emigrated to the United States from India presents with worsening dyspnea on exertion and palpitations. He reports a history of rheumatic fever as a child. A 12-lead ECG show atrial fibrillation with a HR of 110. Transthoracic echocardiogram demonstrates a large secundum atrial septal defect with left to right shunting and moderate right heart enlargement. What additional abnormality is MOST likely to be seen on the echocardiogram?”,”desc”:”EXPLANATION \r\nThe association of an atrial septal defect (ASD) with mitral stenosis (MS) is known as Lutembacher syndrome, named after the first publication in 1916 by a French physician. The ASD is usually congenital, but the MS is almost always due to a complication of rheumatic heart disease. Hence, this entity is more common in areas where rheumatic fever is endemic, such as sub-Saharan Africa and other under-developed countries. An iatrogenic form of Lutembacher syndrome is composed of a residual ASD created during trans-catheter balloon mitral valvuloplasty procedures for MS.\r\n\r\n\r\n \r\nThe natural history and hemodynamic sequelae of Lutembacher syndrome are determined by the size of the ASD, severity of MS, pulmonary vascular resistance, and compliance of the right ventricle. The magnitude of the left to right shunt across the typically large ASD is increased in the presence of severe MS resulting in volume overload of the right ventricle and pulmonary circulation. This will eventually result in right heart failure and pulmonary hypertension. In the presence of a restrictive ASD, the clinical course will be primarily determined by the severity of the MS. Atrial dilatation additionally predisposes patients to atrial fibrillation.\r\n\r\n\r\n\r\nDiagnosis is confirmed by transthoracic echocardiography (TTE) and confirms ASD size and severity of MS. Planimetry is usually preferred in assessing MS severity as doppler gradients across the valve will be significantly reduced due to shunting across the ASD.\r\n\r\n\r\n\r\nTreatment of Lutembacher syndrome in the current era is usually via trans-catheter techniques with balloon valvuloplasty of the mitral valve and device closure of the ASD. Surgical management is indicated for patients deemed unsuitable for trans-catheter procedure, such as inadequate rims around the ASD, left atrial thrombus, or concomitant severe mitral regurgitation.\r\n\r\n\r\n\r\nIn the patient described above, the most likely co-existing abnormality is MS due to the history of rheumatic heart disease. The mitral valve is the most common valve affected by rheumatic heart disease, initially causing mitral regurgitation that may progress to mitral stenosis. A significant ventricular septal defect is likely to result in pulmonary hypertension in a 36-year-old patient and reversal of shunting at level of the ASD. Therefore, answer B is incorrect. Partial anomalous pulmonary venous return is less likely in this patient with a history of rheumatic fever. Furthermore, PAPVR typially associated with sinus venosus ASDs rather than a secundum ASD. \r\n\r\n\r\n \r\nREFERENCES \r\n\r\nAminde LN, Dzudie A, Takah NF, Ngu KB, Sliwa K, Kengne AP. Current diagnostic and treatment strategies for Lutembacher syndrome: the pivotal role of echocardiography. Cardiovas Diag Ther <\/em>.2015; 5:122-132. doi: 10.3978\/j.issn.2223-3652.2015.03.07\r\n\r\n\r\nBashi VV, Ravikumar E, Jairaj PS, et al. Coexistent mitral valve disease with left-to-right shunt at the atrial level: clinical profile, hemodynamics, and surgical considerations in 67 consecutive patients. Am Heart J <\/em>.1987;114:1406-14. \r\n\r\n\r\nNagamani AC, Nagesh CM. Lutembacher Syndrome. In: Vijaylakshmi IB, Rao PS, ChughR, eds. A Comprehensive Approach to Congenital Heart Disease. <\/em> 2nd ed. New Dehli, India: Jaypee Brothers Medical Publishers; 2020:1036-1045.\r\n”,”hint”:””,”answers”:{“rbd2r”:{“id”:”rbd2r”,”image”:””,”imageId”:””,”title”:”A. Partial anomalous pulmonary venous return “},”c9xqe”:{“id”:”c9xqe”,”image”:””,”imageId”:””,”title”:”B. Ventricular septal defect”},”6vou8″:{“id”:”6vou8″,”image”:””,”imageId”:””,”title”:”C. Mitral stenosis”,”isCorrect”:”1″}}}}}