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

{“questions”:{“0dv0a”:{“id”:”0dv0a”,”mediaType”:”image”,”answerType”:”text”,”imageCredit”:””,”image”:””,”imageId”:””,”video”:””,”imagePlaceholder”:””,”imagePlaceholderId”:””,”title”:”Authors: Meera Gangadharan, MBBS, FAAP, FASA – McGovern Medical School, Children\u2019s Memorial Hermann Hospital, Texas and Ruchik Sharma, MD – University of Virginia, Charlottesville, VA \r\n\r\nWhich of the following types of heterotaxy is MOST likely to require pacemaker placement?\r\n”,”desc”:”EXPLANATION \r\nHeterotaxy is a disorder in which the usual arrangement of thoracic and abdominal organs is absent. It is also described with the term right or left atrial isomerism, which is determined by the anatomy of the atrial appendages. Right atrial isomerism or bilateral right-sidedness refers to bilateral atria with anatomic features of a right atrium. Left atrial isomerism or bilateral left-sidedness refers to bilateral atria with anatomic features of a left atrium. Fifty to ninety percent of patients with heterotaxy will also have complex congenital heart disease. Any combination of congenital heart defects may occur in patients with heterotaxy. However, certain combinations of defects appear to be more common in each type of atrial isomerism, which are listed below. \r\n\r\nRight atrial isomerism (RAI) is associated with the following defects:<\/strong> \r\n\u2022\tSingle ventricle physiology\r\n\u2022\tBilateral superior vena cava (right-sided structure)\r\n\u2022\tAtrial septal defect \r\n\u2022\tAbsent coronary sinus (left-sided structure) \r\n\u2022\tDual sinoatrial nodes \r\n\u2022\tAbnormalities of pulmonary veins (i.e. anomalous pulmonary venous return, hypoplastic pulmonary veins) \r\n\u2022\tMalposed great arteries (frequency of 95%) \r\n\u2022\tDouble-outlet right ventricle (frequency of 5%) \r\n\u2022\tPulmonary valve obstruction (i.e. pulmonary stenosis\/atresia, frequency > 90%) \r\n\u2022\tCommon atrioventricular valve \r\n\u2022\tBilateral trilobed lungs \r\n\u2022\tEparterial bronchi \r\n\u2022\tAsplenia\r\n\r\nLeft atrial isomerism (LAI) is associated with the following defects:<\/strong> \r\n\u2022\tInterrupted inferior vena cava (absence of the intrahepatic portion of the inferior vena cava with venous continuation via the azygos vein) \r\n\u2022\tAbsent sinoatrial and atrioventricular nodes \r\n\u2022\tLeft-sided obstructive defects (i.e. mitral stenosis, aortic stenosis, aortic coarctation) \r\n\u2022\tCommon atrioventricular valve \r\n\u2022\tBilateral bilobed lungs \r\n\u2022\tHyparterial bronchi \r\n\u2022\tPolysplenia \r\n\u2022\tBiliary atresia \r\n\u2022\tAbsent\/hypoplastic gallbladder \r\n\r\nPatients with RAI often have dual sinoatrial and atrioventricular nodes, predisposing them to tachyarrhythmias (i.e. supraventricular tachycardia, junctional tachycardia, ectopic atrial tachycardia, and atrial flutter\/fibrillation). Although patients with LAI often have tachyarrhythmias as well, they are more prone to bradyarrythmias (i.e. sinoatrial node dysfunction, atrioventricular block) due to absence of sinoatrial and atrioventricular nodes. Atrial suture lines from previous\/repeat surgical procedures and physiologic derangements may also contribuate to the development of arrhythmias in heterotaxy.\r\n\r\nA single-center, retrospective review by Niu et al. of 337 patients with heterotaxy from 1980 to 2012, over a median seven-year follow-up period, demonstrated that 38% of all heterotaxy patients had been diagnosed with an arrhythmia. Twenty-two percent experienced tachyarrhythmias, while 9% had bradyarrhythmias, and 7% had both. Age, pulmonary venous obstruction, and outflow tract obstruction significantly contributed to the development of arrhythmias. Multivariate analysis revealed that tachyarrhythmias were associated with pulmonary venous obstruction at a hazard ratio (HZ) of 2.33 (95% CI 1.45-3.76), moderate atrioventricular valve regurgitation at a HR of 1.66 (95% C.I. 1.11-2.5), and single ventricle anatomy at a HR of 2.3 (95% CI 1.09-4.85). Ectopic atrial tachycardia (EAT) tended to occur in infants during a perioperative period. Of the patients with perioperative EAT, 50% were weaned from anti-arrhythmic medications over a twelve month period without recurrence. Atrial fibrillation and\/or atrial flutter were more frequent in older patients with a median age of fifteen years. \r\n\r\nBradyarrhythmias occurred in 54 (16% total) patients. Thirty-two had symptomatic sinus bradycardia necessitating pacemaker placement. Twenty-two had a high grade or complete atrioventricular block (AVB). LAI was associated with a higher risk for bradyarrhythmias with a HR of 7.12 (95% CI 3.01-16.9) as compared to RAI. The increased risk persisted when LAI was compared to the mixed or indeterminate subtype of heterotaxy (HR 2.63, (95% CI 1.34-5.16)). Fifty-one patients in the entire cohort (54) required pacemaker placement. Forty-one percent had high-grade atrioventricular block or complete congenital atrioventricular block. Fifty-nine percent had symptomatic sinoatrial bradycardia. In this cohort, the presence of a tachyarrhythmia was associated with an increased risk for death and heart transplantation with a HR of 2.24 (95% CI 1.45-3.46). In contrast, presence of a bradyarrhythmia was not associated with an increased risk of death or need for heart transplantation.\r\n\r\nA smaller, single-center retrospective study by Ozawa et al., demonstrated that of 40 patients with heterotaxy (40% with LAI and 60% with RAI), 21 experienced arrhythmias during a mean follow-up duration of 5.4 years. Of those with arrhythmias, 87% had LAI and 29% had RAI. Of the LAI patients, ten had sinoatrial node dysfunction, three had atrioventricular block and one had supraventricular tachycardia (SVT). In the RAI group, there were five patients with SVT, two with EAT, one with junctional tachycardia and one with AVB. Two patients with AVB in the LAI group received pacemakers. Interestingly this study was conducted in Japan where cilostazol, an anti-platelet medication with antiphosphodiesterase type 3 activity, is used to increase the heart rate in patients. Five patients with LAI and sinus node dysfunction received cilostazol and none required pacemaker placement. \r\n\r\nIn summary, heterotaxy patients with LAI are more likely to exhibit bradyarrhythmias (i.e. AV block) and later require pacemaker placement. Patients with RAI are predisposed to tacharrhythmias, making the need for pacemaker implantation less common. \r\n\r\n\r\n \r\nREFERENCES \r\nAgarwal R, Varghese R, Jesudian V, Moses J. The heterotaxy syndrome: associated congenital\r\nheart defects and management. Indian J Thorac Cardiovasc Surg<\/em>. 2021;37:67-81.\r\n\r\nOzawa Y, Asakai H, Shiraga K, et al. Cardiac Rhythm Disturbances in Heterotaxy Syndrome. Pediatr Cardiol<\/em>. 2019;40(5):909-913. doi:10.1007\/s00246-019-02087-2\r\n\r\nNiu MC, Dickerson HA, Moore JA, et al. Heterotaxy syndrome and associated arrhythmias in pediatric patients. Heart Rhythm<\/em>. 2018;15(4):548-554. doi:10.1016\/j.hrthm.2017.11.013\r\n\r\n”,”hint”:””,”answers”:{“7io0u”:{“id”:”7io0u”,”image”:””,”imageId”:””,”title”:”A. Right atrial isomerism”},”l2ver”:{“id”:”l2ver”,”image”:””,”imageId”:””,”title”:”B. Left atrial isomerism”,”isCorrect”:”1″},”mxox0″:{“id”:”mxox0″,”image”:””,”imageId”:””,”title”:”C. Neither\r\n\r\n”}}}}}

{“questions”:{“4ua5e”:{“id”:”4ua5e”,”mediaType”:”image”,”answerType”:”text”,”imageCredit”:””,”image”:””,”imageId”:””,”video”:””,”imagePlaceholder”:””,”imagePlaceholderId”:””,”title”:”Author: Sana Ullah, MB ChB, FRCA. Children\u2019s Health, Dallas \r\nA 9-month-old infant with a perimembranous ventricular septal defect demonstrates a peak Doppler velocity of 3 m\/s across the defect by transthoracic echocardiography. There is no evidence of right or left ventricular outflow tract obstruction. Vital signs are as follows: HR 120, BP 110\/60, and S_{p<\/sub>O2<\/sub> 98%. What is the estimated pulmonary artery systolic pressure?”,”desc”:”EXPLANATION \r\nIn the presence of regurgitant jets or shunt lesions, Doppler echocardiography is commonly used to estimate intracardiac pressures and gradients using the simplified Bernoulli equation:\r\n\r\nP = 4V^{2<\/sup>\r\n\r\nP = maximum instantaneous pressure gradient\r\n\r\nV = peak velocity (m\/s)\r\n\r\nIn the case of absent right ventricular outflow tract (RVOT) obstruction or pulmonary valve stenosis, the right ventricular systolic pressure (RVSP) approximates the pulmonary artery systolic pressure (PASP). Therefore, Doppler techniques can be used to measure the RVSP and hence approximate PASP. \r\n\r\nIn the presence of a ventricular septal defect (VSD), the peak velocity (V) across the lesion can be used to quantify the pressure gradient between the left and right ventricles during systole. If the left ventricular systolic pressure (LVSP) is known, the RVSP is calculated using the following equation: \r\n\r\nRVSP = LVSP \u2013 4(VVSD<\/sub>)2<\/sup>\r\n\r\nIn the absence of LVOT obstruction, the LVSP is equal to the systolic blood pressure (SBP) measured by the cuff. Hence, \r\n\r\nRVSP = SBP \u2013 4(VVSD<\/sub>)2<\/sup> \r\n\r\nUsing the patient data from the stem into this equation:\r\n\r\nRVSP = 110 \u2013 4(3)2<\/sup>\r\n\r\nRVSP = 110 \u2013 36\r\n\r\nRVSP = 74 mmHg\r\n\r\nAs there is no RVOT obstruction or pulmonary valve stenosis, the PASP is the same as the RVSP, i.e. 74mmHg. \r\n\r\n \r\nREFERENCES \r\nAnderson B. Echocardiography: The Normal Examination and Echocardiographic Measurements<\/em>. (pp. 134-137). Australia. MGA Graphics, 2000.\r\n”,”hint”:””,”answers”:{“mtpor”:{“id”:”mtpor”,”image”:””,”imageId”:””,”title”:”A. 34 mmHg”},”lh3gc”:{“id”:”lh3gc”,”image”:””,”imageId”:””,”title”:”B. 54 mmHg”},”6mhz8″:{“id”:”6mhz8″,”image”:””,”imageId”:””,”title”:”C. 74 mmHg”,”isCorrect”:”1″},”gkqzx”:{“id”:”gkqzx”,”image”:””,”imageId”:””,”title”:”D. Cannot be determined with the information provided”}}}}}}}

{“questions”:{“dnjl1”:{“id”:”dnjl1″,”mediaType”:”image”,”answerType”:”text”,”imageCredit”:””,”image”:””,”imageId”:””,”video”:””,”imagePlaceholder”:””,”imagePlaceholderId”:””,”title”:”Author: Meera Gangadharan, MBBS, FAAP, FASA – UT Houston\/McGovern Medical School \r\n\r\nA 15-year-old female with a history of tricuspid atresia palliated with the Fontan procedure presents for cardiology follow-up. She reports good exercise tolerance, and her vital signs are stable. There are no symptoms or signs of liver disease. A transesophageal echocardiogram demonstrates normal ventricular function, trivial mitral regurgitation, and patent Fontan pathway. According to recommendations by a multidisciplinary group of the American Society of Transplantation, which of the following time intervals following the Fontan procedure is MOST appropriate for planning a surveillance liver biopsy?”,”desc”:”EXPLANATION \r\nAdvancements in the management of univentricular heart disease and the success of the Fontan procedure has resulted in improved survival rates and an increasing population of patients with this unique physiology. In 2020, the number of patients who are living with the Fontan circulation in a total of eleven countries including the United States, Australia, New Zealand and Europe, was estimated to be 66 per one million. Despite its success, the Fontan circulation is associated with many chronic complications, including Fontan associated liver disease (FALD), which significantly impacts morbidity and mortality. \r\n\r\n\r\nAlsaied et al proposed a consensus definition of FALD as, \u201cthe broad spectrum of liver disease and its consequences, attributable to Fontan hemodynamics. FALD includes varying degrees of hepatic fibrosis, compensated and decompensated cirrhosis, focal nodular hyperplasia, laboratory evidence of hepatic injury or impaired synthetic function, and hepatocellular neoplastic lesions.\u201d One of the most serious complications of FALD is hepatocellular carcinoma, with an estimated prevalence of 0.18 to 1.3% in patients palliated with the Fontan procedure. Several factors are believed to play a role in the development of FALD including increased hepatic venous pressure, chronic hypoxia, diminished cardiac output, malfunction of liver sinusoidal endothelial cells resulting in decreased nitric oxide production and increased cytokine and complement secretion, increased inflammatory biomarkers, alterations in the flow of lymphatic fluid, and abnormal neurohormonal activation. It has also been speculated that patient factors predisposing to portal fibrosis before <\/em> the Fontan operation may also contribute to the development of FALD. Currently, there is no consensus on the best surveillance strategy and diagnostic testing for and clinical management of FALD. The diagnosis relies on clinical history and physical examination, serum tests of liver function, various imaging modalities (magnetic resonance imaging (MRI) elastography and contrast imaging, computerized tomography, and liver ultrasound), and histological diagnosis via liver biopsy. \r\n\r\n\r\nHepatic fibrosis has almost been universally demonstrated in this patient population, predominantly through surveillance liver biopsies. However, a healthy clinical appearance, normal laboratory studies and acceptable Fontan hemodynamics do not correlate with the absence of fibrotic changes on surveillance liver biopsies. In 2020, a multi-disciplinary group from the American Society of Transplantation proposed an algorithm to guide the screening and management of FALD in patients palliated with the Fontan procedure. The time which has elapsed following the Fontan procedure is an important risk factor for the development of FALD. Therefore, the algorithm recommends that patients with no clinical evidence of chronic liver disease have a surveillance liver biopsy at ten years post-Fontan procedure. This is ideally performed concurrently with a cardiac catheterization to assess Fontan hemodynamics. Further management recommendations are based on liver biopsy results, which are the following: 1) No hepatic fibrosis<\/strong>: MRI elastography, annual liver laboratory studies, annual liver ultrasound, repeat liver biopsy or imaging based on clinical changes; 2) Mild\/moderate hepatic fibrosis<\/strong>: hepatology referral, liver laboratory studies every six months, address modifiable risk factors such as obesity and alcohol use; 3) Bridging hepatic fibrosis\/cirrhosis<\/strong>: hepatology referral, MRI elastography at least annually, liver laboratory studies every three months, esophagogastroduodenoscopy to evaluate for esophageal varices, consider early referral for combined heart and liver transplantation.\r\n\r\n\r\nIn patients who are more than three years post-Fontan but who have clinical evidence of chronic liver disease, such as ascites, splenomegaly, thrombocytopenia, gastrointestinal bleeding, and jaundice, early referral to hepatology for diagnostic work-up and consideration for combined heart and liver transplantation is recommended. Although liver biopsy is regarded as the gold standard for the diagnosis of FALD, it is an invasive procedure associated with an increased risk of bleeding, particularly in Fontan patients with elevated central venous pressures. In addition, liver biopsy is susceptible to sampling error due to a patchy distribution of liver fibrosis. Treatment of advanced FALD includes lifestyle modifications, optimization of the Fontan circulation (through treatment of elevated pulmonary vascular resistance and\/or Fontan pathway obstruction and creation\/enlargement of a Fontan fenestration), and management of veno-venous collaterals. \r\n\r\n\r\nThe patient in the stem has good functional status with no clinical evidence of liver disease and no echocardiographic evidence of Fontan pathway obstruction. For this patient, recent recommendations suggest routine surveillance of FALD with liver biopsy at ten years post- Fontan operation, ideally performed at the same time as a cardiac catheterization. Liver biopsy at five years post-Fontan is not recommended in a patient without evidence of chronic liver disease. Liver biopsy at fifteen years post-Fontan is longer than the published recommendations for patients without evidence of liver disease. \r\n\r\n\r\n\r\n \r\nREFERENCES \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.\r\n\r\n\r\nde Lange C, M\u00f6ller T, Hebelka H. Fontan-associated liver disease: Diagnosis, surveillance, and management. Front Pediatr<\/em>. 2023;11:1100514. Published 2023 Mar 3. doi:10.3389\/fped.2023.1100514\r\n\r\n\r\nAlsaied T, Rathod RH, Aboulhosn JA, et al. Reaching consensus for unified medical language in Fontan care. ESC Heart Fail<\/em>. 2021;8(5):3894-3905. doi:10.1002\/ehf2.13294\r\n\r\n\r\n”,”hint”:””,”answers”:{“atagk”:{“id”:”atagk”,”image”:””,”imageId”:””,”title”:”A. 5 years”},”vpznh”:{“id”:”vpznh”,”image”:””,”imageId”:””,”title”:”B. 10 years”,”isCorrect”:”1″},”9phzd”:{“id”:”9phzd”,”image”:””,”imageId”:””,”title”:”C. 15 years”}}}}}

{“questions”:{“gi05o”:{“id”:”gi05o”,”mediaType”:”image”,”answerType”:”text”,”imageCredit”:””,”image”:””,”imageId”:””,”video”:””,”imagePlaceholder”:””,”imagePlaceholderId”:””,”title”:”Authors: Lukas Klima, MD- Department of Anesthesiology; Alexandria Duerksen, MS, CCP- Department of Perfusion; Destiny F. Chau, MD- Department of Anesthesiology – Arkansas Children\u2019s Hospital \/University of Arkansas for Medical Sciences, Little Rock, AR \r\n\r\nA 6-year-old child with sickle cell disease and past severe acute vaso-occlusive episodes is scheduled for aortic valve replacement with cardiopulmonary bypass. Preoperative hemoglobin (Hb) is 8 g\/dL, of which the fractional concentration is 85% HbS by electrophoresis. Which of the following transfusion strategies is MOST appropriate in the perioperative period? \r\n”,”desc”:”EXPLANATION \r\nSickle cell anemia is an autosomal recessive genetic disorder affecting the beta-chain of hemoglobin located on chromosome 11, in which the substitution of valine by glutamine leads to a defective hemoglobin subtype, termed HbS. Patients with a homozygous genotype (HbSS), also known as sickle cell disease (SCD), typically have a fractional HbS concentration between 70 and 98%. Patients with the heterozygous genotype (HbAS), known as sickle cell trait (SCT), are generally asymptomatic and have a fractional HbS concentration below 50%. During a sickling crisis, HbS polymerizes and red blood cell (RBC) shape becomes distorted, thereby losing the ability to deform when passing through the microcirculation. This leads to widespread microvascular occlusion and inflammation of the vascular endothelium. These crises clinically manifest as acute chest syndrome or painful vaso-occlusive events due to tissue ischemia. Sickled RBCs have a shorter lifespan and are prone to hemolysis, resulting in anemia and the need for frequent RBC transfusions. Precipitating factors for sickling include hypoxia, acidosis, hypothermia, hypovolemia, infection, vascular stasis, stress, and inflammatory states. Repeated microvascular occlusion causes localized endothelial injury and inflammation, increasing the propensity for further RBC entrapment. When exposed to a partial pressure of oxygen (P_{a<\/sub>O2<\/sub>) below 40 mm Hg, HbSS RBCs undergo sickling, while the HbAS RBCs do not sickle until the Pa<\/sub>O2<\/sub> falls below 15 mmHg. Interestingly, fetal Hb (HbF) is protective against sickling. Thus, symptoms of SCD do not manifest until conversion from the fetal gamma-chain to the adult beta-chain is complete at approximately six months of age. Hydroxyurea has been the mainstay of therapy used to increase the percentage of HbF in patients with SCD. Recently, in December of 2023, the US Food and Drug Administration approved two cell-based gene therapies for the treatment of SCD called Casgevy and Lyfgenia. Both are approved for SCD in patients 12 years and older with recurrent vaso-occlusive crises. Casgevy modifies hematopoietic stem cells by genome editing technology, overall resulting in greater production of HbF. Lyfgenia is a cell-based gene therapy that genetically modifies hematopoietic stem cells to produce adult hemoglobin (HbA). \r\n\r\nPatients with SCD undergoing cardiac surgery with cardiopulmonary bypass (CPB) encounter multiple triggers for sickling of RBCs. The perioperative goal is to reduce or prevent RBC sickling and vaso-occlusive crisis. Transfusion of RBCs is the main treatment toward this goal. RBC sickling is in part dependent on the proportion of HbS present, the patient\u2019s disease phenotype and fragility, and the extent of exposure to triggers. Consensus perioperative recommendations from the American Society of Hematology state that for minor surgery<\/em>, patients with a history of mild vaso-occlusive crises and low percentage of HbS should receive transfusion of allogenic RBCs to a target hemoglobin of 10 g\/dL (without consideration of the proportion of circulating HbS). For major surgery<\/em>, (i.e. cardiac and neurologic) recommendations center on decreasing the fractional concentration of HbS with the goal of less than 30% via exchange transfusion. The clinical reasoning for this approach is patients with a higher fractional concentration of HbS will benefit more from exchange transfusion, as simple transfusion alone will not significantly decrease the proportion of HbS. \r\n\r\nDuring cardiac surgery with cardiopulmonary bypass (CPB), intraoperative exchange transfusion can be accomplished using the bypass circuit to minimize circulating HbS prior to initiating CPB. Whole blood from the patient is separated into components. The RBCs are discarded after separation, and platelets with the plasma are transfused back to the patient at the conclusion of CPB. Although exchange transfusion could be done preoperatively, the CPB circuit streamlines the process. The bypass circuit can be modified to facilitate an exchange transfusion by adding a shunt in the venous line to drain out volume while simultaneously delivering prime volume of washed RBCs and plasma. Other considerations for perfusion include modifications to the bypass circuit and strategies to reduce the risk of vaso-oclusive crisis. A hemoconcentrator can be added to the circuit to facilitate continuous ultrafiltration during CPB, which removes cytokines and increases the hematocrit while preserving plasma proteins and clotting factors. Use of hypothermia during bypass is controversial, but there are reports of successful utilization of hypothermia in this patient group. Although hypothermia is protective, it promotes in vivo sickling due to the vasoconstriction and vascular stasis. Avoidance of hypoxia is crucial to prevent a sickling crisis. Mixed venous oxygen saturation monitoring is a reliable marker for blood oxygenation during CPB. Other goals during CPB include higher pump flow and higher oxygen saturation. \r\n \r\nThe perioperative care of patients with SCD requires a multidisciplinary approach. A history of previous blood transfusions and transfusion reactions is particulary important as patients with SCD have a high rate of alloimmunization and are at increased likelihood of having a positive antibody screen. Performing standard ABO and RhD typing alone puts the patient at risk for delays in antibody identification, locating compatible donor units, and transfusion. Therefore, it is recommended to do an extended red cell antigen profile to facilitate antibody identification and expedite procurement of compatible blood. \r\n\r\nThe patient described in the stem is at high risk of perioperative RBC sickling and vaso-occlusive crisis due to several factors, including a past history of frequent sickle cell crises, high fractional concentration of HbS (85%) and high-risk surgery (cardiac surgery with CPB). Current consensus guidelines recommend exchange transfusion to HbS less than 30%. Patients undergoing minor procedures with a history of mild sickle crises should undergo transfusion to a target HB of 10 g\/dL, which is not applicable to this patient. No transfusion would not be appropriate in this setting either. The patient should also undergo extended RBC antigen screening, in addition to the standard ABO and RhD typing, to expedite blood product procurement. \r\n \r\nREFERENCES \r\nDaaboul DG, Yuki K, Wesley MC, Dinardo JA. Anesthetic and cardiopulmonary bypass considerations for cardiac surgery in unique pediatric patient populations: sickle cell disease and cold agglutinin disease. World J Pediatr Congenit Heart Surg<\/em>. 2011;2(3):364-370. \r\n\r\nUS Food and Drug Administration News Release. December 08, 2023. FDA approves first gene therapies to treat patients with sickle cell disease. Accessed December 19, 2023 at https:\/\/www.fda.gov\/news-events\/press-announcements\/fda-approves-first-gene-therapies-treat-patients-sickle-cell-disease\r\n\r\nSmith MM, Renew JR, Nelson JA, Barbara DW. Red blood cell disorders: perioperative considerations for patients undergoing cardiac surgery. J Cardiothorac Vasc Anesth<\/em>. 2019;33(5):1393-1406. \r\n\r\nMennes I, Van de Velde M, Missant C. Sickle cell anaemia and the consequences on the anaesthetic management of cardiac surgery. Acta Anaesthesiol Belg<\/em>. 2012;63(2):81-89.\r\n\r\nChou ST, Alsawas M, Fasano RM, et al. American Society of Hematology 2020 guidelines for sickle cell disease: transfusion support. Blood Adv<\/em>. 2020;4(2):327-355. \r\n\r\nBocchieri KA, Scheinerman SJ, Graver LM. Exchange transfusion before cardiopulmonary bypass in sickle cell disease. Ann Thorac Surg<\/em>. 2010;90(1):323-324.\r\n \r\n”,”hint”:””,”answers”:{“32mpk”:{“id”:”32mpk”,”image”:””,”imageId”:””,”title”:”A.\tExchange transfusion to HbS < 30%","isCorrect":"1"},"jua41":{"id":"jua41","image":"","imageId":"","title":"B.\tNo transfusion"},"sbqx5":{"id":"sbqx5","image":"","imageId":"","title":"C.\tRBC transfusion to Hb of 10 g\/dL"}}}}}}

{“questions”:{“363zz”:{“id”:”363zz”,”mediaType”:”image”,”answerType”:”text”,”imageCredit”:””,”image”:””,”imageId”:””,”video”:””,”imagePlaceholder”:””,”imagePlaceholderId”:””,”title”:”Authors: Ahmed Zaghw, MD and Destiny F. Chau, MD – Arkansas Children\u2019s Hospital\/University of Arkansas for Medical Sciences, Little Rock, AR \r\nA 19-year-old patient with autism and severe anxiety presents for dental restoration under general anesthesia prior to ventricular septal defect (VSD) repair. The patient has neither cardiac symptoms nor a history of infective endocarditis. A yearly transthoracic echocardiogram demonstrates a 4 mm perimembranous VSD with left to right shunt and a gradient of 90 mmHg across the defect. Both ventricles are of normal size and function. The right aortic cusp prolapses into the VSD, resulting in mild aortic valve insufficiency. In this patient, prevention of which of the following diagnoses is the MOST likely indication for VSD closure? “,”desc”:”EXPLANATION \r\nIsolated ventricular septal defect (VSD) is the most common form of congenital heart disease (CHD). VSDs allow the shunting of blood between the systemic and pulmonary circulations, increasing the volume load of the left heart. The magnitude and direction of the intracardiac shunt depends on the pressure gradient between the ventricular chambers and the resistance to flow, which is largely determined by the size of the shunt. Over time, patients with untreated VSD suffer from decreased exercise tolerance, heart failure, and pulmonary arterial hypertension (PAH). The onset and progression of symptoms are associated with the degree of the intracardiac shunt. Patients with moderate and large VSDs exhibit symptoms of heart failure during early infancy. Volume and pressure overload from intracardiac shunting leads to the development of left atrial and ventricular dilatation with eventual heart failure. Without treatment, the effective systemic cardiac output progressively decreases as a larger proportion of the left ventricular output is circulated through the intracardiac shunt to the pulmonary circulation (Qp) rather than the systemic circulation (Qs), resulting in a Qp:Qs of greater than one. Over time, this increase in pulmonary blood flow may also result in pulmonary vascular disease and pulmonary arterial hypertension (PAH). With long standing, unrestricted left to right intracardiac shunt, pulmonary arterial pressure may exceed systemic arterial pressure, leading to the shunt reversal and Eisenmenger syndrome. \r\n\r\nA long-term follow-up study by Corone et al. of 790 patients with unrepaired VSDs provides interesting insights into the natural history of unrepaired defects. The study showed that the overall survival rate of patients at 25 years of age with small, moderate, and large unrepaired VSDs was 96%, 86%, and 61%, respectively. Patients with Eisenmenger syndrome had the lowest survival rate of 42%. Small restrictive VSDs are usually associated with small intracardiac shunts, a Qp:Qs < 1.5, and near normal pulmonary vascular resistance. Patients with moderately restrictive VSDs and a Qp:Qs \u2265 1.5:1 and < 2:1 often have mild to moderate PAH. Patients with large, nonrestrictive defects are at high risk for early development of PAH and Eisenmenger syndrome. A 2023 Danish study by Eckerstrom et al. examining survival of patients with repaired and unrepaired VSDs demonstrated that the causes of death were cardiac-related in approximately a third of patients with unrepaired defects and approximately two thirds of patients with surgically repaired VSDs. Interestingly, although repaired VSDs have a higher survival than unrepaired patients, their survival is still lower compared with the general population, after excluding operative mortality. The reasons for these differences in mortality are unclear but the authors speculate that the delayed effects of surgery such as intraoperative myocardial injury, residual intraventricular conduction defects, and ventricular dyssynchrony may be contributing factors. Approximately 6% of patients with isolated VSDs develop aortic valve prolapse, which can lead to aortic valve insufficiency (AI). The most affected cusp of the aortic valve is the right cusp. The Venturi effect is hypothesized to be a predominant factor in the development of AI associated with VSD.\r\n\r\nThe 2018 American Heart Association (AHA) guidelines for management of adults with congenital heart disease recommend conservative, watchful management of small restrictive VSDs in the absence of aortic valve prolapse or more than trivial aortic valve insufficiency. Once aortic valve prolapse develops, there is a likelihood of progression and development of AI. Since the likelihood of spontaneous closure of a perimembranous VSD is low, closure may prevent further progression of AI and later need for aortic valve replacement. At the time of the VSD closure, the aortic valve can be inspected and repaired if indicated.\r\n\r\n \r\nPatients with unrepaired VSD have an increased risk of infective endocarditis, usually affecting the tricuspid and pulmonary valves. Those patients with restrictive VSDs and a history of infective endocarditis warrant VSD closure per AHA guidelines. \r\n\r\n\r\nIn summary, the patient in the stem has a restrictive VSD with a high-pressure gradient across the defect (>90 mmHg), lack of left heart enlargement, and lack of cardiac symptoms. Both aortic cusp prolapse and mild AI were newly demonstrated on a yearly echocardiogram, which fall into the AHA criteria for VSD closure. \r\n\r\n\r\n\r\n \r\nREFERENCES \r\nTweddell JS, Pelech AN, Frommelt PC. Ventricular septal defect and aortic valve regurgitation: pathophysiology and indications for surgery. Semin Thorac Cardiovasc Surg Pediatr Card Surg Annu<\/em>. 2006:147-52. doi: 10.1053\/j.pcsu.2006.02.020. \r\n\r\nEckerstr\u00f6m F, Nyboe C, Maagaard M, Redington A, Hjortdal VE. Survival of patients with congenital ventricular septal defect. Eur Heart J<\/em>. 2023 Jan 1;44(1):54-61. doi: 10.1093\/eurheartj\/ehac618. \r\n\r\nStout KK, Daniels CJ, Aboulhosn JA, et al. 2018 AHA\/ACC Guideline for the Management of Adults with Congenital Heart Disease: Executive Summary: A report of the American College of Cardiology\/American Heart Association Task Force on Clinical Practice Guidelines [published correction appears in J Am Coll Cardiol. 2019 May 14;73(18):2361]. J Am Coll Cardiol<\/em>. 2019;73(12):1494-1563. doi: 10.1016\/j.jacc.2018.08.1028 \r\n\r\nBukhari SM, Desai M, Zurakowski D, et al. Fate of aortic regurgitation after isolated repair of ventricular septal defect with concomitant aortic regurgitation in children. JTCVS Open<\/em>. 2023; 13:271-277. Published 2023 Jan 28. doi: 10.1016\/j.xjon.2022.12.015\r\n\r\nCorone P, Doyon F, Gaudeau S et al. Natural history of ventricular septal defect. A study involving 790 cases. Circulation<\/em>. 1977; 55:908-15. \r\n\r\n”,”hint”:””,”answers”:{“azy0y”:{“id”:”azy0y”,”image”:””,”imageId”:””,”title”:”A.\tPulmonary arterial hypertension “},”7xeyn”:{“id”:”7xeyn”,”image”:””,”imageId”:””,”title”:”B.\tModerate\/Severe aortic valve insufficiency “,”isCorrect”:”1″},”hd3gc”:{“id”:”hd3gc”,”image”:””,”imageId”:””,”title”:”C.\tInfective endocarditis”}}}}}