Cardiac Considerations in Pediatrics Part 1 PDF

Cardiac Considerations in Pediatrics Part I Thomas Chan, DO Associate Professor Clinical Specialties Dept [email protected]  Session Objectives 1. Students will be able to identify the fetal circulation shunts and demonstrate an understanding of the m...

Cardiac Considerations in Pediatrics Part I Thomas Chan, DO Associate Professor Clinical Specialties Dept [email protected]  Session Objectives 1. Students will be able to identify the fetal circulation shunts and demonstrate an understanding of the maternal-fetal circulation 2. Students will be able to understand the anatomic, and physiologic basis of the cyanotic congenital heart defects Such as persistent truncus arteriosus, transposition of great vessels, tricuspid atresia, tetralogy of Fallot and total anomalous pulmonary venous return (TAPVR), hypoplastic left heart syndrome , and ebstein’s anomaly 3. Students will apply the clinical signs, symptoms, lab and imaging findings and correlate them to cyanotic congenital heart defects 4. Students will be able to apply information from this lecture to board style questions Session Outline 1. Maternal-fetal Circulation 2. Cyanotic heart defects 1. Persistent Truncus Arteriosus 2. Transposition of Great Vessels 3. Tricuspid Atresia 4. Tetralogy of Fallot 5. Total Anomalous Pulmonary Venous Return 3. A few other defects 1. Hypoplastic left heart 2. Ebstein anomaly 4. Questions  Review: Blood Flow Physics Blood flows from high  low pressure Down the pressure gradient High Areas of higher pressure have more Pressure resistance Blood takes the “path of least resistance” Low As a fetus, RA pressure > LA pressure Pressure After birth Left sided pressures are highter  Embryology Review Neural crest and endocardial cells migrate to form truncal and bulbar ridges  spiral and fuse  form aorticopulmonary septum  ascending aorta & pulmonary trunk Failure of neural crest cells to migrate  outflow tract abnormalities First Aid for USMLE Step 1 2020  Umbilical vein MOM BABY Umbilical arteries Umbilical vein brings oxygen from mom to fetus Umbilical vein = 1 USMLE First aid, 2021 Umbilical ar-TWO-ries  Ductus Venosus: bypasses liver (umbilical vein  IVC) Foramen Ovale: bypasses lungs (RA  LA) Ductus Arteriosus: bypasses lungs (pulmonary artery  aorta) https://www.amboss.com/us/knowledge/Prenatal_and_postnatal_physiology/  Changes at Birth Prior to birth, lungs not inflated and have high pressures First breath  Lungs expand & ↓ pulmonary vascular resistance & pressure  ↑ pulmonary blood flow  ↑ LA pressure First Aid for the Pediatrics Clerkship  Shunt Closures Shunt  Remnant Cause of Closure Result of Closure Ductus venosus  Umbilical cord is clamped  Ligamentum venosum absent blood flow through umbilical vein  closure Foramen ovale  LA pressure > RA pressure ↑ blood to pulmonary Fossa ovalis  LA pressure causes septa trunk because pulmonary to press against each other vascular resistance < systemic resistance Ductus arteriosus  ↑ oxygen & ↑ blood flow to lungs Ligamentum ↓ prostaglandins  closure arteriosum (1-5 days) of Ductus arteriosus Overview of Cyanotic Congenital Heart Defects Right to Left Shunts The 5 T’s 1. Truncus arteriosus (1 Vessel) RA LA 2. Transposition of Great Vessels Tricuspid Mitral (2 switched vessels) Valve Valve 3. Tricuspid atresia (Tri = 3) 4. Tetralogy of Fallot (Tetra = 4) RV LV 5. TAPVR (5 letters in the name) Hypoplastic Left Heart Syndrome Ebstein Anomaly R  L shunt = blue babies eaRLy L  R shunt = blue babies, or problems LateR X-Rays in Cyanotic Heart Disease (CHD) Heart Size and Shape Increased Pulmonary Blood Flow (more White) Decreased Pulmonary Blood Flow (more Dark) Increased pulmonary blood flow Decreased pulmonary blood flow General Clinical Features of Cyanotic Congenital Heart Defects Blue Babies Or Pale, grey Feeding issues Sweating while feeding Failure to thrive Tachypnea Fatigue Hypoxemia Nail clubbing later in life https://www.amboss.com/us/knowledge/Pulmonary_examination/  Persistent Truncus Arteriosus (1 vessel) Pathophysiology: absent or incomplete partitioning of the truncus arteriosus by the aorticopulmonary septum https://www.chop.edu/img/cardiac-center/truncus-arteriosus.html Persistent Truncus Arteriosus Treatment Surgical correction is recommended in the neonatal period Associations: DiGeorge Syndrome Mild cardiomegaly Increased pulmonary markings Persistent Truncus Arteriosus DiGeorge Syndrome Conotruncal anomaly Tetralogy of Fallot Persistent Truncus Arteriosus Hypocalcemia (Sz, tremors) Absent thymus (immune defect) Facies/ low set ears Cleft palate Ch 22q11.2 deletion  Transposition of the Great Vessels Pathophysiology: Failed spiraling of aorticopulmonary septum https://meded.lwwhealthlibrary.com/content.aspx?bookId=2766&sectionId=231397027&resultClick=1#231397107 Transposition of the Great Vessels Treatment Prostaglandin infusion Rashkind balloon – atrial septostomy Jatene procedure - Arterial switch operation within the first two weeks of life Associations: “Egg on a string” CXR Diabetic mom Narrow mediastinum, globular heart https://radiopaedia.org/articles/egg-on-a-string-sign-heart  Tricuspid Valve Atresia Pathophysiology: Absence of tricuspid valve and hypoplastic right ventricle Right atrial dilation Requires both ASD and VSD for viability Treatment: Surgery Prostaglandin to maintain PDA https://www.amboss.com/us/knowledge/Cyanotic_congenital_heart_defects/  Tetralogy of Fallot Pathophysiology: Caused by anterosuperior displacement of the infundibular septum 1. Pulmonary artery stenosis 2. Right ventricular hypertrophy (RVH) 3. Overriding aorta 4. Ventricular septal defect MCC of early childhood cyanosis Severity of the Pul stenosis determines the extent of shunting. Other factors systemic resistance vs Pulm vasc resistance “PROVe them wrong” https://meded.lwwhealthlibrary.com/content.aspx?bookId=2766&sectionId=231397027&resultClick=1#231397107  Tetralogy of Fallot (cont.) Symptoms: failure to thrive, variable cyanosis, clubbing Tet Spells: Exacerbation of RV outflow obstruction or increase of pul pressures (exercise, crying, stress, etc)  ↑ RL shunting  ↑cyanosis Squatting  ↑ SVR  ↓ RL shunt  ↑ pulmonary blood flow, ↑ oxygenation First Aid for the Pediatrics Clerkship First Aid Organ Systems Tetralogy of Fallot Clinical Findings Tet spells: intermittent hypercyanotic, hypoxic episodes Associated with psychological and physical stress (crying, feeding, defecation) PVR or SVR Right-to-left shunting = “blue baby” SQUAT = SVR Right-to-left shunting  Tetralogy of Fallot Treatment Knees to chest position Oxygen, occ morphine Meds to increase systemic resistance (phenylephrine) Prostaglandin E (if PDA dependent) Associations: Chest X-ray = Boot shaped heart EtOH exposure in utero -Upturned Cardiac apex Maternal rubella Normal or decreased pulmonary 22q11 syndromes vascular markings Down syndrome https://radiopaedia.org/cases/tetralogy-of-fallot-6 Total Anomalous pulmonary venous return (TAPVR) Pathophysiology: pulmonary veins drain into the right heart circulation Need ASD +/or PDA https://www.mayoclinic.org/diseases-conditions/total-anomalous-pulmonary-venous-return/cdc-20385613 Total Anomalous pulmonary venous return (TAPVR) Treatment: Surgery ASD necessary for survival PDA allows for oxygenated blood to enter systemic circulation Associations: Males > Females Snowman in a snowstorm -Significantly increased vascular markings  Hypoplastic left heart syndrome Pathophysiology: left side of the heart is hypoplastic/nonfunctional Clinically not always cyanotic, grey, lethargic, looks septic, low O2 sat Treatment: Prostaglandins, surgery Need to PDA to get blood to systemic circulation https://www.amboss.com/us/knowledge/Cyanotic_congenital_heart_defects/  Ebstein Anomaly Tricuspid leaflets displaced into RV  “atrialization” of RV A/w tricuspid regurgitation and R-sided heart failure ASD often present (R to Lt shunt when Rt pressure builds) Symptoms: heart failure, cyanosis, respiratory distress Dx: Significant cardiomegaly on CXR, ECHO A/w Lithium exposure in utero  Ebstein Anomaly Pathophysiology: malformed tricuspid leaflets, and lower position Small RV, larger RA ASD often present leading to R to L shunt Associations: prenatal lithium exposure https://www.amboss.com/us/knowledge/Cyanotic_congenital_heart_defects/ Ebstein Anomaly Significant Cardiomegaly, often decreased vascular markings from poor blood flow to the lungs Question #1 A newborn girl is born to a 25-year-old mother with a past medical history of diabetes. On the second day of life, the infant is noted to be mildly cyanotic with an oxygen saturation of 80%. She is progressively more lethargic than usual with poor feeding. On physical exam, she has increased tachypnea, sternal retractions, and nasal flaring. A chest radiograph shows a narrowed mediastinum, cardiomegaly and increased pulmonary vasculature. What is the most likely diagnosis? a. Tetralogy of Fallot b. Transposition of the Great Vessels c. Tricuspid Atresia d. Persistent Truncus Arteriosus Question #1 A newborn girl is born to a 25-year-old mother with a past medical history of diabetes. On the second day of life, the infant is noted to be mildly cyanotic with an oxygen saturation of 80%. She is progressively more lethargic with poor feeding. On physical exam, she has increased tachypnea, sternal retractions, and nasal flaring. A chest radiograph shows a narrowed mediastinum, cardiomegaly and increased pulmonary vasculature. What is the most likely diagnosis? a. Tetralogy of Fallot b. Transposition of the Great Vessels c. Tricuspid Atresia d. Persistent Truncus Arteriosus A 1-year-old presents to the emergency department with shortness of breath. His mom states that he turned blue after having a temper tantrum. The infant is noted to be mildly cyanotic with an oxygen saturation of 92%. His heart rate is 200 (normal =80-130), respiratory rate 36 (normal = 25-35). On physical exam, the toddler has small, low set ears and a cleft palate. Below is the child’s chest x-ray: What is the most likely diagnosis? a. Total Anomalous Venous Return b. Tetralogy of Fallot c. Persistent Truncus Arteriosus d. Tricuspid Atresia Question #2 A 1-year-old presents to the emergency department with shortness of breath. His mom states that he turned blue after having a temper tantrum. The infant is noted to be mildly cyanotic with an oxygen saturation of 89%. His heart rate is 200 (normal =80-130), respiratory rate 36 (normal = 25-35). On physical exam, the toddler has small, low set ears, a cleft palate and a hx of recurrent pneumonia. Below is the child’s chest x-ray: What is the most likely diagnosis? a. Total Anomalous Venous Return b. Tetralogy of Fallot c. Persistent Truncus Arteriosus d. Tricuspid Atresia Question #2 https://radiopaedia.org/cases/tetralogy-of-fallot-6  Bonus Q A mother brings her 2-year-old male child with Down Syndrome in for evaluation. She notes that he sometimes turns blue-ish after running or crying, and seems to console himself by squatting down. Physical examination reveals loud systolic ejection murmur. Why does the child squat to alleviate his symptoms? A) Decreases energy expenditure B) Increases afterload to decrease right to left shunt C) Decreases afterload to increase right to left shunt D) Increases preload to increase right to left shunt E) Decreases preload to increase left to right shunt  Bonus Q A mother brings her 2-year-old male child with Down Syndrome in for evaluation. She notes that he sometimes turns blue-ish after running or crying, and seems to console himself by squatting down. Physical examination reveals loud systolic ejection murmur. Why does the child squat to alleviate his symptoms? A) Decreases energy expenditure B) Increases afterload to decrease right to left shunt C) Decreases afterload to increase right to left shunt D) Increases preload to increase right to left shunt E) Decreases preload to increase left to right shunt  Important Associations Disorder Defect Alcohol Exposure in Utero VSD, PDA, ASD, Tetralogy of Fallot (TOF) Congenital Rubella PDA, pulmonary artery stenosis, septal defects Down Syndrome AV septal defect, VSD, ASD, TOF Diabetic mother Transposition of the Great Vessels, VSD Prenatal Lithium Exposure Ebstein Anomaly Turner Syndrome Coarctation of the Aorta 22q11 Syndromes Truncus arteriosus, Tetralogy of Fallot  Truncus Transposition Tricuspid Tetralogy of TAPVR Hypoplastic Ebstein Arteriosus of Vessels Atresia Fallot Left Heart Anomaly Pulmonary Increased Increased Decreased/ Decreased Decreased/ Increased --- Blood Flow Increased Increased Abnormal? Common Two separate Tricuspid VSD, Pul Veins Underdevel Abnormal tricuspid trunk, VSD circuits, valve absent overriding feeding back oped LV valve PDA/VSD aorta, RVH, into RA formation Pulmonary stenosis CXR ---- Egg on a string Round Boot Shaped Snowman ---- --- EKG LVH RVH, RAD LVH RVH, RAD RVH, RAH RAH, RVH RAD Auscultatio Holosystolic Soft systolic Harsh systolic Harsh Soft systolic Soft mid Holosysto n murmur ejection murmur LSB systolic ejection systolic lic murmur MLSB ejection murmur LSB murmur murmur murmur LSB LSB Other 22q11 Maternal --- Tet spells, --- --- Lithium syndromes diabetes 22q11 exposure syndromes References Dudek RW. BRS Embryology. 6th ed. Baltimore, MD: Wolters Kluwer; 2014. Le, Tao; Bhushan, Vikas; and Sochat, Matthew. First Aid for the USMLE Step 1 2021. New York: McGraw-Hill Education, 2021 https://www.amboss.com/us/knowledge/Prenatal_and_postnatal_physiology/ https://www.chop.edu/img/cardiac-center/truncus-arteriosus.html https://radiopaedia.org/cases/tetralogy-of-fallot-6  Thank you! Feedback form: https://comresearchdata.nyit.edu/redcap/surveys/?s=HRCY448FWYXREL4R