Cyanotic Heart Disease Nidhi Ravishankar Role number: 1440

Introduction – what is cyanosis? Bluish discolouration of the skin and mucous membranes caused by accumulation of deoxygenated hemoglobin in the affected area. Peripheral and central cyanosis Peripheral: secondary to low cardiac output leading to bluing of the periphery (toes, nails, nose); normal PaO2 Central: bluish discolouration of the skin and mucous membranes with deoxygenated hemoglobin > 3g/dL in arterial blood and > 5g/dL in capillary blood; low PaO2 and SaO2

Cyanotic heart disease A group of heart defects present at birth resulting in a low blood oxygen level increased pulmonary vascularity total anomalous pulmonary venous return (TAPVR) (types I and II) total anomalous pulmonary venous return (TAPVR) transposition of the great arteries (TGA) truncus arteriosus (types I, II and III) truncus arteriosus large AVSDAVSD single ventricle without pulmonary stenosis single ventricle decreased pulmonary vascularity tetralogy of Fallot pentalogy of Cantrell many other combined and infrequent anomalies such as double outlet right ventricle (DORV) with pulmonary stenosis double outlet right ventricle (DORV) single ventricle with pulmonary stenosis Ebstein anomaly with atrial septal defect Ebstein anomalyatrial septal defect Uhl anomaly

Right-to-left shunt (5 Ts) Right-to-Left shunts: eaRLy cyanosis. Tetralogy of Fallot Transposition of the great arteries Tricuspid atresia Truncus arteriosus Total anomalous pulmonary venous return

Tetralogy of Fallot Most common cause of cyanotic congenital heart disease and accounts for 5% of all congenital cardiac malformations Anterolateral displacement of the infundibular septum leading to abnormal septation between the pulmonary trunk and aortic root

Four features - PROVe 1.Pulmonary infundibular stenosis (most important determinant for prognosis) 2.Right ventricular hypertrophy (RVH)— boot- shaped heart on CT 3.Overriding aorta 4.VSD

Clinical manifestation Severity depends on the level of pulmonary outflow obstruction Mild: Resembles an isolated VSD due to left to right sided pressure gradient Severe: Early cyanosis As child’s heart grows, there is progressive weakening Infective endocarditis Paradoxical and systemic embolization Right ventricular failure is RARE!

Clinical signs 1.Polycythemia 2.Hypertrophic osteoarthropathy 3.Harsh SEM over pulmonic area and left sternal border; single S2 Treatment: surgical correction Squatting: increases SVR, decreases right-to-left shunt, less cyanosis

Transposition of Great Arteries/Vessels Discordant connection of the ventricles to their vesicular outflow Abnormal formation of the truncal and aortopulmonary septa so that the aorta arises from the right ventricle and the pulmonary artery emanates from the left ventricle Incompatible with postnatal life unless shunt such as VSD, PDA or patent foramen ovale is placed!

Features 1.Right Ventricular Hypertrophy 2.Left ventricular atropy

Clinical manifestations Cyanosis: Prognosis depending on the magnitude of shunting, the degree of tissue hypoxia, and the ability of the right ventricle to maintain systemic pressures. No murmur auscultated, but loud single S2 Treatment: Surgical intervention Without surgery, even with stable shunting, patients die within first few months of life Youtube link:

Truncus arteriosus Failure to divide pulmonary trunk and aorta due to lack of aorticopulmonary septum formation Most patients have accompanying VSD Treatment Surgical intervention

Total anomalous pulmonary venous return (TAPVR) Pulmonary veins drain out into right heart circulation (eg. SVC, coronary sinus, etc) Associated with ASD and sometimes PDA to allow for right-to-left shunting to maintain CO. Treatment Surgical intervention

Important notes: Signs: cyanosis, clubbed fingers, abnormal heart sounds Tests: chest X-rays, arterial blood gas test Treatment: surgical interventions TOF: PROVe and boot-shaped CT, single S2, harsh 3/6 systolic ejection murmur; TGA: opposite

Tetralogy of fallot A 1-day-old infant in the general care nursery born at full term by uncomplicated spontaneous vaginal delivery is noted to have cyanosis of the oral mucosa. The baby otherwise appears comfortable. On exam, respiratory rate is 40 and pulse oximetry is 80%. A right ventricular lift is palpated, S1 is normal, S2 is single, and a harsh 3/6 systolic ejection murmur is heard at the left upper sternal border.

TGA

References Kumar, Vinay, Abul K. Abbas, Nelson Fausto, Stanley L. Robbins, and Ramzi S. Cotran. Robbins and Cotran Pathologic Basis of Disease. Philadelphia: Elsevier Saunders, Print. Le, Tao., Bhushan, Vikas., Sochat, Matthew. First Aid for the Usmle Step United States: McGraw Hill Education, Print.