DK2985_C000 1..28 - AlSharqia Echo Club

542 Transesophageal Echocardiographypreviously underwent a corrective procedure in infancy orchildhood who survived to adulthood; (2) the patients withan unoperated form of tetralogy of Fallot, either theunusual patient with mild RVOT obstruction, or thepatient with an extreme form of tetralogy with aortopulmonarycollaterals; and (3) the patients who underwent apalliative surgery anteriorly in childhood and who reachadulthood without having undergone corrective surgery.The types of palliation includes: Blalock–Taussig shuntor modification (subclavian artery to pulmonary arteryshunt), Waterston shunt (ascending Ao to right pulmonaryartery), Potts shunt (descending Ao to left pulmonaryartery), central interposition tube graft, infundibulumresection (Brock), or pulmonary valvotomy, RV topulmonary artery conduit without VSD closure or partialclosure of the VSD.TEE in Tetralogy of Fallot (Table 24.2)The role of preoperative echocardiography in nonoperatedtetralogy of Fallot is mainly to evaluate the level andseverity of the RVOT obstruction, demonstrate the size ofthe VSD, and rule out aortic valve incompetence sometimesassociated with aortic root dilatation. Distal pulmonaryarteries and coronary arteries are better evaluated withangiography. The large nonrestrictive perimembranousVSD is best visualized in the mid-esophageal fourchamberview and AoV short- and long-axis views(Fig. 24.22). The appearance is similar to a truncus arteriosusand is differentiated by the identification of a separateorigin of the pulmonary artery. The direction of theshunt can also be evaluated using color flow mapping.Other shunts either at the atrial level or in the trabecularventricular septum should be ruled out. The RVOT isbest visualized with the upper- and mid-esophageal rightventricular outflow views.The immediate postoperative echocardiographic evaluationshould attempt at detecting residual RVOT obstructionand shunt through the VSD, demonstratingregurgitation of either the native pulmonary valve or thevalved conduit or homograft. Evaluation of TR is importantand can also be used to evaluate the RV systolic pressure.This should be completed by the evaluation of RVfunction, size and thickness, LV function, and aorticvalve competence.D. Left Atrial Anomaly1. Cor TriatriatumCor triatriatum sinister is a rare congenital cardiac malformationinvolving the LA, resulting embryologically fromfailure of the common pulmonary vein to become incorporatedinto the LA. The incomplete absorption leaves afibromuscular membrane dividing the left atrial chamberinto a proximal compartment (the atrial accessorychamber) receiving the pulmonary veins and a distal compartmentor true left atrial chamber, which most often containsthe fossa ovalis and the left atrial appendage. The sizeof the communicating hole(s) between the proximal andthe distal chambers determines the clinical picture. Thedegree of obstruction varies from being barely detectableFigure 24.23 Variants of cor triatriatum sinister where the atrial accessory chamber (AC) communicates with the left atrium (LA). (A)Classic cor triatriatum. The atrial AC receives the right pulmonary veins (RPV) and the left pulmonary veins (LPV). The only outlet forpulmonary venous blood is the orifice of the fibromuscular transatrial membrane. (B) Cor triatriatum with anomalous connection betweenthe atrial AC and the right atrium (RA). This communication decompresses the atrial AC and results in a left-to-right shunt at the atriallevel. (C) Cor triatriatum with anomalous pulmonary venous connection. Here the accessory AC is decompressed by way of a verticalvein (VV) to the left innominate vein (IVC, inferior vena cava; LV, left ventricle; RA, right atrium; RV, right ventricle; SVC, superiorvena cava). [Adapted with permission from (11).]