1. Steven H. Todman, M.D. Assistant Professor Pediatric Cardiology LSUHSC-Shreveport

2. Objectives Truncus arteriosus 1. Embryology Understand the embryologic basis of truncus arteriosus 2. Etiology, epidemiology, and genetic implications Understand the genetic implications of truncus arteriosus 3. Anatomy Recognize the commonly associated lesions in a patient with truncus arteriosus Recognize the anatomic details of truncus arteriosus

3. Objectives 4. Physiology -Understand the circulatory physiology in truncus arteriosus 5. Natural history -Understand the natural history of a patient with truncus arteriosus 6. Laboratory findings -Diagnose truncus arteriosus by echocardiography, and recognize important anatomic features Diagnose truncus arteriosus by cardiac MRI/CT scan, and recognize important anatomic features 7. Management, including complications - Plan the surgical approach for palliation or correction of truncus arteriosus Plan appropriate preoperative medical management of a patient with truncus arteriosus Recognize and manage early and long-term postoperative complications following repair of truncus arteriosus

4. Which of the following is false? (A) Truncus arterious usually occurs as part of a genetic syndrome. (B) Maternal diabetes is a risk factor for truncus. (C) The spiral course of the truncoaortic partition produces the normal intertwinement of the great arteries. (D) Deficiency or absence of the conal (infundibular) septum produces a large VSD. (E) Deficiency of the conal septum also can contribute to deformities of the anterior tricuspid leaflet, and the medial tricuspid papillary muscle.

5. Which of the following is false? (A) Truncus arterious usually occurs as an isolated cardiovascular malformation. (B) Maternal diabetes is a risk factor for truncus. (C) The spiral course of the truncoaortic partition produces the normal intertwinement of the great arteries. (D) Deficiency or absence of the conal (infundibular) septum produces a large VSD. (E) Deficiency of the conal septum also can contribute to deformities of the anterior tricuspid leaflet, and the medial tricuspid papillary muscle.

6. Which of the following are false? (A) In type I Truncus, a short puilmonary trunk originates from the truncus arteriousus gives rise to both pulmonary arteries. (B) When both pulmonary arteries separate from the truncus arteriosus, with no MPA, it can be type II or type III. (C) Type A1 is the same as type I (D) Type A2 is types II and III (E) Type A4 is associated with underdevelopment or interruption of the aortic arch.

7. Which of the following are false? All are true.

8. Which of the following are false? (A) The VSD results from absence or deficiency of the infundibular septum. (B) The VSD is cradled between the two limbs of septal band, and is roofed by the truncal valve cusps. (C) Fusion of the inferior limb and the parietal band causes muscular discontinuity between the tricuspid valve and the truncal valve. (D) The VSD in truncus arteriosus is typically membranous.

9. Which of the following are false? (D) The VSD in truncus arteriosus is typically infundibular.

12. Which of the following are false? (A) The truncal valve is tricuspid in 69% of cases, and bicuspid in 9% of cases. (B) The semilunar valve is in fibrous continuity with the tricuspid valve, and usually not in fibrous continuity with the mitral valve. (C) A right aortic arch, with mirror image branching occurs in approximately 26% of patients, second to pulmonary atresia/VSD. (D) Interrupted aortic arch is frequently associated with DiGeorge syndrome.

13. Which of the following are false? (A) The truncal valve is tricuspid in 69% of cases, and bicuspid in 9% of cases. (B) The semilunar valve is in fibrous continuity with the mitral valve, and usually not in fibrous continuity with the tricuspid valve. (C) A right aortic arch, with mirror image branching occurs in approximately 26% of patients, second to pulmonary atresia/VSD. (D) Interrupted aortic arch is frequently associated with DiGeorge syndrome.

14. Which of the following are false? (A) Type I truncus is the most commonly observed form, seen in about 60% of cases. (B) In truncus, the pulmonary artery that is most frequently absent is on the side opposite of the arch, as opposed to TOF where the pulmonary artery absent is on the same side of the arch. (C) The LAD is is frequently small and displaced leftwardly, and the conus branch is usually prominent and supplies several large branches to the RVOT. (D) In truncus, a left coronary dominance pattern ocurs in 27% of patients, which is 3x higher than in the general population.

15. Which of the following are false? (A) Type I truncus is the most commonly observed form, seen in about 60% of cases. (B) In truncus, the pulmonary artery that is most frequently absent is on the side of the arch, as opposed to TOF where the pulmonary artery absent is on the side opposite to the arch. (C) The LAD is is frequently small and displaced leftwardly, and the conus branch is usually prominent and supplies several large branches to the RVOT. (D) In truncus, a left coronary dominance pattern ocurs in 27% of patients, which is 3x higher than in the general population.

16. Which of the following are false? (A) Abnormalities of ostial origin occur in about 43% of cases, and high ostial origin (above the sinotubular junction) occurs often. (B) In cases where the membranous septum is intact, and the VSD is infundibular, the AV conduction tissue is somewhat distant from the rim of the defect. (C) Anomalies most commonly associated with truncus arteriosus are RAA, IAA, absent PDA, PDA, unilateral absence of a pulmonary artery, coronary ostial anomalies, and an incompetent truncal valve.

17. Which of the following are false? All are true.

18. Which of the following are false? (A) Extracardiac anomalies, present in 25% of cases include skeletal deformities, hydroureter, and bowel malrotation. (B) Hypertensive pulmonary vascular disease develops more rapidly and to a more severe extent in truncus arteriosus than in isolated VSD’s. (C) Chronic truncal valve insufficiency can result in pulmonary venous hypertension.

19. Which of the following is false? (A) First heart sound is normal, and is often followed by an ejection click. (B) A thrill is often palpable along the left sternal border. (C) A third heart sound is often present, along with a loud pansystolic murmur at the lower left sternal border. (D) An apical diastolic high-pitched murmur is often heard from flow across the mitral valve. (E) A diastolic high-pitched murmur is heard at the left sternal border from truncal valve insufficiency.

20. Which of the following is false? (A) First heart sound is normal, and is often followed by an ejection click. (B) A thrill is often palpable along the left sternal border. (C) A third heart sound is often present, along with a loud pansystolic murmur at the lower left sternal border. (D) An apical diastolic low-pitched murmur is often heard from flow across the mitral valve. (E) A diastolic high-pitched murmur is heard at the left sternal border from truncal valve insufficiency.

21. Which of the following is false? (A) A continuous murmur is usually suggestive of pulmonary ostial stenosis, but should make you think of PA/VSD with a PDA or collateral vessels than with truncus. (B) EKG axis is normal, but may demonstrate RAD, and often shows BVH. (C) Patients with increased blood flow will often have increased LV forces and LAE. (D) Patients with TA with two PA’s and a pulmonary arteriolar resistance >8 Um2 are at higher risk. (E) Complete repair is preferred in the first weeks of life.

22. All are true.

23. Which of the following is false? (A) Most surgeons prefer a valved conduit. (B) Primary late problem related to extracardiac conduit operation is the need for replacement because of growth or deterioration and calcification of the conduit. (C) Percutaneous valve therapy can be used for the failing conduit. (D) Peak gradient over 50mm Hg in the conduit and RVSP >75 mm Hg is an indication to replace the conduit in adults. (E) Infective endocarditis precautions are not warranted after repair of truncus.

24. Which of the following is false? (A) Most surgeons prefer a valved conduit. (B) Primary late problem related to extracardiac conduit operation is the need for replacement because of growth or deterioration and calcification of the conduit. (C) Percutaneous valve therapy can be used for the failing conduit. (D) Peak gradient over 50mm Hg in the conduit and RVSP >75 mm Hg is an indication to replace the conduit in adults. (E) Infective endocarditis precautions are warranted after repair of truncus.