儿童先天性心脏病（Congenital Heart Disease in childhood）.pptVIP

Tetralogy of Fallot Pathophysiology( hemodynamics ) Vena RA RV PA cava pulmonary blood flow LA LV Ao Pathophysiological implication ◆ Pressures of both ventricles are balanced by a large VSD, RV pressure never exceeds systemic level, so that cardiomegaly / CHF rarely develop ??? ◆ The more stenotic the RV outflow, the more severe the cyanosis. Therefore the two ends of the spectrum: mild PS---- ‘pink’ tetrology vs. most severe PS---- pulmonary atresia with VSD ◆ The PS is relatively fixed, hence the size of R→L is inversely correlated to SVR. Clinical manifestations ◆ Cyanosis typically develops in 3~6 months of age ◆ Mostly symptomatic with dyspnea on exertion and delayed growth may exist ◆ Hypoxemic spells in infancy characterized by ◆ Squatting, usually appears when the patient begins to walk ◆ Brain abscess / thrombosis and tendency of bleeding which may relate to rheological disorder paroxysms of hyperpnea, increasing cyanosis, attenuation of the murmur and may lead to convulsion or even death. Physical examination ◆ Weak pulmonic component makes S2 sounds single and weak, but may be loud reflecting A2 ◆ Systolic ejective murmur at middle left/upper sternal border ◆ Central cyanosis with finger/toe clubing TOF X-Ray Management 1) Medical ◆ Antibiotic prophylaxis against endocarditis ◆ Maintain rheological condition at favorable state ◆ Detect and treat hypoxemic spell 2) Surgical ◆ Palliative procedures such as Blalock- Taussig’s fo