Trái tim univentricular đại diện cho một loạt các bất thường bẩm sinh của tim và các mạch máu lớn, nơi các bất thường phổ biến là một tâm thất duy nhất. Khái niệm này thường liên kết với sáu biến thể có thể giải phẫu của ba lá hẹp | CHAPTER 23 Univentricular heart The univentricular heart represents a broad spectrum of congenital abnormalities of the heart and great vessels where the common abnormality is a single ventricle. This concept is typically associated with any of six possible anatomical variations of tricuspid atresia most of which are associated with a non-existant or rudimentary venous ventricle Figure . The Fontan procedure to separate and redirect venous blood flow presents the most challenging pacing options for the adult with congenital Figure Schematic of tricuspid atresia univentricular heart type 1B . The right ventricle and outflow pulmonary artery are rudimentary and effectively non-existent. In this defect survival depends on an effective atrial septal communication broken ring . 111 112 Chapter 23 Figure Schematic of tricuspid atresia univentricular heart with Fontan repair. In the more classic Fontan surgical repair the atrial septal defect is closed and a direct right atrial RA - pulmonary artery PA anastomosis created. The ultimately elevated atrial pressures often in the range of 20mmHg eventually cause severe atrial dilatation and wall thickening. As expected sinus node dysfunction and atrial arrhythmias are common. heart disease. The operation and its many modifications is performed in up to four surgical procedures ia order to separate the systemic aad pulmonary circulatioas. This is accomplished by either a direct anastomosis of the right atrium to the pulmonary artery Figure or any variations of anastomoses involving the superior and inferior venae cavae to the pulmonary artery using an intra-atrial tunnel or extra-cardiac conduit. These latter techniques are re Pc r red to as total cavopulmonary connection. As might be expected a lateral tunnel or external conduit repair may preclude use of transvenoua atrial paaigg sis ehe venc cavm man no nonger mmmunic-ate with the atrial chamber. Thus it is essential that the operation notes be reviewed
