Final answer:
Left-to-right congenital heart defects, like Tetralogy of Fallot, involve structural abnormalities of the heart present from birth and often require surgical repair after detected by symptoms such as cyanosis and abnormal heart murmurs.
Step-by-step explanation:
Left-to-right congenital heart defects, such as Tetralogy of Fallot and patent foramen ovale, are structural abnormalities of the heart present from birth. These conditions can lead to serious complications including 'blue baby' syndrome due to cyanosis, which is a blue or purple coloration of the skin caused by insufficient oxygenated blood. Tetralogy of Fallot is characterized by four specific heart defects: pulmonary infundibular stenosis, overriding aorta, ventricular septal defect, and right ventricular hypertrophy. These congenital anomalies often require extensive surgical repair for the child to survive, with varying survival rates depending on the severity of the defects and the effectiveness of the medical interventions. Echocardiography imaging plays a crucial role in diagnosing these heart defects, which are sometimes initially indicated by abnormal heart murmurs detected during auscultation.