Final answer:
Tetralogy of Fallot is a congenital condition characterized by right-sided heart failure and hypercyanotic spells. It occurs when there is an opening in the interventricular septum, leading to mixing of oxygen-rich and oxygen-poor blood. Surgical repair is the usual treatment for this condition.
Step-by-step explanation:
Tetralogy of Fallot is the correct answer for the condition characterized by right-sided heart failure and hypercyanotic spells. It is a congenital condition that occurs when there is an opening in the interventricular septum, resulting in blood with low oxygen levels from the right ventricle mixing with oxygen-rich blood from the left ventricle. Symptoms include a distinct heart murmur, low blood oxygen saturation, difficulty in breathing, and cyanosis. Treatment usually involves surgical repair to fix the septal defect and redirect blood flow.