A 3-year-old child has episodes accompanied by cyanosis, sudden anxiety, and squatting. Objectively, the child has drum-stick deformation of the finger phalanges and nails that resemble a clockface. The cardiac dullness boundaries are shifted to the left and right. A systolic tremor can be detected in the second intercostal space near the left edge of the sternum. A coarse systolic murmur can be heard with p.max in the second intercostal space. The second heart sound is weakened over the base of the heart. X-ray shows that the heart is in the form of a "wooden shoe", the pulmonary pattern is poorly visible. What is the most likely diagnosis in this case?