A cardiologist is called to consult on the care of a 2-day-old girl delivered at 33 weeks’ gestation. The infant is lying supine in her isolette. She is acyanotic, but has a heart rate of 192/ min and a respiratory rate of 60/min. She has a nonradiating continuous machinery murmur at the left upper sternal border that remains the same with compression of the ipsilateral, then contralateral jugular veins. S1 and S2 are normal. Her peripheral pulses are bounding. Which of the following is the most likely diagnosis?