The Melody valve, designed for implantation into the pulmonary outflow tract, can also be used to treat the pathology of atrioventricular (AV) valves. Increasing gradients are seen as an indication for re-dilating the valve. Our case demonstrates the heart rate dependency of the gradient across a Melody implanted in the left AV valve position in an infant. Beta blockers were used to lower both heart rate and gradient.