A constricting cord can be delivered to the vicinity of an annulus using an apparatus that includes a set of support arms, with a respective anchor launcher supported by each of the support arms. An inflatable first balloon is configured to push the support arms away from each other when the first balloon is inflated. An inflatable second balloon is mounted to a shaft and is configured for inflation when the second balloon is disposed distally beyond the first balloon. In some embodiments, the distal balloon is inflated while it is in a ventricle. In some embodiments, the distal balloon is inflated while it is in a pulmonary artery.