Methods and devices for transvascular prosthetic chordae tendinea implantation are disclosed. A catheter is advanced into the left atrium. A helical ventricular anchor subassembly is advanceable through the catheter, having a ventricular suture extending proximally through the catheter. A leaflet anchor subassembly is advanceable through the catheter, having a leaflet suture extending proximally through the catheter. From an atrium side, the leaflet anchor subassembly can be anchored to a superior surface of a mitral valve leaflet and a leaflet anchor can be advanced into the mitral valve leaflet to secure the mitral valve leaflet to the leaflet suture. The ventricular anchor subassembly secures the ventricular anchor to a ventricular wall. The leaflet suture and the ventricle suture may be tensioned and connected by a suture lock to form an artificial chordae.