A catheter having a proximal opening, a distal opening, a lumen extending through the catheter and a side opening forming a rapid exchange port dimensioned and configured for insertion of a guiding device through the side opening. The catheter includes a seal movable between a closed position to reduce leakage through the side opening and an open position, wherein the seal is movable to an open position by the guiding device. The catheter can have one or more independently deflectable zones.