An interventional medical device that incorporates an imaging system may be minimally invasive and equipped with an anchoring portion that may be slidable and fixed in a predetermined position of its elongate body outside the human body, the device further comprising deployable first and second balloons for also securing the device to an internal wall, for example, within a human body. The medical device can be in the form of a catheter, a sheath or comprise interventional devices, particularly those suitable for minimally invasive procedures in the pericardium. The dual sealing/locking balloons may comprise a slidably moveable assembly for moving from a first position over an inflation channel to a second position over one inflation/deflation channel for separately inflating a distal balloon and then a proximal balloon to the patient's skin surface.