VFA delivery systems and methods

A medical device delivery system comprising:

• a fixation sheath comprising a fixation element attachable to a right-atrial endocardium in the triangle of Koch region in the right atrium of a patient's heart;
• a steerable sheath defining a lumen and configured to steer the fixation sheath, wherein the fixation sheath is at least partially disposed in the lumen of the steerable sheath and the fixation sheath is freely rotatable relative to the steerable sheath;
• a flexible needle at least partially disposable in a lumen of the fixation sheath and configured to flex with the fixation sheath when disposed in the lumen of the fixation sheath and the fixation sheath is steered by the steerable sheath;
• a guide wire at least partially disposable in the lumen of the fixation sheath, and
• an implantable medical device configured to advance over or along the guide wire, wherein the implantable medical device comprises a left ventricular electrode implantable from the triangle of Koch region of the right atrium through the right-atrial endocardium and central fibrous body and configured to deliver cardiac therapy to or sense electrical activity of the left ventricle in the basal and/or septal region of the left ventricular myocardium of a patient's heart, and
• wherein the fixation element of the fixation sheath is configured to anchor the fixation sheath to the right-atrial endocardium at least during delivery of the flexible needle through the triangle of Koch region in the right atrium of a patient's heart.