A steerable catheter comprises a flexible tubular body (12) having a proximal end (22), a distal end (18), and at least one lumen (not shown); an inflatable annular balloon (26) positioned on or near the distal end (18) of the tubular body; at least one electrode (28) positioned on or near the distal end (18) of the tubular body (12); and a handle (14) attached to the proximal end (22) of the tubular body (12). The handle (14) cooperates with the distal end (18) of the tubular body (12) to steer the catheter. The catheter is especially useful in placing pacemaker or defibrillator leads (not shown) in the heart or coronary sinus. Additionally, the invention also provides a device and platform for providing a variety of medical technologies including angiography, venography, angioplasty, stenting, valvuloplasty, embolization, drug delivery, and additional therapy delivery (e.g., laser, radiofrequency energy, ultrasound, microwave, etc).