Balloon catheters and methods are provided for selectively occluding blood flow into a right atrium of a patient's heart communicating with an inferior vena cava (IVC) and superior vena cava (SVC). In one embodiment, a catheter includes first and second balloons adjacent one another on a distal end of the catheter shaft. During use, the distal end is introduced into the right atrium and positioned such that the first balloon is located within the right atrium. The first balloon is expanded within the right atrium and the catheter shaft directed such that the expanded first balloon engages at least a portion of the IVC to prevent substantial inflow into the right atrium from the IVC. The second balloon is then expanded to limit inflow into the right atrium from the SVC, and a medical procedure is performed within the patient's body.
