Devices for enhancing minimally invasive cardiac surgery include a visualization device including an inflatable balloon at or near the distal end. Some visualization devices also include one or more lumens for allowing the introduction of one or more devices to a surgical site through the visualization device. Systems of the invention involve a visualization device which has at least one lumen for allowing introduction of an ablation device and/or other devices. A visualization device with an inflatable balloon may be positioned to create a space between a heart and pericardium when the balloon is inflated.