A method of treating cardiac tissue is provided, including positioning a first chamber of a medical device adjacent an atrial wall; directing a cryogenic coolant into the first chamber; anchoring the first chamber to the atrial wall through cryoadhesion; directing a distal portion of the medical device into the coronary sinus; and positioning a cardiac lead through at least a portion of the coronary sinus with the distal portion. The method may include measuring a temperature of the first chamber; removing the first chamber from the atrial wall once a predetermined threshold temperature of the first chamber is reached; anchoring a second chamber of the medical device to a portion of the coronary sinus; and/or perfusing blood flow through at least a portion of the second chamber.