A sub-xiphoid ablation clamp for ablating a first portion of tissue of a patient, comprising: a handle; an elongate neck operatively coupled to said handle and sized for insertion within said patient via a sub-xiphoid approach; first and second opposing jaws (38, 40), comprising: first and second opposing relief segments (46, 48) coupled to said elongate neck and being generally co-planar and concave with respect to one another to form a void therebetween, wherein the first and second relief segments are sized to admit the inferior vena cava in the void formed by said first and second relief segments without substantially restricting blood flow through the inferior vena cava; and first and second opposing elongate ablation elements (42, 44) positioned along said first and second opposing jaws and distal of said first and second opposing relief segments relative to said handle, respectively, and configured to ablate said first portion of tissue positioned therebetween; wherein said first and second opposing jaws (38, 40) are sized and shaped for insertion within the patient via said sub-xiphoid approach and are articulate between a closed position and an open position to admit, at least in part, the inferior vena cava of said patient within said void created by said first and second opposing relief segments (46, 48) while said first portion of tissue is positioned between said first and second ablation elements (42, 44) in said closed position. a handle; an elongate neck operatively coupled to said handle and sized for insertion within said patient via a sub-xiphoid approach; first and second opposing jaws (38, 40), comprising: first and second opposing relief segments (46, 48) coupled to said elongate neck and being generally co-planar and concave with respect to one another to form a void therebetween, wherein the first and second relief segments are sized to admit the inferior vena cava in the void formed by said first and second relief segments without substantially restricting blood flow through the inferior vena cava; and first and second opposing elongate ablation elements (42, 44) positioned along said first and second opposing jaws and distal of said first and second opposing relief segments relative to said handle, respectively, and configured to ablate said first portion of tissue positioned therebetween; first and second opposing relief segments (46, 48) coupled to said elongate neck and being generally co-planar and concave with respect to one another to form a void therebetween, wherein the first and second relief segments are sized to admit the inferior vena cava in the void formed by said first and second relief segments without substantially restricting blood flow through the inferior vena cava; and first and second opposing elongate ablation elements (42, 44) positioned along said first and second opposing jaws and distal of said first and second opposing relief segments relative to said handle, respectively, and configured to ablate said first portion of tissue positioned therebetween; wherein said first and second opposing jaws (38, 40) are sized and shaped for insertion within the patient via said sub-xiphoid approach and are articulate between a closed position and an open position to admit, at least in part, the inferior vena cava of said patient within said void created by said first and second opposing relief segments (46, 48) while said first portion of tissue is positioned between said first and second ablation elements (42, 44) in said closed position.