Discloses herein are ablative catheters and methods of use. The catheters can include a cooling chamber for circulating cooling fluid within the catheter tip to reduce hot spots within the catheter tip and/or to reduce the formation of coagulum. A proximal cooling chamber can be positioned proximally to a thermal mass for cooling a proximal portion of the catheter. In addition, or alternatively, a distal cooling chamber can be positioned for cooling a distal portion of the catheter tip. The cooling fluid can flow the ablative catheter in an open, closed, or open and closed loop.