Fig. 4. End-diastolic pressure–length relations in nonischemic myocardium in the apex ( top ) and at the base ( bottom ) before and during coronary occlusion of the left circumflex coronary artery in a typical animal. Data were obtained from consecutive beats during occlusion of the cava vein. Note that during occlusion all data above the end-diastolic pressure of the baseline state are discarded so the pressure–length relations cover the same pressure range. Curves were fitted through the data using the following equation: LVEDP = Aek·EDL. During baseline the base is much stiffer than the apex. Moreover, the increase in k during remote ischemia that occurs in both nonischemic areas is more pronounced in the base. EDL = end-diastolic length; k = chamber stiffness constant; LVEDP = end-diastolic pressure.