Oxygen Consumption in Dog Left Ventricle
نویسندگان
چکیده
In 10 excised, cross-circulated, isovolumically beating dog left ventricles, we examined the effects of bigeminy, including, paired-pulse stimulation, on cardiac oxygen consumption (Vo2) and evaluated whether the Vo2 versus pressure-volume area (PVA) relation obtained from regularly beating hearts in our previous studies could account for the changes in Vo2 during bigeminies with various coupling intervals. The extrasystolic interval (ESI) was decreased in four steps from 300 msec (regular rhythm) to paired-pulse stimulation (<210 msec). The sum of ESI and the postextrasystolic interval was always held constant (600 msec); therefore, the number of excitations was 200/min at any ESI. Both Vo2 and PVA were measured in four runs:
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