Influence of lung volume on the interaction between cardiac output and cerebrovascular regulation during extreme apnoea.

New Findings What is the central question of this study? Does the reduction in cardiac output observed during extreme voluntary apnoea, secondary to high lung volume, result in a reduction in cerebral blood flow, perfusion pressure and oxygen delivery in a group of elite free divers?, What is the main finding and its importance? High lung volumes reduce cardiac output and ventricular filling during extreme apnoea, but changes in cerebral blood flow are observed only transiently during the early stages of apnoea. This reveals that whilst cardiac output is important in regulating cerebral haemodynamics, the role of mean arterial pressure in restoring cerebral perfusion pressure is of greater significance to the regulation of cerebral blood flow., We investigated the role of lung volume-induced changes in cardiac output ( [ABSTRACT FROM AUTHOR]