Effects of intra-aortic ballon pumping on renal sympathetic nerve activityand renal circulation in dogs

Background. Little is known on how intra-aortic balloon pumping (IABP) affe cts neural circulatory regulation, even though many studies have been done to clarify the effects of IABP on hemodynamics, Although IABP is used clini cally in patients with severe heart failure, whose sympathetic nerve activi ty is increased, there are no previous reports that demonstrate the effects of,IABP on neural regulation in heart failure. The aim of this study is to determine the effects of IABP on neural regulation of fend circulation wit h both normal and failing heart condition in dogs. Methods. We directly measured fend sympathetic nerve activity and hemodynam ic parameters (heart rate, central venous pressure, distal aortic pressure, proximal aortic pressure, left ventricular pressure, renal sympathetic ner ve activity, ascending aortic flow, and renal arterial flow) before and dur ing IABP driving in both normal and failing heart condition in dogs (n=7), Acute heart failure models were made by coronary ligation, Results, IABP dr iving inhibits renal sympathetic nerve activity and improves renal circulat ion in failing heart condition, while these phenomena do not occur in norma l heart condition. Conclusions, These findings suggest that IABP may show its full effect on r enal circulation via neural regulation especially in failing heart conditio n.