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Figure 1 Individual recordings of the effects of dobutamine infusion on heart rate (HR), mean blood pressure (MBP), and sympathetic nerve activity (MSNA). In a young control, arterial baroreceptor activation produced by marked increases in MBP with dobutamine inhibits MSNA and limits the rise in HR. In a control subject matched to the congestive heart failure (CHF) patient, dobutamine does not increase MBP, and, in the absence of arterial baroreflex activation, MSNA remains unchanged, and the chronotropic effect of dobutamine is preserved. In a CHF patient, dobutamine produces similar effects to those seen in the matched control, except that HR does not increase.
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