We report here the acute systemic and regional hemodynamic effects of ANF in patients with established essential hypertension. The most common hemodynamic response to ANF observed in this group of hypertensives was a reduction in cardiac output. This was accounted for by a decrease in stroke volume, since heart rate did not change. The reduced stroke volume during ANF infusion might be accounted for either by a reduction in blood volume and/or venous return or by a decrease in ventricular contractility. Our data do not permit distinction among these possibilities. On the other hand, the possibility that ANF provokes a reduction in blood volume, as suggested by previous authors, is only partially supported by our findings since only a slight fall in left ventricular filling pressure was recorded on average and right atrial pressure was not affected by ANF. Also, however, the possibility that direct and/or indirect negative effects of ANF on ventricular contractility are responsible for the ANF-induced blood pressure lowering effect is not fully supported by the observation that the contractility indices used in our study did not change during the administration of the peptide. It should be noted, however, that these indices can be affected by concurrent changes in preload and afterload; therefore, the occurrence of contrasting effects on the left ventricle (that is, reduction inventricular filling and impedance and a decrease in myocardial contractility) cannot be excluded. Although the relevance of our findings to the physiologic actions of ANF in the control of blood pressure and systemic circulation in normal or pathologic states requires further studies, we have shown that endogenous infusion of ANF at relatively high doses induces pronounced hemodynamic changes in human hypertension.
|Issue number||SUPPL. 25|
|Publication status||Published - 1988|
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