In congestive heart failure, an increase in impedance to left ventricular ejection appears to
be an important factor in impairing left ventricular performance. Arteriolar narrowing and
decreased arterial compliance will decrease the left ventricular ejection fraction, whereas
reduction in venous capacitance will shift blood centrally and increase cardiac filling. These
vascular events may result from activation of the sympathetic nervous system and the renin-
angiotensin system. Vasodilator drugs, by relaxing the increased vascular tone, will reduce …