Chapter 7. Hemodynamic Assessment of Renal Artery Stenosis
The administration of adenosine:
A. Induces vasodilatation in coronary and renal arteries
B. Induces vasoconstriction in coronary arteries, especially in case of mild stenosis, and vasodilatation of renal arteries
C. Induces vasodilatation in coronary arteries and vasoconstriction in renal arteries
D. Has no effects in coronary and renal arteries
Vasoconstriction is mediated by adenosine A1 receptors, which are predominant in the renal arteries.
What is a central component of arterial hypertension in case of renal stenosis?
A. The activation of the renin-angiotensin system, resulting in angiotensin II–mediated vasoconstriction
B. An increase in the excretion of sodium, namely “pressure natriuresis”
C. The increasing levels of angiotensin II that induce vasodilatation
D. The decrease in glomerular filtration
Renovascular hypertension fundamentally depends on the presence and magnitude of a pressure drop due to the stenosis. The activation of the renin-angiotensin system resulting in angiotensin II–mediated vasoconstriction is a central component to this process. This decrease in systemic pressure will in turn decrease the perfusion pressure in the stenotic kidney and further stimulate the release of renin. Elevated levels of angiotensin II induce vasoconstriction and trigger the secretion of aldosterone.
A. Is mostly caused by the presence of renal artery stenosis (RAS)
B. Is mostly caused by the presence the parenchymal disease
C. Is mostly caused by the association of RAS and parenchymal disease
D. Is independent from renal anatomic modification
The most common cause of renal failure in patients with RAS is the association of the RAS with parenchymal disease. In contrast, the occurrence of renal failure solely due to a stenosis in the trunk of the renal artery is exceptional in unilateral RAS and rare in bilateral RAS in the absence of parenchymal disease or nephrotoxic medications.
The renal resistance index is defined as:
A. (2 – [end-diastolic velocity/minimal systolic velocity]) × 100
B. (1 – [end-diastolic velocity/peak systolic velocity]) × 100