Benefit of glyceryl trinitrate on arterial stiffness is directly due to effects on peripheral arteries.
OBJECTIVE
To determine how the vasodilator glyceryl trinitrate (GTN) alters arterial stiffness and improves left ventricular afterload.


METHODS
Ascending aortic pressure waves were measured with fluid filled catheters of high fidelity in 50 patients undergoing cardiac surgery, before cardiopulmonary bypass, both before and after intravenous infusion of GTN. In all 50 patients, wave reflection was identifiable as a secondary boost to late systolic pressure, permitting the pressure wave to be separated into a primary component, attributable to left ventricular ejection and properties of the proximal aorta, and a secondary component, attributable to reflection of the primary wave from the peripheral vasculature.


RESULTS
GTN infusion caused no change in amplitude of the primary wave (mean (SD) 0.0 (1.4) mm Hg, not significant) but substantial reduction (14.6 (9.6) mm Hg, p < 0.0001) in amplitude of the secondary reflected wave. Fall in mean pressure was attributable to a mix of arteriolar and venous dilatation, with relative contributions unable to be separated.


CONCLUSIONS
Favourable effects of GTN on arterial stiffness can be attributed to effects on peripheral muscular arteries, causing reduction in wave reflection. Results conform with previous invasive studies on vasodilator agents and their known effects on calibre and compliance of muscular arteries.
Pauca
A L
AL
Department of Anesthesiology, Wake Forest University School of Medicine, Winston-Salem, North Carolina, USA.
Kon
N D
ND
O'Rourke
M F
MF
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001011:Aorta / Q000187:drug effects* / Q000502:physiology; D001794:Blood Pressure / Q000187:drug effects*; D002318:Cardiovascular Diseases / Q000503:physiopathology; D003187:Compliance; D005260:Female; D006801:Humans; D007262:Infusions, Intravenous; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000098:blood supply; D005996:Nitroglycerin / Q000494:pharmacology*; D017534:Radial Artery / Q000187:drug effects* / Q000502:physiology; D014655:Vascular Resistance / Q000187:drug effects; D014665:Vasodilator Agents / Q000494:pharmacology*; D016276:Ventricular Function / Q000502:physiology
D014665:Vasodilator Agents; D005996:Nitroglycerin