title: Use of simultaneous pressure and velocity measurements to estimate arterial wave speed at a single site in humans.
abstract: It has not been possible to measure wave speed in the human coronary artery, because the vessel is too short for the conventional two-point measurement technique used in the aorta. We present a new method derived from wave intensity analysis, which allows derivation of wave speed at a single point. We apply this method in the aorta and then use it to derive wave speed in the human coronary artery for the first time. We measured simultaneous pressure and Doppler velocity with intracoronary wires at the left main stem, left anterior descending and circumflex arteries, and aorta in 14 subjects after a normal coronary arteriogram. Then, in 10 subjects, serial measurements were made along the aorta before and after intracoronary isosorbide dinitrate. Wave speed was derived by two methods in the aorta: 1) the two-site distance/time method (foot-to-foot delay of pressure waveforms) and 2) a new single-point method using simultaneous pressure and velocity measurements. Coronary wave speed was derived by the single-point method. Wave speed derived by the two methods correlated well (r = 0.72, P < 0.05). Coronary wave speed correlated with aortic wave speed (r = 0.72, P = 0.002). After nitrate administration, coronary wave speed fell by 43%: from 16.4 m/s (95% confidence interval 12.6-20.1) to 9.3 m/s (95% confidence interval 6.5-12.0, P < 0.001). This single-point method allows determination of wave speed in the human coronary artery. Aortic wave speed is correlated to coronary wave speed. Finally, this technique detects the prompt fall in coronary artery wave speed with isosorbide dinitrate.
authors.affiliation: International Centre for Circulatory Health, St. Mary's Hospital & Imperial College, 59-61 North Wharf Rd., Paddington, London W2 1LA, UK. wavespeed@heart123.com
authors.forename: Justin E
authors.initials: JE
authors.lastname: Davies
authors.forename: Zachary I
authors.initials: ZI
authors.lastname: Whinnett
authors.forename: Darrel P
authors.initials: DP
authors.lastname: Francis
authors.forename: Keith
authors.initials: K
authors.lastname: Willson
authors.forename: Rodney A
authors.initials: RA
authors.lastname: Foale
authors.forename: Iqbal S
authors.initials: IS
authors.lastname: Malik
authors.forename: Alun D
authors.initials: AD
authors.lastname: Hughes
authors.forename: Kim H
authors.initials: KH
authors.lastname: Parker
authors.forename: Jamil
authors.initials: J
authors.lastname: Mayet
mesh_terms: D001011:Aorta / Q000502:physiology*; D001783:Blood Flow Velocity; D001794:Blood Pressure; D002309:Cardiology / Q000379:methods*; D003331:Coronary Vessels / Q000502:physiology*; D005260:Female; D006801:Humans; D007269:Injections, Intra-Arterial; D007548:Isosorbide Dinitrate / Q000008:administration & dosage / Q000494:pharmacology; D008297:Male; D008875:Middle Aged; D008955:Models, Cardiovascular; D014665:Vasodilator Agents / Q000008:administration & dosage / Q000494:pharmacology
chemical_list: D014665:Vasodilator Agents; D007548:Isosorbide Dinitrate