BACKGROUND: Endothelial function is routinely assessed with high frequency ultrasound of the brachial artery. Fixed time points (1' post-occlusion and 3' post-nitrate) are commonly used to assess dynamic changes in brachial artery diameter. The underlying assumption is the lack of variability in temporal response to both endothelium-dependent and -independent stimuli. OBJECTIVE: To evaluate the temporal course of endothelium-dependent (flow-mediated) and endothelium-independent (nitrate-induced) vasodilation of the brachial artery in patients with coronary artery disease (CAD) using high resolution (10 MHz) ultrasound. METHODS: Thirty-seven patients with angiographically assessed CAD were prospectively enrolled in the study. End-diastolic, two-dimensional, long axis ultrasonographic images of the brachial artery were digitally stored on-line every 10 s, from baseline up to 4' during flow-mediated and up to 7' during 300 micrograms sublingual nitrate-induced vasodilation of the brachial artery. RESULTS: The mean percent endothelium-dependent flow-mediated maximal dilation (FMD) measured at 60 s was lower than the mean peak FMD (4.8 +/- 4.1 vs. 6.6 +/- 5.2%; p < 0.01). By 60 s only eight patients (35%) reached their maximum FMD response. The mean time to reach peak FMD was 87 +/- 33 s. The mean time for the peak nitrate dilation was 291 +/- 73 s. The peak nitrate-induced percent dilation was higher than that measured at 3 min (12.2 +/- 6.7 vs. 5.4 +/- 4.5%; p < 0.001). By 190 s, only four patients (11%) reached their maximum nitrate response. CONCLUSION: The routinely used measurement time points for evaluation of FMD and endothelium-independent vasodilation may not be adequate to detect the peak responses of individual patients with CAD.
BACKGROUND: Endothelial function is routinely assessed with high frequency ultrasound of the brachial artery. Fixed time points (1' post-occlusion and 3' post-nitrate) are commonly used to assess dynamic changes in brachial artery diameter. The underlying assumption is the lack of variability in temporal response to both endothelium-dependent and -independent stimuli. OBJECTIVE: To evaluate the temporal course of endothelium-dependent (flow-mediated) and endothelium-independent (nitrate-induced) vasodilation of the brachial artery in patients with coronary artery disease (CAD) using high resolution (10 MHz) ultrasound. METHODS: Thirty-seven patients with angiographically assessed CAD were prospectively enrolled in the study. End-diastolic, two-dimensional, long axis ultrasonographic images of the brachial artery were digitally stored on-line every 10 s, from baseline up to 4' during flow-mediated and up to 7' during 300 micrograms sublingual nitrate-induced vasodilation of the brachial artery. RESULTS: The mean percent endothelium-dependent flow-mediated maximal dilation (FMD) measured at 60 s was lower than the mean peak FMD (4.8 +/- 4.1 vs. 6.6 +/- 5.2%; p < 0.01). By 60 s only eight patients (35%) reached their maximum FMD response. The mean time to reach peak FMD was 87 +/- 33 s. The mean time for the peak nitrate dilation was 291 +/- 73 s. The peak nitrate-induced percent dilation was higher than that measured at 3 min (12.2 +/- 6.7 vs. 5.4 +/- 4.5%; p < 0.001). By 190 s, only four patients (11%) reached their maximum nitrate response. CONCLUSION: The routinely used measurement time points for evaluation of FMD and endothelium-independent vasodilation may not be adequate to detect the peak responses of individual patients with CAD.
Authors: H Shige; T Ishikawa; M Suzukawa; T Ito; K Nakajima; K Higashi; M Ayaori; S Tabata; F Ohsuzu; H Nakamura Journal: Am J Cardiol Date: 1999-11-15 Impact factor: 2.778
Authors: H Kawano; T Motoyama; O Hirashima; N Hirai; Y Miyao; T Sakamoto; K Kugiyama; H Ogawa; H Yasue Journal: J Am Coll Cardiol Date: 1999-07 Impact factor: 24.094
Authors: L Ghiadoni; A E Donald; M Cropley; M J Mullen; G Oakley; M Taylor; G O'Connor; J Betteridge; N Klein; A Steptoe; J E Deanfield Journal: Circulation Date: 2000-11-14 Impact factor: 29.690
Authors: D S Celermajer; K E Sorensen; V M Gooch; D J Spiegelhalter; O I Miller; I D Sullivan; J K Lloyd; J E Deanfield Journal: Lancet Date: 1992-11-07 Impact factor: 79.321