Objectives: The study objective was to determine the effects of salbutamol and nitroglycerin (NTG) on the luminal diameter of the left anterior descending (LAD) coronary artery, as measured noninvasively by the novel technique of high-resolution transthoracic echocardiography (HRTTE). Background: Invasive studies of the coronary arteries have demonstrated vasodilatation by salbutamol and NTG. By using a novel technique of HRTTE, combined with assessment of augmentation index (AIx, a marker of peripheral arterial stiffness) by means of applanation tonometry from the radial artery (pulse wave analysis), we studied the vasomotion of the proximal LAD in healthy volunteers. Methods: Nineteen male subjects (age 31 ± 5 years, mean ± standard deviation) underwent HRTTE measurement of the wall thickness, luminal diameter, and external diameter of the proximal LAD, and AIx at baseline and 5, 10, 15, and 20 minutes after administration of inhaled salbutamol (400 μg) and, after return to baseline, sublingual NTG (300 μg). Results: Salbutamol induced a 44% ± 28% increase in LAD luminal diameter (2.8 ± 0.8 mm to 3.7 ± 0.9 mm, P < .001) and a reduction in AIx (-13.4% ± 6.6%, P < .001). NTG induced greater changes in both parameters (60% ± 30% increase in luminal diameter from baseline, 2.7 ± 0.9 mm to 4.4 ± 1.1 mm, P < .001; and reduction in AIx -24.1% ± 8.2%, P < .001). Changes in LAD diameter and AIx were related after both salbutamol (r = -0.53, P = .02) and NTG (r = -0.57, P = .01). No significant change was detected in wall thickness. Conclusion: HRTTE is able to detect the LAD coronary artery vasodilating effects of NTG and salbutamol and correlates with peripheral vascular reactivity to these vasodilators. This approach provides a useful tool for the noninvasive assessment of coronary vasoreactivity.
|Number of pages||5|
|Journal||Journal of the American Society of Echocardiography|
|Publication status||Published - 1 Feb 2008|
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging
- Cardiology and Cardiovascular Medicine