CLINICAL RESEARCH: ULTRASOUND AND VASCULAR FUNCTION
Noninvasive Low-Frequency Ultrasound Energy Causes Vasodilation in Humans
Kiyoshi Iida, MD,
Huai Luo, MD,
Kohsuke Hagisawa, MD,
Takashi Akima, MD,
Prediman K. Shah, MD, FACC,
Tasneem Z. Naqvi, MD, FACC and
Robert J. Siegel, MD, FACC*
Division of Cardiology, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California
Manuscript received January 23, 2006;
revised manuscript received March 10, 2006,
accepted March 16, 2006.
* Reprint requests and correspondence: Dr. Robert J. Siegel, Division of Cardiology, Room 5623, Cedars-Sinai Medical Center, 8700 Beverly Boulevard, Los Angeles, California 90048
(Email: siegel{at}cshs.org).
OBJECTIVES: We evaluated the potential vasodilator effects of transcutaneous low-frequency ultrasound (US) in human brachial arteries.
BACKGROUND: Recent data show that transthoracic low-frequency US energy results in canine coronary artery vasodilation.
METHODS: Brachial artery diameters were measured before and after low-frequency US (29 kHz, 1.4 W/cm2) exposure using US imaging with a linear-array transducer. We assessed the time course of diameter changes after US in 20 subjects. In 10 of 20 subjects, brachial artery flow-mediated vasodilation (FMD) was measured to compare the effect of US to a standard method of evaluating endothelial function.
RESULTS: Significant vasodilation was seen after 2 min of US compared with baseline values. At 5 min of US, the brachial artery diameter increased by 4.1%. In addition, the arteries continued to dilate after US exposure. At 3 min after US there was a 5.4%, and at 5 min after US a 6.0% increase in vessel diameter (p < 0.001). These diameters returned to baseline dimensions about 20 min after stopping US. Ultrasound-mediated vasodilation and percentage FMD showed good correlation (r = 0.87; p < 0.001).
CONCLUSIONS: This is the first study to demonstrate that noninvasive transcutaneous low-frequency US energy dilates human brachial arteries. This arterial vasodilator effect has a rapid onset (within 2 min), lasts about 20 min, and is similar in magnitude to that of FMD. The vasodilator effect of US may have diagnostic and therapeutic potential in patients with or at risk for vascular disease.
|
Abbreviations and Acronyms
| | NO = nitric oxide | | FMD = flow-mediated vasodilation | | UMD = ultrasound-mediated vasodilation | | US = ultrasound | | VTI = velocity-time integral |
|
This article has been cited by other articles:
|
|
|
|
 
S. Kaul
Sonothrombolysis: A Universally Applicable and Better Way to Treat Acute Myocardial Infarction and Stroke? Who Is Going to Fund the Research?
Circulation,
March 17, 2009;
119(10):
1358 - 1360.
[Full Text]
[PDF]
|
|
|
|
