Coronary vasodilation by noninvasive transcutaneous ultrasound: an in vivo canine study.
OBJECTIVE
We evaluated the coronary vasodilatory effects of transcutaneous low-frequency (27-kHz) ultrasound (USD).


BACKGROUND
Ultrasound has been shown to affect vascular function.


METHODS
Ultrasound energy was administered transcutaneously to 12 dogs. Coronary arterial dimensions were assessed using intravascular coronary ultrasound (IVUS) and quantitative coronary angiography (QCA).


RESULTS
The IVUS mid-left anterior descending (LAD) luminal area was 6.77 +/- 1.27 mm(2) at baseline. After 30 s of ultrasound, this area increased by 9% (7.40 +/- 1.44 mm(2), p < 0.05), after 3 min by 19% (8.05 +/- 1.72 mm(2), p < 0.05) and after 5 min increased by 21% (8.16 +/- 1.29 mm(2), p < 0.05). The mean coronary diameter (2.69 +/- 0.33 mm) at baseline (QCA of three segments of LAD and three segments of left circumflex coronary artery) increased by 19.3% (3.21 +/- 0.28 mm) after 5 min of USD exposure. After a 90-min observation period there was a return to baseline values (p = NS). Intracoronary nitroglycerin (NTG) administered to five dogs revealed a similar magnitude of vasodilation as USD.


CONCLUSIONS
Noninvasive, transthoracic low-frequency USD energy results in coronary artery vasodilation within seconds of exposure. The vasodilation is reversible and is similar in magnitude to that induced by NTG. Further evaluation is needed to assess its potential applications in humans.
Division of Cardiology, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California 90048, USA.
Takashi
T
Miyamoto
Yoram
Y
Neuman
Huai
H
Luo
Doo-Soo
DS
Jeon
Sergio
S
Kobal
Fumiaki
F
Ikeno
Michael
M
Horzewski
Yasuhiro
Y
Honda
James M
JM
Mirocha
Takahiro
T
Iwami
Debra
D
Echt
Michael C
MC
Fishbein
Robert J
RJ
Siegel
D000279:Administration, Cutaneous; D000818:Animals; D017023:Coronary Angiography; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000628:therapy*; D003331:Coronary Vessels / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D004195:Disease Models, Animal; D004285:Dogs; D004452:Echocardiography; D004730:Endothelium, Vascular / Q000000981:diagnostic imaging / Q000503:physiopathology; D013997:Time Factors; D014464:Ultrasonic Therapy; D018084:Ultrasonography, Interventional; D014664:Vasodilation / Q000502:physiology*