Effects of Different Therapeutic Ultrasound Waveforms on Endothelial Function in Healthy Volunteers: A Randomized Clinical Trial

Comparison of the effects of 1 MHz and 3 MHz therapeutic ultrasound on endothelium-dependent vasodilation of humans: a randomised clinical trial

“…CUT was applied for 5 minutes at an intensity of 0.4 W/cm 2 spatial averaged-temporal intensity (SATA). PUT was applied with a 20% duty cycle (2 milliseconds on, 8 milliseconds off), which represents 0.08 W/cm 2SATA [6,[16][17][18]. The sessions were performed on three consecutive days.…”

“…Arterial endothelium-dependent vasodilation was evaluated by FMD in the same place where the ultrasound was applied, with high-resolution vascular ultrasound and a 5 to 12 MHz linear transducer (Logiq P6, GE Healthcare, GE Ultrasound Korea Ltd, Seoul, Korea) according to the American Heart Association Guidelines and adjustments [5,6,12,19]. Briefly, after adjustments, the baseline image was acquired, and changes in the brachial artery diameter until 60 seconds of reactive hyperaemia after deflation of the cuff positioned around the upper arm and inflated to 50 mmHg above systolic blood pressure for 5 minutes were compared with baseline measures.…”

“…The increased diameter after a sublingual nitroglycerin spray (0.4 mg) was used as a measurement of endothelium-independent vasodilation. Vessel diameter responses to reactive hyperaemia and nitroglycerin are expressed as percentage changes in relation to diameter before cuff inflation and before drug administration [5,6,12,20]. Measurements of brachial artery diameter were accomplished offline by two evaluators (blind measures) after interventions.…”

“…The molecular and cellular action of therapeutic ultrasound is the goal of treatment; however, the mechanisms and parameters are still not fully understood [4]. Clinical trials and experimental studies have revealed that therapeutic ultrasound is able to improve endothelial function [5,6], and increase endothelial NO release [1,7] and vascular angiogenesis [8].…”

“…A wave frequency of 3 MHz is absorbed at a depth of approximately 1 to 2 cm and has surface action at skin level [2,3]. Previous studies demonstrating improvement in endothelial function after the application of ultrasound have used low wave frequencies (in kHz) [1,5,7,8] or 1 MHz [6]; however, to the authors' knowledge, no studies to date have evaluated the endothelial response using a wave frequency of 3 MHz. Thus, the aim of this study was to compare the effects of CUT and PUT waveforms of 1 MHz and 3 MHz therapeutic ultrasound on the endothelial function of humans.…”